Association between executive function, risking injection practices and HCV among injection drug users

Aim: To measure associations between impaired executive functioning (e.g., planning ability) measured by the Tower of London (TOL) and risky injection practices and Hepatitis C Virus (HCV) among injection drug users (IDU).

Hypothesis: Among male and female IDUs, impaired executive function (EF) will be associated with risky injection and HCV. Methods: Data from the Neuro-HIV Epidemiologic Study, a study of neurobehavioral risk factors of infectious disease among drug users in Baltimore, were restricted to those who had ever injected (n=458). We estimated gender-specific adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for associations between impaired EF, defined as a TOL standardized total excess moves score below the 10th percentile, and dichotomous outcomes of risky injection practices (ever having shared needles, cookers, cotton, or rinse water and ever having backloaded) and HCV as indicated by a positive antibody blood test result.

Results: Among men, impairment on the TOL was significantly associated with over twice the odds of each risky injection practice and appeared to be independently associated with HCV infection (AOR: 2.76, 95% CI: 0.83-9.15) of HCV. Analyses suggested that risky injection practices mediated the association between TOL and HCV. Associations differed significantly by gender; among females, impaired planning was not associated with risky injection or HCV.

Conclusion: There is evidence interventions designed to improve planning may reduce risky injection and infection among men. Given risky injection and infection are high among all women, including those with intact EF, additional factors must be considered to reduce women's infection risk.