Coronavirus disease 2019 (COVID-19) is an infectious disease responsible for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection is highly contagious requiring restrictive and stressful measures for patients, family members and ICU healthcare providers. To avoid contagion, patient isolation has become the rule. For patients, these measures add stress to the ICU environment and deprive them of unrestricted family visits. Family members are not only left with fear but also many unanswered questions. In end-of-life situations, many family members are unable to say good-bye and unable to provide support to their loved-one throughout the process. The impact of exclusion or limited inclusion certainly needs to be explored. Moreover, ICU caregivers are having to face new challenges and to work in a unknown situation, juggling with both professional issues such as increased workload, working longer hours and safety issues, and personal issues such as child care and transport as well as family transmission of the virus. The main objective of this study is to demonstrate that the COVID-19 pandemic, as compared to seasonal flu and community acquired pneumonia, significantly increases post-traumatic stress disorder (PTSD) in family members of critically ill patients. PTSD-related symptoms will be assessed in family members using the IES-R (impact of event scale revised) during a telephone interview 90 days after ICU discharge. The IES-R is a 22-item self-report measure that assesses subjective distress caused by traumatic events. It will be compared across the three groups (COVID-19, FLU and CAP).