Study Design, Participant Selection, and Study Procedures

This study was a prospective, cluster-randomized, controlled trial. Fifteen prehospital emergency medical service units (Service d'Aide Médicale d'Urgence) in France participated in the study from November 2009 through October 2011. These units are ambulance base stations equipped with one or more mobile intensive care units, consisting of an ambulance driver, a nurse, and a senior emergency physician as the minimum team.13 Simple randomization procedures were used to assign eight of the participating units to the intervention and seven to the control.

We included adult family members of adult patients in cardiac arrest occurring at home. We evaluated only one first-degree relative per patient. The relative was chosen in accordance with the legislation on hospitalization at the request of a third party in the following order of preference: spouse, parent, offspring, sibling. Exclusion criteria were communication barriers with the relative and cardiac-arrest cases in which resuscitation was not attempted.

For emergency medical service units assigned to the intervention, a medical team member systematically asked family members whether they wished to be present during the resuscitation. A communication guide (see Table S1 in the Supplementary Appendix, available with the full text of this article at NEJM.org) that was developed from published guidelines was available to help introduce the relative to the resuscitation scene and, when required, to help with the announcement of the death.5,14,15 For units assigned to the control, family members were not routinely given the option to be present during CPR; instead, the physician team leaders interacted with these family members in a standard manner during CPR. Relatives who chose to witness the resuscitation were taken to the room where it was being performed. Relatives who chose not to witness the resuscitation were taken to another room of the home or were taken outside the home if the space inside was insufficient.

The study was approved by the institutional review board (Comité de Protection des Personnes Ile-de-France 10). In accordance with French law, the board waived the requirement for obtaining informed consent from patients because of the emergency setting of the research; however, deferred consent of the family members was required. All the relatives participating in the study provided written informed consent before the departure of the health care team from the home. The first, next-to-last, and last authors assume responsibility for the completeness and accuracy of the data and analyses and for the fidelity of the study to the protocol, which is available at NEJM.org.

Follow-up and Psychological Assessment of Family Members

Ninety days after resuscitation, a trained psychologist who was unaware of the study-group assignments asked enrolled relatives to answer a structured questionnaire by telephone. The interviewer asked relatives to complete the Impact of Event Scale (IES) and the Hospital Anxiety and Depression Scale (HADS).16,17 A relative was deemed unreachable after 15 telephone calls had gone unanswered.

The IES has been widely used for many years and is reliable across a broad range of traumatic events.18 Each of the 15 items is scored on a scale from 0 to 5, so the total score ranges from 0 (no PTSD-related symptoms) to 75 (severe PTSD-related symptoms).19 The HADS is made up of two subscales, one evaluating symptoms of anxiety (HADS A , seven items) and the other assessing symptoms of depression (HADS D , seven items).17 Subscale scores range from 0 (no distress) to 21 (maximum distress). HADS subscale scores higher than 10 indicate moderate-to-severe symptoms of anxiety or depression.10,20 The satisfaction of the relatives at having been absent or present was also recorded.

The primary end point was the proportion of relatives with PTSD-related symptoms (as indicated by an IES score higher than 30) on day 90, in agreement with previous reports.15,18

Secondary Analyses

Secondary end points included the effect of family presence on medical efforts at resuscitation, the well-being of the health care team, and the occurrence of medicolegal claims. Demographic and clinical data for the resuscitated patients were recorded according to the Utstein style.21 A series of items reflecting the relative's behaviors and the type of invasive procedures witnessed by the relative during CPR was recorded. The level of emotional stress in the medical team was evaluated after each resuscitation with the use of a visual-analogue scale and a nine-item questionnaire adapted from the literature review.22 Once the recruitment was completed, the principal investigator asked all center investigators to report medicolegal claims, complaints, and words of thanks.

Statistical Analysis

Assumptions for sample-size calculation were based on the study by Azoulay et al.18 In that study, 28 family members of patients who died in the intensive care unit (50%) had an IES score higher than 30 at 90 days.18 On the basis of this expected percentage, a sample of 340 relatives for whom data could be analyzed was required to provide 80% power to detect a 15% difference between the two groups, with a two-sided type I error rate of 0.05 in the case of independent statistical units. Because of the cluster randomization, the final sample required was 460 relatives for whom data could be analyzed.

The main analysis of the primary end point was based on the intention-to-treat population (i.e., all randomly assigned patients). For this main analysis, we classified participants who did not complete the IES assessment because of emotional distress as having PTSD-related symptoms, and we used multiple imputation for the other participants with missing data.23 Prespecified additional analyses according to family-presence status and two sensitivity analyses for IES score were performed. First, we restricted the analysis to the participants who completed the IES assessment (observed-cases population). Second, we restricted the analysis to family members whose relatives were deceased at day 28. No interim analysis was performed.

Data are reported as means (±SD) or medians and interquartile ranges for continuous variables and as percentages for categorical variables. Univariate associations were evaluated with the use of Student's t-test or the Wilcoxon signed-rank test for continuous data and the chi-square test or Fisher's exact test, as appropriate, for categorical data. For psychological-assessment analyses, generalized estimating equations were used for categorical data, and a mixed-model analysis of variance was used for continuous data, with study center as a random effect and adjustment for the relative's relationship to the patient. When necessary, normalizing transformations were performed. All statistical tests were two-tailed, with a type I error rate of 0.05. A P value of less than 0.05 was considered to indicate statistical significance. Statistical tests were performed with the use of SAS software, version 9.2 (SAS Institute).