Interstitial Lung Disease in the United States: CDC Mortality Trends (1999–2024)

Interstitial lung diseases (ILDs) comprise a heterogeneous group of pulmonary disorders associated with substantial morbidity and mortality. We examined mortality attributed to selected J84-coded ILDs in the United States from 1999 to 2024 using CDC WONDER underlying-cause-of-death data. Age-adjusted mortality rates (AAMRs) per 100,000 population were standardized to the 2000 U.S. population and stratified by sex and race. Joinpoint regression was used to identify changes in temporal slope and estimate annual percent change (APC), average annual percent change (AAPC), 95% confidence intervals (CIs), and p-values. After the removal of overlapping years between the CDC WONDER database series, 444,573 unique deaths occurred. Annual deaths increased from 11,358 in 1999 to 22,849 in 2024, while AAMR increased from 4.2 to 5.1 per 100,000. Overall, AAMR increased during 1999–2004 (APC 2.32%, 95% CI 1.39–3.26; p < 0.001) and more slowly during 2004–2024 (APC 0.36%, 95% CI 0.16–0.56; p = 0.001), with an overall AAPC of 0.75% (95% CI 0.60–0.90; p < 0.001). Male AAMRs remained higher than female AAMRs, while race-specific trends were heterogeneous. No temporal reduction in population mortality coincided with the introduction of antifibrotic therapies; however, this ecological analysis cannot evaluate treatment effectiveness or individual treatment exposure.