BREATHEIN: Better understanding obstructive REspiratory Airway disease Treatment and HEalth: a nationwide INvestigative survey in Denmark—a study protocol

Abstract

Introduction

Understanding patient perspectives on asthma and chronic obstructive pulmonary disease (COPD) is limited, with no prior studies employing such a large-scale, proactive survey to systematically target individuals with a confirmed prescription for inhalation medication. This study aims to explore how patients with asthma or COPD manage their lives, including treatment experiences, symptoms and impacts on daily life.

Methods and analysis

A nationwide survey will be launched in January 2025, targeting adults (≥18 years) in Denmark diagnosed with asthma or COPD and prescribed or dispensed inhalation medication between 1 October 2023 and 30 September 2024. Data from the Danish Health Data Authority’s Register of Medicinal Product Statistics will identify eligible individuals. The electronic survey will be distributed via e-Boks to approximately 450 000 individuals.

The questionnaire integrates validated tools—COPD Assessment Test, Modified Medical Research Council scale, EuroQol 5-Dimension 5-Level and Asthma Control Test—alongside expert-developed questions on symptoms, diagnosis, disease control, treatment and patient experiences. Questionnaire development included 10 cognitive interviews with patients from the Outpatient Clinic at Vejle Hospital.

Descriptive statistics will be used to analyse both continuous and categorical data, with sensitivity analyses conducted as well. Data management will be handled in Research Electronic Data Capture, and statistical analyses will be performed using Stata V.18.0.

Ethics and dissemination

The study is registered with the Danish Data Protection Agency (24/5229) and Open Patient Data Explorative Network (OP_2094) and follows the Declaration of Helsinki. Results will be published in peer-reviewed journals, presented at national and international conferences and shared through patient associations.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This study uses a nationwide survey design, allowing for inclusion of individuals with asthma or chronic obstructive pulmonary disease across all regions of Denmark.

• The methodology includes the use of unique personal identifiers to reach a clearly defined and complete population.

• The survey is co-developed with patient representatives and clinical experts, which enhances the content validity of the questionnaire.

• As with all survey-based research, there is a risk of response bias, including potential differences between responders and non-responders.

• The cross-sectional design limits the ability to assess causality or changes over time.

Introduction

Asthma and chronic obstructive pulmonary disease (COPD) are common airway diseases causing breathing difficulties and affecting millions globally, representing a major health burden.¹,³

In Denmark, both conditions are significant public health concerns, with asthma affecting 7–11% and COPD 6.8% of the population.^{4 5}

Understanding asthma-related health-related quality of life (HRQoL) offers valuable insights for clinicians, yet the patient perspective is often under-represented.⁶ Patients report that asthma impacts multiple life domains—physical, emotional and social—through symptoms, treatment side effects and the burden of a chronic illness.^{6 7} Similarly, COPD is a progressively disabling disease, where symptom severity reduces HRQoL.⁸ Patients with asthma or COPD also face higher risks of anxiety and depression compared with the general population.⁹,¹¹

Despite established guidelines, asthma remains underdiagnosed and undertreated.¹² Barriers include embarrassment, denial, medication fears and unpredictability of symptoms.¹³

Similarly, patients with COPD report unmet physical, psychosocial and practical needs, often tied to shame, regret and symptom variability.^{14 15} Patients with either condition often feel isolated in managing their illness,¹⁶ and non-adherence remains a significant issue, with nearly half of patients with COPD not following treatment regimens.¹⁷

The patient–physician relationship is vital for effective disease management and medication adherence,¹⁸ and the Global Initiative for Asthma report 2024² and the Global Initiative for Chronic Obstructive Lung Disease, 2024 GOLD Report¹ underline the importance of incorporating the patient perspective into care strategies.

Our national survey aims to gain insight into everyday life of patients living with asthma or COPD. We wish to explore how patients manage their condition, their treatment experiences, symptom burden and its impact on daily life.

Methods and analyses

This study is a nationwide survey questionnaire targeting adults ≥18 years (registered 1 October 2023) with asthma or COPD, who have redeemed a prescription for inhalation medication (Anatomical Therapeutic Chemical Classification System R03) between 1 October 2023 and 30 September 2024. Additionally, the population must reside in a Danish municipality and have a valid civil personal registration number. Figure 1 illustrates the process elements of conducting the survey.

