Study	Reason for exclusion
Angelico 1995b	This study is a randomised cross‐over clinical trial. Forty anti‐HCV positive patients were randomised to receive IFN alpha, from day 0 to 180, plus TUDCA, from day 61 to 240; or TUDCA, from day 0 to 180, plus IFN alpha from day 61 to 240. The two interventions did not differ significantly. The trial does not fulfill our inclusion criteria.
Attilli 1994	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. Thirty‐six patients with chronic active hepatitis were included. Patients were randomly allocated to receive 600 mg UDCA per day or placebo. Clinical and biochemical follow‐up was performed at three‐month intervals. A percutaneous liver biopsy was performed before and after one year of treatment. Multifactorial covariance analysis showed that the reductions in ALT, AST, and GGT were significantly higher in UDCA group than in the placebo group. Biochemical remission was not observed in either group. No differences were found in the two groups before or after treatment in histological activity index.
Buzzelli 1991	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. A total of 40 patients with chronic active hepatitis were randomised to oral UDCA 300 mg two times a day or S‐adenosyl‐methionine (200 mg two times a day) for six months. Treatment with UDCA produced a statistically significant reduction in ALT, AST, and GGT compared with SAMe.
Buzzelli 1992	This study is a randomised clinical trial, but the type of viral hepatitis can not be identified. A total of 36 patients with chronic hepatitis B and/or C were included. Eighteen were randomised to 300 mg of UDCA‐hemisuccinate orally twice a day for six months and 18 randomised to 200 mg of S‐adenosyl‐methionine twice a day for six months. Treatment with UDCA produced a statistically significant reduction in ALT, AST and GGT compared with SAMe.
Crosignani 1991	This study is not a randomised clinical trial, but a case series. The effects of UDCA on liver function tests and on bile acid metabolism were investigated in 18 patients with chronic active hepatitis. Three different doses of UDCA ‐ 250 mg, 500 mg, and 750 mg ‐ were administered daily to each patient for two months. A significant decrease in serum aminotransferase occurred with the lowest dose of UDCA, which corresponded to four mg/kg body weight/day, and no further significant decrease in serum aminotransferases with the higher doses was seen.
Crosignani 1998(a)	This study is a randomised clinical trial, but the type of viral hepatitis can not be identified. One hundred and fifty‐five patients with chronic active hepatitis were randomly assigned to receive TUDCA at the daily doses of 250, 500, and 1000 mg, or no treatment for six months. Serum aminotransferase and GGT activities decreased with each dose of TUDCA compared with controls (P < 0.001). The 1000 mg dose was followed by more marked improvement compared with the 250 mg dose (P < 0.05). An improvement of ALT with time (P < 0.05) was found only with the two higher doses.
Del Vecchio 1982	This study is a randomised clinical trial, but the type of viral hepatitis can not be identified. Forty‐four in‐patients with low activity chronic hepatitis were included in this study. Patients were randomly allocated to receive in a double‐blind way UDCA (10 mg/kg/day) or placebo in divided doses for three months. In both groups there was a significant improvement in all biochemical variables but without a statistically significant difference between treatments.
Italian 1990	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. Sixty‐three chronic active hepatitis patients were enrolled in three participating centres: 34 received UDCA and 29 placebo. Serum AST and GGT activities were significantly reduced (P < 0.05 and P < 0.01, respectively) during the treatment with UDCA but not with placebo. Liver histology remained substantially unchanged in terms of periportal necrosis, intralobular degeneration, portal inflammation, and fibrosis in patients treated with UDCA or placebo.
Kadayifci 1997	This study is a case‐report. A 38‐year‐old man had pruritus and jaundice of eight weeks, initially compatible with acute hepatitis B. The patient took 10 mg/kg bodyweight/day UDCA, and the symptoms began to improve after two weeks. Bilirubin levels also gradually reduced. After 14 weeks of UDCA therapy, bilirubin levels and all other laboratory parameters returned to normal, hepatitis B surface antigen disappeared, and hepatitis B antibody became positive.
