Abstract
Background
We describe the epidemiology of asthma, chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) from 2004 to 2023 in England, Wales, Scotland and Northern Ireland (NI) using a harmonised approach.
Methods
Data from the National Health Service England (NHSE), Clinical Practice Research Datalink Aurum in England, Secure Anonymised Information Linkage Databank in Wales, DataLoch in South-East Scotland and the Honest Broker Service in NI were used. A harmonised approach to COPD, asthma and ILD case definitions, study designs and study populations across the four nations was performed. Age-sex-standardised incidence rates and point prevalence were calculated between 2004 and 2023 depending on data availability. Logistic and negative binomial regression compared incidence and prevalence rates between the start and end of each study period. Linear extrapolation projected incidence rates between 2020 and 2023 to illustrate how observed and projected rates differed.
Results
Incidence rates were lower in 2019 versus 2005 for asthma (England: incidence rate ratio 0.89, 95% CI 0.88 to 0.90; Wales: 0.66, 0.65 to 0.68; Scotland: 0.67, 0.64 to 0.71; NI: 0.84, 0.81 to 0.86), COPD (England: 0.83, 0.82 to 0.85; Wales: 0.67, 0.65 to 0.69) and higher for ILD (England: 3.27, 3.05 to 3.50; Wales: 1.39, 1.27 to 1.53; Scotland: 1.63, 1.36 to 1.95; NI: 3.03, 2.47 to 3.72). In NHSE, the incidence of asthma was similar in June 2023 versus November 2019, but lower for COPD and higher for ILD. Prevalence of asthma in 2019 in England, Wales, Scotland and NI was 9.7%, 15.9%, 13.2% and 7.0%, respectively, for COPD 4.5%, 5.1%, 4.4% and 3.0%, and for ILD 0.4%, 0.5%, 0.6% and 0.3%. Projected incidence rates were 2.8, 3.4 and 1.8 times lower for asthma, COPD and ILD compared with observed rates at the height of the pandemic.
Interpretation
Asthma, COPD and ILD affect over 10 million people across the four nations, and a substantial number of diagnoses were missed during the pandemic.
Keywords: Asthma Epidemiology, COPD epidemiology, Interstitial Fibrosis
WHAT IS ALREADY KNOWN ON THIS TOPIC
The burden of asthma, chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) has been explored in standalone countries with varying study designs and methods, thus limiting the comparability and representativeness of study results.
WHAT THIS STUDY ADDS
This is the first study to describe the burden of asthma, COPD and ILD across England, Wales, Scotland and Northern Ireland over a 20-year period using harmonised electronic health records and paves the way for federated data analyses across the UK.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
This study demonstrates the value of using a harmonised methodological approach to using national electronic healthcare records across the UK to allow for large-scale comparable, replicable and updatable data that can be used for future policy and public health planning.
Introduction
Asthma, chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) are the three most common chronic respiratory diseases worldwide and in the UK and are associated with substantial morbidity and mortality.1 2 While previous studies have investigated changes in incidence and prevalence of asthma over time, these have been limited to specific populations, such as paediatric asthma populations, or are now outdated with data up until 2016.3,5 In addition, many studies have used data from England only, and no studies have investigated trends across England, Wales and Scotland combined. Similarly, the prevalence of COPD over time has been investigated in England only up until 2019 and studies investigating trends in incidence and prevalence of COPD and ILD across the UK are lacking and outdated.6,8
Cross-national studies of the burden of asthma, COPD and ILD in the UK are assessed through the metric of health service use. This metric is important for public health planning and identifying areas for future research and development to improve patient care. It is also important to understand in which groups of people incidence of asthma, COPD and ILD are higher to target these groups with more efficient interventions to reduce the burden of these three conditions. Likewise, given the emphasis on health inequalities in research and policy, it is important to understand where and in whom incidence or prevalence is perhaps lower than expected to target disease awareness and management campaigns. No previous studies have described the burden of these diseases across the UK in a harmonised way whereby results are more comparable. Similarly, no studies have estimated the burden of these diseases across the pandemic period where healthcare utilisation dramatically changed.
Our aim was to describe the changing epidemiology of asthma, COPD and ILD between 2004 and 2023 in England, Wales, Scotland and Northern Ireland (NI) using electronic healthcare records (EHR) through standardised methodologies to improve the understanding of the evolving impacts of these diseases on individuals and provide robust methodology which can be repeated going forward to monitor trends.
Methods
Databases
For England, primary care EHRs from the Clinical Practice Research Datalink (CPRD) Aurum (February 2022 build), for data between 2004 and 2019 and the General Practice Extraction Service for Pandemic Planning and Research (GDPPR) through the National Health Service England Secure Data Environment, via the British Heart Foundation Data Science Centre’s CVD-COVID-19 UK/COVID-19 IMPACT consortium, for data between 2019 and June 2023, were used (online supplemental file 1).9 For Wales, primary care data from the Welsh Longitudinal General Practice data set (WLGP) through the Secure Anonymised Information Linkage (SAIL) Databank was used to provide data between 2004 and 2019. For Scotland, the DataLoch service was used to provide data between 2004 and March 2023, which included primary care data from~80% of general practices (GPs) in Lothian (South-East Scotland) and linked secondary care data. For NI, primary care data from the Honest Broker Service (HBS) was used to provide data between 2004 and 2022. Harmonisation of key variables between CPRD, SAIL and DataLoch has been described previously, and online supplemental table S1 summarises the harmonisation methods taken to standardise these variables across all five data sources. Our previous work contains detailed information on how key variables were harmonised.10
Chronic respiratory disease definitions (defining the numerator)
People with diagnosed and recorded asthma, COPD and ILD were defined using a harmonised approach to data curation across the databases to ensure cohort definitions were the same. Details of the methodology used have been described previously.10 For each disease, to be included as a case, individuals had to have at least one valid code within their primary care record, and the date of diagnosis was defined as a minimum of the earliest event date in primary or secondary care, using International Classification of Disease 10th revision codes in the primary position for hospitalisations. For NI, only primary care data were available and thus only a primary care diagnosis date was used. For COPD and ILD events, people were required to be at least 40 years old. In CPRD Arum, DataLoch and SAIL, for all three diseases, people had to have at least 1 year of follow-up from GP registration prior to their incidence code to be included in the numerator. Code lists for the asthma, COPD and ILD definitions are available on GitHub (https://github.com/NHLI-Respiratory-Epi/Curation-Harmonisation).
Defining the denominator
The number of patients and patient follow-up time in the total CPRD population were obtained from patient denominator files provided by CPRD per data release for all ‘acceptable’ (ie, research-ready) patients and was limited to those with linkage eligibility.10 For National Health Service England (NHSE), the denominator was derived from GDPPR and therefore included patients with active, current GP registrations at participating practices in England (98% of GP practices in England), who were alive on 1 November 2019. Additional inclusion and exclusion criteria were applied for quality assurance purposes (online supplemental file 1). For SAIL Databank, the total number of patients was the population who had an active GP registration in the WLGP data set in Wales and who had 1 year of follow-up following GP registration. For DataLoch, people were included in the denominator if they were alive, registered and research-ready (ie, had a valid unique Community Health Index (CHI) and date of birth and sex matching CHI) with a DataLoch-registered GP and had 1 year of follow-up following GP registration. For HBS, the denominator was the mid-year estimate of the NI population (https://data.nisra.gov.uk/). For incidence rates, the denominator was the person-time for each time period in which individuals were still alive and registered with their GP and had not been diagnosed with the condition of interest. In NI, the denominator was incidence, which was defined as the number of people in each time period who were still alive and had not been diagnosed with the condition of interest. For prevalence, the denominator was the number of people who were still alive and or remained registered at their GP for each time period.
The same age restrictions for the numerator were applied to the denominator; for COPD and ILD, namely people aged 40 years or older were included, and there were no age restrictions for asthma.
Statistical analysis
Data were analysed separately for each data source. In England, yearly incidence rates were calculated from 2004 to 2019 in CPRD, and monthly incidence rates were calculated between November 2019 and June 2023 in NHSE. In Wales, yearly incidence rates were calculated between 2004 and 2019 in SAIL. In NI, yearly incidence was calculated from 2004 to 2022. In South-East Scotland, yearly incidence rates were calculated from 2004 to 2019 and 3-monthly incidence rates were calculated between January 2020 and March 2023 in DataLoch due to data availability. Monthly or 3-monthly rates were calculated to better understand the changing epidemiology during and after the COVID-19 pandemic in more granular detail; however, yearly incidence was calculated for NI due to data availability. Incidence rates were based on the number of incident cases in a specific year or month divided by the person-time at risk for each person in each time period presented as per 1000 person-years. In NI, incidence was based on the number of incident cases in a specific year divided by mid-year population and presented as per 1000 persons. Incidence or incidence rates for each disease were stratified by age and sex in all nations and were additionally stratified by region for CPRD and NHSE, Index of Multiple Deprivation (IMD) and ethnicity in NHSE and IMD in HBS (online supplemental file 1). In addition, to facilitate comparisons between the four nations, incidence rates were directly standardised to the European 2013 standard population.11
Annual point prevalence of diagnosed and recorded disease was calculated using point prevalence for each disease for each year on 1 July from 2004 to 2019 for CPRD, SAIL and from 2004 to 2022 for DataLoch. For HBS, prevalence was calculated from 2011 to 2022 as the data sets used to identify study exit (ie, medications, secondary care utilisation and outpatient use) were available from 2010.
Crude incidence rate ratios (IRR) were calculated to compare the incidence of asthma, COPD and ILD in 2019 compared with 2005 in CPRD, SAIL and DataLoch. For HBS, the incidence risk ratio was calculated for each disease for 2019 compared with 2005. 2005 rather than 2004 was used for this analysis due to the introduction of the quality and outcomes framework in 2004 which could have led to more biased estimates in 2004 compared with those in 2005. For NHSE, IRRs were calculated to compare the incidence rates of asthma, COPD and ILD in June 2023 with November 2019 to determine whether incidence pre-COVID-19 pandemic differed from the most up-to-date estimates. Crude ORs were calculated to compare the prevalence of asthma, COPD and ILD in 2019 with 2005 in CPRD, SAIL and DataLoch, and in 2019 with 2011 in HBS.
Exploratory analyses
To illustrate how incidence rates of asthma, COPD and ILD would have differed if the pandemic had not occurred, we projected incidence rates for England and South-East Scotland from January 2020 to June or March 2023, respectively. In addition, linear extrapolation was used to understand whether more recent incidence rates were similar to what would have been expected if the pandemic had not occurred. This method used estimated incidence rates based on the last two data points and was based on incidence rates in 2018 and 2019 for each country separately (online supplemental file 1).
