Increased Dose of Prescription Opioids Raises Risk of Suicide among Veterans with Chronic Non-Cancer Pain
BACKGROUND:
Although prior studies identify forms of chronic pain as markers of increased suicide risk, none have examined pain treatment as a potential additional indicator for risk among those with pain. Some express concern that the under-treatment of pain could place individuals with pain at elevated risk for suicide. However, prescription opioids are being increasingly used in the U.S. to treat chronic pain, and it is possible that access to opioids could increase the risk of suicide. This retrospective study examined the association between prescribed opioid dose and suicide in a national sample of VA patients with a chronic non-cancer pain condition who received opioid therapy. Using VA data, investigators identified 123,946 Veterans with chronic non-cancer pain who received opioids in FY2004-2005. [Veterans being treated with palliative or hospice care were excluded.] Investigators used data from the National Death Index to examine rates of suicide death by any method, including intentional overdose death, from 2004 to 2009. This study focused on maximum prescribed morphine-equivalent daily opioid dose and opioid fill type as the primary predictors. Other variables included: pain and other physical conditions (i.e., headache, neuropathy, chronic pain, acute pain, COPD, cardiovascular disease, sleep apnea), in addition to psychiatric conditions (i.e., depression, PTSD, substance use disorders). Patient demographics also were examined.
FINDINGS:
- Increased dose of opioids was found to be a marker of increased suicide risk, even when relevant demographic and clinical factors were statistically controlled. Compared to those receiving <20 milligrams/day (mg/d), hazard ratios were 1.48 for 20 to <50 mg/d, 1.69 for 50 to <100 mg/d, and 2.15 for 100+ mg/d. Type of opioid dosing schedule (i.e., regularly scheduled, as needed, or both) did not significantly affect suicide risk after accounting for other factors.
- Similar to the U.S. population and other large studies of VA patients, the vast majority of suicides involved firearms (64%; n=1,669), with overdose accounting for 20% (n=532) of all suicides.
IMPLICATIONS:
- Risk of suicide mortality was greater among Veterans receiving higher doses of opioids, thus providers may want to view high opioid dose as a marker of elevated risk for suicide.
LIMITATIONS:
- Suicide rates in VA are higher than the general population, and risk factors (i.e., pain and opioid use) may also function differently in VA.
- Other covariates found to be predictive of Veteran suicide (e.g., McCarthy et al 2015) including TBI, homelessness, or critical service encounters were not assessed.
- This study did not include duration or severity of chronic pain, and longer pain duration and/or greater pain severity may predict both higher opioid dose and increased suicide risk.
- The data used in this study are more than 10 years old, and do not account for more recent suicide prevention interventions that have been implemented within the VA healthcare system.
AUTHOR/FUNDING INFORMATION:
Dr. Bohnert was supported by an HSR&D Career Development Award. Drs. Ilgen, Bohnert, Ganoczy, McCarthy, and Blow are part of HSR&D's Center for Clinical Management Research (CCMR) in Ann Arbor, MI; Dr. Bair is part of HSR&D's Center for Health Information and Communication (CHIC) in Indianapolis, IN.
Ilgen M, Bohnert A, Ganoczy D, Bair M, McCarthy J, and Blow F. Opioid Dose and Risk of Suicide. Pain. January 5, 2016; Epub ahead of print.