Abstract
Introduction
Although the population was aging, interstitial lung disease mortality had remained relatively stable until it rose following the COVID-19 pandemic in the United States. Despite the consistent overall mortality trend prior to the pandemic, significant demographic and geographic disparities persist across the country.
Methods
Disparities in ILD-related mortality were analyzed temporally using the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiological Research (CDC WONDER) database. Using ICD Codes J84.1, J84.8, and J84.9 ILD-related crude mortality (CMR) and age-adjusted mortality rates (AAMR) were calculated, and the Join-point Regression Program was used to determine mortality trends between 1999 and 2022. ILD-related mortality was identified using the International Classification of Diseases, 10th Revision, and clinical modification codes J84.1 (Other interstitial pulmonary diseases with fibrosis), J84.8 (Other specified interstitial pulmonary diseases), and J84.9 (Interstitial pulmonary disease, unspecified) were used in patients ≥ 45 years.
Results
Based on the results of this study, there have been 609,157 deaths due to ILD during this study period, with the highest mortality rates seen in the Non-Hispanic (NH) American Indian or Alaskan Native population, and the lowest mortality rates seen in the NH African American population. Hispanic or Latinos and NH Whites experienced similar mortality. Males had higher mortality rates than females in all racial groups. Regarding region, the Northeast had significantly lower mortality rates than all other census areas throughout the entire study period. The results of this study demonstrate large increases in AAMR at the onset of COVID-19 beginning in 2020, peaking in 2021, and decreasing in 2022.
Conclusions
The COVID-19 pandemic posed unique challenges to our society, especially for patients with interstitial lung disease. While further research is needed to better understand these trends, it is concerning that ILD-related mortality increased throughout the study period. Medical professionals should be cognizant of these trends when treating patients diagnosed with ILD.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12931-025-03350-2.
Introduction
Interstitial lung disease (ILD) impacts hundreds of thousands of Americans annually. This condition is marked by inflammation and/or fibrosis in the lungs, leading to symptoms like shortness of breath and often necessitating supplemental oxygen. Prior to an ILD diagnosis, patients are frequently exposed to various pollutants, including urban pollution, metal dust, and wood dust. ILD can progress to pulmonary fibrosis, a severe and largely irreversible disease that further compromises respiratory function. In 2019, there were 654,841 diagnosed cases of ILD in the U.S., with the average age at diagnosis ranging from 67 to 72 years. ILD can be classified into three stages, with the most severe stage having a 1-year mortality rate of 39.2% and a 3-year mortality rate of 76.8% [1].
COVID-19 is an acute respiratory disease that first arose in 2019 and quickly spread worldwide. The clinical presentation has been quite uneven across populations, ranging from mild to severe cases, and at times leading to patient death [2]. Across the literature, it has been shown that those experiencing severe COVID-19 were more likely to be from an elderly population or those with pre-existing health conditions [3].
COVID-19 is primarily known for causing respiratory symptoms like cough, shortness of breath, and fever. However, it can also result in more severe conditions such as pneumonia and acute respiratory distress syndrome (ARDS). While many cases are acute, COVID-19 can continue to impact patients long after the initial infection. Long COVID, which usually emerges around four weeks after the acute phase ends, can lead to persistent symptoms such as brain fog, fatigue, and ongoing shortness of breath [4]. Furthermore, meta-analysis of long-term COVID-19 effects have illustrated an increased risk of developing other health conditions, such as diabetes, cardiovascular disease, and mental health disorders after COVID-19 infections [5].
The complete effects of COVID-19 on health remain unclear. In this study, we will explore the CDC WONDER database to assess how the COVID-19 pandemic has influenced trends in interstitial lung disease (ILD). We will examine both quantitative and descriptive statistics across various variables. This research aims to provide a deeper understanding of COVID-19’s impact, particularly on patients and the broader healthcare system.