Results
Online supplemental figure S1 reports the number of people in each nation with at least one chronic respiratory condition or a combination of diseases.
Trends in incidence
Asthma
Yearly adjusted incidence rates of asthma declined between 2004 and 2019 in all four nations (figure 1, online supplemental file 2). Across England, Wales and Scotland, incidence rates of asthma declined more rapidly between 2004 and 2010 (standardised incidence rates for England, Wales and Scotland from 2004 to 2010: 7.30 (95% CI 7.05 to 7.57) to 5.55 (95% CI 5.33 to 5.77), 12.16 (95% CI 11.69 to 12.65) to 4.47 (95% CI 4.18 to 4.77) and 6.85 (95% CI 6.49 to 7.22) to 4.22 (95% CI 3.94 to 4.51) per 1000 person-years (PY), respectively; online supplemental file 2). In NI, a substantial decline in asthma incidence was observed between 2004 and 2007: 3.86 (95% CI 3.59 to 4.14) to 2.60 (95% CI 2.38 to 2.83) per 1000 persons. From 2011 to 2019 the incidence of asthma remained more stable in all four nations (standardised incidence rates for England, Wales and Scotland in 2019: 5.52 (95% CI 5.32 to 5.72), 5.08 (95% CI 4.77 to 5.40) and 3.79 (CI 3.53 to 4.07) per 1000 PY, respectively. Incidence in NI in 2019: 2.66 (95% CI 2.44 to 2.90); online supplemental file 2). During the early COVID-19 pandemic years, the incidence of asthma declined rapidly (2020–2022), before increasing to 4.57 (95% CI 4.27 to 4.87) per 1000 person-years in June 2023 in England and to 4.25 (95% CI 3.97 to 4.55) per 1000 person-years between January and March 2023 in Scotland. Incidence rates of asthma were lower in 2019 compared with 2005 in England (0.89, 95% CI 0.88 to 0.90), Wales (0.66, 95% CI 0.65 to 0.68), South-East Scotland (0.67, 95% CI 0.64 to 0.71) and incidence in NI (0.84, 95% CI 0.81 to 0.86) (figure 2, online supplemental table S2).
Figure 1. Age and sex adjusted incidence rate of asthma, COPD and ILD. Estimates illustrate incidence rates of asthma, COPD and ILD per 1000 person-years and 95% CIs calculated separately at each time point for England, Wales and Scotland. Yearly incidence rates were calculated for the years 2004 up until the end of 2020 for CPRD, SAIL and DataLoch, monthly incidence rates were calculated from November 2019 up until June 2023 for NHSE and 3-monthly incidence rates were calculated from January 2020 up until March 2023. Yearly incidence was calculated for Northern Ireland. COPD, chronic obstructive pulmonary disease; CPRD, Clinical Practice Research Datalink; ILD, interstitial lung disease; NHSE, National Health Service England; SAIL, Secure Anonymised Information Linkage.
Figure 2. Crude incidence rate ratios (IRR) or incidence ratio (IR) of (A) asthma, (B) COPD and (C) ILD in 2019 versus 2005 for England, Wales, South-East Scotland and Northern Ireland and in June 2023 versus November 2019 for NHSE. Estimates illustrate IRR and 95% CIs for England, Wales and Scotland and IR for Northern Ireland. COPD, chronic obstructive pulmonary disease; CPRD, Clinical Practice Research Datalink; ILD, interstitial lung disease; IR, incidence ratio; IRR, incidence rate ratio; NHSE, National Health Service England.
Overall, differences were seen across all nations by sex whereby female adults had higher rates of asthma compared with males and males less than 18 had higher rates of asthma than females less than 18. In terms of age, younger individuals had the highest rates of asthma, although the rates have decreased since 2004 in these age groups. Rates were similar over time across regions for asthma. When incidence rates were stratified by IMD and ethnicity in NHSE, the incidence of asthma was higher in those in the more deprived IMD deciles and differed by ethnicity (online supplemental figures S2–S4 and S9–S11).
Chronic obstructive pulmonary disease
Incidence rates of COPD remained stable between 2004 and 2019 in England (standardised incidence rates in 2004 and 2019: 4.74 (95% CI 4.57 to 4.91) and 4.66 (95% CI 4.50 to 4.82); online supplemental file 2, figure 1). In Scotland, incidence rates of COPD declined between 2004 and 2009 (standardised incidence rates in 2004 and 2009: 5.60 (95% CI 5.19 to 6.04) and 4.33 (95% CI 3.97 to 4.71)) but remained stable between 2010 and 2019 (standardised incidence rates in 2010 and 2019: 5.11 (95% CI 4.72 to 5.53) and 4.96 (95% CI 4.58 to 5.37)). However, the incidence of COPD declined in Wales between 2004 and 2015 (standardised incidence rates in 2004 and 2015: 7.86 (95% CI 7.36 to 8.37) and 4.26 (95% CI 3.91 to 4.64)) and remained stable between 2016 and 2019 (standardised incidence rates in 2016 and 2019: 4.45 (95% CI 4.09 to 4.84) and 4.32 (95% CI 3.96 to 4.70)). In NI, COPD incidence increased substantially during the period, with largely consistent year-on-year increases observed between 2004 and 2019 (1.23, 95% CI 1.02 to 1.46) and 3.44 (95% CI 3.10 to 3.82) per 1000 persons, respectively. During the pandemic years, the incidence of COPD declined rapidly before increasing back to similar pre-pandemic rates in June 2023 in England and March 2023 in Scotland (standardised incidence rates: 4.09 (95% CI 3.72 to 4.50) and 4.33 (95% CI 3.97 to 4.71), respectively). Crude incidence rates of COPD were also lower in 2019 compared with 2005 in England (0.83, 95% CI 0.82 to 0.85) and Wales (0.67, 95% CI 0.65 to 0.69) but were similar in South-East Scotland (1.06, 95% CI 0.99 to 1.13), and incidence was higher in NI (2.82, 95% CI 2.62 to 3.03).
Males had higher incidence rates than females. In terms of age, older individuals had the highest incidence rates. A slight difference in rates was seen for COPD in more recent years whereby northern regions had higher incidence rates of COPD. When incidence rates were stratified by IMD and ethnicity in NHSE, incidence of asthma was higher in those in the more deprived IMD deciles and differed by ethnicity (online supplemental figures S5 and S6 and S9–S11).
Interstitial lung disease
Incidence rates of ILD increased in England, Scotland and NI between 2004 and 2019, but this trend was not seen for Wales (figure 1, online supplemental file 2). In England, the incidence of ILD increased between 2004 and 2006 (standardised incidence rates in 2004 and 2006: 0.20 (95% CI 0.17 to 0.24) and 0.57 (95% CI 0.51 to 0.63)) but remained similar between 2007 and 2010 (standardised incidence rates in 2007 and 2010: 0.59 (95% CI 0.53 to 0.65) and 0.60 (95% CI 0.55 to 0.66)) and increased between 2011 and 2019 (standardised incidence rates in 2011 and 2019: 0.62 (95% CI 0.56 to 0.68) and 0.76 (95% CI 0.71 to 0.82)). In Scotland, incidence rates increased between 2004 and 2010 (standardised incidence rates in 2004 and 2010: 0.61 (95% CI 0.47 to 0.77) and 0.95 (95% CI 0.78 to 1.15)), remained similar between 2011 and 2016 (standardised incidence rates in 2011 and 2016: 0.76 (95% CI 0.62 to 0.96) and 0.77 (95% CI 0.62 to 0.95)) and increased up until 2019 (standardised incidence rates 2019: 1.03 (95% CI 0.85 to 1.24)). In NI, incidence increased substantially between 2004 and 2019 (standardised incidence in 2004 and 2019: 0.18 (95% CI 0.13 to 0.28) and 0.49 (95% CI 0.37 to 0.64), respectively). In Wales, the incidence of ILD decreased between 2004 and 2009 (standardised incidence rates in 2004 and 2009: 0.83 (95% CI 0.67 to 1.01) and 0.52 (95% CI 0.40 to 0.68)), remained similar between 2010 and 2014 (standardised incidence rates for 2010 and 2014: 0.57 (95% CI 0.44 to 0.73) and 0.59 (95% CI 0.46 to 0.75)) and increased between 2015 and 2019 (standardised incidence rates in 2015 and 2019: 0.65 (95% CI 0.51 to 0.82) and 0.78 (95% CI 0.62 to 0.96)). During the pandemic years, the incidence of ILD declined before increasing back to similar pre-pandemic rates in June 2023 in England, but lower rates were seen in March 2023 in Scotland compared with pre-pandemic rates (standardised incidence rates: 0.75 (95% CI 0.59 to 0.93) and 0.78 (95% CI 0.62 to 0.96), respectively). Crude incidence rates of ILD were higher in 2019 compared with 2005 in England (3.27, 95% CI 3.05 to 3.50), Wales (1.39, 95% CI 1.27 to 1.53), South-East Scotland (1.63, 95% CI 1.36 to 1.95) and incidence was higher in NI (3.03, 95% CI 2.47 to 3.72). Crude incidence rates of asthma, COPD and ILD in England were lower in June 2023 compared with November 2019 (0.92, 95% CI 0.90 to 0.94, 0.91, 95% CI 0.89 to 0.94 and 0.93, 95% CI 0.87 to 0.99, respectively.)
Males had higher incidence rates than females. In terms of age, older individuals had the highest incidence rates. Rates were similar over time across regions. When incidence rates were stratified by IMD and ethnicity in NHSE, the incidence of asthma was higher in those in the more deprived IMD deciles and differed by ethnicity (online supplemental figures S7–S11).
