Visual memory effects on intraoperator study design: determining a minimum time gap between case reviews to reduce recall bias.

Abstract

The objective of this research was to determine test intervals between intraoperator case reviews to minimize the impact of recall. Three pathologists were presented with a group of 120 slides and subsequently challenged with a study set of 120 slides after 2-week and 4-week intervals. The challenge set consisted of 60 slides seen during the initial review and 60 slides previously unseen within the study. Pathologists rendered a diagnosis for each slide and indicated whether they recalled seeing the slide previously (yes/no). Two weeks after having been shown 60 cases from a challenge set of 120 cases, the pathologists correctly remembered 26, 22, and 24 cases or 40% overall. After 4 weeks, the pathologists correctly recalled 31% of cases previously seen. Pathologists were capable of recalling from memory cases seen previously at 2 and 4 weeks. Recall rates may be sufficiently high to affect intraobserver study design.