Risk of Suicide Among Patients With Major Physical Disorders Considering Comorbidities of Mental Disorders: An Instrumental Variable Analysis

Suicide is an important health concern. Excepting cancer, the association between physical disorders and suicidal risk is comparatively less explored. Instrumental variable analysis has been suggested as a powerful technique to deal with possible bias caused by unmeasured confounders in observational research. This population-based study set out to assess the suicidal risk of patients with major physical disorders by employing the instrumental variable analysis. Data were retrieved from the National Health Insurance Research Database and the Death Certification Registry in Taiwan (years 2010–2018). The Cox proportional hazards model with an instrumental variable estimator was performed, adjusting for comorbidities of mental disorders and other covariates. Analytical results showed that compared to their counterparts, patients with major physical disorders had an elevated risk of death by suicide within one year and three years after diagnosis of physical illness. Only did epilepsy not demonstrate a statistically significant impact on the risk of suicide.