Lu 1995	This study is not a randomised clinical trial, but a case‐control study. It was conducted to evaluate the efficacy of UDCA in the treatment of Chinese patients with chronic hepatitis C. Patients who failed to have sustained responses to IFN therapy, refused to take IFN, or were unsuitable for IFN treatment, were enrolled. Fifteen patients received UDCA 600 mg orally per day for six months. Another fifteen patients were chosen as the control group. After the treatment period, the mean serum ALT activities in both groups were not significantly different and mean serum ALT activities in the UDCA‐treated group did not decrease after the treatment.
Pinto 1992	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. Forty patients (15 M, 25 F) with biopsy proven chronic liver disease were randomly allocated to two treatment groups. Twenty patients received UDCA 600 mg/day and 20 patients received placebo for six months. Serum ALT activities were significantly reduced in the treated group when compared with placebo group at the end of treatment.
Podda 1989	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. Forty‐eight patients (30 with PBC, six with PSC and 12 with chronic hepatitis) were included in this trial. UDCA was administered at dosages of 250, 500, and 750 mg/day for two months. Highly significant decreases in serum aminotransferase activities were observed in all groups, but there is no significant difference for the decrease in serum aminotransferase activities between the 500 and the 750 mg/day doses.
Podda 1990	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. The trial compared the effects of UDCA, taurine, or a combination of the two on indices of liver injury in 24 patients with chronic active hepatitis. They were assigned at random to two of the four following treatments: UDCA (600 mg/day), taurine (1.5 g/day), UDCA (600 mg/day) plus taurine (1.5 g/day) or placebo, given in two successive cycles of two months each. UDCA and the combination of UDCA and taurine significantly decreased serum AST, ALT, and GGT at the end of treatment when compared with taurine alone.
Podda 1995	This study is a randomised clinical trial, but the type of viral hepatitis can not be identified. In seven Italian centres, 155 patients with histological diagnosis of chronic active hepatitis were enrolled. They were randomly assigned to receive a six‐months course of TUDCA at the daily doses of 250 mg, 500 mg, 1000 mg, or no treatment. After six months of treatment, AST, ALT, and GGT decreased in patients administered TUDCA compared to patients receiving no treatment (P < 0.001).
Portincasa 1993	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. A total of 53 patients with histologic evidence of chronic active hepatitis were enrolled in the study. TUDCA 500 mg/day divided into two doses with meals was given to 27 patients; 26 patients served as controls. Follow‐ups were performed for one month, two months, and the end of the study period. TUDCA significantly lowered AST (‐44%), ALT (‐49%), and GGT(‐38%). Throughout the study, serum levels of alkaline phosphatases and serum bilirubin concentration remained within normal range in all patients.
Rolandi 1991	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. Twenty‐six patients with serum ALT values at least twice the upper normal limit in two of three pre‐treatment tests received UDCA 450 mg/day or a placebo for twelve weeks. In all UDCA‐treated patients, serum AST, ALT, GGT and alkaline phosphatases fell significantly after four weeks of treatment when compared with patients in placebo group. Four weeks after suspension of therapy, there was no significant difference between UDCA group and placebo group in serum aminotransferase.
Song 1998	This study is a randomised clinical trial, but the type of viral hepatitis cannot be identified. Seventy‐nine patients with chronic active hepatitis were divided into two groups. Forty‐two patients in the treatment group received UDCA 300‐450 mg a day and thirty‐seven patients in control group received no treatment. The treatment group improved the serum GGT activities significantly when compared to the control group.
Zhu 1997	This study is not a randomised clinical trial, but a control series. Fifty‐three patients with chronic hepatitis C received UDCA 600 mg a day with the combination of ribaviram 900 mg a day and polyinosine polycytidylic acid four mg once in two days. Forty‐seven patients with chronic hepatitis C received ribaviram 900 mg a day and polyinosine polycytidylic acid four mg once in two days as control group. A significant improvement on biochemical response at the end of treatment in UDCA group was observed when compared with the control group.

ALT: alanine aminotransferase. 
 AST: aspartate aminotransferase. 
 GGT: gamma glutamyltranspeptidase. 
 IFN: interferon. 
 TUDCA: tauro‐ursodeoxycholic acid. 
 UDCA: ursodeoxycholic acid.