Long-Term Mental Health Morbidity in Adult Survivors of COVID-19 Critical Illness: A Population-Based Cohort Study

Abstract

Background: Surviving COVID-19 critical illness may be associated with important long-term sequelae, but little is known regarding mental health outcomes. Research Question: What is the association between COVID-19 critical illness and new mental health diagnoses after discharge? Study Design and Methods: We conducted a population-based cohort study in Ontario, Canada (January 1, 2020-March 31, 2022). We included consecutive adult survivors (aged ≥ 18 years) of COVID-19 critical illness and compared them with consecutive adult survivors of critical illness from non-COVID-19 pneumonia. The primary outcome was a new mental health diagnosis (a composite of mood, anxiety, or related disorders; schizophrenia or psychotic disorders; and other mental health disorders) after hospital discharge. We compared patients using overlap propensity score-weighted, cause-specific proportional hazard models. Results: We included 6,098 survivors of COVID-19 critical illness and 2,568 adult survivors of critical illness from non-COVID-19 pneumonia at 102 centers. Incidence of new mental health diagnosis among survivors of COVID-19 critical illness was 25.3 diagnoses per 100 person-years (95% CI, 24.0-26.6 diagnoses), and 25.9 diagnoses per 100 person-years (95% CI, 24.0-27.8 diagnoses) among survivors of non-COVID-19 pneumonia. After propensity weighting, COVID-19 critical illness was not associated with increased risk of new mental health diagnosis overall (hazard ratio [HR], 1.08; 95% CI, 0.96-1.23), but was associated with increased risk in the category of new mood, anxiety, or related disorders (HR, 1.21; 95% CI, 1.05-1.40). No difference was seen in psychotic disorders, other mental health diagnoses, social problems, or deliberate self-harm. Interpretation: As compared with survival after critical illness resulting from non-COVID-19 pneumonia, survival after COVID-19 critical illness was not associated with increased risk of the composite outcome of new mental health diagnosis, but was associated with elevated risk of new mood, anxiety, or related disorders. Clinical Trial Registry: Center for Open Science; URL: www.archive.org/details/osf-registrations-pfn6q-v1