Mortality and survival of patients with rheumatoid arthritis and symptomatic diffuse interstitial lung disease

Abstract

Introduction: In Spain, few data have been reported on mortality and survival in rheumatoid arthritis with diffuse interstitial lung disease. Objectives: To estimate mortality and survival for patients with symptomatic diffuse interstitial lung disease and rheumatoid arthritis and to analyze the effect of clinical factors. Methods: We performed an observational study between 2007 and 2018 at the Interdisciplinary Rheumatology and Pulmonology Clinic, from a tertiary Hospital. Patients with rheumatoid arthritis and symptomatic of diffuse interstitial lung disease confirmed by high-resolution computed tomography were included. Causes of death and clinical factors were reported. Results: We identified 90 patients with rheumatoid arthritis and symptomatic interstitial lung disease. Twenty-six patients died and diffuse interstitial lung disease was the most frequent cause (50%). The overall mortality rate was 19.7 per 1000 patient-years (95% CI: 13.4 - 29). The multivariate model revealed the predictors of mortality to be a long time between diagnosis of rheumatoid arthritis and lung involvement (HR = 1.17; p = 0.003) and low forced vital capacity (HR = 0.02; p = 0.018). The probability of survival was 50% at 10.2 years from diagnosis of interstitial lung disease. Comparison of survival did not reveal significant differences by type of radiologic pattern (p = 0.823). Conclusions: The fact that almost one-third of patients died and that survival is 50% at 10 years highlights the important role of diffuse interstitial lung disease in rheumatoid arthritis. The radiologic pattern does not seem to be as important for survival as forced vital capacity at diagnosis and the time between diagnosis of rheumatoid arthritis and lung involvement. Key points 1. DILD is associated with shorter survival in patients with RA. 2. The radiologic pattern does not seem to influence the survival in patients with RA and DILD. 3. The FVC at diagnosis is an important factor that influences the prognosis of patients with RA and DILD.