Feasibility and reliability of the pandemic-adapted online-onsite hybrid graduation OSCE in Japan

Objective structured clinical examination (OSCE) is widely used to assess medical students’ clinical skills. Virtual OSCEs were used in place of in-person OSCEs during the COVID-19 pandemic; however, their reliability is yet to be robustly analyzed. By applying generalizability (G) theory, this study aimed to evaluate the reliability of a hybrid OSCE, which admixed in-person and online methods, and gain insights into improving OSCEs’ reliability. During the 2020–2021 hybrid OSCEs, one examinee, one rater, and a vinyl mannequin for physical examination participated onsite, and a standardized simulated patient (SP) for medical interviewing and another rater joined online in one virtual breakout room on an audiovisual conferencing system. G-coefficients and 95% confidence intervals of the borderline score, namely border zone (BZ), under the standard 6-station, 2-rater, and 6-item setting were calculated. G-coefficients of in-person (2017–2019) and hybrid OSCEs (2020–2021) under the standard setting were estimated to be 0.624, 0.770, 0.782, 0.759, and 0.823, respectively. The BZ scores were estimated to be 2.43–3.57, 2.55–3.45, 2.59–3.41, 2.59–3.41, and 2.51–3.49, respectively, in the score range from 1 to 6. Although hybrid OSCEs showed reliability comparable to in-person OSCEs, they need further improvement as a very high-stakes examination. In addition to increasing clinical vignettes, having more proficient online/on-demand raters and/or online SPs for medical interviews could improve the reliability of OSCEs. Reliability can also be ensured through supplementary examination and by increasing the number of online raters for a small number of students within the BZs.