Psychometric properties of the German version of Observer OPTION5

BACKGROUND In order to conduct studies on shared decision-making (SDM) and to implement SDM in routine practice, psychometrically tested measures are needed. The development of the short 5-item version of the OPTION scale (Observer OPTION5) allows to assess SDM from an observer perspective. Observer OPTION5 is so far only available in English and Dutch. The aim of this study was to translate the Observer OPTION5 rating scale into German and to test its psychometric properties. METHODS The German Observer OPTION5 was tested in a secondary data analysis of audio-recordings of patient-physician-consultations (N = 79) in German primary care practices. Demographic data were analysed using descriptive statistics. To assess inter- and intra-rater reliability, intraclass correlation coefficients (ICCs) were calculated. For assessing concurrent validity, a correlation (Spearman's Rho) of the sum score of Observer OPTION5 and Observer OPTION12 was calculated. RESULTS The consultations dealt with decisions regarding type 2 diabetes (N = 31), chronic back pain (N = 23), depression (N = 20), and other diseases (N = 5). Analysis of inter-rater reliability yielded an ICC of 0.82 for the sum score; across the five single items ICCs ranged between 0.45 and 0.77. For the intra-rater reliability an ICC of 0.83 was observed for the total score; across the five single items ICCs ranged between 0.45 and 0.86. The Observer OPTION5 had a mean total score of 11.84 (SD = 11.92) and the Observer OPTION12 had a mean total score of 10.3 (SD = 7.9), both on a potential range of 0 to 100. The correlation between the total scores of Observer OPTION5 and Observer OPTION12 was r = 0.47 (p = 0.01). CONCLUSIONS The results regarding inter- and intra-rater reliability were excellent on the total score level. Observer OPTION5 showed moderate concurrent validity using Observer OPTON12. The results are generally comparable to the results of the original English version of Observer OPTION5. The German version of Observer OPTION5 can be used in research and evaluation of clinical practice. Nevertheless, further testing is adviced.