Trends in prevalence
Asthma
In England, Wales and Scotland, the prevalence of asthma increased between 2004 and 2019 and between 2011 and 2019 in NI (figure 3, online supplemental table S3, online supplemental file 3). In England and Scotland, the prevalence of asthma increased between 2004 and 2015 (prevalence of asthma in 2004 and 2015: 5.79 (95% CI 5.78 to 5.81) and 9.53 (95% CI 9.52 to 9.55) in England and 10.87 (95% CI 10.79 to 10.94) and 13.07 (95% CI 13.0 to 13.14) in Scotland). The prevalence of asthma in England and Scotland was similar between 2016 and 2019. However, in Wales, the difference in prevalence between 2004 and 2010 was smaller, and prevalence of asthma increased between 2011 and 2019 to a larger extent (prevalence of asthma in 2004, 2010 and 2019 in Wales: 12.28 (95% CI 12.23 to 12.32), 13.25 (95% CI 13.21 to 13.29) and 16.43 (95% CI 16.38 to 16.47)). Crude odds of asthma were higher in 2019 compared with 2005 in England (2.37, 95% CI 2.34 to 2.40), Wales (1.35, 95% CI 1.34 to 1.35) and Lothian Scotland (1.18, 95% CI 1.17 to 1.20) (figure 4). In NI, crude OR of asthma was higher in 2019 compared with 2011 (1.10, 95% CI 1.09 to 1.11).
Figure 3. Point prevalence of asthma, COPD and ILD. Estimates illustrate point prevalence per 100 individuals and 95% CIs calculated separately at each time point. Point prevalence was calculated on the first of July of each year between 2004 and 2019 for England and Wales and between 2004 and 2022 for Lothian, Scotland and Northern Ireland. COPD, chronic obstructive pulmonary disease; CPRD, Clinical Practice Research Datalink; ILD, interstitial lung disease; SAIL, Secure Anonymised Information Linkage.
Figure 4. Crude odds ratios (OR) for the odds of (A) asthma, (B) COPD and (C) ILD in 2019 versus 2005 in England, Wales and South-East Scotland and 2019 versus 2011 in Northern Ireland. Estimates illustrate OR and 95% CIs. COPD, chronic obstructive pulmonary disease; ILD, interstitial lung disease.
Chronic obstructive pulmonary disease
In England and Scotland, the prevalence of COPD increased between 2004 and 2015 (prevalence of COPD in 2004 and 2015: 2004 and 2015 in England and Scotland: 2.15 (95% CI 2.14 to 2.16) and 4.20 (95% CI 4.18 to 2.22) in England and 3.00 (95% CI 2.94 to 3.05) and 4.14 (95% CI 4.08 to 4.20) in Scotland). The prevalence of COPD in England and Scotland was similar between 2016 and 2019. However, in Wales, the difference in prevalence between 2004 and 2010 was smaller. Crude odds of COPD were also higher in 2019 compared with 2005 in England (1.54, 95% CI 1.51 to 1.56), Wales (1.89, 95% CI 1.87 to 1.91) and South-East Scotland (1.34, 95% CI 1.31 to 1.37). In NI, crude OR of COPD was higher in 2019 compared with 2011 (1.85, 95% CI 1.82 to 1.89).
Interstitial lung disease
Prevalence of ILD increased steadily between 2004 and 2019 in England and Scotland (prevalence of ILD in 2004 and 2019 in England: 0.08 (95% CI 0.08 to 0.09) and 0.40 (95% CI 0.40 to 0.41), respectively, and in Scotland: 0.33 (95% CI 0.31 to 0.35) and 0.57 (95% CI 0.55 to 0.60), respectively; figure 4 and online supplemental file 3). In NI, prevalence increased between 2011 and 2019 (0.17 (95% CI 0.15 to 0.2) and 0.36 (95% CI 0.32 to 0.40), respectively; figure 4 and online supplemental file 3). In Wales, prevalence increased steadily between 2004 and 2014 (0.40 (95% CI 0.39 to 0.41) and 0.47 (95% CI 0.46 to 0.48), respectively; figure 4 and online supplemental file 3), before increasing more rapidly up to 2019 (0.56 (95% CI 0.55 to 0.58); figure 4 and online supplemental file 3). Crude odds of ILD were higher in 2019 compared with 2005 in England (4.07, 95% CI 3.82 to 4.33). Crude odds of ILD were also higher in 2019 compared with 2005 in Wales and South-East Scotland, but at a smaller magnitude (Wales 1.34, 95% CI 1.30 to 1.39 and Scotland 1.63, 95% CI 1.42 to 1.75). In NI, crude OR of ILD was higher in 2019 compared with 2011 (1.85 95% CI 1.73 to 1.97).
Observed versus projected incidence rates during the COVID-19 pandemic
The lowest incidence rate of asthma, COPD and ILD over the COVID-19 period in England was 1.86, 1.28 and 0.42 per 1000 person-years in May 2020, respectively. These were 2.8, 3.4 and 1.8 times lower than projected rates of asthma, COPD and ILD, respectively. The lowest incidence rate of asthma, COPD and ILD over the COVID-19 period in South-East Scotland was 1.65, 1.96 and 0.67 per 1000 person-years in April 2020, respectively. These were 2.4, 2.3 and 1.8 times lower than projected rates of asthma, COPD and ILD, respectively (online supplemental figure S12).
Discussion
This is the first study to describe incidence and prevalence trends in asthma, COPD and ILD in England, Wales, Scotland and NI using harmonised methodologies and to describe the trends pre and post COVID-19. We found a decrease in the incidence of asthma in all four nations between 2004 and 2019, and a decrease in the incidence of COPD in Wales and England. The incidence of asthma, ILD and COPD declined during the COVID-19 pandemic period, but since then has gradually increased close to pre-pandemic rates. The prevalence of asthma has increased in four nations; however, a plateau was seen in South-East Scotland and England between 2015 and 2020, with a decrease during the pandemic. The prevalence of COPD also increased across all nations and decreased during the pandemic; however, the prevalence of ILD has increased over the study period and the decrease during the pandemic was much smaller relative to the other diseases.
Asthma
Previous studies have found that the prevalence of asthma has increased over time in adults but has declined in children.3,512 13 While we did not stratify our prevalence rates by age group, we did find that incidence rates differed by age group and children aged less than 10 years had the steepest decline in asthma incidence between 2004 and 2019 compared with other age groups. The more pronounced decline seen in this population could be due to healthcare providers not giving children with suspected asthma a confirmed diagnosis of asthma, instead using a diagnosis of preschool wheeze when asthma is suspected.14 In addition, there has been a shift in attitudes to diagnosing asthma, as previously it tended to be overdiagnosed and in more recent years it is possible that physicians are more cautious when making a diagnosis of asthma, particularly in children.15 The incidence of asthma also varied by men and women in different age groups. It is well known that asthma is more common in males during childhood as compared with females, but in an adult population, asthma is more common in females than males.16 This is thought to be hormone-related, whereby after puberty the rise in oestrogen has an inflammatory effect which can lead to the development of inflammatory diseases including asthma.17
We also found that the incidence of asthma varied by IMD with higher rates of diagnoses made in more deprived individuals. This is consistent with the literature and persisted over the COVID-19 pandemic period too.18 19 Higher incidence rates in those who are more deprived may be due to factors including housing conditions, occupational exposures and air pollution.20 Similarly, there was some variation by ethnicity whereby people with Asian and mixed ethnicity had higher rates than those with other or unknown ethnicity. While the trends are less clear, other studies have found that people with black and Asian ethnicity also have poorer asthma outcomes, including asthma exacerbations and hospitalisations.21 Further research into understanding reasons for these disparities is crucial to determining where efforts are needed to reduce the incidence of asthma in these populations.
Chronic obstructive pulmonary disease
Previous studies, including global estimates from the Global Burden of Disease study, have found that the incidence of COPD has decreased since 2004 and prevalence has increased, which is in line with our findings.7 22 23 While some studies have found that there are still disparities in people being diagnosed with COPD across the UK, others have found that the proportion of people dying of COPD and who had received a diagnosis of COPD has increased with time.24 One explanation for the decline in COPD incidence could be reduced levels of smoking over time, notably since the introduction of smoke-free legislation in 2006/2007.25 Interestingly, we did not find a decline in the incidence of COPD in Scotland or NI. In Scotland, this could be due to a higher prevalence of cigarette smoking compared with England and Wales, found notably in men in 2006.26 In NI, smoking cessation trends have been less pronounced than in other UK nations and air quality in Belfast remains among the worst in the UK.27 28 Across all UK nations, COPD prevalence increased, likely due to better diagnosis, improved treatments and ageing population.6 10
In addition, one systematic review found that the prevalence of COPD has historically been higher in males compared with females, but that the prevalence is similar between the two sexes in more recent years.29 While we did not stratify prevalence by sex, we did find that the incidence of COPD was consistently higher in males compared with females and varied by region, with the highest incidence in Northeast England in keeping with other work.8 29 The incidence of COPD was also higher in people with white ethnicity; however, it is possible that healthcare access in this group is more accessible and therefore individuals are more likely to get a diagnosis of COPD compared with other ethnic groups who have worse access to healthcare.30 31 On the other hand, in England, the incidence of COPD was higher in the most deprived populations, which could be due to higher smoking rates and more exposure to pollution.32
In England, the incidence of COPD was higher in people who were more socioeconomically deprived and who had white ethnicity. As with asthma, factors such as occupation and housing may play a role as well as cigarette smoking.33 Unlike asthma, people with white ethnicity had the highest rates of COPD diagnoses. Studies report that white ethnicity was more likely to be breathless, which could suggest that people with white ethnicity were more likely to seek healthcare when symptomatic.30
Interstitial lung disease
There is a smaller body of research for ILD; however, evidence suggests that the incidence and prevalence of ILD have been increasing over time in all nations which were in our study, but also across Europe.34 One reason for the increased incidence and prevalence over time could be increased awareness of ILD and improved diagnosis and management of people with this disease.35 However, similarly to COPD, it could also be due to an ageing population, given that older age is a risk factor for ILD.36 Studies have also found that the prevalence of ILD is higher in males compared with females and a higher mortality rate for more deprived people with ILD.37 38 While we did not look at disparities in prevalence or mortality, we did find that the incidence of ILD was higher in males compared with females, and there was evidence to suggest that incidence was higher in people who were most deprived compared with those who were least deprived; however, the difference was relatively small.
While incidence rates of ILD in England were less clear by socioeconomic deprivation, people with Asian and white ethnicity had higher rates over time. It is unclear as to why these differences exist, and they could be largely due to residual confounding, particularly with socioeconomic status. Further understanding into why disparities in chronic respiratory diseases exist is crucial to improving population health.
COVID-19
The incidence of clinically recorded COPD, asthma and ILD declined during the pandemic and gradually increased close to pre-pandemic levels by June 2023. The reduction in clinically recorded diagnoses reflects access to care during the pandemic and changes in health-seeking behaviours.39 40 Specifically, there were fewer face-to-face GP and outpatient appointments during the early months of the pandemic, leading to fewer diagnoses.41 The incidence rates of asthma, COPD and ILD in June 2023 remained slightly lower than the incidence rate in November 2019. This lag in diagnosing people with chronic respiratory disease could be due to the need for spirometry, which would have been limited during the pandemic.42 In addition, based on projected rates for if the pandemic had not occurred, up to 2.8 times fewer people were diagnosed with asthma, 3.4 times fewer people were diagnosed with COPD and 1.8 times fewer people were diagnosed with ILD at the height of the pandemic. Given the changes in diagnostic practices during the pandemic, the observed decline in incidence rates suggests that there were missed diagnoses, which could have a great impact on the future health of people with chronic respiratory diseases but who may not be diagnosed with the condition due to changes in care during the pandemic. Not only does this affect individuals who may be living with an undiagnosed respiratory disease, but it would affect individuals who are diagnosed with a respiratory disease later on in their disease trajectory. This is particularly important for people with ILD as diagnosis is less straightforward and is already diagnosed at a late stage whereby patients have a short life expectancy. Further studies are needed to quantify the long-term burden of undiagnosed and late-diagnosed individuals.
Implications for policy, practice and research
Given the Office for National Statistis (ONS) population estimates in 2023 and assuming no dramatic increase in prevalence over the pandemic years, our prevalence estimates suggest that approximately 5.5 million (9.6%) people are living with asthma in England, 590 000 (16.4%) in Wales, 720 000 (13.2%) in Scotland and 146 000 (7.6%) in NI. For COPD our prevalence estimates in 2019 reflect approximately 2.5 million (4.5%) people in England, 185 000 (5.9%) in Wales, 241 000 (4.4%) in Scotland and 58 000 (3.0%) in NI. For ILD our prevalence estimates in 2019 reflect approximately 230 000 (0.4%) in England, 18 000 (0.6%) in Wales, 31 000 (0.6%) in Scotland and 6000 (0.3%) in NI. Overall, these three diseases affect over 10 million people across the UK, highlighting the importance of continued research into these diseases to improve management of people with asthma, COPD and ILD, to reduce morbidity and mortality. These estimates suggest that the UK still has some of the worst respiratory outcomes worldwide, as mean global age-standardised prevalence estimates for 2019 for asthma and COPD were lower than those seen in our study however, the declining trends seen in our study have also been reported globally.23
Our study is one of the first studies to use cross-national data in a harmonised approach to describe trends in the three most prevalent chronic respiratory diseases of asthma, COPD and ILD over a 20-year period. Our harmonised methodology not only allows more comparable findings across the four UK nations, but also allows more replicable and updatable cohorts of people with asthma, COPD and ILD in the UK.
Limitations
Despite our study’s strengths, limitations exist. First, EHR data were used, which may have limitations in terms of coding of diagnoses; however, we used codes that have been validated in CPRD for COPD, asthma and ILD diagnoses to minimise any biases from this.43,45 Second, the GDPPR primary care data set in NHSE includes all individuals in England who are alive with active registration on 1 November 2019 and therefore we were unable to estimate monthly prevalence rates. Third, we were unable to stratify by region, IMD and ethnicity in CPRD due to the lack of denominator data for these specific variables. Fourth, this paper investigated trends in diagnosed disease and cannot separate out changes related to diagnosis and coding practices from true changes in incidence and prevalence. Fifth, denominators over the pandemic period varied by England and Scotland (monthly vs 3-monthly) which could have led to less variation in rates in Scotland over this period. In addition, the rates over the pandemic period could have been affected by seasonality and should be interpreted with this in mind. Furthermore, there is possible overlap between people included in CPRD and NHSE; however, this would have only occurred for the months of November and December in NHSE, and rates were similar. In addition, extrapolation assumed linearity; however, data from 2004 to 2019 was relatively linear for CPRD and DataLoch. Moreover, for NI data the definition of study exit was pragmatic and may have led to the inappropriate exclusion of some prevalent cases who still resided in NI, especially those with less severe diseases who may not be in regular contact with the healthcare system. Furthermore, data were analysed separately for each data source and aggregate data were combined. Therefore, incidence rates were age and sex standardised to the European Union (EU) standard population to allow for comparable rates across the data sources and no other covariates were adjusted for. Lastly, case definitions were based on diagnoses made in primary and secondary care alone as spirometry measurements were not used. A previous systematic review found that between 50% and 75% of COPD populations in the literature had airflow obstruction as defined using post-bronchodilator spirometry. On the other hand, spirometry-confirmed COPD without a clinically recorded diagnosis was common.46 Similarly for asthma, misdiagnosis is possible, notably in those who did not have testing for airflow limitation.47 Therefore, it is possible that the incidence and prevalence of COPD, asthma and ILD could have been over or under-estimated; however, we used algorithms for disease diagnosis that have been validated in UK EHRs to reduce the risk of misdiagnosis.43,45
Conclusion
This is the first study using harmonised EHR data from the four nations in the UK to describe the trend in epidemiology of three chronic respiratory diseases over a combined 20-year period. In the four nations, the incidence of asthma has decreased, the incidence of ILD has increased; however, the incidence of COPD has decreased in England and Wales only. Changes in incidence rates were likely due to changes in behaviours and disease awareness. Disparities in incidence rates exist by sex, age, region, IMD and ethnicity, and missed diagnoses from the COVID-19 pandemic could have a great impact on the future health of people with chronic respiratory diseases. Overall, these data form a strong baseline for future policy work and public health planning.
Supplementary material
Acknowledgements
This work was carried out with the support of the BHF Data Science Centre led by HDR UK (BHF Grant no. SP/19/3/34678). This study makes use of de-identified data held in NHS England’s Secure Data Environment service for England and made available via the BHF Data Science Centre’s CVD-COVID-UK/COVID-IMPACT consortium. This work used data provided by patients and collected by the NHS as part of their care and support. We would also like to acknowledge all data providers who make health-relevant data available for research.
Footnotes
Funding: This work was partly funded by BREATHE-The Health Data Research Hub for Respiratory Health (MC_PC_19004) and the Health Data Research (HDR) UK Inflammation and Immunity programmes (DRUK2023.0027). In addition, an NIHR BRC grant funded access to the British Heart Foundation Data Science Centre for use of the NHSE SDE data (BRC RS Pil PSO767). The British Heart Foundation Data Science Centre (grant No SP/19/3/34678, awarded to Health Data Research (HDR) UK) funded co-development (with NHS England) of the Secure Data Environment service for England, provision of linked data sources, data access, user software licences, computational usage and data management and wrangling support, with additional contributions from the HDR UK Data and Connectivity component of the UK Government Chief Scientific Adviser’s National Core Studies programme to coordinate national COVID-19 priority research. Consortium partner organisations funded the time of contributing data analysts, biostatisticians, epidemiologists and clinicians. This research is part of the Data and Connectivity National Core Study, led by Health Data Research UK in partnership with the Office for National Statistics and funded by UK Research and Innovation (grant ref: MC_PC_20058).
Provenance and peer review: Not commissioned; externally peer reviewed.
Patient consent for publication: Not applicable.
Collaborators: CVD-COVID-UK/COVID-IMPACT Consortium: Barts Health NHS Trust: Alastair Proudfoot; Barts Health NHS Trust: Andrew Constantine; Barts Health NHS Trust: Dan Jones; Barts Health NHS Trust: Krishnaraj Rathod; Barts Health NHS Trust: Nida Ahmed; Barts Health NHS Trust: Richard Fitzgerald; British Heart Foundation: Dan O’Connell; British Heart Foundation: Rony Arafin; British Heart Foundation: Sonya Babu-Narayan; British Heart Foundation: Zainab Karim; Cancer Research UK: Jon Shelton; Cancer Research UK: Martina Slapkova; Cancer Research UK: Rosie Hinchliffe; Cancer Research UK: Shane Johnson; Cardiff Metropolitan University: Renin Toms; Cardiff University: Julia Townson; European Bioinformatics Institute: Ewan Birney; European Bioinformatics Institute: Moritz Gerstung; European Bioinformatics Institute: Tomas Fitzgerald; Great Ormond Street Hospital: Katherine Brown; Guy’s and St Thomas’ NHS Foundation Trust: Benjamin Zuckerman; Guy’s and St Thomas’ NHS Foundation Trust: Ernest Wong; Guy’s and St Thomas’ NHS Foundation Trust: Lily Benton; Guy's and St Thomas' NHS Foundation Trust: Tasanee Braithwaite; Health Data Research UK: Alexis Webb; Health Data Research UK/BHF Data Science Centre: Anna Stevenson; Health Data Research UK/BHF Data Science Centre: Annette Jackson; Health Data Research UK/BHF Data Science Centre: Cathie Sudlow; Health Data Research UK/BHF Data Science Centre: Fionna Chalmers; Health Data Research UK/BHF Data Science Centre: Jadene Lewis; Health Data Research UK/BHF Data Science Centre: James Farrell; Health Data Research UK/BHF Data Science Centre: Jemma Austin; Health Data Research UK/BHF Data Science Centre: John Nolan; Health Data Research UK/BHF Data Science Centre: Lars Murdock; Health Data Research UK/BHF Data Science Centre: Lynn Morrice; Health Data Research UK/BHF Data Science Centre: Mehrdad Mizani; Health Data Research UK/BHF