Figure 1. Flow chart of Danish National Questionnaire Survey ‘BREATHEIN’.

Participants

From 1 January to 1 April 2025, we are planning to distribute the survey questionnaire electronically via e-Boks to all individuals in Denmark with a redeemed prescription for inhalation medication. In Denmark, e-Boks is a secure digital platform for receiving official communications from public authorities and private companies.¹⁹ The total population redeeming prescriptions for inhalation medication is estimated to be approximately 450 000, based on sales data. We expect to distribute the questionnaire every other year.

Data collection

Data will be collected and managed using Research Electronic Data Capture (REDCap) electronic data capture tools.^{20 21} REDCap is a secure web application that is designed to handle both online and offline data collection for research studies and operations.

The questionnaires are scheduled to be distributed with a capacity of 1000 questionnaires per hour. Individuals who receive the questionnaire early in the distribution period will have up to 3 months to respond, while those receiving it closer to the closing date on 14 April will have 14 days to complete it. Based on prior experience, we expect that if a person does not respond within 14 days, the likelihood of receiving a response is low. Due to budget constraints, no reminders will be sent, as each distribution incurs a cost.

All participants receive clear written information on how to take part in the survey and complete the questionnaire, which takes approximately 10–15 min. Patients have to provide consent to participate. If they decline, this is recorded as an active choice of ‘no’ or a non-respondent. We are able to track the number of individuals who have selected these two options.

Survey outcomes

Our questionnaire (see online supplemental material S1) consists of validated questionnaires and expert-developed questions modified from other validated and well-known questionnaires.^{22 23} Specific validated questionnaires are used to assess asthma or COPD, respectively.

The Asthma Control Test (ACT) is a valid tool for identifying patients with poorly controlled asthma.²⁴ It consists of five items, uses a 4-week recall period and employs a 5-point scale. The ACT evaluates shortness of breath, general asthma symptoms, use of rescue medications, the effect of asthma on daily activities and the patient’s overall self-assessment of asthma control.²⁴ Scores range from 5 (poor asthma control) to 25 (complete control), with higher scores indicating better asthma management.²⁴ An ACT score >19 signifies well-controlled asthma.²⁴

To assess patients’ self-perceived breathlessness in COPD, the modified Medical Research Council (mMRC) scale is used.²⁵ The scale ranges from 0 to 4 with higher scores representing more breathlessness. The mMRC is recommended in respiratory guidelines and therefore used in the present survey.²⁶

To examine how COPD affects patients’ daily life, the COPD Assessment Test (CAT) score is applied.²⁷ CAT consists of eight questions with a score between 0 and 5, leading to a total score of 0–40, where a score of 0 reflects no impact of COPD on the patient’s health and a score of 40 reflects a severe impact.²⁷

The EuroQol 5-Dimension 5-Level (EQ-5D-5L) is a generic quality-of-life (QoL) questionnaire that we use in this survey to assess the HRQoL of both patients with asthma and COPD.²⁸ EQ-5D-5L is one of the most widely used generic preference-based measures of HRQoL.²⁸ The five dimensions are the following: Mobility, Self-Care, Usual Activities, Pain/Discomfort and Anxiety/Depression. The five levels are the following: none, slight, moderate, strong and extreme difficulties.²⁸ The expert-developed questions cover the following areas: demographics and socioeconomic status, symptoms, smoking status, diagnosis and control, medical treatment and patients’ experience of their own illness.

Patient and public involvement

To ensure that all questionnaire items and response options are relevant, clear to understand and acceptable from the respondents’ perspective, the first author (KKH) conducted 10 cognitive interviews²⁹ with volunteer patients from the Outpatient Clinic during their scheduled control visits. The conduct of the cognitive interviews is a part of the patient involvement in co-production and contribution to refining the questionnaire, ensuring it captures meaningful and relevant outcomes for their daily lives.

Cognitive interviews

To capture variation of perspectives, patients of different ages and genders were included. This group consisted of six women and four men, aged between 25 and 74 years, with either asthma or COPD (five with asthma and five with COPD). None of the participants had prior knowledge of the survey. Each interview lasted between 18 and 34 min.

The patients were asked to complete two additional tasks during the interview. First, they were encouraged to think aloud (“Tell me everything that comes to mind as you answer the questions”). Second, they were asked follow-up questions (‘probes’) about specific terms, phrases and the overall meaning of the questions.²⁹ In this cognitive interview process, each question or set of questions was presented, followed by probing questions, before moving on to the next item.

