Acupuncture treatment is associated with a decreased risk of developing stroke in patients with depression: A propensity-score matched cohort study

Background: Depression had a significantly increased risk of stroke. Some patients with depression seek acupuncture treatment. The aim of this study is to investigate the association between acupuncture treatment and risk of developing stroke in patients with depression. Methods: Patients with newly diagnosed depression above 18 years old between 1997 and 2010 were selected from the Taiwanese National Health Insurance Research Database, and followed up until the end of 2013. The 1: 1 propensity score method was used to match an equal number of patients (N = 13,823) in the acupuncture and non-acupuncture cohorts, based on characteristics including sex, age, baseline comorbidity and drug used. The outcome measurement was the comparison of stroke incidence in the two cohorts. We used the Cox regression model and the Kaplan-Meier method to estimate the risk of developing stroke. Results: Compared with the non-acupuncture cohort, patients who received acupuncture treatment had a lower risk of stroke (adjusted hazard ratio (HR)= 0.49, 95% confidential interval = 0.45-0.52) after adjustment for age, sex, comorbidities and drugs used. Regarding the two types of stroke, acupuncture users also had lower risk of hemorrhagic or ischemic stroke (adjusted HR = 0.37 and 0.49, respectively). The cumulative incidence of stroke in the acupuncture cohort was significantly lower than that of the non-acupuncture cohort (log-rank test, p < 0.001). At the 5th year of follow-up, 7.22% of acupuncture users had stroke onset compared with 14% in the non-acupuncture cohort. Limitations: The database provided information of antidepressants but not the severity of depression. Details of the life style and selection of acupoints were also not provided. Conclusions: The present study revealed that acupuncture reduced the risk of developing stroke in depression patients in Taiwan. Further clinical studies investigating the mechanisms and efficacy of acupuncture are warranted.