Validation of SDM-Q-Doc Questionnaire to measure shared decision-making physician's perspective in oncology practice.

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.