Performance-based assessment in continuing medical education for general practitioners: construct validity.

The use of performance-based assessment has been extended to postgraduate education and practising doctors, despite criticism of validity. While differences in expertise at this level are easily reflected in scores on a written test, these differences are relatively small on performance-based tests. However, scores on written tests and performance-based tests of clinical competence generally show moderate correlations. A study was designed to evaluate construct validity of a performance-based test for technical clinical skills in continuing medical education for general practitioners, and to explore the correlation between performance and knowledge of specific skills. A 1-day skills training was given to 71 general practitioners, covering four different technical clinical skills. The effect of the training on performance was measured with a performance-based test using a randomized controlled trial design, while the effect on knowledge was measured with a written test administered 1 month before and directly after the training. A training effect could be shown by the performance-based test for all four clinical skills. The written test also demonstrated a training effect for all but one skill. However, correlations between scores on the written test and on the performance-based test were low for all skills. It is concluded that construct validity of a performance-based test for technical clinical skills of general practitioners was demonstrated, while the knowledge test score was shown to be a poor predictor of competence for specific technical skills.