Methods
Study design and database
Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) was used to identify ILD-related deaths occurring within the United States [6]. The Multiple Cause-of-Death Public Use Record and the CDC WONDER database death certificate records were analyzed to determine ILD-related cause of death as a contributing cause on nationwide death certificate records. This database has been previously used in several other studies to analyze nationwide trends in mortality of pulmonary heart disease [7]. ILD-related mortality was identified using the International Classification of Diseases, 10th Revision, and clinical modification codes J84.1 (Other interstitial pulmonary diseases with fibrosis), J84.8 (Other specified interstitial pulmonary diseases), and J84.9 (Interstitial pulmonary disease, unspecified) were used in patients ≥ 45 years [8]. Codes included in the study are summarized in Supplemental Table 1. Code J84.0 (Alveolar and parieto-alveolar conditions) was excluded from this study due to minimal reported data of only 4,494 reported deaths between 1999 and 2022. Patients under the age of 45 years old were also excluded because ILD is infrequent in these populations. The study was exempt from institutional review board approval because the CDC WONDER database contains anonymized, publicly available data.
Demographic and geographical study groups
We extracted data regarding ILD-related deaths from 1999 to 2022. Data on demographic and regional groups were extracted, including gender, race/ethnicity, age, and census region. Racial/ethnicity groups were defined as non-Hispanic (NH) White, NH Black, NH American Indian/Alaskan Native, NH Asian/Pacific Islander, and Hispanic people as identified on death certificates. Age groups were defined as 45 to 54, 55 to 64, 65 to 74, 75 to 85, and 85 + years of age. Regions were classified into Northeast, Midwest, South, and West according to the Census Bureau definitions [9]. Location of death included medical facilities (outpatient, emergency room, inpatient, death on arrival, or status unknown), home, hospice, and nursing home/long-term care.
Statistical analysis
ILD-related crude and age-adjusted mortality rates (AAMR) were calculated. Crude mortality rates were calculated by dividing the number of ILD-related deaths by the corresponding United States population. AAMR were standardized using the 2000 United States standard population [10]. The Join point Regression Program (Join point version 4.9.0.0 available from National Cancer Institute, Bethesda, Maryland) was used to determine trends in mortality within the study period [11]. This program identifies significant changes in annual mortality trends over time through Join point regression, which fits models of linear segments where significant temporal variation occurred. Annual percentage change (APC) with 95% confidence intervals (CIs) for the AAMRs were calculated for the line segments linking a Join point using the Monte Carlo permutation test. The weighted average of the APCs was calculated and reported as AAPCs and corresponding 95% CIs as a summary of the reported mortality trend for the entire study period. APC and AAPCs were considered increasing or decreasing if the slope describing the change in mortality over the time interval was significantly different from zero using 2-tailed t-test. Statistical significance was set at p ≤ 0.05 [12].
Results
In this study, we analyzed mortality trends based on gender, race, combinations of gender and race, 10-year age groups, census regions, and places of death. Throughout the study period, males consistently had higher mortality rates than females, though both genders showed similar average annual percentage changes (AAPCs). Non-Hispanic American Indian or Alaskan Natives had the highest average annual mortality rates (AAMR), while NH Whites experienced the most significant AAPC in mortality among the racial groups studied. When examining race and gender together, Hispanic or Latino males had the highest AAPC, while White males showed a similar trend in mortality but had slightly higher AAMR for most of the study period. Non-Hispanic American Indian or Alaskan Native males had the highest AAMR throughout the study. The Northeast saw the greatest increase in AAMR, though it maintained the lowest mortality rates overall. The West, Midwest, and South regions showed more comparable mortality rates, with AAMRs consistently higher than those in the Northeast. Adults aged 85 and older had the highest mortality rates by a significant margin. The most common place of death due to ILD was inpatient medical facilities each year, although the number of deaths occurring at home increased the most over the study period.
Overall
From 1999 to 2022, there were 609,157 reported deaths due to interstitial lung disease in the United States. The overall AAMR and AAPC over the study period are summarized in Table 1; Fig. 1. Overall, AAMR peaked in 2021, reaching 26.5 (95% CI 26.2 to 26.8) compared to 22.6 (95% CI 22.4 to 22.9) in 2020 (Fig. 1) (Supplemental Table 2).
Table 1.
AAMR from ILD and its AAPC between 1999–2022 in males and females
| Group | AAMR 1999 (95% CI) | AAMR 2022 (95% CI) | AAPC (95% CI) |
|---|---|---|---|
| Overall | 18.8 (18.5–19.1) | 25.3 (25.1–25.6) | 1.20* (0.96–1.44) |
| Males | 24.7 (24.2–25.2) | 33.2 (32.7–33.7) | 1.23* (1.04–1.48) |
| Females | 15.1 (14.8–15.4) | 19.7 (19.4–24.0) | 1.33* (1.01–1.61) |
Fig. 1.
