Increasing fracture incidence over 13 years in patients with rheumatoid arthritis from the IORRA cohort

This study aimed to evaluate fracture incidence in patients with rheumatoid arthritis (RA) over 13 years in the Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort study.

The IORRA is a prospective observational cohort study of Japanese patients with RA. Between 2011 and 2023, 10,257 patients with RA were enrolled. Clinical parameters and data on fractures were collected biannually using self-reported questionnaires. The fracture incidence, standardized by sex, age, and Japanese Health Assessment Questionnaire score, was calculated for each two-year period.

From 2011 to 2023, the proportions of patients achieving Disease Activity Score in 28 joints remission, using biologic disease-modifying antirheumatic drugs, and taking osteoporosis medications increased (38.0% to 64.7%, 14.2% to 42.2%, and 31.6% to 38.3%, respectively), while the proportion of glucocorticoid use decreased (38.3% to 22.2%). The incidence of all and non-vertebral fractures increased from 47.2 and 36.7/1000 person-years in 2011 to 52.8 and 43.0/1000 person-years in 2023, respectively. Using 2023 as the reference, the standardized incidence ratios for all and non-vertebral fractures were: 2011-2012, 0.90 [95% confidence interval (CI) 0.82-0.98] and 0.86 (95% CI 0.78-0.95); 2013-2014, 0.88 (95% CI 0.81-0.96) and 0.84 (95% CI 0.76-0.93); 2015-2016, 0.94 (95% CI 0.86-1.02) and 0.89 (95% CI 0.80-0.98); 2017-2018, 0.97 (95% CI 0.88-1.07) and 0.94 (95% CI 0.84-1.05); 2019-2020, 0.95 (95% CI 0.84-1.07) and 0.93 (95% CI 0.81-1.06); 2021-2022, 1.00 (95% CI 0.89-1.13) and 0.99 (95% CI 0.86-1.13).

Despite advancements in RA management over 13 years, fracture incidence may have increased in patients with RA.