This longitudinal cohort study used the Taiwanese National Health Insurance Research Database to identify 112,458 newly diagnosed vertigo patients aged ≥20 years who received treatment between 1998 and 2007. Among these patients, 53,203 (47.31%) received TCM after vertigo onset (TCM users), and the remaining 59,201 patients were designated as a control group (non-TCM users). All enrollees received follow-up until the end of 2012 to measure stroke incidence. Cox proportional hazards regression was used to compute the hazard ratio (HR) of stroke in recipients of TCM services.
During 15-year follow-up, 5532 TCM users and 12,295 non-TCM users developed stroke, representing an incidence rate of 13.10% and 25.71% per 1000 person-years. TCM users had a significantly reduced risk of stroke compared to non-TCM users (adjusted HR=0.64; 95% confidence interval CI=0.59-0.74). The predominant effect was observed for those receiving TCM for more than 180 days (adjusted HR=0.52; 95% CI=0.49–0.56). Commonly used TCM formulae, including Ban-Xia-Bai-Zhu-Tian-Ma-Tang, Ling-Gui-Zhu-Gan-Tang, Bai Zhi (Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav., root), Ge Gen (Pueraria lobata (Willd.) Ohwi, root) and Hai Piao Xiao (Endoconcha Sepiae, Cuttlefish Bone) were significantly associated with lower risk of stroke.
Results of this population-based study support the effects of TCM on reducing stroke risk, and may provide a reference for stroke prevention strategies. The study results may also help to integrate TCM into clinical intervention programs that provide a favorable prognosis for vertigo patients.