Non-fatal self-injury after a diagnosis of cancer: A population-based study.

Abstract

e18577 Background: Psychological distress is a key construct of patient-centred cancer care. While an increased risk of suicide for cancer patients has been reported, more frequent consequences of distress after a cancer diagnosis, such as non-fatal self-injury (NFSI), remain largely unknown. We examined the risk for NFSI after a cancer diagnosis. Methods: Using linked administrative databases we identified adults diagnosed with cancer between 2007-2019. Cumulative incidence of NFSI, defined as emergency department presentation of self-injury, was computed accounting for the competing-risk of death from all causes. Factors associated with NFSI were assessed using multivariable Fine and Gray models. Results: Of 806,910 included patients, 2,482 had NFSI and 182 died by suicide. 5-year cumulative incidence of NFSI was 0.27% [95%CI 0.25-0.28%]. After adjusting for key confounders, prior severe psychiatric illness whether requiring inpatient care (sub-distribution hazard ratio (sHR) 12.6, [95% CI 10.5-15.2]) or outpatient care (sHR 7.5, 95% CI 6.48-8.84), and prior self-injury (sHR 6.6 [95% CI 5.5-8.0]) were associated with increased risk of NFSI. Young adults (age 18-39) had the highest NFSI rates, relative to individuals >70 (sHR 5.4, [95% CI 4.5-6.5]). The magnitude of association between prior severe psychiatric illness and NFSI was greatest for young adults (interaction term p < 0.01). Certain cancer subsites were also at increased risk, including head and neck (sHR1.52, [95%CI 1.19-1.93]). Conclusions: Patients with cancer have higher incidence of NFSI than suicide after diagnosis. Younger age, prior severe psychiatric illness, and prior self-injury were independently associated with NFSI. These exposures act synergistically, placing young adults with a prior mental health history at greatest risk for NFSI events. Those factors should be used to identify at-risk patients for psycho-social assessment and intervention.