Moss J, Roberts MB, Shea L, Jones CW, Kilgannon H, Edmondson DE, Trzeciak S, Roberts BW. Perceived Threat a Partial Mediator Between Respiratory Instability and Post-traumatic Stress Disorder Symptoms. Accepted for presentation at Society for Academic Emergency Medicine Annual Meeting, Denver, CO, May 12-15, 2020.

Background:

We previously found among patients presenting to an urban academic emergency department (ED) with respiratory instability, 31% had clinically significant post-traumatic stress disorder symptoms (PSS) 30 days after discharge, compared to only 16% of patients who presented for cardiovascular instability. We also found perceived threat (patients’ perceptions of life threat and personal vulnerability) was higher among patients with respiratory instability. However, it is currently unclear to what degree perceived threat mediates the association between respiratory instability and the development of PSS.

Methods:

We performed an analysis of the prospective cohort study described above. We included adult patients requiring an acute intervention in the ED for resuscitation of a potentially life-threatening medical emergency, defined as respiratory or cardiovascular instability. We measured patient perceived threat in the ED using a validated patient self-assessment measure (score range 0-21, with higher scores indicating greater perceived threat). We performed blinded assessment of PSS 30 days after discharge using the Post-traumatic Stress Disorder Checklist for Diagnostic and Statistical Manual of Mental Disorders (PCL-5). Cronbach’s alpha was used to test the reliability of the perceived threat score among patients with respiratory instability. Structural equation modeling with bootstrap confidence intervals (CI) was used to determine the total effect of respiratory instability on PSS and the indirect effect of PSS mediated by perceived threat on PSS.

Results:

We included 113 subjects; 40% were female and the mean (SD) age was 58 (13). Sixty- one percent presented with respiratory instability. The perceived threat scale had good reliability (Cronbach’s alpha = 0.85). We found respiratory instability was associated with PSS [total effect β = 8.66 (95% CI 2.48 – 14.83)], and was partially mediated by perceived threat [indirect effect β = 2.61 (95% CI 0.21 – 5.0)].

Conclusion:

Respiratory instability in the ED is an independent predictor of PSS at 30 days after discharge. Perceived threat was found to mediate ~30% of the association between respiratory instability and the development of PSS. Further interventions aimed at reducing perceived threat among patients with respiratory instability are warranted.

Jeena Moss, M3, Cooper Medical School of Rowan University