Inter-observer and Intra-observer Agreement in Pathological Evaluation of Non-alcoholic Fatty Liver Disease Suspected Liver Biopsies.
BACKGROUND
Histopathologic assessment of liver tissue is an essential step in management and follow-up of non-alcoholic fatty liver disease (NAFLD) while inter- and intra-observer variations limit the accuracy of these assessments.


OBJECTIVE
The aim of this study was to assess the inter- and intra-observer reproducibility of histopathologic assessment of liver biopsies based on NAFLD activity score (NAS) scoring system.


METHODS
The anonymous liver biopsy samples of 100 consecutive NAFLD suspected adults were randomly assigned to four pathologists. Then, the samples were randomly reassigned to the pathologists for the second time in a way that each sample would be evaluated by two different pathologists. Biopsies were revisited by their first evaluator after two months. The results were reported based on NAS scoring system.


RESULTS
Inter-observer agreement of the pathology scores based on NAS scoring system was acceptable for steatosis, lobular inflammation, and fibrosis, but not for hepatocyte ballooning. The intra-observer agreement was acceptable in all scales, with lowest intra-class correlation observed for lobular inflammation.


CONCLUSIONS
NAS scoring system has good overall inter- and intra-observer agreement, but more attention should be given to defining the hepatocyte ballooning and lobular inflammation, and training the pathologists to improve the accuracy of pathology reports.
Department of Medical Informatics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran ; Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, IR Iran.
Omid
O
Pournik
Middle East Liver Diseases Center (MELD), Tehran, IR Iran ; Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallh University of Medical Sciences, Tehran, IR Iran.
Seyed Moayed
SM
Alavian
Mental Health Research Center, Iran University of Medical Sciences, Tehran, IR Iran.
Leila
L
Ghalichi
School of Medicine, Shahid Beheshti Hospital, Hamedan University of Medical Sciences, Hamedan, IR Iran.
Bahram
B
Seifizarei
Middle East Liver Diseases Center (MELD), Tehran, IR Iran.
Leila
L
Mehrnoush
Department of Medical Informatics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran.
Azam
A
Aslani
Reference Health Laboratories Research Center, Tehran, IR Iran.
Soghra
S
Anjarani
Department of Medical Informatics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran ; Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, IR Iran.
Saeid
S
Eslami
Fatty Liver; Observer Variation; Pathology