Results of the cognitive interviews

During the interviews, all patients found the questionnaire relevant and comprehensive and there were no concerns about the format and length of the questionnaire. At the beginning of the questionnaire, patients were required to choose either the asthma or COPD questionnaire. If they had both conditions, we asked them to select the questionnaire that best represented their lung disease. However, one patient pointed out that some patients may be uncertain about which option to select, COPD or asthma, if they have asthma-COPD overlap syndrome.

Based on the interviews, additional response options were added to the questionnaire (see online supplemental material S2 for more detailed information).

Data analysis

The analytical framework will be structured around four planned papers for both asthma and COPD, each addressing a core domain of patient experience: (1) disease burden and characteristics, (2) medication use and adherence, (3) healthcare contact and perceived quality and (4) physical activity and mental health. Paper 1 focuses on characterising the asthma and COPD populations, including symptom burden, comorbidities and lifestyle factors. Paper 2 investigates patterns of medication use and adherence, identifying predictors of suboptimal use. Paper 3 explores healthcare utilisation and patient-reported quality of care. Paper 4 examines physical activity, barriers to exercise and mental well-being, with regression models linking symptoms and psychosocial factors to activity levels and mental health scores.

We plan to assess the association between living area and access to specialist treatment and patient satisfaction by comparing participants’ known region of residence with the number of specialists and physicians available in those specific areas.

Across all papers, we will apply descriptive statistics to summarise demographic, clinical and psychosocial variables. Comparative analyses between individuals with asthma and COPD will be performed. Where relevant, we will perform cluster analysis to identify patient subgroups based on behavioural or symptom profiles.

Available data, such as age, sex and medication use, for non-responders will be compared with responders using the national medicine registry, focusing on the number of different inhalation medications and treatment adherence.

Statistical methods

Continuous data (eg, age, cigarettes smoked daily and cigarette pack-years) are checked for normal distribution and descriptive analyses are performed. Categorical data (eg, education, employment status, comorbidities and smoking status) and dichotomous binary variables (eg, sex, marital status and previous assistance with smoking cessation) will be summarised by counts and proportions expressed as percentages (%). Continuous data will be summarised by mean (SD) for normally distributed data and median (IQR) for not normally distributed continuous data.

Sensitivity analyses will be performed, categorising relevant variables into groups, for example, age, sex, education level, employment status, living area (regions), lung function and number of comorbidities. To compare the results in the sensitivity analyses, parametric unpaired t-tests are used for normally distributed continuous data. Non-parametric Mann-Whitney U tests are used for not normally distributed continuous data and χ² is used for categorical data.³⁰

To identify factors associated with key outcomes, we will perform multivariable logistic and linear regression analyses. These include models for outcomes such as low adherence, poor perceived healthcare quality and reduced physical activity. Covariates in adjusted models will include age, sex, education level, employment status and comorbidity burden.

Depending on the type and the underlying cause of missing data, the data may be handled through imputation. This will be based on whether the data are missing at random or not missing at random.

Statistical analysis will be performed using Stata V.18.0.

Discussion

To our knowledge, this study is the first large-scale, proactive survey to systematically target individuals with a confirmed prescription for inhalation medication, aiming to explore patients’ experiences of living with asthma or COPD. It encompasses an understanding of the unmet needs, which can significantly impact their daily lives. This knowledge can be difficult to capture through clinical measurements alone.

Two COPD surveys from the UK,^{31 32} with responses from 41 769 and 74 827 patients,f respectively, investigated patient experiences with COPD care. The study by Philip et al³² revealed significant gaps in care experiences that remained unchanged over a 5-year period. Furthermore, Williams et al³¹ found that individuals with COPD expressed a need for increased support and better access to healthcare services, based on data collected between 2014 and 2022. A review from 2006,³³ based on 24 patient with asthma surveys in Europe and North America, showed that patients frequently endured poor symptom control, had limited knowledge of proper medication use and showed inadequate adherence to treatment. Many also had low expectations regarding the effectiveness of therapy or the likelihood of a positive interaction with healthcare professionals.

