Higher risk of hospitalized infection, cardiovascular disease, and fracture in patients with rheumatoid arthritis determined using the Japanese health insurance database.

To evaluate the risk of hospitalized infection (HI), cardiovascular disease (CVD), stroke, and fracture in rheumatoid arthritis (RA) patients compared with non-RA patients using the Japanese health insurance database. Among individuals aged ≥18 years, RA cases were defined to have one RA diagnostic code and receiving ≥1 disease-modifying antirheumatic drug between 2005 and 2013 ( = 6,712). Age-, sex-, calendar year of the observation start-, and observation length-matched non-RA cases were selected at 1:5 ( = 33,560). Hazard ratios (HRs) were calculated using the time-dependent Cox regression analysis. Median age of the patients was 52.0 years. The incidence rates of HI, CVD, and fracture in the RA group were 2.42/100 person-years (PY), 4.94/1,000 PY, and 10.59/1,000 PY. The crude incidence rate ratios (95% CI) (RA vs. non-RA) for HI, CVD, and fracture were 2.47 (2.20-2.77), 1.89 (1.49-2.41), and 3.35 (2.80-4.02). The adjusted HR (95% CI) (RA vs. non-RA) was significantly elevated (HI, 1.74 [1.52-1.99], CVD, 1.38 [1.04-1.85], and fracture, 1.88 (1.54-2.31)]. The relatively young RA population had significantly higher risks of these complications than the non-RA, indicating importance of prevention of them even at young ages in clinical settings.