Predictors of mortality in rheumatoid arthritis-related interstitial lung disease

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) has a heterogeneous clinical presentation and disease course. Establishing prognosis for these patients is challenging. Identifying the factors that predict mortality in patients with RA-ILD could help guide management. A detailed systematic review was conducted in order to identify individual variables that predict mortality in RA-ILD. A literature review was performed using keywords and medical subject headings to identify all articles relating to the prognosis of RA-ILD. Studies were included if they identified predictors of mortality in adults with RA-ILD, were published in English, and included at least 10 patients with RA-ILD. Two authors independently reviewed each citation and extracted data from all studies meeting inclusion criteria. Any differences were then resolved by consensus. A total of 10 studies met our inclusion criteria. All were observational cohort studies of variable quality. Mean age of reported patients ranged from 55 to 69 years, and 41.7% of all patients were male. Median survival ranged from 3.2 to 8.1 years. Significant predictors of mortality on multivariate analysis were older age, male gender, lower diffusion capacity for carbon monoxide, extent of fibrosis, and the presence of usual interstitial pneumonia pattern. Mortality in RA-ILD is associated with several patient- and ILD-specific variables; however, previous studies are of low quality.