Randomized, controlled trial of three levels of critical incident stress intervention

Stress debriefing following exposure to a critical incident is becoming more prevalent. Its aim is to prevent or minimize the development of excessive stress response symptoms that lead to loss of productivity or effectiveness in the workplace or at home. There is little evidence that any form of psychological debriefing is effective. This study evaluated the effectiveness of three intervention strategies, and attempted to correlate the symptoms with the severity of the incident and level of intervention.

A randomized, controlled trial of three levels of critical stress intervention was conducted in the British Columbia Ambulance Service (BCAS), in British Columbia, Canada, among paramedics and emergency medical technicians (EMTs), reporting critical incident stress. Outcomes were measured at one week (Stanford Acute Stress Reaction Questionnaire (SASRQ), the Life Impact Score (LIS), and Schedule of Recent Events (SRE)), and at three months and six months following the intervention (Impact of Events (IE), Coping Mechanisms, LIS, and SRE).

Fifty calls were received during the 26-month study period (<1 per 10,000 BCAS response calls): 23 were by third parties, but the involved EMT did not call; nine were placed by crew unwilling to participate in the study; 18 subjects enrolled, but six completed no forms. No correlation was found between severity of the incident and scores on the SASRQ, IE, or LIS, or between any of these scores. There was no consistent pattern in the stress scores over time.

Requests for critical incident stress intervention were uncommon. The need for intervention may not be as great as generally is assumed. Further randomized trials, ideally multicenter studies, are indicated.