Kawata 1994.

Methods	Generation of allocation sequence: unclear (no description). Allocation concealment: unclear (no description). Double blinding: unclear (no information). Withdrawal: unclear (no information). Sample size calculation: no information. Intention‐to‐treat analysis: no information.
Participants	Country: Japan. Type of hepatitis: chronic hepatitis C. INCLUSION CRITERIA ‐ anti‐HCV positive; ‐ chronic hepatitis; ‐ ALT levels persistently greater than two times the upper normal limit. PARTICIPANTS UDCA plus IFN group (n = 35). IFN group (n = 35). Proportion of patients with cholestasis: no information. Proportion of patients with cirrhosis: no information.
Interventions	UDCA plus IFN group: UDCA ‐ Dose: 600 mg/day; ‐ Route: orally; ‐ Duration: 48 weeks. IFN ‐ IFN alpha 2a six million units a day for two weeks then thrice weekly for 22 weeks. IFN group: ‐ IFN alpha 2a six million units a day for two weeks then thrice weekly for 22 weeks.
Outcomes	‐ Normalisation of serum ALT at the end of treatment and follow‐up. ‐ Absence of serum HCV RNA at the end of treatment and follow‐up.
Notes	Follow‐up time: six months after the end of IFN treatment. We sent letter for more information on trial methodological quality and missing data on April 17, 2001, but no response was received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear