Risk factors and socioeconomic status associated with carpal tunnel syndrome: A retrospective nationwide 11-year population-based cohort study in South Korea

Importance There have been only a few large-scale studies for risk factor analysis for CTS. No prior study has investigated the relationship between the occurrence of CTS and stratified socioeconomic status which is closely related to a person’s type of job. Objective To determine the correlation between stratified socioeconomic status and the occurrence of CTS. Design We conducted this study using a retrospective cohort model based on the combined databases of the Korean National Health Insurance System from 2003 to 2013; the national periodic health screening program database in 2002–2003 and health insurance database of reimbursement claims from 2003 through 2013. Setting The setting was a population-based retrospective cohort study. Participants First, we randomly sampled 514,795 patients who represented 10% of the 5,147,950 people who took part in periodic health screenings in 2002–2003. Existing CTS patients were excluded from this group. Therefore, this study finally included 512,942 participants and followed up their medical records from 2003 to 2013. Main Outcomes and Measures Desired outcomes were the incidence rate of CTS according to the stratified socioeconomic status and the correlation between the stratified socioeconomic status and the occurrence of the disease (the hazard ratios). Results The incidence rate was higher in people in the lower socioeconomic status. Correlation analysis showed that CTS was more likely to occur in lower socioeconomic status regardless gender. Conclusions and Relevance In our large-scale cohort study, CTS was associated with people of a lower socioeconomic status who usually work in simple but repetitive manual labor jobs in female as well as male population. We believe that the results of our study will be helpful to determine the pathophysiology of CTS and to set up a new industrial health policy for this condition