摘要：Objectives. We investigated potential risk factors for active injection drug use (IDU) in an inner-city cohort of patients infected with hepatitis C virus (HCV). Methods. We used log-binomial regression to identify factors independently associated with active IDU during the first 3 years of follow-up for the 289 participants who reported ever having injected drugs at baseline. Results. Overall, 142 (49.1%) of the 289 participants reported active IDU at some point during the follow-up period. In a multivariate model, being unemployed (prevalence ratio [PR] = 1.93; 95% confidence interval [CI] = 1.24, 3.03) and hazardous alcohol drinking (PR = 1.67; 95% CI = 1.34, 2.08) were associated with active IDU. Smoking was associated with IDU but this association was not statistically significant. Patients with all 3 of those factors were 3 times as likely to report IDU during follow-up as those with 0 or 1 factor (PR = 3.3; 95% CI = 2.2, 4.9). Neither HIV coinfection nor history of psychiatric disease was independently associated with active IDU. Conclusions. Optimal treatment of persons with HCV infection will require attention to unemployment, alcohol use, and smoking in conjunction with IDU treatment and prevention. Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. About 130 million people are estimated to be infected worldwide with HCV, 1 including 3.2 million in the United States, 2 and mortality from HCV in the United States is increasing. 3 Injection drug use (IDU) is the single most important risk factor for HCV infection in the United States 2,4 with an estimated 40% to 50% of infections attributable to IDU. 5 Of increasing concern is the substantial proportion of HCV-infected patients who are coinfected with HIV. 6 Because HIV and HCV are each transmitted by blood-contaminated needles and syringes, approximately 30% of all HIV-infected individuals are also infected with HCV 1,7 ; in cohorts of intravenous drug users, the proportion of HCV-infected persons with HIV coinfection can be as high as 41%. 8 Because IDU is a significant risk factor for HCV transmission, ongoing drug abuse is common in HCV-infected populations. Such ongoing drug use has been documented as a potential barrier in managing the infection. 9,10 Moreover, former IDUs can be concerned about relapse with performing self-injection as part of interferon treatment. 11 Thus, understanding factors associated with active IDU may inform pragmatic approaches to improving acceptability of HCV treatment and increasing patients’ chances of successfully treating their disease. Other barriers to treatment of HCV infection have been described and are associated with IDU, such as alcohol use, psychiatric disease, and HIV coinfection. 9,10,12–14 Concurrent alcohol abuse has, in some studies, distinguished persistence of IDU from cessation of IDU; however, in other reports, the association of heavy alcohol use did not remain after adjustment for known risk factors. 15,16 Co-occurring mental disorders are frequently associated with poorer health and worse treatment outcomes among drug users and may lead to an increased level of drug use and riskier drug use behavior. 17 HIV infection has been hypothesized to be associated with IDU in contrasting ways. Those who are HIV-infected may have more frequent contact with health services and thus referral to drug treatment; conversely, increased depression following diagnosis may lead to increased drug use. 16 Individual patterns of drug use vary over time. Whereas some studies have indicated a trend toward decreased IDU over time in longer-term cohort studies, others have found that many injection drug users are unable to maintain sustained cessation of IDU. 17–23 In addition to the direct morbidity and mortality associated with IDU, continued use may make it more difficult for patients to effectively manage their disease. Evaluating predictors of ongoing IDU in these populations may help identify avenues to facilitate long-term cessation of IDU. Our goals were to investigate risk factors for active IDU in a cohort of patients infected with hepatitis C, with specific focus on alcohol use, smoking, psychiatric disease, and HIV coinfection.
