Non-medical use of prescription opioids is associated with heroin initiation among US veterans: a prospective cohort study

AimsTo estimate the influence of non-medical use of prescription opioids (NMUPO) on heroin initiation among US veterans receiving medical care. DesignUsing a multivariable Cox regression model, we analyzed data from a prospective, multi-site, observational study of HIV-infected and an age/race/site-matched control group of HIV-uninfected veterans in care in the United States. Approximately annual behavioral assessments were conducted and contained self-reported measures of NMUPO and heroin use. SettingVeterans Health Administration (VHA) infectious disease and primary care clinics in Atlanta, Baltimore, New York, Houston, Los Angeles, Pittsburgh and Washington, DC. ParticipantsA total of 3396 HIV-infected and uninfected patients enrolled into the Veterans Aging Cohort Study who reported no life-time NMUPO or heroin use, had no opioid use disorder diagnoses at baseline and who were followed between 2002 and 2012. MeasurementsThe primary outcome measure was self-reported incident heroin use and the primary exposure of interest was new-onset NMUPO. Our final model was adjusted for socio-demographics, pain interference, prior diagnoses of post-traumatic stress disorder and/or depression and self-reported other substance use. FindingsUsing a multivariable Cox regression model, we found that non-medical use of prescription opioids NMUPO was associated positively and independently with heroin initiation [adjusted hazard ratio (AHR)=5.43, 95% confidence interval (CI)=4.01, 7.35]. ConclusionsNew-onset non-medical use of prescription opioids (NMUPO) is a strong risk factor for heroin initiation among HIV-infected and uninfected veterans in the United States who reported no previous history of NMUPO or illicit opioid use.