Study designs of evaluations included in the review
Randomised controlled trials (RCTs) of cross-over or parallel design that compared different schedules of IFN treatment with or without a control group receiving either placebo or no therapy were included if they were published as full length papers in English. Studies with the following criteria were excluded: randomised only end of treatment responders; pooled randomised with non-randomised patients; or rate of patients normalising amino transferases was not reported.
Specific interventions included in the review
Interferon alpha (IFN) including recombinant, human lymphoblastoid alpha-N 1 , and human leukocyte derived was studied. Total dose of IFN ranged from 19.5 to 1365 mega-units and the length of treatment ranged from 4 to 104 weeks. IFN was administered in various fixed, variable and adjusted doses. Studies were included if they used combination therapy or IFN-beta.
Participants included in the review
Naive adult patients with biopsy-proven chronic non-A, non-B or type C hepatitis with or without cirrhosis either post transfusion of community acquired and with abnormal aminotransferases for at least 2 months were included. Proportion of cirrhotic patients ranged from 0% to 100%. Patients with haemophilia were excluded.
Outcomes assessed in the review
Treatment effectiveness was assessed by alanine aminotransferase (ALT) normalisation. End of treatment response was defined as complete ALT normalisation during IFN treatment with any other behaviour being defined as non-response. Sustained response was defined as complete ALT normalisation during IFN treatment persisting up to the end of the post treatment follow up (> = 4 months, range 4 to 18 months).
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the reviewers performed the selection.