Data Science Centre: Melissa Webb; Health Data Research UK/BHF Data Science Centre: Ross Forsyth; Health Data Research UK/BHF Data Science Centre: Rouven Priedon; Health Data Research UK/BHF Data Science Centre: Samaira Khan; Health Data Research UK/BHF Data Science Centre: Steffen Petersen; Health Data Research UK/BHF Data Science Centre: Thomas Bolton; Health Data Research UK/BHF Data Science Centre: Zach Welshman; Healthcare Quality Improvement Partnership: Caroline Rogers; Hull York Medical School: Donna Wakefield; Imperial College London: Alun Davies; Imperial College London: Arunashis Sau; Imperial College London: Costas Kallis; Imperial College London: Fu Siong Ng; Imperial College London: Hannah Whittaker; Imperial College London: Ioanna Tzoulaki; Imperial College London: Jennifer Quint; Imperial College London: Juliette Unwin; Imperial College London: Libor Pastika; Imperial College London: Petter Brodin; Imperial College London: Philip Stone; Imperial College London: Safa Salim; Imperial College London: Sarah Cook; Imperial College London: Sarah Onida; Imperial College London (LCP): Alistair Marsland; Imperial College London (LCP): Andrew Thompson; Imperial College London (LCP): Sara Holloway; Imperial College London (LCP): Thomas Porter; INSIGHT: Alastair Denniston; Keele University: Mamas Mamas; King's College London: Abdel Douiri; King's College London: Adejoke Oluyase; King's College London: Ajay Shah; King's College London: Alexandru Dregan; King’s College London: Amy Ronaldson; King's College London: Anna Bone; King's College London: Antonio Cannata; King's College London: Ben Bray; King's College London: Charles Wolfe; King's College London: Daniel Bromage; King's College London: Dominic Oliver; King's College London: Elena Nikiphorou; King's College London: Emeka Chukwusa; King's College London: Gareth Williams; King's College London: Gayan Perera; King's College London: Harry Watson; King’s College London: Iain Marshall; King's College London: Irene Higginson; King's College London: Javiera Leniz Martelli; King's College London: Jayati Das-Munshi; King's College London: Joanna Davies; King's College London: Johnny Downs; King's College London: Katherine Sleeman; King’s College London: Laia Becares; King’s College London: Linglong Qian; King’s College London: Matthew O'Connell; King's College London: Mevhibe Hocaoglu; King’s College London: Natasha Chilman; King's College London: Rachel Cripps; King's College London: Richard Killick; King's College London: Theresa McDonagh; King's College London: Vasa Curcin; King’s College London: Zeljko Kraljevic; Leeds Teaching Hospitals NHS Trust: Carin van Doorn; London School of Economics & Political Science: Rocco Friebel; London School of Hygiene & Tropical Medicine: Antonio Gasparrini; London School of Hygiene & Tropical Medicine: Arturo de la Cruz; London School of Hygiene & Tropical Medicine: Dorothea Nitsch; London School of Hygiene & Tropical Medicine: Julian Matthewman; London School of Hygiene & Tropical Medicine: Neil Pearce; London School of Hygiene & Tropical Medicine: Patrick Bidulka; London School of Hygiene & Tropical Medicine: Qiuju Li; London School of Hygiene & Tropical Medicine: Sinéad Langan; London School of Hygiene & Tropical Medicine: Thiago Silva; London School of Hygiene & Tropical Medicine: Zhengnan Zhu; Manchester University NHS Foundation Trust: Martin Rutter; Newcastle-upon-Tyne Hospitals NHS Foundation Trust: Alex Grundmann; NHS England: Adam Hollings; NHS England: Angeliki Antonarou; NHS England: Daniel Schofield; NHS England: Deborah Lowe; NHS England: Elizabeth Kelly; NHS England: Richardson; NHS England: Humaira Hussein; NHS England: Jake Kasan; NHS England: Nickie Wareing; NHS England: Russell Healey; NHS England: Shoaib Ali Ajaib; NHS Lanarkshire: Mark Barber; NHS Scotland: Carole Morris; NICE: Felix Greaves; NICE: Jennifer Beveridge; NICE: Seamus Kent; NICE: Thomas Lawrence; NICE: Vandana Ayyar-Gupta; Office for National Statistics: Myer Glickman; Office for National Statistics: Vahé Nafilyan; Queen Mary University of London: Deepti Gurdasani; Queen's University Belfast: Frank Kee; Royal Brompton and Harefield Hospitals: Paz Tayal; Royal College of Surgeons of England: David Cromwell; Royal Free London NHS Foundation Trust: Amar Shah; Royal Free London NHS Foundation Trust: Swapna Mandal; Royal Papworth Hospital NHS Foundation Trust: Florian Falter; Royal Papworth Hospital NHS Foundation Trust: Joseph Newman; Royal United Hospitals Bath NHS Foundation Trust: Jennifer Rossdale; St George’s University of London: Baboucarr Njie; St George’s University of London: Elijah Behr; St George’s University of London: Nuria Sanchez; St George’s University of London: Xinkai Wang; Swansea Bay University Health Board: Daniel Harris; Swansea University: Amanda Marchant; Swansea University: Ashley Akbari; Swansea University: Daniel King; Swansea University: David Powell; Swansea University: Elizabeth A Ellins; Swansea University: Fatemeh Torabi; Swansea University: Gareth Davies; Swansea University: Hoda Abbasizanjani; Swansea University: Huw Strafford; Swansea University: Jane Lyons; Swansea University: Julian Halcox; Swansea University: Laura North; Swansea University: Marcos del Pozo Banos; Swansea University: Owen Pickrell; Swansea University: Ronan Lyons; Swansea University - DATAMIND: Ann John; University College: Robert Aldridge; University College London: Abraham Olvera-Barrios; University College London: Adnan Tufail; University College London: Alasdair Warwick; University College London: Alex Handy; University College London: Alexei Yavlinsky; University College London: Alvina Lai; University College London: Ami Banerjee; University College London: Ana Torralbo; University College London: Ana-Catarina Pinho-Gomes; University College London: Andrej Ivanovic; University College London: Andrew Lambarth; University College London: Anthony Khawaja; University College London: Ashkan Dashtban; University College London: Ashley Dickson; University College London: Becky White; University College London: Christina Pagel; University College London: Christopher Tomlinson; University College London: Chu Siyu; University College London: David Selby; University College London: Eloise Withnell; University College London: Emma Whitfield; University College London: Eva Keller; University College London: Evaleen Malgapo; University College London: Ferran Espuny-Pujol; University College London: Flavien Hardy; University College London: Floriaan Schmidt; University College London: Freya Allery; University College London: Harry Hemingway; University College London: Honghan Wu; University College London: Jinge Wu; University College London: Johan Thygesen; University College London: Johannes Heyl; University College London: Julia Ive; University College London: Kate Cheema; University College London: Katie Harron; University College London: Ken Li; University College London: Kerrie Stevenson; University College London: Laura Pasea; University College London: Louise Choo; University College London: Luca Grieco; University College London: Manuel Gomes; University College London: Matt Sydes; University College London: Mehrdad Mizani; University College London: Michalis Katsoulis; University College London: Mohamed Mohamed; University College London: Naomi Launders; University College London: Nushrat Khan; University College London: Paula Lorgelly; University College London: Pedro Machado; University College London: Pia Hardelid; University College London: Qi Huang; University College London: Riyaz Patel; University College London: Roy Schwartz; University College London: Rui Providencia; University College London: Ruth Gilbert; University College London: Samuel Kim; University College London: Simon Ellershaw; University College London: Sonya Crowe; University College London: Spiros Denaxas; University College London: Tuankasfee Hama; University College London: Waty Lilaonitkul; University College London: Yi Mu; University College London: Yohhei Hamada; University College London: Yoryos Lyratzopoulos; University College London / DATAMIND: David Osborn; University Hospital of North Midlands: Arun Pherwani; University of Aberdeen: Mary Joan Macleod; University of Birmingham: Sarah Wang; University of Birmingham and Queen Elizabeth Hospital Birmingham: Mark Thomas; University of Bristol: Arun Karthikeyan Suseeladevi; University of Bristol: Ben Gibbison; University of Bristol: Dann Mitchell; University of Bristol: Deborah Lawler; University of Bristol: Eleanor Walsh; University of Bristol: Elsie Horne; University of Bristol: Ewan Walker; University of Bristol: Gianni Angelini; University of Bristol: Jeremy Chan; University of Bristol: John Macleod; University of Bristol: Jonathan Sterne; University of Bristol: Katharine Looker; University of Bristol: Kurt Taylor; University of Bristol: Livia Pierotti; University of Bristol: Luisa Zuccolo; University of Bristol: Martha Elwenspoek; University of Bristol: Marwa Al Arab; University of Bristol: Massimo Caputo; University of Bristol: Mira Hidajat; University of Bristol: Neil Davies; University of Bristol: Paul Madley-Dowd; University of Bristol: Rachel Denholm; University of Bristol: Rochelle Knight; University of Bristol: Shubhra Sinha; University of Bristol: Tim Dong; University of Bristol: Tom Palmer; University of Bristol: Venexia Walker; University of Bristol: Yueying Li; University of Bristol: Yvonne Nartey; University of Cambridge: Alexia Sampri; University of Cambridge: Angela Wood; University of Cambridge: Carmen Petitjean; University of Cambridge: Chimweta Chilala; University of Cambridge: Chriselda Oliver; University of Cambridge: David Brind; University of Cambridge: Elena Raffetti; University of Cambridge: Elias Allara; University of Cambridge: Emanuele Di Angelantonio; University of Cambridge: Eoin McKinney; University of Cambridge: Eric Harshfield; University of Cambridge: Fabian Falck; University of Cambridge: Genevieve Cezard; University of Cambridge: Hannah Harrison; University of Cambridge: Haoting Zhang; University of Cambridge: Holly Pavey; University of Cambridge: Isabel Walter; University of Cambridge: Jessica Barrett; University of Cambridge: John Danesh; University of Cambridge: John Ford; University of Cambridge: Katie Saunders; University of Cambridge: Lisa Pennells; University of Cambridge: Lois Kim; University of Cambridge: Mayank Dalakoti; University of Cambridge: Megan Ritson; University of Cambridge: Mike Inouye; University of Cambridge: Millie Zhou; University of Cambridge: Robert Fletcher; University of Cambridge: Rutendo Mapeta; University of Cambridge: Samantha Ip; University of Cambridge: Spencer Keene; University of Cambridge: Stelios Boulitsakis Logothetis; University of Cambridge: Stephen Kaptoge; University of Cambridge: Tianxiao Wang; University