Injection Drug Use, Unemployment, and Severe Food Insecurity Among HIV-HCV Co-Infected Individuals: A Mediation Analysis

  • Taylor McLinden
  • Erica E. M. Moodie
  • Anne-Marie Hamelin
  • Sam Harper
  • Sharon L. Walmsley
  • Gilles Paradis
  • Wusiman Aibibula
  • Marina B. Klein
  • Joseph Cox
Original Paper

Abstract

Severe food insecurity (FI), which indicates reduced food intake, is common among HIV-hepatitis C virus (HCV) co-infected individuals. Given the importance of unemployment as a proximal risk factor for FI, this mediation analysis examines a potential mechanism through which injection drug use (IDU) is associated with severe FI. We used biannual data from the Canadian Co-infection Cohort (N = 429 with 3 study visits, 2012–2015). IDU in the past 6 months (exposure) and current unemployment (mediator) were self-reported. Severe FI in the following 6 months (outcome) was measured using the Household Food Security Survey Module. An overall association and a controlled direct effect were estimated using marginal structural models. Among participants, 32% engaged in IDU, 78% were unemployed, and 29% experienced severe FI. After adjustment for confounding and addressing censoring through weighting, the overall association (through all potential pathways) between IDU and severe FI was: risk ratio (RR) = 1.69 (95% confidence interval [CI] = 1.15–2.48). The controlled direct effect (the association through all potential pathways except that of unemployment) was: RR = 1.65 (95% CI = 1.08–2.53). We found evidence of an overall association between IDU and severe FI and estimated a controlled direct effect that is suggestive of pathways from IDU to severe FI that are not mediated by unemployment. Specifically, an overall association and a controlled direct effect that are similar in magnitude suggests that the potential impact of IDU on unemployment is not the primary mechanism through which IDU is associated with severe FI. Therefore, while further research is required to understand the mechanisms linking IDU and severe FI, the strong overall association suggests that reductions in IDU may mitigate severe FI in this vulnerable subset of the HIV-positive population.

Keywords

HIV Hepatitis C virus Injection drug use Unemployment Severe food insecurity 

Supplementary material

10461_2017_1850_MOESM1_ESM.docx (39 kb)
Supplementary material 1 (DOCX 39 kb)

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Copyright information

© Springer Science+Business Media, LLC 2017

Authors and Affiliations

  • Taylor McLinden
    • 1
  • Erica E. M. Moodie
    • 1
  • Anne-Marie Hamelin
    • 1
  • Sam Harper
    • 1
  • Sharon L. Walmsley
    • 2
    • 3
  • Gilles Paradis
    • 1
  • Wusiman Aibibula
    • 1
  • Marina B. Klein
    • 4
    • 5
  • Joseph Cox
    • 1
    • 4
    • 5
  1. 1.Department of Epidemiology, Biostatistics and Occupational HealthMcGill UniversityMontrealCanada
  2. 2.Department of MedicineUniversity of TorontoTorontoCanada
  3. 3.Division of Infectious DiseasesUniversity Health NetworkTorontoCanada
  4. 4.Chronic Viral Illness ServiceMcGill University Health CentreMontrealCanada
  5. 5.CIHR Canadian HIV Trials NetworkVancouverCanada

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