Risk factors associated with the occurrence of distal radius fractures in Japanese patients with rheumatoid arthritis: a prospective observational cohort study

The aims of this study were to evaluate the association between potential risk factors and the occurrence of distal radius fractures in Japanese patients with rheumatoid arthritis (RA). A total of 9,987 patients (82.0 % female; mean age, 55.7 years) with RA were enrolled in a prospective, observational study from 2000 to 2011. Self-reported distal radius fractures were verified using patient medical records. Cox proportional hazards models were used to analyze independent contributions of various risk factors to distal radius fracture occurrence. During a mean follow-up of 5.7 years, 139 patients reported 153 distal radius fractures. Among these patients, 85 distal radius fractures following minor trauma in 85 patients (6 men, 79 women) were verified with medical records. Female gender (hazard ratio [HR], 2.96; 95 % confidence interval [CI], 1.18-7.45; P = 0.021), age (per 10 years, HR 1.55; 95 % CI, 1.24-1.95, P = 0.00016), body mass index (BMI) (per 1 kg/m(2), HR, 1.11; 95 % CI, 1.03-1.19; P = 0.0034), daily prednisolone dose (per milligram per day, HR, 1.10; 95 % CI, 1.05-1.16; P = 0.00015), and physician global visual analog scale (0-10 cm, HR, 0.98; 95 % CI, 0.96-1.00; P = 0.034) were significantly associated with the occurrence of distal radius fractures in Japanese patients with RA. A reduction in the daily prednisolone dose, together with the prevention of falls in female patients of advanced age with RA and a high BMI may be important in preventing distal radius fractures.