Patients' and Observers' Perceptions of Involvement Differ. Validation Study on Inter-Relating Measures for Shared Decision Making

Abstract

ObjectivePatient involvement into medical decisions as conceived in the shared decision making method (SDM) is essential in evidence based medicine. However, it is not conclusively evident how best to define, realize and evaluate involvement to enable patients making informed choices. We aimed at investigating the ability of four measures to indicate patient involvement. While use and reporting of these instruments might imply wide overlap regarding the addressed constructs this assumption seems questionable with respect to the diversity of the perspectives from which the assessments are administered.MethodsThe study investigated a nested cohort (N = 79) of a randomized trial evaluating a patient decision aid on immunotherapy for multiple sclerosis. Convergent validities were calculated between observer ratings of videotaped physician-patient consultations (OPTION) and patients' perceptions of the communication (Shared Decision Making Questionnaire, Control Preference Scale & Decisional Conflict Scale).ResultsOPTION reliability was high to excellent. Communication performance was low according to OPTION and high according to the three patient administered measures. No correlations were found between observer and patient judges, neither for means nor for single items. Patient report measures showed some moderate correlations.ConclusionExisting SDM measures do not refer to a single construct. A gold standard is missing to decide whether any of these measures has the potential to indicate patient involvement.Practice ImplicationsPronounced heterogeneity of the underpinning constructs implies difficulties regarding the interpretation of existing evidence on the efficacy of SDM. Consideration of communication theory and basic definitions of SDM would recommend an inter-subjective focus of measurement.Trial RegistrationControlled-Trials.com ISRCTN25267500.

Shared decision making: Concepts, evidence, and practice

“…One reason for this absence of evidence is the lack of good measurement instruments, particularly to assess the actual realization of SDM [23,24]. Research on methods to assess SDM appeared relatively late.…”

Some but not all dyadic measures in shared decision making research have satisfactory psychometric properties

“…While we observed no relationship between the third-observed OPTION scale and our proposed dyadic measures, previous studies have reported that observer-coded measures may not be adequate to interpret the patient's perception of the physician's behavior [41,42]. observer-coded measures should be used to complement self-report measures, given that relying solely on patients' perceptions has its limitations.…”

Measurement issues of shared decision making in mental health: challenges and opportunities

“…Related to this, research is needed on the comparison of patients', professionals' and objective assessments, which have shown poor correlation in previous studies (Kasper et al 2011;Kasper et al 2012;Scholl, Kriston, Dirmaier & Harter 2012;Kasper et al 2012;Kasper et al 2011). Some authors have tried to develop dyadic measures, instruments with the same underlying structure for patients and professionals that enable a direct comparison of both perspectives (Melbourne et al 2011;Kasper et al 2012;Kasper et al 2011;Kriston et al 2012). It is also necessary more research on the predictive performance of measures of SDM on behavioral (adherence, self-management), and health outcomes (symptoms, health-related quality of life).…”

“…treatment options knowledge; congruence between values and choices), or professionals' perspectives on SDM as a processare underrepresented in existing measures. It is also necessary to compare patients', professionals' and objective assessments, which have shown poor correlation in studies in physical health care settings (Scholl, Kriston, Dirmaier & Harter 2012;Kasper et al 2012;Kasper et al 2011). In summary, data on convergent/discriminant validity are needed to better delimitate the proposed constructs.…”