MedEdPublish (Sep 2018)
Competency-based Standard Setting for a High-stakes Objective Structured Clinical Examination (OSCE): Validity Evidence
Abstract
Introduction Medical educators need to demonstrate that their trainees meet expected competency levels when progressing through medical education. This study aimed to develop competency-based pass/fail cut-scores for a graduation required Objective Structured Clinical Examination (OSCE), and examine validity evidence for new standards. Methods Six clinicians used the modified Angoff method to determine the cut-scores for an 8-station OSCE. The clinicians estimated the percentage of minimally competent students who would answer each checklist item correctly. Inter-rater reliability, differences in other academic achievements between pass/fail groups, educational impact, and response process were examined. Results One hundred seventy-four rising 4th-year medical students participated in the OSCE. The cut-scores determined for the OSCE resulted in a substantially lower failure rate (5% vs. 29% of the previous year). The inter-rater reliability across domains and cases was .98 (95% CI = .97 - .99). The pass/fail groups significantly differed in six of the eight measures of academic achievements included in the study. Discussion The impact of the standards setting was substantial as it significantly reduced the failure rate and burdens of remediation for both students and faculty. The very high inter-rater reliability indicates that the modified Angoff method produced reliable cut-scores. The significant differences between the pass/fail groups in other measures support external validity of the standards and ensure no false passes. The study also supports response process validity by including discussion among judges and check of previous student performances, as well as recruiting and training multiple clinician educators experienced in medical student teaching. Conclusion Findings of the study provide strong evidence supporting validity of the new cut-scores from a wide spectrum of validity metrics, including response process, internal structure, relations to other variables, and consequences. The study also added to the literature the value of the modified Angoff method in determining competency-based standards for OSCEs.
