Development of a Measure of Hepatitis C-alcohol Knowledge.

Alcohol use by persons with hepatitis C (HCV) increases the risk of cirrhosis and hepatocellular carcinoma, yet no measures on knowledge of the effects of alcohol use on HCV have been published. We developed 7 items assessing knowledge of the relationship between HCV and alcohol use. We enrolled 53 patients with HCV and risky alcohol use in an HCV-alcohol treatment study. All 53 participants completed a baseline interview, with 35 and 45 participants completing additional interviews at three and six months, respectively. We used generalized estimating equations (GEE) regression to account for non-independence of subjects and attrition. We assessed changes in HCV-alcohol knowledge at three and six months compared to baseline. Knowledge significantly increased at three months, compared to baseline (β=0.392, p=0.005), and had a trend toward significance at six months, compared to baseline (β=0.232, p=0.074). We also tested for between-subject differences in HCV-alcohol knowledge by demographic variables. HCV-alcohol knowledge did not significantly vary by gender, age, baseline HIV status, or baseline depression. Participants with higher educational attainment (β=0.052, p=0.057) had a trend toward significantly higher HCV-alcohol knowledge scores, and White participants had higher HCV-alcohol knowledge scores (β=0.349, p=0.002) than participants of all other races combined. In a second GEE regression model, we examined the relationship between change in HCV-alcohol knowledge and change in alcohol use severity scores over time. Increases in one's HCV-alcohol knowledge score were significantly related to greater reductions in alcohol use severity scores (β=-0.052, p=0.027). Thus, the seven-item HCV-alcohol Knowledge Scale successfully identified changes in HCV-alcohol knowledge after exposure to HCV-alcohol education. In addition, improvements in HCV-alcohol knowledge, as assessed by the scale, predicted decreases in alcohol use over time. These findings support the use of the HCV-alcohol Knowledge Scale as both a research and clinical tool.