Twenty-year changes in mortality rates and underlying causes of death in patients with rheumatoid arthritis-associated interstitial lung disease.

: Despite recent advances in the treatment of rheumatoid arthritis (RA), few population-based studies have assessed the mortality rates and the underlying causes of death (UCDs) among patients with RA and RA-associated interstitial lung disease (RA-ILD). This study evaluated the trends in mortality rates, demographic characteristics, and UCDs among patients with RA-ILD.: Using data from death certificates (1999-2018) from the US Centers for Disease Control and Prevention Multiple Cause of Death files, we explored the trends in mortality rates and UCD for patients with RA and RA-ILD. Moreover, we examined the crude and age-standardized mortality rates (ASMRs) for such patients.: Among patients with RA or RA-ILD, ASMR variation decreased over 20 years. The ASMR ratio of RA-ILD to RA decreased by 5.84%. The ASMR for RA and RA-ILD stratified by gender or age group also decreased. The change in the ASMR ratio of RA-ILD to RA trended downwards in women and upwards in men. Arthropathies and ILD were the most frequent UCDs for RA-ILD, while arthropathies and ischaemic heart disease were the most frequent UCDs for RA.: Although RA and RA-ILD presented a downward trend in mortality, RA combined with ILD may reduce life expectancy. Specifically, the mortality rate for patients with RA-ILD remained relatively stable during the study period when ILD was the UCD, suggesting the need for active prevention, early diagnosis, and effective management of RA-ILD.