[Measuring shared decision making].

Since October 2001 the German Ministry of Health and Social Security has been funding 10 projects to introduce shared decision making in clinical practice. A national meeting was held on assessment procedures to achieve consensus on a core set of instruments for the measurement of process and outcome of shared decision making. Project collaboration is co-ordinated through the methodological centre in Freiburg. Currently there are no validated measuring instruments available for German-speaking countries. Thus four international questionnaires were translated into German. In a second step the questionnaires were validated on a sample of 646 patients across 10 different diseases. To this purpose, the data of these 10 projects were combined in one database. Comprehensibility of the questionnaires used was checked in patient interviews. Moreover, the semantic structure of the questionnaires was tested by the Centre for Surveys. Methods and Analyses (ZUMA) in Mannheim. The results of this assessment process point towards problems of both comprehensibility and lack of specification of reference points for clinical decision. The statistical results for two of these questionnaires deviate from previous studies. These data indicate a potential for improving the instruments currently used for shared decision making. Separate validation across different languages and health care systems is needed in the field of shared decision making. Further research efforts on the methodological field now focus on the integration of these results with a new measuring instrument and the validation of this tool.