Inter-school variations in the standard of examiners’ graduation-level OSCE judgements

INTRODUCTION: Ensuring equivalence in high-stakes performance exams is important for patient safety and candidate fairness. We compared inter-school examiner differences within a shared OSCE and resulting impact on students' pass/fail categorisation. METHODS: The same 6 station formative OSCE ran asynchronously in 4 medical schools, with 2 parallel circuits/school. We compared examiners' judgements using Video-based Examiner Score Comparison and Adjustment (VESCA): examiners scored station-specific comparator videos in addition to 'live' student performances, enabling 1/controlled score comparisons by a/examiner-cohorts and b/schools and 2/data linkage to adjust for the influence of examiner-cohorts. We calculated score impact and change in pass/fail categorisation by school. RESULTS: On controlled video-based comparisons, inter-school variations in examiners' scoring (16.3%) were nearly double within-school variations (8.8%). Students' scores received…