The effect of candidate familiarity on examiner OSCE scores

Abstract

Although examiners are a large source of variability in the objective structured clinical examination (OSCE), the exact causes of examiner variance remain understudied. This study aimed to determine whether examiner familiarity with candidates influences candidate scores. A total of 24 candidates from 4 neonatal-perinatal training programmes participated in a 10-station OSCE. Sixteen trainees and 7 examiners came from a single centre (site A) and 8 candidates and 5 examiners came from the other 3 centres. Examiners completed station-specific binary checklists and an overall global rating; standardised patients (SPs) and standardised health professionals (SHPs) completed 4 process ratings and the overall rating. A fixed-effect, 2-way analysis of variance was performed to ascertain whether there was interaction between examiner site and candidate site. Interstation Cronbach's alpha was 0.80 for the examiner checklist, 0.88 for the examiner global rating and 0.88 for the SP or SHP global rating. Although the checklist scores awarded by site A examiners were significantly higher than those awarded by non-site A examiners, there was no significant interaction between examiner and candidate site (P = 0.124). Similarly, the interaction between examiner and candidate site for the global rating was not significant (P = 0.207). Global ratings awarded by SPs and SHPs were also higher in stations where site A faculty examined site A candidates, suggesting the observed differences may have been related to performance. Results from this small dataset suggest that examiner familiarity with candidates does not influence how examiners score candidates, confirming the objective nature of the OSCE. Confirmation with a larger study is required.