Methods: This study used toxicology data on 1,470 individuals, collected from the Marion County Coroner’s Office in Indiana from 2016-2019. Demographics (including military involvement) were obtained from death certificates. Bivariate analyses assessed differences in opioid-polysubstance patterns in fatal overdoses among those with and without military involvement. Four opioid-polysubstance combinations were of focus, based on common patterns identified in previous literature, including opioid-benzodiazepine, opioid-methamphetamine, opioid-cocaine, and opioid-alcohol. A logistic regression model also assessed if these combinations were able to predict military involvement.
Results: The majority of the sample was male (67.8%) and White (74.1%). The mean age was 40.50 years (SD=12.69) and 7.3% of individuals had military involvement (n=108). Regarding toxicology results, those with military involvement most commonly had opioids and alcohol present (27.8%, n=237) while those without military involvement most often had opioids and benzodiazepine present (27.8%, n=379). Bivariate analysis results indicated that persons with military involvement (18.5%, n=20) were significantly less likely to have opioids and benzodiazepine present in their toxicology results than those without military involvement (27.8%, n=379; χ2(1) = 4.384, p<.05, V=.055), along with opioids and methamphetamine (military involvement: 12.0%, n=13; no military involvement: 20.4%, n=278; χ2(1) = 4.420, p<.05, V=.055). However, those with military involvement (27.8%, n=30) were significantly more likely to have opioids and alcohol present (no military involvement: 17.4%, n=237; χ2(1) = 7.249, p<.01, V=.070).
The logistic regression model was significant (χ2(4, N=1,470) =15.073, p<.01, V=.051, Nagelkerke R2=.025). Opioid-alcohol and opioid-benzodiazepine combinations were significant predictors of military involvement. Those with alcohol and opioids present had significantly greater odds of having military involvement (AOR=1.798, p<.05) while those with benzodiazepine and opioids present had significantly lower odds of having military involvement (AOR=.601, p <.05).
Conclusions: Opioid-polysubstance toxicology patterns clearly differ between those with and without military involvement. Thereby, it is crucial to implement policy and programming that addresses the specific polysubstance patterns present within each population to effectively reduce overdose fatalities.