I undersøgelserne måltes behandlingens virkning ved registrering af, hvordan leverbeskadigelsen havde udviklet sig efter 48 ugers behandling (ved mikroskopisk undersøgelse af en leverbiopsi, dvs. en prøve af levervævet), foruden ved registrering af andre sygdomstegn som koncentrationen af et leverenzym (ALT) eller mængden af virus- dna i patientens blod.
The studies measured the effectiveness of the treatment by looking at how the liver damage had evolved after 48 weeks treatment (using a liver biopsy, when a sample of liver tissue is taken and examined under a microscope) as well as measuring other signs of the disease such as the levels of a liver enzyme (ALT) or viral DNA circulating in the blood of the patients.