BACKGROUND: Registered nurses working on the frontline during the COVID-19 pandemicencountered significant challenges, including exposure to critical incidents. Critical incidentsrefer to sudden unexpected clinical events that surpass an individual’s ability to cope, leading toconsiderable psychological distress, which could potentially result in the development of posttraumaticstress disorder symptoms. Research has shown a high prevalence of post-traumaticstress disorder symptoms among healthcare workers, particularly those in close contact withCOVID-19 patients.

OBJECTIVE: To assess the levels of post-traumatic stress symptoms among registered nurses inrelation to exposure to working conditions during the COVID-19 pandemic, such as how muchtheir work was affected by the pandemic, re-deployment, working hours hindering sufficientrecovery between shifts and critical incidents.

DESIGN: Cross sectional study.

SETTING(S): The registered nurses working in multiple health care services covering all 21geographic regions in Sweden.

PARTICIPANTS: A total of 1,923 registered nurses, who are part of a Swedish national cohort andhave been followed since their nursing education, were invited to participate in a survey in lateSeptember 2021 (15 to 19 years post graduation).

METHODS: The data were analyzed using descriptive statistics, unpaired t-tests, and one-wayanalysis of variance. Cohen’s d was employed to quantify differences in mean levels betweensubgroups.