Objective-To assess the coping strategies used by family decision makers of adult critical care patients during and after the critical care experience and the relationship of coping strategies to posttraumatic stress symptoms experienced 60 days after hospitalization.Design-A single-group descriptive longitudinal correlational study.Setting-Medical, surgical, and neurological ICUs in a large tertiary care university hospital.Patients-Consecutive family decision makers of adult critical care patients from August 2012 to November 2013. Study inclusion occurred after the patient's fifth day in the ICU. Interventions-None.Measurements and Main Results-Family decision makers of incapacitated adult ICU patients completed the Brief COPE instrument assessing coping strategy use 5 days after ICU admission and 30 days after hospital discharge or death of the patient and completed the Impact of Event Scale-Revised assessing post-traumatic stress symptoms 60 days after hospital discharge. Seventy-seven family decision makers of the eligible 176 completed all data collection time points of this study. The use of problem-focused (p = 0.01) and emotion-focused (p < 0.01) coping decreased over time while avoidant coping (p = 0.20) use remained stable. Coping strategies 30 days after hospitalization (R 2 = 0.50, p < 0.001) were better predictors of later posttraumatic stress symptoms than coping strategies 5 days after ICU admission (R 2 = 0.30, p = 0.001) controlling for patient and decision-maker characteristics. The role of decision maker for a parent and patient death were the only noncoping predictors of post-traumatic stress symptoms. Avoidant coping use 30 days after hospitalization mediated the relationship between patient death and later posttraumatic stress symptom severity.Conclusions-Coping strategy use is a significant predictor of posttraumatic stress symptom severity 60 days after hospitalization in family decision makers of ICU patients.For information regarding this article, abp19@case.edu. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's website (http://journals.lww.com/ccmjournal).Dr. Hoffer has disclosed that he does not have any potential conflicts of interest. Some family members of critically ill patients experience tremendous psychological distress during the ICU experience (1-5). Lemiale et al (6) reported in a French cohort that 36% of ICU family members are taking anxiolytic or antidepressant drugs on discharge or death of their family member. In the months following the ICU experience, family members are at risk for ongoing psychological distress, including symptoms of generalized anxiety disorder, depression, panic disorder, posttraumatic stress disorder (PTSD), and complicated grief (7-12). Specifically, the prevalence and severity of PTSD symptoms in post-ICU family members have been increasingly recognized in the literature (7-10, 13-18). HHS Public Acce...