In qualitative studies, patients with asthma describe how the disease affects every aspect of their lives.³⁴,³⁶ The negative impacts include physical, emotional and interpersonal burdens. A study by Forster et al describes the need to improve practical and emotional support services for patients with asthma and their carers.³⁴

Our survey is designed to assess the satisfaction of patients with asthma or COPD regarding their medical treatment. For example, if the study reveals low medication adherence or significant negative impacts of the disease on daily life, it will provide valuable insights into how asthma and COPD affect patients’ everyday experiences. This understanding may lead to the development, dissemination and implementation of targeted disease management programmes. By capturing direct patient feedback, our survey highlights the areas needing improvement, the treatment elements that matter most and the factors influencing patients’ lives.

The results of our survey could provide valuable insights for politicians and decision makers, helping them shape strategies and policies to enhance treatment approaches for asthma and COPD in the future. By integrating patient perspectives, these initiatives can aim to improve symptom control, optimise medical treatment, reduce disease burden and enhance both quality of life and life expectancy.

With this survey, we aim to explore whether there is an association between patients’ living area or access to specialist treatment and their satisfaction with care. While the survey cannot establish causality, existing literature indicates that, despite Denmark being a small country with relatively short distances to healthcare services compared with many others, access to care is more limited in certain regions outside the capital area.^{37 38} Additionally, factors such as education level, environment, upbringing and culture influence patients’ motivation and adherence to treatment.^{37 38} These influences are also relevant in many other countries worldwide.³⁹,⁴²

Strengths

A strength of our study is that it is, to our knowledge, the first large-scale, proactive survey to systematically include individuals with a confirmed prescription for inhalation medication, with the aim of exploring their lived experiences with asthma or COPD.

Another strength of this study is that the results will capture regional and geographical variations, as well as patients’ perceived access to general practitioners and lung specialists across the country. Additionally, the survey format allows for easy distribution to a large number of patients, enabling broader and more representative data collection than what individual interviews could achieve.

Our survey specifically focuses on the patients’ perspective regarding daily life with asthma or COPD. It explores their experiences with healthcare services, including treatment, monitoring, symptoms, diagnosis, exacerbations and hospitalisations. This approach may help identify unmet needs and highlight potential gaps in current care by directly capturing patients’ voices.

Finally, this study actively promotes patient involvement. By soliciting patients’ experiences and opinions, we demonstrate that their views are valued. This may enhance their engagement in managing their own treatment, although research on the direct causal link between patient involvement and health outcomes remains limited.⁴³,⁴⁶

Limitations

A possible limitation of our study is that patients with higher socioeconomic status, higher education levels and less severe disease may be more likely to participate in the study. In order to try to eliminate bias, we distribute the survey to all citizens in Denmark, who have redeemed a prescription for inhalation treatment.

Additionally, the use of self-reported measures for medication use, symptoms and quality of life may introduce information bias. Furthermore, asking patients to recall exacerbations and medication use over the past year carries a risk of recall bias.⁴⁷

Relying on predefined answer categories with no open text boxes may limit participants from fully expressing their experiences with their disease, and the questionnaire does not capture the full range of treatment options, including non-pharmacological approaches.

Finally, we include all individuals who get inhalator medication, not only those having asthma or COPD. It will automatically result in a low response rate; thus, those who get inhalator medication for another respiratory disease will not answer the questionnaire. We inform individuals that only patients with asthma or COPD should complete the questionnaire. However, we cannot fully rule out the possibility that some responses may come from individuals without either condition.

Unfortunately, it is not possible to determine why non-responders do not participate.

Ethics and dissemination

According to Danish legislation, this study did not require ethical approval from the National Committee on Health Research Ethics. The study was registered with the Danish Data Protection Agency (24/5229) and the Open Patient Data Explorative Network, Odense University Hospital (OP_2094). Patients participating in the cognitive interviews signed a statement of consent. Participants in the survey gave their consent by answering the questionnaire. We have obtained licensing agreement for EQ-5D-5L used in the survey.

Our study adds valuable knowledge to the Danish Government’s recent healthcare initiative. The goal is for more people to live a good and long life with their chronic disease.⁴⁸

The results of the survey will be published in national and international peer-reviewed journals and a report (white book) will be conducted, relevant for stakeholders, including clinicians, hospital administrators and policy makers. We will reach out to patient advocacy groups, to inform members and the public about the questionnaire beforehand and to share the survey results afterwards. We will present our findings at relevant national and international conferences.

Study enrolment and data collection are ongoing. We expect to repeat this survey in the coming years.