Comorbid risks of psychological disorders and gastroesophageal reflux disorder using the national health insurance service—National Sample Cohort: A STROBE-compliant article

This study was performed to examine the comorbidity risks between psychological disorders, such as depression, and gastroesophageal reflux disease (GERD) using nationally representative data from a National Sample Cohort of the National Health Insurance Service in Korea. The National Health Insurance Service—National Sample Cohort (NHIS–NSC) database from 2010 to 2012 was used in this study. GERD patients were defined as those diagnosed with specific tests, with screened medication, and without any other gastrointestinal diseases. Propensity score matching for age, sex, and economic status was applied to form a control cohort. Incidence rate, relative risks, Cox proportional-hazards modeling, and Kaplan–Meier analysis were applied to examine the differences between the GERD and control cohorts with regard to the risk of subsequent psychological disorders. The results showed that patients in the GERD cohort (n = 9503) had significantly higher risks of psychological disorders than those without GERD (adjusted hazard ratio [HR] 1.25, 95% confidence interval [CI] 1.07–1.47, P = .006). Specifically, the risk of depressive disorder was significantly higher for patients in the GERD cohort than in the control cohort (adjusted HR 1.41, 95% CI 1.04–1.91, P = .027). Kaplan–Meier analysis showed that the estimated probability of psychological disorders was significantly higher in the GERD cohort compared with the control cohort (log-rank test, P = .007). This study suggested that GERD may be a risk factor for subsequent psychological disorders, specifically, depressive disorder. The results of this study in GERD patients compared with non-GERD patients in Korea suggested that psychological disorders and GERD may be inter-related.