Biopsies from adult patients enrolled in either the Database study or pretreatment biopsies from the adult treatment trial (Pioglitazone versus Vitamin E versus Placebo for the Treatment of Nondiabetic Patients with NASH) (PIVENS) were reviewed in a standardized blinded fashion by the Pathology Committee of the NASH CRN, composed of a pathologist from each of the 8 clinical centers, and one from the National Cancer Institute. Assignment of a diagnostic category was based on consensus recognition of the distinctive features of SH independent of the degree of NAFLD severity as indicated by the NAS. Biopsies that had been classified by the Pathology Committee during Central Review as “cirrhosis with or without features of NAFLD or NASH” were excluded from this analysis, as it is well recognized that the active lesions of steatohepatitis may not be retained in cirrhosis. Biopsies with the zone 1 borderline pattern were also excluded as this is a pattern that most commonly occurs in pediatric NAFLD and was rare among our adult cases. When more than one biopsy for a subject was available, only the first biopsy was used in the analysis. Histologic and clinical data were analyzed as described below.