Measuring differential attainment: a longitudinal analysis of assessment results for 1,512 medical students at four Scottish medical schools

Objective: To measure Differential Attainment (DA) among Scottish medical students and to explore whether attainment gaps increase or decrease during medical school.

Design: A retrospective analysis of undergraduate medical student performance on written assessment, measured at the start and end of medical school.

Setting: Four Scottish medical schools (universities of Aberdeen, Dundee, Edinburgh and Glasgow). Participants 1512 medical students who attempted (but did not necessarily pass) final written assessment.

Main outcome measures: The study modelled the change in attainment gap during medical school for four student demographical categories (white/non-white, international/Scottish domiciled, male/female and with/without a known disability) to test whether the attainment gap grew, shrank or remained stable during medical school. Separately, the study modelled the expected versus actual frequency of different demographical groups in the top and bottom decile of the cohort.

Results: The attainment gap grew significantly for white versus non-white students (t(449.39)=7.37, p=0.001, d=0.49 and 95% CI 0.34 to 0.58), for internationally domiciled versus Scottish-domiciled students (t(205.8) = -7, p=0.01, d=0.61 and 95% CI -0.75 to -0.42) and for male versus female students (t(1336.68)=3.54, p=0.01, d=0.19 and 95% CI 0.08 to 0.27). International, non-white and male students received higher marks than their comparison group at the start of medical school but lower marks by final assessment. No significant differences were observed for disability status. Students with a known disability, Scottish students and non-white students were over-represented in the bottom decile and under-represented in the top decile.

Conclusions: The tendency for attainment gaps to grow during undergraduate medical education suggests that educational factors at medical schools may - however inadvertently - contribute to DA. It is of critical importance that medical schools investigate attainment gaps within their cohorts and explore potential underlying causes.