A short scale for measuring attitudes towards the doctor-patient relationship: psychometric properties and measurement invariance of the German Patient- Practitioner-Orientation Scale (PPOS

Background. The Patient-Practitioner Orientation Scale (PPOS) was originally developed to compare doctor's and patient's consensus regarding patient centeredness. Research assumed PPOS measurements to be comparable across different groups of participants, however, without assessing the actual validity of this assumption. In this study, we investigate the psychometric properties and measurement invariance of a short version of the German translation of the PPOS. Methods. Based on a cross-sectional survey of N = 332 medical students, we present a short version of the German Patient-Practitioner-Orientation Scale (PPOS-D6) and examine its psychometric properties as well as measurement invariance across participants with varying levels of medical experience and gender using multigroup confirmatory factor analyses. Results. Results indicate that PPOS-D6 provides valid and reliable measurements of patient-centeredness that are invariant across participants with different medical experience. Preliminary results also suggest invariance across gender. Conclusion. PPOS-D6 is a suitable and efficient measure to compare group-specific attitudes towards the doctor-patient interaction. Additional research on convergent and discriminant validity and divergent study samples is advised.