<qa>  What group of injectors will be compared to?This will focus specifically on long term outcomes for patients who are current and past injecting drug users at the time of their treatment. Injecting drug users who have already completed therapy and achieved SVR will be asked to return for assessment. During this study, the investigators will also enquire about any drug use prior to, during and after completing therapy. The investigators will compare this group with past injectors, last injected at least 6 months prior to starting treatment a group that most centres would consider appropriate for treatment. 