Age adjusted mortality rates stratified by gender in ILD-related mortality from 1999–2022 in the United States
Demographic differences
Gender stratified
From 1999 to 2022, interstitial lung disease caused 326,915 deaths in males and 282,242 deaths in females in the United States (Supplemental Table 2). The AAMR and AAPC data for males and females over the study period are summarized in Fig. 1; Table 1. Both male and female populations had significant peaks in AAMR during the year of 2021. The APC for males and females are summarized in Table 2.
Table 2.
APC data for ILD mortality in males and females between 1999–2022
| Gender | Time Period | APC (95% CI) |
|---|---|---|
| Male | 1999–2018 | 0.38* (0.10–0.65) |
| 2018–2022 | 5.44* (3.80–7.96) | |
| Female | 1999–2002 | 3.49* (0.58–7.49) |
| 2002–2015 | −0.31* (−2.68 - −0.02) | |
| 2015–2020 | 1.97* (0.51–2.76) | |
| 2020–2022 | 7.41* (4.14–10.66) |
Race stratified
The NH American Indian or Alaska Native population consistently had the highest AAMR during the study period. The AAMR and AAPC data for all racial groups are summarized in Fig. 2; Table 3. The AAMR data for each year of the study period is included in Supplemental Table 3. NH Whites saw the greatest increase in AAMR over the period of the study (Fig. 2). NH Black or African Americans consistently had the lowest mortality from ILD, but like other groups also saw an increase over the period of the study (Fig. 2). Each demographic group experienced large increases in AAMR at the onset of COVID-19, peaked in 2021, and decreased in 2022. The APC data for all groups is summarized in Table 4.
Fig. 2.
Age adjusted mortality rates stratified by race/ethnicity in ILD-related mortality from 1999–2022 in the United States
Table 3.
AAMR from ILD and its AAPC stratified by race between 1999–2022
| Race | AAMR 1999 (95% CI) | AAMR 2022 (95% CI) | AAPC (95% CI) |
|---|---|---|---|
| NH American Indian or Alaska Native | 35.96 (28.52–41.60) | 36.74 (32.70–40.79) | 0.44 (−0.05–1.04) |
| NH Whites | 19.12 (18.81–19.42) | 26.69 (26.39–27.00) | 1.32* (1.08–1.58) |
| Hispanic or Latino | 21.75 (20.33–23.18) | 27.54 (26.65–28.43) | 1.02* (0.76–1.32) |
| NH Black or African | 12.98 (12.19–13.77) | 15.33 (14.68–15.99) | 0.65* (0.39–0.92) |
Table 4.
APC data for ILD mortality stratified by race between 1999–2022
| Race | Time Period | APC (95% CI) |
|---|---|---|
| NH American Indian or Alaska Native | 1999–2022 | 0.44 (−0.05–1.04) |
| NH Whites | 1999–2018 | 0.53* (0.20–0.79) |
| 2018–2022 | 5.82* (3.12–9.50) | |
| Hispanic or Latino | 1999–2016 | −0.10 (−0.61–0.34) |
| 2016–2022 | 4.27* (2.99–6.50) | |
| NH Black or African American | 1999–2016 | −0.69* (−1.13 - −0.32) |
| 2016–2022 | 4.53* (3.13–6.56) |
Race and gender stratified
The population with consistently lower annual AAMR between 1999 and 2022 was NH African American females (Fig. 3) (Table 5). The population with consistently higher annual AAMR during this period was NH American Indian or Alaskan Native males (Fig. 3) (Table 5). Hispanic or Latino males had the greatest increase in AAMR from ILD. The AAMR and AAPC data for all race and gender stratified groups are summarized in Fig. 3; Table 5. The AAMR data for each year of the study is included in Supplemental Table 4. Each group experienced large increases in AAMR at the onset of COVID-19 in 2020, peaked in 2021, and decreased in 2022. The APC data for all groups is summarized in Table 6.
Fig. 3.
Age adjusted mortality rates stratified by gender and race/ethnicity in ILD-related mortality from 1999–2022 in the United States
Table 5.
