Spontaneously retrievable knowledge of German general practitioners depending on time since graduation, measured with the progress test medicine.

General practitioners and general internists occupy a key position in German and Austrian healthcare systems. They provide primary care and act as gatekeepers between medical disciplines and sectors of care. Their explicit medical knowledge levels, however, can be quite disparate. This study analyses whether general practitioners' performances on a standardised knowledge test changes with four relevant socio-demographic variables. The survey was based on the Progress Test Medicine (PTM), a standardised 200 item knowledge test on graduate level. After formal blueprinting and item analysis, 60 items of PTM were selected ("PTM-GP") for our study. PTM-GP was presented ad hoc to general practitioners and internists from Germany and Austria at a number of professional meetings in 2011. 161 volunteers completed the survey. For evaluation, correlation analysis (Spearman), Kruskal Wallis-tests for non-parametric data and an analysis of covariance (ANCOVA) were calculated. Overall, four indicators turned out to be slightly significant for the performance on the PTM-GP, namely: time passed since graduation, the grade received in the licensing examination, the type of institution for postgraduate training, and the medical specialisation. Recent graduates performed better in the PTM-GP; a doctor's licensing examination grade as well as training at a university hospital correlated positively with PTM-GP performance. A general doctor's knowledge level is moderately influenced by exam grades, time since graduation, the institutional affiliation of postgraduate training and medical specialisation. Individual changes in knowledge over time have to be deliberately considered in lifelong learning. In consequence, the on-going teaching of medical knowledge should be integrated mandatory and verifiable into general doctors' everyday practices, e.g. through repetitive knowledge tests with individual feedback and recommendations for further continuing medical education (CME).