THE DECISIONAL CONFLICT SCALE AS A DYADIC MEASURE OF SHARED DECISION MAKING: COMPARISON BETWEEN THE PATIENT'S AND THE PHYSICIAN'S VERSIONS

Purpose.   To assess the comparability of the patient’s and the physician’s versions of the Decisional Conflict Scale, a dyadic shared decision-making instrument assessing decisional conflict.

 Methods.   Data originated from a before-and-after study for which the overall goal was to implement shared decision making in clinical primary care practices. Clinical teachers and residents from five family practice teaching units and their patients completed independently a post-clinical encounter questionnaire, the Decisional Conflict Scale, assessing their respective level of decisional conflict regarding the decision that had been made.  Parallel confirmatory factor analysis across physicians’ and patients’ performance on the Decisional Conflict Scale was performed using a multivariate test of equality of correlational structure and a latent-variable model through structural equation modeling.

 Results.   A total of 112 physicians in family medicine (63 clinical teachers and 49 residents) and a single patient for each (n = 112) are included in the present study. Mean age for physicians (67% female) was 35.5 ± 9.3 years and 48.4 ± 17.2 years for patients (55% female). Multivariate test of equality of correlational structure revealed that intra and interpersonal correlation do not differ across physicians and patients performance on the Decisional Conflict Scale  (chi square (20) = 25.18, p = 0.195, CFI = 0.991 and RMSEA = 0.05) and that the variances of the subscales of the DCS differ (chi square difference test (5) = 27.65, p <0.0001). Furthermore, the latent-variable model revealed that the subscales of the Decisional Conflict Scale have the same meaning for both physicians and patients (chi square difference test (4) = 3.56, p = 0,47) and that the variance of the factor “decisional conflict” do not differ across physicians and patients (chi square difference test (5) = 3.91, p = 0.56).

 Conclusion.   The Decisional Conflict Scale shows appropriate dyadic psychometric properties and may be compared or combined across physicians and patients. Therefore, it can be used in dyadic studies in shared decision making to help assess the interdependence occurring between physicians and patients.