of Cambridge: Tom Pape; University of Cambridge: Wen Shi; University of Cambridge: Xilin Jiang; University of Cambridge: Xiyun Jiang; University of Cambridge: Yanfan Li; University of Dundee: Daniel Morales; University of Dundee: Huan Wang; University of Dundee: Ify Mordi; University of Dundee: Samira Bell; University of Edinburgh: Alan Carson; University of Edinburgh: Alice Hosking; University of Edinburgh: Annemarie Docherty; University of Edinburgh: Athina Spiliopoulou; University of Edinburgh: Baljean Dhillon; University of Edinburgh: Carlos Sanchez Soriano; University of Edinburgh: Caroline Jackson; University of Edinburgh: Christian Schnier; University of Edinburgh: Claire Tochel; University of Edinburgh: Gwenetta Curry; University of Edinburgh: Helen Colhoun; University of Edinburgh: Joe Mellor; University of Edinburgh: Kelly Fleetwood; University of Edinburgh: Laura Sherlock; University of Edinburgh: Luke Blackbourn; University of Edinburgh: Michelle Williams; University of Edinburgh: Miguel Bernabeu Llinares; University of Edinburgh: Niamh McLennan; University of Edinburgh: Rebecca Reynolds; University of Edinburgh: Richard Chin; University of Edinburgh: Steven Kerr; University of Edinburgh: Tim Wilkinson; University of Edinburgh: Verónica Cabreira; University of Edinburgh: William Berthon; University of Edinburgh: William Whiteley; University of Exeter: John Dennis; University of Exeter: Kerry Pearn; University of Exeter: Michael Allen; University of Glasgow: Angela Henderson; University of Glasgow: Clea du Toit; University of Glasgow: Colin Berry; University of Glasgow: Craig Melville; University of Glasgow: Deborah Kinnear; University of Glasgow: Dennis Tran; University of Glasgow: Filip Sosenko; University of Glasgow: Frederick Ho; University of Glasgow: Jill Pell; University of Glasgow: Jocelyn Friday; University of Glasgow: John Cleland; University of Glasgow: Naveed Sattar; University of Glasgow: Ninian Lang; University of Glasgow: Salil Deo; University of Glasgow: Sandosh Padmanabhan; University of Glasgow: Terry Quinn; University of Leeds: Jianhua Wu; University of Leeds: Ramesh Nadarajah; University of Leicester: Anna Hansell; University of Leicester: Anvesha Singh; University of Leicester: Cameron Razieh; University of Leicester: Claire Lawson; University of Leicester: Clare Gillies; University of Leicester: Francesco Zaccardi; University of Leicester: Iain Squire; University of Leicester: Kamlesh Khunti; University of Leicester: Matthew Bown; University of Leicester: Muhammad Rashid; University of Leicester: Sharmin Shabnam; University of Leicester: Shirley Sze; University of Leicester: Tom Yates; University of Leicester: Yogini Chudasama; University of Liverpool: Andrew Mason; University of Liverpool: Benedict Michael; University of Liverpool: Caroline Dale; University of Liverpool: David Hughes; University of Liverpool: Francesca Zaccagnino; University of Liverpool: Maria Sudell; University of Liverpool: Mark Green; University of Liverpool: Munir Pirmohamed; University of Liverpool: Pardis Biglarbeigi; University of Liverpool: Reecha Sofat; University of Liverpool: Rohan Takhar; University of Liverpool: Ruwanthi Kolamunnage-Dona; University of Liverpool: Stephen McKeever; University of Manchester: Bernard Keavney; University of Manchester: Catriona Harrison; University of Manchester: Craig Smith; University of Manchester: David Jenkins; University of Manchester: Eva Henning; University of Manchester: Evan Kontopantelis; University of Manchester: George Tilston; University of Manchester: Glen Martin; University of Manchester: Hector Chinoy; University of Manchester: Joseph Firth; University of Manchester: Lana Bojanić; University of Manchester: Matthew Sperrin; University of Manchester: Max Lyon; University of Manchester: Maya Buch; University of Manchester: Richard Williams; University of Manchester: Ruth Norris; University of Manchester: Ruth Watkinson; University of Manchester: Sarah Steeg; University of Manchester: Simon Frain; University of Manchester: Simon Williams; University of Manchester: Steven Zhao; University of Manchester: Zenas Yiu; University of Newcastle: Camille Carroll; University of Newcastle: Charlotte Parbery-Clark; University of Newcastle: Dexter Canoy; University of Newcastle: Precious Onyeachu; University of Nottingham: Fiona Pearce; University of Nottingham: Laila Tata; University of Nottingham: Ralph Akyea; University of Nottingham: Stephanie Lax; University of Oxford: Aashna Uppal; University of Oxford: Akshay Shah; University of Oxford: Antonella Delmestri; University of Oxford: Antony Palmer; University of Oxford: Ben Goldacre; University of Oxford: Ben Lacey; University of Oxford: Dani Prieto-Alhambra; University of Oxford: Eva Morris; University of Oxford: George Nicholson; University of Oxford: Hayley Evans; University of Oxford: James Sheppard; University of Oxford: Joseph Kamtchum Tatuene; University of Oxford: Julia Hippisley-Cox; University of Oxford: Kazem Rahimi; University of Oxford: Linxin Li; University of Oxford: Lucy Wright; University of Oxford: Marta Pineda Moncusi; University of Oxford: Mohammad Mamouei; University of Oxford: Nick Hall; University of Oxford: Parag Gajendragadkar; University of Oxford: Paula Dhiman; University of Oxford: Qingze Gu; University of Oxford: Raph Goldacre; University of Oxford: Salma Chaudhry; University of Oxford: Sara Khalid; University of Oxford: Seb Bacon; University of Oxford: Seyed Alireza Hasheminasab; University of Oxford: Shishir Rao; University of Oxford: Xiaomin Zhong; University of Oxford: Zeinab Bidel Taleshmekaeil; University of Oxford/KU Leuven: Nathalie Conrad; University of Plymouth: Marie-Louise Zeissler; University of Sheffield: Jen-Yu Amy Chang; University of Sheffield: Norman Briffa; University of Sheffield: Peter Bath; University of Sheffield: Simone Croft; University of Sheffield: Suzanne Mason; University of Sheffield: Tim Chico; University of Southampton: Nazrul Islam; University of Strathclyde: Amanj Kurdi; University of Strathclyde: Kim Kavanagh; University of Strathclyde: Marion Bennie; University of Strathlcyde: Tanja Mueller; University of Warwick: Harry Wilde; University of Warwick: Majel McGranahan; University of York: Christina van der Feltz-Cornelis; University of York: Han-I Wang; University of York: Lorna Fraser; Wellcome Sanger Institute: Tapiwa Tungamirai.
Data availability free text: The data used in this study are available in NHS England’s Secure Data Environment (SDE) service for England, but as restrictions apply, they are not publicly available (https://digital.nhs.uk/coronavirus/coronavirus-data-services-updates/trusted-research-environment-service-for-england; https://digital.nhs.uk/services/secure-data-environment-service). The CVD-COVID-UK/COVID-IMPACT programme led by the BHF Data Science Centre (https://bhfdatasciencecentre.org/; https://www.hdruk.ac.uk/helping-with-health-data/bhf-data-science-centre/) received approval to access data in NHS England’s SDE service for England from the Independent Group Advising on the Release of Data (IGARD) (https://digital.nhs.uk/about-nhs-digital/corporate-information-and-documents/independent-group-advising-on-the-release-of-data) via an application made in the Data Access Request Service (DARS) Online system (ref. DARS-NIC-381078-Y9C5K) (https://digital.nhs.uk/services/data-access-request-service-dars/dars-products-and-services). The CVD-COVID-UK/COVID-IMPACT Approvals & Oversight Board (https://bhfdatasciencecentre.org/areas/cvd-covid-uk-covid-impact/; https://www.hdruk.ac.uk/projects/cardiovasculard-covid-uk-project/) subsequently granted approval to this project to access the data within NHS England’s SDE service for England. The de-identified data used in this study were made available to accredited researchers only. Those wishing to gain access to the data should contact bhfdsc@hdruk.ac.uk in the first instance. The Northeast - Newcastle and North Tyneside 2 research ethics committee provided ethical approval for the CVD-COVID-UK/COVID-IMPACT research programme (REC No 20/NE/0161) to access, within secure SDE trusted research environments, unconsented, whole-population, de-identified data from EHR data collected as part of patients’ routine healthcare. Our analysis was performed according to a prespecific analysis plan published on GitHub, along with the phenotyping and analysis code (https://github.com/BHFDSC/CCU052_01). To ensure anonymity and compliance with the NHSE SDE CVD-COVID-UK consortium rules of statistical disclosure, all reported numbers were rounded to the nearest 5. Counts less than 10 were expressed as '<10'. CPRD has NHS Health Research Authority (HRA) Research Ethics Committee (REC) approval to allow the collection and release of anonymised primary care data for observational research (NHS HRA REC reference number: 05/MRE04/87). Each year CPRD obtains Section 251 regulatory support through the HRA Confidentiality Advisory Group (CAG), to enable patient identifiers, without accompanying clinical data, to flow from CPRD contributing GP practices in England to NHSE, for the purposes of data linkage (CAG reference number: 21/CAG/0008). The protocol for this research was approved by CPRD’s Research Data Governance (RDG) Process (protocol number: 22_001769) and the approved protocol is available upon request. Linked pseudonymised data was provided for this study by CPRD. Data is linked by NHSE, the statutory trusted third party for linking data, using identifiable data held only by NHSE. Select general practices consent to this process at a practice level with individual patients having the right to opt-out. All work conducted in SAIL Databank was completed under the permission and approval of the SAIL independent Information Governance Review Panel (IGRP) under project number 1387. Researchers can apply for the data and scripts within the SAIL trusted research environment, subject to the standard SAIL project application process (saildatabank.com/contact). The DataLoch work was reviewed and approved under the project number DL_2022_054. The underlying DataLoch data are available as part of the DataLoch Respiratory Registry—a de-identified registry of linked respiratory data from the South-East Scotland region—which can be accessed by application to the DataLoch service (dataloch.org/connect-with-us). Accredited researchers could only access the de-identified HBS data used in this study by signing a Disclosure Policy Agreement and Research Data Access Agreement. The data was accessible from a secure location, the UK Secure e-Research Platform (UK SeRP). Ethical approval was not required for this study as it was facilitated via HBS. Consent was not required for this study as data was provided in anonymised format, the rights of individuals are respected with adequate privacy protection.
