Comprehensive Assessment of Rehabilitation Experience Using the SAFE Scale (CARE-SAFE)

Participants allocated to the SAFE group will undergo an individual training session with the healthcare professionals involved in the study. During this session, the SAFE scale and its administration procedures will be explained in detail.

According to the procedures established for the SAFE scale, caregivers will complete the scale after a 2-week observation period of the patient's behaviours (T1). The SAFE scale will then be completed again by the caregiver 4 weeks after the first administration (corresponding to 6 weeks after the initial training session performed at baseline, T2).

Caregivers will be asked to complete also the following questionnaire:

Brief Illness Perception Questionnaire (BIPQ; Broadbent et al., 2006)

The intervention will consist of caregiver training and completion of the SAFE scale (Magnani et al., 2025). The SAFE is an observational tool developed to allow caregivers of patients with Disorders of Consciousness (DoC) to systematically report cognitively mediated behaviours based on daily interactions with the patient over the previous two weeks. Derived from the Coma Recovery Scale-Revised (CRS-R; Giacino et al., 2020), the SAFE includes simplified items designed for non-professional users. Preliminary results have shown good reliability, internal consistency, and correlation with the CRS-R. Following a standardized explanation provided by trained clinicians, caregivers will complete the scale by reporting behaviours observed during the previous 15 days. For each item, caregivers will answer "Yes" or "No" regarding the presence of a specific voluntary/non-reflexive behaviour associated with sensory or cognitive domains.

• scale administration

Participants allocated to the NO-SAFE group will receive the standard clinical care provided by the rehabilitation unit. They will receive the Fondazione Don Gnocchi educational booklet "Il paziente con GCA: guida per le famiglie" as the minimum psychoeducational intervention.

Two weeks after enrolment and delivery of the educational booklet, caregivers will be asked to complete the following questionnaire:

Brief Illness Perception Questionnaire (BIPQ; Broadbent et al., 2006).

Caregivers allocated to the NO-SAFE group will receive the standard clinical care provided by the rehabilitation unit. They will receive the Fondazione Don Gnocchi educational booklet "Il paziente con GCA: guida per le famiglie" as the minimum psychoeducational intervention and will participate in routine clinical meetings with the physicians of the rehabilitation unit.

Measure: The primary endpoint is the score on the Illness Coherence item of the Brief Illness Perception Questionnaire (BIPQ; Broadbent et al., 2006) at T2. This item assesses caregivers' perceived understanding of their relative's clinical condition in the context of Disorders of Consciousness (DoC). The item is scored on a scale from 0 to 10, with higher scores indicating greater perceived understanding of the clinical condition (better outcome).

Measure: Family Satisfaction in the Intensive Care Unit (FS-ICU; Heyland & Tranmer, 2001; Italian version: Pagnamenta et al., 2016; Danielis et al., 2023).

Family satisfaction with the patient's care pathway will be assessed using the Family Satisfaction in the Intensive Care Unit (FS-ICU). The overall score ranges from 0 to 100, with higher scores indicating greater satisfaction with care (better outcome).

Measure: Decisional Conflict Scale (DCS; O'Connor, 1993; Chiavari et al., 2013; Esposito et al., 2020).

Decisional conflict will be assessed using the Decisional Conflict Scale (DCS). The total score ranges from 0 to 100, with higher scores indicating greater decisional conflict and uncertainty (worse outcome).

Measure: Beck Depression Inventory-II (BDI-II; Beck et al., 1996; Steer, 1999; Ghisi et al., 2006).

Depressive symptoms will be assessed using the Beck Depression Inventory-II (BDI-II), a 21-item self-report measure. Total scores range from 0 to 63, with higher scores indicating greater severity of depressive symptoms (worse outcome).

Measure: State-Trait Anxiety Inventory - Form Y, State Anxiety subscale (STAI-Y; Spielberger et al., 1997).

State anxiety will be assessed using the State Anxiety subscale of the State-Trait Anxiety Inventory - Form Y (STAI-Y). The subscale score ranges from 20 to 80, with higher scores indicating greater state anxiety (worse outcome).

Measure: State-Trait Anxiety Inventory - Form Y, Trait Anxiety subscale (STAI-Y; Spielberger et al., 1997).

Trait anxiety will be assessed using the Trait Anxiety subscale of the State-Trait Anxiety Inventory - Form Y (STAI-Y). The subscale score ranges from 20 to 80, with higher scores indicating greater trait anxiety (worse outcome).

Measure: Prolonged Grief Disorder-12 (PG-12; Prigerson et al., 2009). Prolonged grief symptoms will be assessed using the Prolonged Grief Disorder-12 (PG-12). The PG-12 is a self-report measure assessing symptoms of prolonged grief. The total score ranges from 11 to 55, with higher scores indicating greater severity of prolonged grief symptoms (worse outcome).

Measure: Family Strain Questionnaire (FSQ; Vidotto et al., 2009). Caregiver strain will be assessed using the Family Strain Questionnaire (FSQ). The total score ranges from 0 to 30, with higher scores indicating greater caregiver strain and psychological burden (worse outcome).