Observer error in biopsy interpretations and outcome in chronic hepatitis

To assess the effect of inter- and intra-observer error on the diagnosis of chronic hepatitis, we reexamined liver biopsy slides from 30 patients whose biopsies were obtained more than five years ago. Each slide was reviewed on two separate occasions, without knowledge of previous diagnoses, by three pathologists from two hospitals. Patient outcome was assessed using a telephone questionnaire. intra-observer agreement ranged from 83% to 96%. The two pathologists from the same hospital agreed 90% of the time, but over-all, the three pathologists disagreed on 27% of the slides (P<.01). Four of the original 30 diagnoses were unanimously reversed. This study confirms the benign prognosis of chronic persistent hepatitis compared to chronic active hepatitis, but emphasizes that interobserver variability reduces the predictive value of a single biopsy report. This has serious implications with regard to choice of therapy.