AAMR from ILD and its AAPC stratified by race and gender between 1999–2022
| Group | AAMR 1999 (95% CI) | AAMR 2022 (95% CI) | AAPC (95% CI) |
|---|---|---|---|
| NH American Indian or Alaskan Native Female | 31.99 (24.64–40.86) | 34.83 (29.54–40.12) | 0.53 (−0.04–1.00) |
| NH American Indian or Alaskan Native Male | 40.79 (29.75–54.58) | 39.73 (33.33–46.13) | 0.66* (0.07–1.41) |
| NH Black or African American Female | 11.63 (10.68–12.58) | 13.91 (13.11–14.71) | 0.66* (0.18–1.14) |
| NH Black or African American Male | 15.53 (14.08–16.97) | 17.88 (16.71–19.05) | 0.50 (−0.09–1.00) |
| NH White Female | 14.99 (14.64–15.33) | 20.33 (19.97–20.69) | 1.34* (0.98–1.77) |
| NH White Male | 25.49 (24.92–26.05) | 35.35 (34.81–35.89) | 1.33* (1.11–1.57) |
| Hispanic or Latino Female | 19.99 (18.24–21.74) | 23.08 (22.02–24.14) | 0.65* (0.27–1.04) |
| Hispanic or Latino Male | 24.45 (21.99–26.91) | 33.96 (32.39–35.52) | 1.36* (1.04–1.72) |
Table 6.
APC data for ILD mortality stratified by race and gender between 1999–2022
| Group | Time Period | APC (95% CI) |
|---|---|---|
| NH American Indian or Alaskan Native Female | 1999–2019 | −0.55* (−1.30 - −0.05) |
| 2019–2022 | 8.02* (2.26–16.10) | |
| NH American Indian or Alaskan Native Male | 1999–2022 | 0.66* (0.07–1.41) |
| NH Black or African American Female | 1999–2016 | −0.75* (−1.72 - −0.12) |
| 2016–2022 | 4.78* (2.37–10.86) | |
| NH Black or African American Male | 1999–2016 | −0.77* (−2.38 - −0.07) |
| 2016–2022 | 4.16* (1.42–11.69) | |
| NH White Female | 1999–2002 | 4.06* (0.52–10.43) |
| 2002–2016 | −0.19 (−2.78–0.23) | |
| 2016–2022 | 3.61* (2.14–6.42) | |
| NH White Male | 1999–2018 | 0.50* (0.21–0.75) |
| 2018–2022 | 5.38* (3.49–8.87) | |
| Hispanic or Latino Female | 1999–2016 | −0.29 (−1.18–0.24) |
| 2016–2022 | 3.39* (1.70–7.86) | |
| Hispanic or Latino Male | 1999–2016 | 0.04 (−0.57–0.57) |
| 2016–2022 | 5.19* (3.69–8.10) |
10-Year age gaps
ILD-related mortality correlated positively with 10-year age cohorts every year between 1999 and 2022. The 85 + year old cohort consistently had the highest mortality from ILD, while also seeing the greatest rise during the pandemic period (Fig. 4) (Table 7). The 75- to 84-year-old cohort also had crude mortality rates that increased considerably during this period. The AAMR and AAPC data for all age cohorts are summarized in Fig. 4; Table 7. The AAMR data for each year of the study is included in Supplemental Table 5. The APC data for all age cohorts is summarized in Table 8.
Fig. 4.
Crude mortality rates stratified by 10-year age groups in ILD-related mortality from 1999–2022 in the United States
Table 7.
AAMR from ILD and its AAPC stratified by race and gender between 1999–2022
| Age Group (years) | AAMR 1999 (95% CI) | AAMR 2022 (95% CI) | AAPC (95% CI) |
|---|---|---|---|
| 45–54 | 2.05 (1.90–2.19) | 2.07 (1.93–2.21) | 0.30 (−0.26–0.80) |
| 55–64 | 6.69 (6.36–7.02) | 7.92 (7.65–8.19) | 0.83* (0.43–1.24) |
| 65–74 | 23.72 (23.02–24.42) | 25.90 (25.35–26.44) | 0.28 (−0.01–0.54) |
| 75–84 | 56.67 (55.34–58.01) | 79.02 (77.70–80.33) | 1.44* (1.18–1.79) |
| 85+ | 102.38 (99.31–105.46) | 167.83 (164.67–170.98) | 2.00* (1.74–2.28) |
Table 8.