Contributor Information
on behalf of the CVD-COVID-UK/COVID-IMPACT Consortium:
Alastair Proudfoot, Andrew Constantine, Dan Jones, Krishnaraj Rathod, Nida Ahmed, Richard Fitzgerald, Dan O’Connell, Rony Arafin, Sonya Babu-Narayan, Zainab Karim, Jon Shelton, Martina Slapkova, Rosie Hinchliffe, Shane Johnson, Renin Toms, Julia Townson, Ewan Birney, Moritz Gerstung, Tomas Fitzgerald, Katherine Brown, Benjamin Zuckerman, Ernest Wong, Lily Benton, Tasanee Braithwaite, Alexis Webb, Anna Stevenson, Annette Jackson, Cathie Sudlow, Fionna Chalmers, Jadene Lewis, James Farrell, Jemma Austin, John Nolan, Lars Murdock, Lynn Morrice, Mehrdad Mizani, Melissa Webb, Ross Forsyth, Rouven Priedon, Samaira Khan, Steffen Petersen, Thomas Bolton, Zach Welshman, Caroline Rogers, Donna Wakefield, Alun Davies, Arunashis Sau, Costas Kallis, Fu Siong Ng, Hannah Whittaker, Ioanna Tzoulaki, Jennifer Quint, Juliette Unwin, Libor Pastika, Petter Brodin, Philip Stone, Safa Salim, Sarah Cook, Sarah Onida, Alistair Marsland, Andrew Thompson, Sara Holloway, Thomas Porter, Alastair Denniston, Mamas Mamas, Adejoke Oluyase Abdel Douiri, Ajay Shah, Alexandru Dregan, Amy Ronaldson, Anna Bone, Antonio Cannata, Charles Wolfe Ben Bray, Daniel Bromage, Dominic Oliver, Elena Nikiphorou, Emeka Chukwusa, Gareth Williams, Gayan Perera, Harry Watson, Iain Marshall, Irene Higginson, Javiera Leniz Martelli, Jayati Das-Munshi, Joanna Davies, Johnny Downs, Katherine Sleeman, Laia Becares, Linglong Qian, Matthew O'Connell, Mevhibe Hocaoglu, Natasha Chilman, Rachel Cripps, Richard Killick, Theresa McDonagh, Vasa Curcin, Zeljko Kraljevic, Carin van Doorn, Rocco Friebel, Antonio Gasparrini, Arturo de la Cruz, Dorothea Nitsch, Julian Matthewman, Neil Pearce, Patrick Bidulka, Qiuju Li, Sinéad Langan, Thiago Silva, Zhengnan Zhu, Martin Rutter, Alex Grundmann, Adam Hollings, Angeliki Antonarou, Daniel Schofield, Deborah Lowe, Elizabeth Kelly, Humaira Hussein Richardson, Jake Kasan, Nickie Wareing, Russell Healey, Shoaib Ali Ajaib, Mark Barber, Carole Morris, Felix Greaves, Jennifer Beveridge, Seamus Kent, Thomas Lawrence, Vandana Ayyar-Gupta, Myer Glickman, Vahé Nafilyan, Deepti Gurdasani, Frank Kee, Paz Tayal, David Cromwell, Amar Shah, Swapna Mandal, Florian Falter, Joseph Newman, Jennifer Rossdale, Baboucarr Njie, Elijah Behr, Nuria Sanchez, Xinkai Wang, Daniel Harris, Amanda Marchant, Ashley Akbari, Daniel King, David Powell, Elizabeth A Ellins, Fatemeh Torabi, Gareth Davies, Hoda Abbasizanjani, Huw Strafford, Jane Lyons, Julian Halcox, Laura North, Marcos del Pozo Banos, Owen Pickrell, Ronan Lyons, Ann John, Robert Aldridge, Abraham Olvera-Barrios, Adnan Tufail, Alasdair Warwick, Alex Handy, Alexei Yavlinsky, Alvina Lai, Ami Banerjee, Ana Torralbo, Ana-Catarina Pinho-Gomes, Andrej Ivanovic, Andrew Lambarth, Anthony Khawaja, Ashkan Dashtban, Ashley Dickson, Becky White, Christina Pagel, Christopher Tomlinson, Chu Siyu, David Selby, Eloise Withnell, Emma Whitfield, Eva Keller, Evaleen Malgapo, Ferran Espuny-Pujol, Flavien Hardy, Floriaan Schmidt, Freya Allery, Harry Hemingway, Honghan Wu, Jinge Wu, Johan Thygesen, Johannes Heyl, Julia Ive, Kate Cheema, Katie Harron, Ken Li, Kerrie Stevenson, Laura Pasea, Louise Choo, Luca Grieco, Manuel Gomes, Matt Sydes, Mehrdad Mizani, Michalis Katsoulis, Mohamed Mohamed, Naomi Launders, Nushrat Khan, Paula Lorgelly, Pedro Machado, Pia Hardelid, Qi Huang, Riyaz Patel, Roy Schwartz, Rui Providencia, Ruth Gilbert, Samuel Kim, Simon Ellershaw, Sonya Crowe, Spiros Denaxas, Tuankasfee Hama, Waty Lilaonitkul, Yi Mu, Yohhei Hamada, Yoryos Lyratzopoulos, David Osborn, Arun Pherwani, Mary Joan Macleod, Sarah Wang, Mark Thomas, Arun Karthikeyan Suseeladevi, Dann Mitchell Ben Gibbison, Deborah Lawler, Eleanor Walsh, Elsie Horne, Ewan Walker, Gianni Angelini, Jeremy Chan, John Macleod, Jonathan Sterne, Katharine Looker, Kurt Taylor, Livia Pierotti, Luisa Zuccolo, Martha Elwenspoek, Marwa Al Arab, Massimo Caputo, Mira Hidajat, Neil Davies, Paul Madley-Dowd, Rachel Denholm, Rochelle Knight, Shubhra Sinha, Tim Dong, Tom Palmer, Venexia Walker, Yueying Li, Yvonne Nartey, Alexia Sampri, Angela Wood, Carmen Petitjean, Chimweta Chilala, Chriselda Oliver, David Brind, Elena Raffetti, Elias Allara, Emanuele Di Angelantonio, Eoin McKinney, Eric Harshfield, Fabian Falck, Genevieve Cezard, Hannah Harrison, Haoting Zhang, Holly Pavey, Isabel Walter, Jessica Barrett, John Danesh, John Ford, Katie Saunders, Lisa Pennells, Lois Kim, Mayank Dalakoti, Megan Ritson, Mike Inouye, Millie Zhou, Robert Fletcher, Rutendo Mapeta, Samantha Ip, Spencer Keene, Stelios Boulitsakis Logothetis, Stephen Kaptoge, Tianxiao Wang, Tom Pape, Wen Shi, Xilin Jiang, Xiyun Jiang, Yanfan Li, Daniel Morales, Huan Wang, Ify Mordi, Samira Bell, Alan Carson, Alice Hosking, Annemarie Docherty, Athina Spiliopoulou, Baljean Dhillon, Carlos Sanchez Soriano, Caroline Jackson, Christian Schnier, Claire Tochel, Gwenetta Curry, Helen Colhoun, Joe Mellor, Kelly Fleetwood, Laura Sherlock, Luke Blackbourn, Michelle Williams, Miguel Bernabeu Llinares, Niamh McLennan, Rebecca Reynolds, Richard Chin, Steven Kerr, Tim Wilkinson, Verónica Cabreira, William Berthon, William Whiteley, John Dennis, Kerry Pearn, Michael Allen, Angela Henderson, Clea du Toit, Colin Berry, Craig Melville, Deborah Kinnear, Dennis Tran, Filip Sosenko, Frederick Ho, Jill Pell, Jocelyn Friday, John Cleland, Naveed Sattar, Ninian Lang, Salil Deo, Sandosh Padmanabhan, Terry Quinn, Jianhua Wu, Ramesh Nadarajah, Anna Hansell, Anvesha Singh, Cameron Razieh, Claire Lawson, Clare Gillies, Francesco Zaccardi, Iain Squire, Kamlesh Khunti, Matthew Bown, Muhammad Rashid, Sharmin Shabnam, Shirley Sze, Tom Yates, Yogini Chudasama, Andrew Mason, Benedict Michael, Caroline Dale, David Hughes, Francesca Zaccagnino, Maria Sudell, Mark Green, Munir Pirmohamed, Pardis Biglarbeigi, Reecha Sofat, Rohan Takhar, Ruwanthi Kolamunnage-Dona, Stephen McKeever, Bernard Keavney, Catriona Harrison, Craig Smith, David Jenkins, Eva Henning, Evan Kontopantelis, George Tilston, Glen Martin, Hector Chinoy, Joseph Firth, Lana Bojanić, Matthew Sperrin, Max Lyon, Maya Buch, Richard Williams, Ruth Norris, Ruth Watkinson, Sarah Steeg, Simon Frain, Simon Williams, Steven Zhao, Zenas Yiu, Camille Carroll, Charlotte Parbery-Clark, Dexter Canoy, Precious Onyeachu, Fiona Pearce, Laila Tata, Ralph Akyea, Stephanie Lax, Aashna Uppal, Akshay Shah, Antonella Delmestri, Antony Palmer, Ben Lacey Ben Goldacre, Dani Prieto-Alhambra, Eva Morris, George Nicholson, Hayley Evans, James Sheppard, Joseph Kamtchum Tatuene, Julia Hippisley-Cox, Kazem Rahimi, Linxin Li, Lucy Wright, Marta Pineda Moncusi, Mohammad Mamouei, Nick Hall, Parag Gajendragadkar, Paula Dhiman, Qingze Gu, Raph Goldacre, Salma Chaudhry, Sara Khalid, Seb Bacon, Seyed Alireza Hasheminasab, Shishir Rao, Xiaomin Zhong, Zeinab Bidel Taleshmekaeil, Nathalie Conrad, Marie-Louise Zeissler, Jen-Yu Amy Chang, Norman Briffa, Peter Bath, Simone Croft, Suzanne Mason, Tim Chico, Nazrul Islam, Amanj Kurdi, Kim Kavanagh, Marion Bennie, Tanja Mueller, Harry Wilde, Majel McGranahan, Christina van der Feltz-Cornelis, Han-I Wang, Lorna Fraser, and Tapiwa Tungamirai
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
References
- 1.Mukherjee M, Stoddart A, Gupta RP, et al. The epidemiology, healthcare and societal burden and costs of asthma in the UK and its member nations: analyses of standalone and linked national databases. BMC Med. 2016;14:113. doi: 10.1186/s12916-016-0657-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.GBD 2015 Chronic Respiratory Disease Collaborators Global, regional, and national deaths, prevalence, disability-adjusted life years, and years lived with disability for chronic obstructive pulmonary disease and asthma, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet Respir Med. 2017;5:(2213-2619 (Electronic)). doi: 10.1016/S2213-2600(17)30293-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Kallis C, Maslova E, Morgan AD, et al. Recent trends in asthma diagnosis, preschool wheeze diagnosis and asthma exacerbations in English children and adolescents: a SABINA Jr study. Thorax. 2023;78:1175–80. doi: 10.1136/thorax-2022-219757. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Bloom CI, Saglani S, Feary J, et al. Changing prevalence of current asthma and inhaled corticosteroid treatment in the UK: population-based cohort 2006–2016. Eur Respir J. 2019;53:(1399-3003 (Electronic)). doi: 10.1183/13993003.02130-2018. [DOI] [PubMed] [Google Scholar]
- 5.Simpson CR, Sheikh A. Trends in the epidemiology of asthma in England: a national study of 333,294 patients. J R Soc Med. 2010;103:98–106. doi: 10.1258/jrsm.2009.090348. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Stone PW, Osen M, Ellis A, et al. Prevalence of Chronic Obstructive Pulmonary Disease in England from 2000 to 2019. Int J Chron Obstruct Pulmon Dis. 2023;18:1565–74. doi: 10.2147/COPD.S411739. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Simpson CR, Hippisley-Cox J, Sheikh A. Trends in the epidemiology of chronic obstructive pulmonary disease in England: a national study of 51 804 patients. Br J Gen Pract. 2010;60:e277–84. doi: 10.3399/bjgp10X514729. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Nacul L, Soljak M, Samarasundera E, et al. COPD in England: a comparison of expected, model-based prevalence and observed prevalence from general practice data. J Public Health (Oxf) 2011;33:108–16. doi: 10.1093/pubmed/fdq031. [DOI] [PubMed] [Google Scholar]
- 9.NHS General practice extraction service (GPES) data for pandemic planning and research: a guide for analysts and users of the data. 2024. [19-Mar-2024]. https://digital.nhs.uk/coronavirus/gpes-data-for-pandemic-planning-and-research/guide-for-analysts-and-users-of-the-data Available. Accessed.
