Selection and academic success of medical students in Hamburg, Germany

BACKGROUND: Student selection at Hamburg medical school is based on the combination of a natural science knowledge test (HAM-Nat) and pre-university educational attainment.

METHOD: Of the 1565 medical students enrolled in Hamburg from 2012 to 2015 about half were admitted by an entrance test, half by quotas. First, we analysed sociodemographic determinants of entrance test performance. Then, we used regression analysis to describe the interplay of variables in the prediction of study outcome, the role of sociodemographic factors, and differences in the calibration of educational attainment specific to German federal states.

RESULTS: Better performance in the entrance test was associated with age over 21, male gender, German nationality, first language German and both parents holding an academic degree - effect sizes were small. No differences were found for the birthplaces of parents (a proxy for migration background). Study outcome differed considerably among admission paths: Students admitted by entrance test or the quota for excellent pre-university educational attainment performed markedly better during the first 3 terms than students admitted by the waiting list quota and the quota for foreign students. Gender differences in study outcome were slight with better performance by males. The relation of pre-university educational attainment to study outcome was moderated by the federal state in which secondary schooling took place. Methods for the equating of state-specific grades are explored. The predictive validity of the HAM-Nat after correction for range restriction was r = .31. The relatively low value of this coefficient may be attributed to 3 factors: 1. self-selection of applicants which leads to a validity-enhancing effect that is not revealed by the predictor-outcome correlation, 2. reduction of variance due to a high selection ratio, and 3. high test difficulty, exceeding the demands of the medical curriculum.

CONCLUSION: The HAM-Nat achieves a small amount of incremental validity over pre-university educational attainment. This effect, obtained from correlational analysis, underestimates the validity of the test, because it does not reflect the role of self-selection and other validity enhancing features of the selection process.