Psychometric evaluation of an instrument to assess patient-reported ‘psychosocial care by physicians’: a structural equation modeling approach

Abstract

The objective of our study was to develop a theory-based and empirically tested instrument for measuring patient-reported 'psychosocial care by physicians'. We propose a model integrating patients' perceptions with respect to: (i) devotion by physicians, (ii) support by physicians, (iii) information by physicians and (iv) shared decision-making (SDM). Data were gathered during 2001 within a cross-sectional, retrospective mail survey. A total of 4192 inpatients of six German hospitals. Specific scales of the Cologne Patient Questionnaire were used. A two-step structural equation model procedure was applied. In the first structural equation model, all items were modeled as indicators of the intended underlying latent construct, 'psychosocial care by physicians'. In the second structural equation model, criterion-related validity of the intended construct was tested with respect to patients' 'satisfaction', 'trust in physicians' and the 'image of the hospital'. The results confirmed that the aspects of psychosocial care provided by physicians measured by the scale items are indeed indicators of the same construct. Furthermore, indicator reliabilities and selectivities revealed that the content of all 13 items was highly representative of the underlying construct. The second structural equation model showed that 'psychosocial care by physicians' is related to 'patients' satisfaction', 'trust in physicians' and 'hospital-image' in a significant and relevant manner. On the basis of our instrument's reported psychometric characteristics and of the initial validity indicators, it may be regarded as an adequate measure for further use in outcome and intervention research, and as a quality indicator for the physician-patient relationship.