Effects of cognitive flexibility on the relationship between needle sharing and hepatitis c infection

AIMS: To assess whether cognitive flexibility mediates the relationship between needle sharing and Hepatitis C (HCV) infection among injection drug users in Baltimore, Maryland. METHOD: A secondary data analysis of injection drug users (N = 628; 55.7% African American; 56.1% male, mean age = 32.9) enrolled in a NIDA-funded NEURO-HIV Epidemiologic study. Biological samples were obtained to test for HCV. Participants completed a battery of neuropsychological measures and a structured psychosocial interview to assess drug use and high-risk behaviors. Trails Making Test (Part B) completion time was used to measure cognitive flexibility. RESULTS: 303 (48.2%) participants tested positive for HCV. Needle sharing was a significant predictor of HCV infection (Z=9.14, p<.001). Those reporting lifetime needle sharing performed significantly worse on the cognitive flexibility task than those who reported no needle sharing (t=2.29, p=.022). Impaired cognitive flexibility was also a significant predictor of HCV status (Z=4.31, p<.001). Using the Preacher and Hayes (2008) INDIRECT macro for SPSS to test for mediation with 1000 bootstrapped samples, the positive relationship between needle sharing and HCV was mediated by cognitive flexibility (Z=8.95, p<.001). The indirect effects of the mediator are considered significant as zero is not included in the 95% biased-corrected and accelerated confidence interval. Race and intelligence were entered as covariates. Overall, the model accounted for 27.3% of the variance in HCV status. CONCLUSIONS: When injection drug users are confronted with the decision of whether or not to share needles, they may struggle with weighing the risks and rewards as a result of their diminished cognitive flexibility.