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.

FIGURE 1

Age-adjusted all-cause mortality in AIDS Linked to the Intravenous Experience study (ALIVE), 1988–2018. Scatterplots represent the age-adjusted all-cause mortality in each year. The overall curve was constructed using the locally weighted scatterplot smoothing (LOWESS) method

FIGURE 2

Trends in cause-specific mortality rates and key causal variables in AIDS Linked to the Intravenous Experience study (ALIVE), 1988–2018. All curves were constructed using the locally weighted scatterplot smoothing (LOWESS) method. (a) HIV/infectious disease (HIV/ID) mortality (per 1000 person-years) among all participants and median CD4⁺ cell count. among people with HIV in the cohort; (b) chronic disease mortality (per 1000 person-years) and median age among all survived participants of the cohort; (c) drug-related mortality (per 1000 person-years), proportion of active injecting and proportion of non-medical use of prescription drugs in the cohort