Risk of venous thromboembolism in patients with rheumatoid arthritis: a meta-analysis of observational studies

Thrombotic events, such as venous thromboembolism (VTE) are a major health complication linked to rheumatoid arthritis (RA). We performed a meta-analysis to evaluate the risk of VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE), in adults with RA compared to the general population. MEDLINE and EMBASE databases were searched from inception to April 2022 to identify publications meeting the following criteria: (1) prospective and retrospective original data from cohort or case-control studies; (2) pre-specified RA definition; (3) clearly defined VTE outcomes; (4) reported risk estimate and 95% confidence intervals (95% CIs); (5) at least sex- and age-matched to comparison group; and (6) English language. Of 372 studies screened, 14 were included (602,760 RA patients, 123,076 VTE events) and their quality was assessed by an adaptation of the STROBE quality scoring scale. The pooled risk ratios of VTE, DVT and PE in patients with RA were 1.57 (95% CI 1.41–1.76), 1.58 (95% CI 1.26–1.97) and 1.57 (95% CI 1.30–1.88), respectively. The I2 value of 92%, 94% and 92% for VTE, DVT and PE analyses, suggesting considerable heterogeneity. There were no significant differences in risk estimates among the five subgroup analyses: quality score (P = 0.35, I2 = 0%); sex (P = 0.31, I2 = 1.7%); study year (P = 0.81, I2 = 0%); population source (P = 0.35, I2 = 0%); study design (P = 0.62, I2 = 0%). Results show that patients with RA are at a higher risk of VTE, DVT and PE compared to the general population.