Risk Factors of Carpal Tunnel Syndrome in Taiwan A Population-Based Cohort Study

Background: Carpal tunnel syndrome (CTS), 1 of the most common peripheral neuropathies of the upper extremity, has been studied for decades regarding its epidemiology and associated medical conditions. We conducted a large-scale, age- and gender-matched study from an Asian population database to investigate the relationship between the incidence and the demographic characteristics. Methods: A retrospective cohort study using data of National Health Insurance Research Database was conducted. One million enrollees in Taiwan was used to identify 9442 patients with CTS and 37,768 randomly selected controls, in a control-case ratio of 4:1. Diagnoses of CTS were ascertained from January 1, 2003, toDecember 31, 2012. Sociodemographic andmedical characteristicswere evaluated to assess the correlation with CTS. Results: Annual incidence of CTS was approximately 0.4% during the 10-yearperiod in Taiwan, with higher incidence rate in female sex and middle age of group (50-59 years). Among the medical conditions, previous wrist injuries, obesity, gout, and rheumatoid arthritiswere associated with CTSmost significantly. Conclusions: Carpal tunnel syndrome has presented a relatively constant incidence in Taiwan. Female gender with middle age seemed to have the highest incident rate during a 10-year period from 2003 to 2012. Among the risk factors of CTS, previous wrist injuries, obesity, gout, and rheumatoid arthritis were demonstrated to be the most significantly correlated comorbidities.