Table 1 Preliminary key mechanisms. This table outlines the nine key mechanisms that were originally identified by our team following data synthesis. These mechanisms were incorporated into the initial program theory and presented to stakeholders for confirmation, refinement, and refutation

Health care provider recognition of need for decision

Health care provider and patient preference/willingness for engagement

Health care provider perception of patient competency/capacity

Health care provider perception of time available and required for SDM

Patient anxiety

Patient capacity to access external support and information

Patient belief in their ability (self-efficacy) to participate in SDM

Health Care System Support (including decision aids)

Patient trust in individual health care provider as a person and as a professional