APC data for ILD mortality stratified by age between 1999–2022
| Age Group (years) | Time Period | APC (95% CI) |
|---|---|---|
| 45–54 | 1999–2018 | −1.10* (−1.77 - −0.63) |
| 2018–2022 | 7.19* (2.46–16.93) | |
| 55–64 | 1999–2018 | −0.69* (−1.18 - −0.26) |
| 2018–2022 | 8.33* (4.85–14.21) | |
| 65–74 | 1999–2018 | −0.56* (−0.94 - −0.27) |
| 2018–2022 | 4.36* (2.05–9.05) | |
| 75–84 | 1999–2003 | 2.95* (0.96–7.64) |
| 2003–2017 | 0.25 (−1.96–0.56) | |
| 2017–2022 | 3.64* (2.21–6.55) | |
| 85+ | 1999–2016 | 1.18* (0.70–1.55) |
| 2016–2022 | 4.36* (3.12–7.00) |
Regional variation
Census region
The census region with the greatest increase in AAMR throughout the study period was the Northeast region. The AAMR and AAPC data for all census regions are summarized in Fig. 5; Table 9. The AAMR data for each year of the study is included in Supplemental Table 6. Each census region experienced large increases in AAMR at the onset of COVID-19 in 2020, peaked in 2021, and decreased in 2022. The APC data for all regions is summarized in Fig. 5; Table 10.
Fig. 5.
Age adjusted mortality rates stratified by region in ILD-related mortality from 1999–2022 in the United States
Table 9.
AAMR from ILD and its AAPC stratified by census region between 1999–2022
| Region | AAMR 1999 (95% CI) | AAMR 2022 (95% CI) | AAPC (95% CI) |
|---|---|---|---|
| Northeast | 15.4 (14.90–15.90) | 22.10 (21.50–22.60) | 1.64* (1.37–1.91) |
| Midwest | 19.70 (19.20–20.30) | 25.90 (25.30–26.40) | 1.40* (1.11–1.69) |
| South | 19.20 (18.80–19.70) | 25.9 (25.50–26.30) | 1.08* (0.86–1.33) |
| West | 20.50 (19.90–21.10) | 26.60 (26.10–27.20) | 1.13* (0.85–1.41) |
Table 10.
APC data for ILD mortality stratified by census region between 1999–2022
| Region | Time Period | APC (95% CI) |
|---|---|---|
| Northeast | 1999–2002 | 4.03* (1.28–8.07) |
| 2002–2017 | 0.57 (−0.60–0.81) | |
| 2017–2022 | 3.47* (2.33–5.59) | |
| Midwest | 1999–2002 | 3.52* (0.77–7.54) |
| 2002–2019 | 0.21 (−0.67–0.40) | |
| 2019–2022 | 6.17* (3.69–10.18) | |
| South | 1999–2016 | −0.04 (−0.43–0.28) |
| 2016–2022 | 4.33* (3.10–6.23) | |
| West | 1999–2018 | 0.28 (−0.11–0.57) |
| 2018–2022 | 5.24* (2.89–10.71) |
Place of death
Annual deaths occurring at the decedent’s home increased the most during the study period, from 3,612 deaths in 1999 to 13,099 in 2022 (Fig. 6). Annual deaths occurring at an inpatient medical facility also increased, most prominently during the pandemic period between 2020 and 2021. Inpatient medical facility annual deaths increased from 10,334 in 1999 to 12,678 in 2020, and then increased sharply to 16,623 in 2021. The majority of total deaths from ILD between 1999 and 2022 occurred in inpatient medical facilities. (Fig. 6).
Fig. 6.
