Mortality among people who inject drugs: a prospective cohort followed over three decades in Baltimore, MD, USA

Abstract

Background and aims: During the past decades, people who inject drugs (PWID) have been impacted by the development of combination antiretroviral therapy (cART) to combat HIV/AIDS, the prescription opioid crisis and increased use of lethal synthetic opioids. We measured how these dynamics have impacted mortality among PWID in an urban US city.

Design: Prospective cohort study using data from the AIDS Linked to the Intravenous Experience (ALIVE).

Setting: Baltimore, MD, USA from 1988 to 2018.

Participants: A total of 5506 adult PWIDs (median age at baseline 37 years).

Measurements: Mortality was identified by linkage to National Death Index-Plus (NDI-Plus) and categorized into HIV/infectious disease (HIV/ID) deaths, overdose and violence-related (drug-related) deaths and chronic disease deaths. Person-time at risk accrued from baseline and ended at the earliest of death or study period. All-cause and cause-specific mortality were calculated annually. The Fine & Gray method was used to estimate the subdistribution hazards of cause-specific deaths accounting for competing risks.

Findings: Among 5506 participants with 84 226 person-years of follow-up, 43.9% were deceased by 2018. Among all deaths, 30.5% were HIV/ID deaths, 24.4% drug-related deaths and 33.3% chronic disease deaths. Age-standardized all-cause mortality increased from 23 to 45 per 1000 person-years from 1988 to 1996, declined from 1996 to 2014, then trended upward to 2018. HIV/ID deaths peaked in 1996 coincident with the availability of cART, then continuously declined. Chronic disease deaths increased continuously as the cohort aged. Drug-related deaths declined until 2011, but increased more than fourfold by 2018. HIV/HCV infection and active injecting were independently associated with HIV/ID and drug-related deaths. Female and black participants had a higher risk of dying from HIV/ID deaths and a lower risk of dying from drug-related deaths than male and non-black participants.

Conclusions: Deaths in Baltimore, MD, USA attributable to HIV/ID appear to have declined following the widespread use of combination antiretroviral therapy. Increases in the rates of drug-related deaths in Baltimore were observed prior to and continue in conjunction with national mortality rates associated with the opiate crisis.

Keywords: HIV/AIDS; chronic diseases; mortality; opioid epidemic; overdose; people who inject drugs.