Multivariate analysis of survival from birth showed that, in patients with RA-DB, an early onset of DB (HR, 15.4; 95% CI, 2.1 to 113.2; P = 0.0072) and CF/CFTR-RD mutations (HR, 7.2; 95% CI, 1.4 to 37.1; P = 0.018) were the two major determinants associated with poorer survival (Table 2). This evidence concerns the gene CFTR and rheumatoid arthritis.