Resumen:
Objective: To study prognostic factors in different types of idiopathic inflammatory myopathies (IIM) associated with interstitial lung disease (ILD). Patients and methods: Multicenter retrospective study of a Spanish cohort of patients diagnosed with IIM. Patients were classified into four categories: polymyositis (PM), dermatomyositis (DM), antisynthetase syndrome (ASS), and overlap myositis (OM). Sociodemographic data, clinical characteristics, antibodies, and treatments were collected. Cox regression models were calculated to identify factors associated with mortality, the necessity for long-term oxygen therapy (LTOT), and deterioration in respiratory function tests (RFT). Results: The number of patients included was 478, of whom 112 (23.4%) suffered from ILD: 17% PM, 16% DM, 45% ASS, and 22% OM. Factors associated with mortality in the multivariate analysis were clinically meaningful progression of ILD after 3 months (CMP 3m) (hazard ratio (HR) 9.48, p = 0.005), severe infections (HR 6.41, p = 0.016), heliotrope erythema (HR 31.1, p = 0.002), delay in diagnosis (HR 1.29; p = 0.011), and Raynaud's phenomenon (HR 11.9, p = 0.007). However, being female (HR 0.19, p = 0.044) and positivity solel...