Reliability Testing of the CollaboRATE and SHARED Patient-Reported Measures of Shared Decision Making within Surgical Treatment Pathways: A Mixed-Methods Study

PURPOSE: Patient-reported measurement of shared decision making (SDM) is widely used in research and quality improvement (QI). The reliability of measurement instruments is not well established, making it difficult to interpret scores, evaluate interventions and design policies to strengthen SDM. This study examined the test-retest reliability of the CollaboRATE and SHARED instruments and explored factors influencing the stability of patient-reported experiences of SDM. DESIGN: This mixed-methods prospective study was nested within a QI programme at a single tertiary National Health Service hospital in the United Kingdom. Adults (>18 y) booked for elective surgery completed CollaboRATE (3 items assessing the perceptions of clinicians' SDM skills) and SHARED (10 items assessing patient experiences of making treatment decisions) questionnaires at baseline (surgical booking consultation) and retest (5-10 d later) time points. Intraclass correlation (ICC) and kappa coefficients at item, total and top-score levels assessed test-retest reliability, with Bland-Altman plots describing agreement. Semi-structured interviews exploring the stability of patients' experiences of SDM were conducted with a purposive subsample and inductive coding identified themes. Integration of qualitative results indicated 2 drivers of instability: 1) reflection on the SDM process and 2) need for greater support in SDM. CONCLUSION/IMPLICATIONS: CollaboRATE and SHARED patient-reported SDM instruments show fair-to-moderate test-retest reliability in a real-world surgical setting. Instability may reflect not only the measurement properties of instruments also but an evolution in patients' perceptions of SDM. Clinicians, researchers and policy makers should consider the dynamic nature of SDM when planning the timing of SDM measurement and interpreting instrument scores.