[Survival analysis and risk factors for survival in idiopathic inflammatory myopathies: a retrospective cohort study]

To study predominant risk factors for survival in idiopathic inflammatory myopathies (JIM).The clinical data of 163 cases of IIM were reviewed, who received the diagnosis and treatments in West China Hospital from January 1997 to December 2010. Kaplan-Meier survival curve was used for the survival analysis of these patients with IIM. Univariate and multivariate analysis of risk factors for survival in the patients with IIM were carried out by Log-rank test, univariate Cox regression analysis and Cox regression model respectively.There were 21 death occured among 163 patients with IIM, and the estimated 3, 5, 10-year survival rate was 93%, 89%, 80% respectively. The mortality of the patients with dermatomyositis (DM) or amyophathic dermatomyositis(ADM) increased significantly when compared with polymyositis (PM, P=0. 033, P= 0. 06). The mortality of IIM patients complicated with tumor or cadiovascular involvement was much higher than that of those patients without any complications (P0. 001, P=0. 015). Tumor and cadiovascular involvement were two independent risk factors for the survival of IIM individuals.DM and ADM have much unfavorable prognosis than PM. Tumor and cadiovascular involvement are two major risk factors for the survival of IIM patients.