- 10.Hatam S, Scully ST, Cook S, et al. A Harmonised Approach to Curating Research-Ready Datasets for Asthma, Chronic Obstructive Pulmonary Disease (COPD) and Interstitial Lung Disease (ILD) in England, Wales and Scotland Using Clinical Practice Research Datalink (CPRD), Secure Anonymised Information Linkage (SAIL) Databank and DataLoch. Clin Epidemiol. 2024;16:235–47. doi: 10.2147/CLEP.S437937. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Eurostat . Revision of the European standard population, EE Commision, editor. 2013. [Google Scholar]
- 12.Anandan C, Nurmatov U, Van Schayck OCP, et al. Is the prevalence of asthma declining? Systematic review of epidemiological studies. Allergy. 2010;65:(1398-9995 (Electronic)) doi: 10.1111/j.1398-9995.2009.02244.x. [DOI] [PubMed] [Google Scholar]
- 13.NICE . What is the prevalence of asthma?, N.I.f.H.a.C. excellence, Editor. 2023. [Google Scholar]
- 14.Looijmans-van den Akker I, van Luijn K, Verheij T. Overdiagnosis of asthma in children in primary care: a retrospective analysis. Br J Gen Pract. 2016;66:e152–7. doi: 10.3399/bjgp16X683965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Kavanagh J, Jackson DJ, Kent BD. Over- and under-diagnosis in asthma. Breathe (Sheff) 2019;15:(1810-6838 (Print)) doi: 10.1183/20734735.0362-2018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Dharmage SC, Perret JL, Custovic A. Epidemiology of Asthma in Children and Adults. Front Pediatr. 2019;7:246. doi: 10.3389/fped.2019.00246. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Radzikowska U, Golebski K. Sex hormones and asthma: The role of estrogen in asthma development and severity. Allergy. 2023;78:620–2. doi: 10.1111/all.15548. [DOI] [PubMed] [Google Scholar]
- 18.Ellison-Loschmann L, Sunyer J, Plana E, et al. Socioeconomic status, asthma and chronic bronchitis in a large community-based study. Eur Respir J . 2007;29:897–905. doi: 10.1183/09031936.00101606. [DOI] [PubMed] [Google Scholar]
- 19.Schyllert C, Lindberg A, Hedman L, et al. Low socioeconomic status relates to asthma and wheeze, especially in women. ERJ Open Res . 2020;6:00258–2019. doi: 10.1183/23120541.00258-2019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.On the edge: how inequality affects people with asthma, a. UK, editor. 2018
- 21.Hayanga B, Stafford M, Bécares L-O. Ethnic Inequalities in Healthcare Use and Care Quality among People with Multiple Long-Term Health Conditions Living in the United Kingdom: A Systematic Review and Narrative Synthesis. Int J Environ Res Public Health. 2021;18:12599. doi: 10.3390/ijerph182312599. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Snell N, Strachan D, Hubbard R, et al. S32 Epidemiology of chronic obstructive pulmonary disease (COPD) in the uk: findings from the british lung foundation’s ‘respiratory health of the nation’ project. Thorax. 2016;71:A20. doi: 10.1136/thoraxjnl-2016-209333.38. [DOI] [Google Scholar]
- 23.Momtazmanesh S. Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019. EClinicalMedicine. 2023;59:101936. doi: 10.1016/j.eclinm.2023.101936. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Gayle A, Lenoir A, Minelli C, et al. Are we missing lifetime COPD diagnosis among people with COPD recorded death? A population-based retrospective cohort study. BJGP Open. 2022;6:BJGPO.2022.0060. doi: 10.3399/BJGPO.2022.0060. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Dai X, Gakidou E, Lopez AD. Evolution of the global smoking epidemic over the past half century: strengthening the evidence base for policy action. Tob Control. 2022;31:129–37. doi: 10.1136/tobaccocontrol-2021-056535. [DOI] [PubMed] [Google Scholar]
- 26.S Government . Scottish health survey: topic report UK comparisons, Ed. 2010. [Google Scholar]
- 27.Swinney, K.E.V.Q.P . Cities outlook 2020 holding our breath, centreforcities, editor. 2020. [Google Scholar]
- 28.ONS Adult smoking habits in the UK: 2022. 2023. https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/healthandlifeexpectancies/bulletins/adultsmokinghabitsingreatbritain/2022 Available.
- 29.Stolz D, Kostikas K, Loefroth E, et al. Differences in COPD Exacerbation Risk Between Women and Men: Analysis From the UK Clinical Practice Research Datalink Data. Chest. 2019;156:(1931-3543 (Electronic)) doi: 10.1016/j.chest.2019.04.107. [DOI] [PubMed] [Google Scholar]
- 30.Martin A, Badrick E, Mathur R, et al. Effect of ethnicity on the prevalence, severity, and management of COPD in general practice. Br J Gen Pract . 2012;62:e76–81. doi: 10.3399/bjgp12X625120. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Ajayi Sotubo O. A perspective on health inequalities in BAME communities and how to improve access to primary care. Future Healthc J . 2021;8:36–9. doi: 10.7861/fhj.2020-0217. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Levin KA, Anderson DR, Crighton EM. Prevalence of COPD by age, sex, socioeconomic position and smoking status; a cross-sectional study. HE. 2020;120:275–88. doi: 10.1108/HE-06-2020-0044. [DOI] [Google Scholar]
- 33.Hitchman SC, Fong GT, Zanna MP, et al. Socioeconomic status and smokers’ number of smoking friends: Findings from the International Tobacco Control (ITC) Four Country Survey. Drug Alcohol Depend. 2014;143:158–66. doi: 10.1016/j.drugalcdep.2014.07.019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34.Salciccioli JD, Marshall DC, Goodall R, et al. Interstitial lung disease incidence and mortality in the UK and the European Union: an observational study, 2001-2017. ERJ Open Res. 2022;8:00058-2022. doi: 10.1183/23120541.00058-2022. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Silva M, Fernandes A, Pereira AR, et al. Awareness towards the main ILD among primary care physicians. Multidiscip Respir Med. 2022;17:(1828-695X (Print)) doi: 10.4081/mrm.2022.848. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Choi W-I, Dauti S, Kim HJ, et al. Risk factors for interstitial lung disease: a 9-year Nationwide population-based study. BMC Pulm Med. 2018;18:(1471-2466 (Electronic)) doi: 10.1186/s12890-018-0660-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Kawano-Dourado L, Glassberg MK, Assayag D, et al. Sex and gender in interstitial lung diseases. Eur Respir Rev. 2021;30:210105. doi: 10.1183/16000617.0105-2021. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Goobie GC, Ryerson CJ, Johannson KA, et al. Neighborhood-Level Disadvantage Impacts on Patients with Fibrotic Interstitial Lung Disease. Am J Respir Crit Care Med. 2022;205:(1535-4970 (Electronic)) doi: 10.1164/rccm.202109-2065OC. [DOI] [PubMed] [Google Scholar]
- 39.Van den Bulck S, Crèvecoeur J, Aertgeerts B, et al. The impact of the Covid-19 pandemic on the incidence of diseases and the provision of primary care: A registry-based study. PLoS ONE. 2022;17:(1932-6203 (Electronic)) doi: 10.1371/journal.pone.0271049. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40.Mansfield KE, Mathur R, Tazare J, et al. Indirect acute effects of the COVID-19 pandemic on physical and mental health in the UK: a population-based study. Lancet Digit Health. 2021;3:e217–30. doi: 10.1016/S2589-7500(21)00017-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Bottle A, Neale FK, Foley KA, et al. Impact of COVID-19 on outpatient appointments in children and young people in England: an observational study. BMJ Open . 2022;12:e060961. doi: 10.1136/bmjopen-2022-060961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42.Qi C, Osborne T, Bailey R, et al. Impact of COVID-19 pandemic on incidence of long-term conditions in Wales: a population data linkage study using primary and secondary care health records. Br J Gen Pract. 2023;73:e332–9. doi: 10.3399/BJGP.2022.0353. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 43.Quint JK, Müllerova H, DiSantostefano RL, et al. Validation of chronic obstructive pulmonary disease recording in the Clinical Practice Research Datalink (CPRD-GOLD) BMJ Open. 2014;4:e005540. doi: 10.1136/bmjopen-2014-005540. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Nissen F, Morales DR, Mullerova H, et al. Validation of asthma recording in the Clinical Practice Research Datalink (CPRD) BMJ Open. 2017;7:e017474. doi: 10.1136/bmjopen-2017-017474. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Morgan A, Gupta RS, George PM, et al. Validation of the recording of idiopathic pulmonary fibrosis in routinely collected electronic healthcare records in England. BMC Pulm Med. 2023;23:256. doi: 10.1186/s12890-023-02550-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46.Perret J, Yip SWS, Idrose NS, et al. Undiagnosed and “overdiagnosed” COPD using postbronchodilator spirometry in primary healthcare settings: a systematic review and meta-analysis. BMJ Open Respir Res. 2023;10:e001478. doi: 10.1136/bmjresp-2022-001478. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 47.Aaron SD, Vandemheen KL, FitzGerald JM, et al. Reevaluation of Diagnosis in Adults With Physician-Diagnosed Asthma. JAMA . 2017;317:269. doi: 10.1001/jama.2016.19627. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
All data relevant to the study are included in the article or uploaded as supplementary information.