Measurement tool | Completed by | Timing of measurement | |||
---|---|---|---|---|---|
Primary outcome | T0 | T1 | T2 | ||
Level of engagement with ACP | ACP Engagement Survey 15-item version [24] • Reported on an overall average 5-point Likert scale (range 1–5) | Patient | X | X | X |
ACP Self-efficacy | ACP Self-efficacy Scale (ACP-SE) [25] • 17 items • Reported on an overall average 5-point Likert scale (range 1–5) • 1 additional general item including all advance care planning can be used for comparison to the scale | GP | X | X | X |
Secondary outcomes | |||||
Health-related quality of life | Short Form Health Questionnaire (SF-12v2) [26] • Physical Health (PCS) and Mental Health (MCS) summary scores (range 0–100) | Patient | X | X | X |
Anxiety | Generalized Anxiety Disorder Questionnaire (GAD-7) [27] • Sum score (range 0–21) | Patient | X | X | X |
Depression | Patient Health Questionnaire (PHQ-9) [28] • Sum score (range 0–27) | Patient | X | X | X |
Appointment of a substitute decision maker | GP report ACP engagement survey “readiness to sign official papers assigning a SDM” item | Patient GP | X | X | X |
Completion of new ACP documents | Patient report GP report ACP engagement survey “readiness to sign official papers stating medical wishes” item | Patient | X | X | |
Thinking about ACP | 1 self-developed item, 10-point Likert (“How much have you thought about ACP in the last 3 months?”; response categories range from “not at all” to “very much”) | Patient | X | X | X |
Communication with the GP | 4 self-developed items, 10-point Likert (e.g., “To what extent did the GP listen to your concerns about your future health?”; response categories range from “not at all” to “very much”) | Patient | X | X | X |
ACP Practices | • Next Steps training program questionnaire [29] (4 items) • 2 items specific to practices with patients with chronic, life-limiting illness (“Which percentage of your patients has a chronic, life-limiting illness” and “With which percentage of your patients with a chronic, life-limiting illness do you conduct ACP conversations?”; 4 response options per item) [25] • 8 additional items regarding ACP practices (e.g., “Where do the ACP conversations you conduct usually take place?”) | GP | X | X | X |
ACP Attitudes | Next Steps training program questionnaire [29] • 9 items; 5-point Likert scale ranging from “Completely disagree” to “Completely agree”; adapted to the Belgian legal context | GP | X | X | X |
ACP Knowledge | Next Steps training program questionnaire [29, 30] • 10 items; correct/not correct/don’t know; adapted to the Belgian legal context | GP | X | X | X |
Documentation of ACP discussion outcomes | Documentation template review | GP | X | X | |
Level of engagement with ACP | ACP Engagement Survey, substitute decision maker version [31] • 17 items; 5-point Likert scales • 3 domain scores (“Serving as SDM”, “Contemplation”, Readiness”) computed as the unweighted average of items per domain (range 1–5) | SDM | X | X | X |
Other measurements | |||||
Demographic information | For patients and surrogate decision makers: • Gender • Age • Marital status • Highest completed education • Religion • Patient/SDM relationship • Whether patient and SDM live together or apart For patients: • Previous completion of any advance directives (“wilsverklaringen”) For surrogate decision makers: • How long they have known the patient For GPs: • Gender • Age • Graduation year • Practice setting(s) • Years of experience as a GP • Graduating university • Working in a palliative home care team (yes/no) • Working as a “coordinating and advising practitioner” in a residential care facility (yes/no) • Prior formal ACP education or training (intensive/introductory/none) • Prior formal palliative care education or training (intensive/introductory/none) | GP Patient SDM | X | ||
Process evaluation | |||||
RE-AIM domain | Operationalization | Measurement | |||
Reach | • Comparing the characteristics of participating patients with non-participants | • Documentation of the recruitment process by the researchers • Documentation of reasons given for not participating • Participant demographics | |||
Efficacy/effectiveness | • Primary and secondary outcomes of the RCT | • See primary and secondary outcomes above • Reports of any adverse effects | |||
Adoption | • ACP discussion documents uploaded • Patient use of the work booklet • Experiences of GPs and patients applying intervention steps • Changes in GP practice | • Training topic checklist (after each training) • Questionnaire for GPs regarding their ACP practices and conversations in the last 3 months (T1) • Questionnaire for patients regarding ACP conversations with their GP in the last 3 months (T1) • Documentation template review (T1, T2) • Contents of work booklet from a sample of patients in the intervention group (physical copy or digital scan) (T1, T2) • Check-in discussions between GPs and trainers (continuous) • Focus groups with GPs (after T2) • Semi-structured interviews with patients and SDM (after T2) | |||
Implementation | • Fidelity: the extent to which the steps of the intervention were followed as specified in the protocol • Patient and GP barriers/facilitators to following the steps of the intervention • Satisfaction of GPs and patients with the intervention components | • Training topic checklist (after each training) • Check-in discussions between GP and trainers (continuous) • Audio recordings of ACP consultations between GP and patient (and SDM if present) • Documentation template review (T1, T2) • Satisfaction questionnaire for intervention GPs and patients (T1) • Focus groups with GPs (after T2) • Semi-structured interviews with patients and SDM (after T2) | |||
Maintenance | • GP intention for using the intervention materials in the future • Recommendations by the GP and patients to improve intervention usability in the future | • Satisfaction questionnaires for intervention GPs and patients (T1) • Focus groups with GPs (after T2) • Semi-structured interviews with patients and SDM (after T2) |