Age adjusted mortality rates stratified by place of death in ILD-related mortality from 1999–2022 in the United States
Discussion
Our data is consistent with other studies which have examined ILD’s impact on COVID-19 disease severity and mortality. A meta analysis by Cavasin et al. found that idiopathic pulmonary fibrosis (IPF) patients in particular had a 34% mortality rate from COVID-19, much higher than the general population [12]. Similarly, Aveyard et al. found that patients with IPF as well as other causes of ILD were at increased risk of mortality, with hazard ratios of up to 2.31 [13]. When looking at the overall increase in AAMR among patients with ILD, a key factor to consider is the age of the diseased population in the United States. While ILD is a broad term encompassing a heterogenous group of diseases, it is primarily a disease that afflicts older adults, which is a growing cohort within our population [14]. Additionally, the impact of the COVID-19 pandemic is readily noticeable in almost all our data sets. There is an incomplete understanding of the relationship between respiratory infection and ILD pathogenesis and exacerbation [15]. However, existing literature does suggest a plausible link. The pathophysiologic changes seen in ILD, including impaired immune cell trafficking and dysfunctional lung repair mechanisms, have been proposed as contributors to increased COVID-19 mortality in this population. As Zhao et al. describe, these alterations may heighten vulnerability to severe outcomes following viral infection [16].
Furthermore, systemic factors during the early pandemic—such as healthcare staffing shortages—also compounded mortality risk among individuals with ILD. Lasater et al. estimate that during the pandemic, each patient added beyond a registered nurse’s average pre-pandemic workload was associated with a 20% higher odds of in-hospital mortality and 15% higher odds of 30-day mortality for patients during the pandemic [17]. Al-Amin et al. also found that higher levels of registered nurses and emergency medicine physicians were associated with decreased COVID-19 mortality rates [18].
Another important factor to consider is smoking, a well-documented risk factor for the development of interstitial lung disease (ILD). This factor may be relevant when examining the differences in average annual mortality rates (AAMR) between men and women, as men not only have higher mortality rates but also generally use more tobacco products than women [19]. The link between ILD and smoking could also help explain some of the observed variations in ILD-related mortality across different ethnic groups. The American Lung Association (ALA) reports that non-Hispanic American Indian and Alaskan Natives have the highest adult smoking rate at 21.9%, and they also had the highest AAMR from ILD in our study [20]. Interestingly, while 24.0% of non-Hispanic American Indian and Alaskan Native females smoke compared to 19.0% of males, our study found that non-Hispanic American Indian and Alaskan Native males had significantly higher mortality rates than females. This discrepancy might partially clarify why non-Hispanic American Indian and Alaskan Native females experience higher ILD mortality rates compared to females of other ethnic groups with lower smoking rates. Furthermore, the ALA indicates that African Americans have the second-highest smoking rate at 16.8%, yet they have the lowest AAMR from ILD. These findings suggest that while smoking is a useful predictor of ILD mortality, other contributing factors are also at play.
The finding that African Americans have lower mortality rates from ILD has already been studied and documented. Adegunsoye et al. demonstrated that mortality in African Americans from ILD was 19% compared to 27% in non-African Americans in a study that included 1640 patients with ILD [21]. In our study, NH African American males had lower mortality than Hispanic and NH White females, which is inconsistent with the finding that men had overall higher mortality rates compared to women. The explanation for African Americans having significantly lower mortality from ILD is still not completely understood, and is widely multifactorial, which indicates a need for further research.
In this study, the Northeast region had significantly lower AAMRs from ILD than other regions. The AAMRs did not increase as much during the COVID-19 pandemic compared to other regions in the United States. Although likely multifactorial in nature, one possible contributing factor is that ILD is simply underdiagnosed in this region due to greater population and population density [22]. Hence, further research is necessary to explain these effects.
Finally, it is interesting to note that deaths at home steadily increased throughout the duration of the study period. While the slight increase between 2019 and 2021 may be attributable to the COVID-19 pandemic and fears of going to the hospital during that time, the pandemic does not explain why deaths at home increased steadily between 1999 and 2019. This reflects a larger shift in end-of-life care in the United States which has been seen with an overall increase in home deaths beyond just those of ILD patients. Cross et al. found that between 2003 and 2017, the percentage of deaths occurring at home across all disease groups increased from 23.8 to 30.7% [23].
