Risk of suicide attempts among colorectal cancer patients: A nationwide population-based matched cohort study.

Objective: Patients with colorectal cancer (CRC) have been found to have a higher risk of suicide in limited-number studies. However, data on the actual incidence rate of suicide remain scarce.
Methods: Using Taiwan's National Health Insurance Research Database, we examined whether patients with CRC in Taiwan are at increased risk of suicide attempts. In this retrospective matched cohort study, data of 96 470 cases of CRC during 1 January 2000 to 31 December 2010 were collected. The control group was derived from general population by frequency matching 2 individuals without CRC for each individual with CRC by year of CRC diagnosis, age, and sex. The suicide risk in the CRC group compared with the control group was determined through Cox proportional hazard regression. We also compared the Kaplan-Meier analyses to competing risk cumulative incidence curves using the Aalen-Johansen estimator.
Results: A statistically significant 103% higher risk of suicide was observed in the CRC group compared with the control group (adjusted hazard ratio: 2.03; 95% confidence ratio: 1.60-2.56). Additional stratified analyses revealed a significantly elevated risk across almost all demographic groups but limited to rectum location, short follow-up time (<5 years), and without comorbidity.
Conclusions: Our study suggested that patients with CRC in Taiwan have an elevated risk of suicide. Oncologists should pay attention to these patients and should consider referring them for psychological consultation to prevent suicide.
(© 2018 John Wiley & Sons, Ltd.)