Determinants of successful chronic hepatitis C case finding among patients receiving opioid maintenance treatment in a primary care setting

Abstract

Aims Injection drug users are at high risk for chronic hepatitis C virus infection (CHC). Opioid maintenance treatment (OMT) offers a unique opportunity to screen for CHC. This study proposed the hypothesis that a general practitioner (GP) with special interest in addiction medicine can achieve CHC screening rates comparable to specialized centres and aimed to investigate determinants for a successful CHC case finding in a primary care setting. Design and participants Retrospective medical record analysis of 387 patients who received opioid maintenance therapy between 1 January 2002 and 31 May 2008 in a general practice in Zurich, Switzerland. Measurements Successful CHC assessment was defined as performance of hepatitis C virus (HCV) serology with consecutive polymerase chain reaction‐based RNA and genotype recordings. The association between screening success and patient characteristics was assessed using multiple logistic regression. Findings Median (interquartile range) age and duration of OMT of the 387 (268 males) patients was 38.5 (33.6–44.5) years and 34 (11.3–68.0) months, respectively. Fourteen patients (3.6%) denied HCV testing and informed consent about screening was missing in 13 patients (3.4%). In 327 of 360 patients (90.8%) with informed consent a successful CHC assessment has been performed. Screening for HCV antibodies was positive in 136 cases (41.6%) and in 86 of them (63.2%) a CHC was present. The duration of OMT was an independent determinant of a successful CHC assessment. Conclusions In addicted patients a high CHC assessment rate in a primary care setting in Switzerland is feasible and opioid substitution provides an optimal framework.