One of the strengths of this study was the size and reliability of the database used. The CDC WONDER database is a large, national database that encompasses anonymized, public death certificate records, and allowed this study to undergo an extensive statistical analysis of trends seen in ILD-related mortality in various demographic and geographical populations. This makes it a powerful tool for this study, as the large volume of data collected on the national level makes the results of our study more generalizable. Limitations of this study include the heterogeneous nature of ILD and possible discordance between what is reported on a patient’s death certificate and the actual pathology resulting in death, especially considering the frequency of misdiagnosis [22]. Additionally, while the CDC WONDER database contains a wealth of data, we were limited in our ability to analyze the role of confounding variables such as socioeconomic factors and geographical cultural differences when interpreting the results of our study. We acknowledge that these variables are important factors to either analyze for or control for when determining trends in mortality data. While socioeconomic status and cultural differences are critically important in accurately estimating ILD mortality risk, we were not able to directly account for them with the data available to us, which is also true for individual-level behaviors such as smoking.
Conclusion
The COVID-19 pandemic posed unique challenges to our society, especially for patients with interstitial lung disease. Using the CDC WONDER Database, results demonstrated that ILD-related mortality rates predictably increased during the COVID-19 pandemic in all study populations, but especially affected NH American Indian and Alaskan Native females. In agreement with prior literature, the African American population experienced the smallest increase in mortality. Lastly, home deaths have been uptrending, a finding that began prior to and continued throughout the COVID-19 pandemic. While further research is needed to better understand these trends, it is concerning that ILD-related mortality is increasing. Hence, medical professionals should be cognizant of these trends when treating patients diagnosed with ILD.
Supplementary Information
Authors’ contributions
C.L. Responsible for drafting the main manuscript and data interpretation; Primary author for the manuscript. C.B. Responsible for drafting the manuscript as well as data analysis and interpretation; Co-author for the manuscript. N.B. Responsible for interpretation of the data; critically reviewed manuscript for important intellectual content; final approval of manuscript. A.A. Concept and design of the work; primary data analysis and interpretation of data for the work. A.M. Reviewed the manuscript critically for important intellectual content. M.M. Reviewed the manuscript critically for important intellectual content. A.T. Principal Investigator; Mentor; Reviewed the manuscript critically for intellectual content; Final approval of the manuscript.
Funding
Not applicable.
Data availability
No datasets were generated or analysed during the current study.
Declarations
Ethics approval and consent to participate
The study was exempt from institutional review board approval because the CDC WONDER database contains anonymized, publicly available data. Research was conducted in accordance with the Declaration of inki.
Human subjects were not used in this research study. consent for participation is not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Maher TM. Interstitial lung disease: A review. JAMA. 2024;331(19):1655–65. 10.1001/jama.2024.3669. [DOI] [PubMed] [Google Scholar]
- 2.Gao Y, Chen Y, Liu M, Shi S, Tian J. Impacts of uncontrolled COVID-19 pandemic on the healthcare systems and delivery around the world: A review. Viruses. 2023;15(1):175. 10.3390/v15010175. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Zheng Z, Peng F, Xu B, Zhao J, Liu H, Peng J, Li Q, Jiang C, Zhou Y, Liu S, Ye C, Zhang P, Xing Y, Guo H, Tang W. Risk factors of critical & mortal COVID-19 cases: a systematic literature review and meta-analysis. J Infect. 2020;81(2):e16-25. 10.1016/j.jinf.2020.04.021. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Antonelli M, Penfold RS, Merino J, Sudre CH, Molteni E, Berry S, Canas LS, Graham MS, Klaser K, Modat M, Murray B, Kerfoot E, Chen L, Deng J, Österdahl MF, Cheetham NJ, Drew DA, Nguyen LH, Pujol JC, Steves CJ. Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID symptom study app: A prospective, community-based, nested, case-control study. Vaccine. 2023;41(22):3374–82. 10.1016/j.vaccine.2023.03.093. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Al-Aly Z, Bowe B, Xie Y. Long COVID risk and pre-COVID health conditions. JAMA Health Forum. 2023;4(4):e230565. 10.1001/jamahealthforum.2023.0565. [Google Scholar]
- 6.Centers for Disease Control and Prevention, National Center for Health Statistics. National Vital Statistics System, Mortality 1999–2020 on CDC WONDER Online Database, released in 2021. Data are from the multiple cause of death files, 1999–2020, as compiled from data provided by the 57 vital statistics jurisdictions through the vital statistics cooperative program.
