weekly sessions for small groups of caregivers, led by two psychologists acting as moderators and using a systemic approach, as suggested in other peer-support groups using a problem-based method

Anxiety (HA) and depression (HD) were identified by the validated French version of the Hospital Anxiety and Depression Scale (HADS), which is composed of 14 items, self-rated using a 4-point Likert scale (0 to 3). The sub-scale scores of anxiety and depression range respectively from 0 to 7 (no distress), 8 to 10 (borderline), 11 to 15 (significant) and 16 to 21 (severe distress).

Burnout was evaluated using the Maslach Burnout Inventory (MBI) in its Fontaine French version; it is composed of 22 questions on a 7-point Likert scale (0 to 6). This tool measures the 3 dimensions of burnout independently: emotional exhaustion, depersonalisation, and personal accomplishment. Scores of ≥ 27, ≥ 10, or ≤33 respectively for the 3 dimensions, can be a sign of burnout. A severe burnout can also be defined as the cumulated score of MBI of > -9.

ICU activities and absenteeism were analysed during 4 three-month time periods, i.e. 3 months before [Before] (January to March 2009), 3 months during [During] (randomly picked out as September and November 2009, and January 2010), 3 months following the end of the intervention [After] (April to June 2010) and from 7 to 10 months after intervention [At 6 months] (November, December 2010 and January 2011). Absenteeism was defined as the number of caregivers absent at least once per time period, independently of the duration of the absence.

We identified how many persons had quitted the ICU between the beginning and the end of the intervention (inclusion time).