Validation of the Sahred Decision Making Questionnaire-Physician version (SDM-Q-Doc) in oncology practice

Abstract

Objective The aim of this study was to analyze the psychometric properties of the Shared Decision-Making Questionnaire-Physician version (SDM-Q-Doc) in a sample of medical oncologists who provide adjuvant treatment to patients with non-metastatic resected cancer and the correlations between the total SDM-Q-Doc score and physician satisfaction with the information provided. Methods Prospective, observational and multicenter study in which 32 medical oncologists and 520 patients were recruited. The psychometric properties, dimensionality, and factor structure of the SDM-Q-Doc were assessed. Results Exploratory factor analyses suggested that the most likely solution was two-dimensional, with two correlated factors: one factor regarding information and another one about treatment. Confirmatory factor analysis based on cross-validation showed that the fitted two-dimensional solution provided the best fit to the data. Reliability analyses revealed good accuracy for the derived scores, both total and sub-scale, with estimates ranging from 0.81 to 0.89. The results revealed significant correlations between the total SDM-Q-Doc score and physician satisfaction with the information provided (p\0.01); between information sub-scale scores (factor 1) and satisfaction (p\0.01), and between treatment sub-scale scores (factor 2) and satisfaction (p\0.01). Medical oncologists of older age and those with more years of experience showed more interest in the patient preferences (p = 0.026 and p = 0.020, respectively). Patient age negatively correlated with SDM information (p\0.01) and physicians appear to provide more information to young patients. Conclusion SDM-Q-Doc showed good psychometric properties and could be a helpful tool that examines physician's perspective of SDM and as an indicator of quality and satisfaction in patients with cancer.