- 7.Arif W, Bhimani RK, Shah A, Tausif M, Nisar Z, Kumar U, Bhimani R, Shoaibullah PD, Naveed S, Raja MA, Raja A, Deepak S, Shafique F, M. A., Mustafa MS. Unraveling disparities: probing gender, race, and geographic inequities in pulmonary heart disease mortality in the united states: an extensive longitudinal examination (1999–2020) leveraging CDC WONDER data. Curr Probl Cardiol. 2024;49(6):102527. 10.1016/j.cpcardiol.2024.102527. [DOI] [PubMed] [Google Scholar]
- 8.World Health Organization. (2004). ICD-10: international statistical classification of diseases and related health problems: tenth revision, 2nd ed. World Health Organization.
- 9.Multiple Cause of Death, 1999–2020 Request. Accessed September 9. 2024. https://wonder.cdc.gov/mcd-icd10.html
- 10.Anderson RN, Rosenberg HM. Age Standardization of Death Rates; Implementation of the Year 2000 Standard. Accessed September 9, 2024. https://stacks.cdc.gov/view/cdc/13357 [PubMed]
- 11.Program JR. Version 5.0.2 - May 2023. Statistical methodology and applications branch, Surveillance Research Program, National Cancer Institute.
- 12.Cavasin D, Zanini U, Montelisciani L, Valsecchi MG, Fabbri L, Antolini L, Luppi F. (2024). The impact of COVID-19 infection on idiopathic pulmonary fibrosis mortality: a systematic review and meta-analysis. monaldi archives for chest disease = archivio monaldi per Le malattie Del Torace, 10.4081/monaldi.2024.3070. Advance online publication. https://doi.org/10.4081/monaldi.2024.3070. [DOI] [PubMed]
- 13.Aveyard P, Gao M, Lindson N, Hartmann-Boyce J, Watkinson P, Young D, Coupland CAC, Tan PS, Clift AK, Harrison D, Gould DW, Pavord ID, Hippisley-Cox J. Association between pre-existing respiratory disease and its treatment, and severe COVID-19: a population cohort study. Lancet Respiratory Med. 2021;9(8):909–23. 10.1016/S2213-2600(21)00095-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Ageing and Health. Accessed September 9. 2024. https://www.who.int/news-room/fact-sheets/detail/ageing-and-health
- 15.Azadeh N, Limper AH, Carmona EM, Ryu JH. The Role of Infection in Interstitial Lung Diseases. Chest. 2017;152(4):842–52. 10.1016/j.chest.2017.03.033. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Zhao J, Metra B, George G, Roman J, Mallon J, Sundaram B, Li M, Summer R. Mortality among patients with COVID-19 and different interstitial lung disease subtypes: a multicenter cohort study. Ann Am Thorac Soc. 2022;19(8):1435–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Lasater KB, Aiken LH, Sloane DM, French R, Martin B, Reneau K, Alexander M, McHugh MD. Chronic hospital nurse understaffing Meets COVID-19: an observational study. BMJ Qual Saf. 2022;31(8):601–13. 10.1136/bmjqs-2021-013614. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Al–Amin M, Islam MN, Li K, Shiels N, Buresh J. Is there an association between hospital staffing levels and inpatient–COVID–19 mortality rates? PLoS One. 2022;17(10): e0275500. 10.1371/journal.pone.0275500. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.CDC. Current cigarette smoking among adults in the united states. Centers for disease control and prevention, October 11, 2023. https://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm
- 20.American Lung Association. (2023, May 31). Tobacco use in racial and ethnic populations. https://www.lung.org/quit-smoking/smoking-facts/impact-of-tobacco-use/tobacco-use-racial-and-ethnic
- 21.Adegunsoye A, Oldham JM, Bellam SK, Chung JH, Chung PA, Biblowitz KM, Montner S. African-American race and mortality in interstitial lung disease: a multicentre propensity-matched analysis. Eur Respir J. 2018. 10.1183/13993003.00255-2018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Cosgrove GP, Bianchi P, Danese S, Lederer DJ. Barriers to timely diagnosis of interstitial lung disease in the real world: the INTENSITY survey. BMC Pulm Med. 2018;18(1): 9. 10.1186/s12890-017-0560-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Cross S, Warraich H. Changes in place of death in the United States (CS202A). J Pain Symptom Manage. 2020;60(1July 1,):196. 10.1016/j.jpainsymman.2020.04.039. [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
No datasets were generated or analysed during the current study.