The global prevalence of interstitial lung disease in patients with rheumatoid arthritis: a systematic review and meta-analysis

This study aims to review the literature and estimate the global pooled prevalence of interstitial lung disease among patients with rheumatoid arthritis (RA-ILD). The influence of risk factors like geography, socioeconomic status, smoking and DMARD use will be explored. A systematic review was performed according to the PRISMA and JBI guidelines. Studies published between January 1980 and February 2024 were sourced from 7 electronic databases and screened for eligibility. A random-effects meta-analysis model was used to produce pooled prevalences and the potential between-study heterogeneity was identified using sensitivity, subgroup, meta-regression and correlation analyses. 33 studies were included in this meta-analysis containing 14,281 RA patients. The global pooled prevalence of RA-ILD was 21.38% (CI: 0.1542-0.2886), with a high heterogeneity (I2) of 98%. The prevalence of usual interstitial pneumonia and non-specific interstitial pneumonia among RA patients were 11.01% and 6.86% respectively. Africa had the highest RA-ILD prevalence with an imprecise estimate of 38.15% (95% Confidence Interval [CI]: 2.29-94.2) and Europe had the lowest prevalence of 10.15% (CI: 2.86-30.23). Other risk factors associated with a higher prevalence of RA-ILD included living in low-income countries, smoking and DMARD use. The biggest limitation of this study is the high heterogeneity of results and underrepresentation of Oceania and low-income countries. This study has clarified the global prevalence of RA-ILD. The risk factors identified in this study can aid clinicians in identifying high-risk populations and highlight the need for screening these populations. Smoking cessation should also be encouraged.