Predictive validity of a written knowledge test of skills for an OSCE in postgraduate training for general practice

Purpose To examine the validity of a written knowledge test of skills for performance on an OSCE in postgraduate training for general practice. Methods A randomly-selected sample of 47 trainees in general practice took a knowledge test of skills, a general knowledge test and an OSCE. The OSCE included technical stations and stations including complete patient encounters. Each station was checklist rated and global rated. Results The knowledge test of skills was better correlated to the OSCE than the general knowledge test. Technical stations were better correlated to the knowledge test of skills than stations including complete patient encounters. For the technical stations the rating system had no influence on the correlation. For the stations including complete patient encounters the checklist rating correlated better to the knowledge test of skills than the global rating. Conclusion The results of this study support the predictive validity of the knowledge test of skills. In postgraduate training for general practice a written knowledge test of skills can be used as an instrument to estimate the level of clinical skills, especially for group evaluation, such as in studies examining the efficacy of a training programme or as a screening instrument for deciding about courses to be offered. This estimation is more accurate when the content of the test matches the skills under study. However, written testing of skills cannot replace direct observation of performance of skills.