1026 — Factors Associated with Opioid Overdose Death among VHA Patients Age 50 and Older Prescribed Opioids
Bohnert AS, COIN - Ann Arbor; Levine DA, COIN - Ann Arbor; Ganoczy D, COIN - Ann Arbor; Nafiu I, University of Michigan; Blow FC, COIN - Ann Arbor;
In all-age samples of patients treated with opioids for pain, a number of treatment and patient factors are associated with overdose. These associations have not been studied in aging adults (age 50+), a group vulnerable to opioid-related complications. The objective of this study was to examine prescribed opioid regimen and patient characteristics in association with opioid overdose mortality among patients age 50 and older.
This study used a case-cohort design with VHA patients in fiscal year (FY) 2004 and/or 2005 who were age 50 or older at the start of FY2004. The sample was followed through FY2008 (n = 118,730). Medical record data were matched to National Death Index mortality data. The outcome was unintentional opioid overdose death (ICD-10 underlying cause of death X42, X44, Y12, or Y14, in combination with T-code 40.2). Patient and time-varying prescribing characteristics were entered into a Cox proportional hazards model.
There were 346 overdose deaths observed. In multivariable modeling, maximum prescribed daily opioid dose was associated with opioid overdose; compared to 1 to < 20 morphine-equivalent mg/day, the hazard ratio (HR) was 1.86 (95% CI:1.19-2.90) for 20 to < 50 mg/day, 3.95 (CI:2.40-6.52) for 50 to < 100 mg/day, and 7.81 (CI:4.67-13.03) for 100+ mg/day. Acute pain was associated with overdose death (HR = 1.60, CI:1.16-2.21), as was substance use disorders (HR = 2.85; CI:2.04-3.99) but not other psychiatric disorders. Patients who were between the ages of 50 to 59 at the start of FY2004 were more likely to die from opioid overdose than patients age 60+.
The risk of opioid overdose death doubled with each category increase in prescribed opioid dose. Those ages 50 to 59 had greater risk of overdose than older ages, which may be due in part to a "baby boomer" cohort effect. Non-substance psychiatric disorders appear to have a less salient role in risk of overdose among adults over 50 compared to those younger than 50.
VHA clinicians should have an increased index of concern regarding overdose for older patients with the factors identified in this study. These patients may require special care to reduce the risk of opioid overdose.