Rheumatoid arthritis (RA) patients have increased risk of developing stroke. The use Chinese herbal medicines (CHMs) is increasing, but whether they can reduce the risk of developing stroke remains unclear. We conducted a longitudinal cohort study to compare the effect of CHMs use on the subsequent stroke risk in RA individuals.
Using claims data from the National Health Insurance of Taiwan, we identified 7925 newly-diagnosed RA patients with no history of previous stroke who were 20 years of age or older between 1998 and 2010. From this sample, we enrolled 3134 CHMs users and 3134 non-CHMs users, randomly selected using propensity scores matching from the remaining cases. They were followed until the end of 2012 to record stroke incidence. A Cox proportional hazards regression model was used to compute the hazard ratio of stroke with regard to CHMs use.
During the follow-up, 299 CHMs users and 395 non-CHMs users developed stroke, representing incidence rates of 10.94 and 16.69, respectively, per 1000 person-years. CHMs use was associated with 38% (adjusted HR: 0.62; 95% confidence interval: 0.54-0.73) lower subsequent risk of stroke. The most prominent effect was observed in those receiving CHMs for over two years. The following seven commonly-prescribed CHMs were found to lessen the stroke risk: Dan-Shen, Tian-Hua-Feng, Fu-Zi, Shao-Yao-Gan-Cao-Tang, Jia-Wei-Xiao-Yao-San, Ge-Gen-Tang, and Gui-Zhi-Shao-Yao-Zhi-Mu-Tang.
The CHMs use was associated with lower risk of stroke for RA patients, suggesting that it could be integrated into conventional therapy to prevent subsequent stroke incident.