To evaluate the effect of a pre-existing posttraumatic stress disorder (PTSD) diagnosis on suicide and non-suicide mortality among men with newly diagnosed prostate cancer, and examine potential mediating factors for the relationship between PTSD and suicide.
We used patient-level data from Veterans Health Administration electronic medical records to identify men (age ≥40 years) diagnosed with prostate cancer between 2004-2014. We used Fine and Gray regression to estimate risk for competing mortality outcomes (suicide, non-suicide, alive). We used structural equation models to evaluate mediating factors.
Our cohort comprised 214,649 men with prostate cancer, of whom 12,208 (5.7%) had a pre-existing PTSD diagnosis. Patients with PTSD compared to those without utilized more health care services and had lower risk cancer at diagnosis. Additionally, they experienced more suicide deaths (N=26, 0.21% vs. N=269, 0.13%) and fewer non-suicide deaths (N=1,399, 11.5% vs. N=45,625, 22.5%). On multivariable analysis, PTSD was an independent suicide risk factor (HR=2.35; 95% CI: 1.16, 4.78). Depression, substance use disorder, and any definitive prostate cancer treatment were partial mediators. However, PTSD was associated with lower non-suicide mortality risk (HR=0.86; 95% CI: 0.77, 0.96).
Patients with PTSD experienced greater suicide risk even after adjusting for important mediators. They may have experienced lower non-suicide mortality risk due to favorable physical health resulting from greater health care service use and early diagnosis of lower risk cancer. Our findings highlight the importance of considering psychiatric illnesses when treating patients with prostate cancer and the need for interventions to ameliorate suicide risk. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.