# Substance use and use disorders among Veterans on long-term opioid therapy

## TL;DR

One in four Veterans on long-term opioid therapy use substances or have substance use disorders, which increases their risk of death and overdose.

## Contribution

This study is the first to comprehensively analyze substance use and its health risks among Veterans on long-term opioid therapy using national health records.

## Key findings

- 25% of Veterans on long-term opioid therapy have substance use or substance use disorders.
- Substance co-use is linked to higher mortality and overdose risks compared to opioid therapy alone.
- Stimulant use triples the risk of fatal overdose among these Veterans.

## Abstract

Few studies have reported on the prevalence and health risks associated with substance use and substance use disorder (SU/SUD) in Veterans who use long-term opioid therapy (LTOT). We leveraged health record data to estimate SU/SUD prevalence and its association with mortality among Veterans on LTOT.

We conducted a secondary analysis of cohort data for Veterans on LTOT within Veterans Health Administration outpatient settings (2014–2019). SU/SUD was defined as a positive screen for risky alcohol use; a positive urine drug screen for cannabis, benzodiazepines, or stimulants; or a documented SUD diagnosis. We fit Cox models for all-cause mortality, fatal overdose, and traumatic deaths, comparing Veterans on LTOT with SU/SUD vs. LTOT-only.

One in four (25.0 %) Veterans on LTOT have risky alcohol use, tested positive for other substances, or had a diagnosed SUD. Alcohol was the most common SU/SUD (9.8 %), followed by sedative (8.1 %), cannabis (6.6 %), and stimulant (0.6 %). Relative to Veterans on LTOT only, mortality rates were higher for Veterans on LTOT with cannabis (HR=1.16, 95 % CI=1.03, 1.30), sedative (HR=1.29, 95 % CI=1.10, 1.52), or stimulant SU/SUD (HR=1.54, 95 % CI=1.17, 2.02). Fatal overdose rates were higher for LTOT with alcohol (HR=1.43, 95 % CI=1.10, 1.86), sedatives (HR=1.40, 95 % CI=1.04, 1.91), or stimulant SU/SUD (HR=3.29, 95 % CI=1.60, 6.77). LTOT with sedative SU/SUD was associated with traumatic death rates (HR=1.30, 95 % CI=1.05, 1.61).

Substance co-use is common among Veterans on LTOT and is associated with elevated mortality and overdose risks. Comprehensive screening and targeted interventions may be needed.

•1 in 4 Veterans on LTOT engage in substance use (SU) or have a diagnosed SUD.•Alcohol is the most common SU/SUD, followed by sedatives and cannabis.•Cannabis, sedative, or stimulant SU/SUD is associated with higher all-cause mortality.•Sedative SU/SUD is associated with increased fatal overdose and traumatic death.•Stimulant SU/SUD triples fatal overdose rates among Veterans on LTOT.

1 in 4 Veterans on LTOT engage in substance use (SU) or have a diagnosed SUD.

Alcohol is the most common SU/SUD, followed by sedatives and cannabis.

Cannabis, sedative, or stimulant SU/SUD is associated with higher all-cause mortality.

Sedative SU/SUD is associated with increased fatal overdose and traumatic death.

Stimulant SU/SUD triples fatal overdose rates among Veterans on LTOT.