The 5-Year Incidence of Mental Disorders in a Population-Based ICU Survivor Cohort

Objective: To estimate incidence of newly diagnosed mental disorders among ICU patients. Design: Retrospective-matched cohort study using a population-based administrative database. Setting: Manitoba, Canada. Participants: A total of 49,439 ICU patients admitted between 2000 and 2012 were compared with two control groups (hospitalized:n= 146,968 and general population:n= 141,937), matched on age (+/- 2 yr), sex, region of residence, and hospitalization year. Intervention: None. Measurements and Main Results: Incident mental disorders (mood, anxiety, substance use, personality, posttraumatic stress disorder, schizophrenia, and psychotic disorders) not diagnosed during the 5-year period before the index ICU or hospital admission date (including matched general population group), but diagnosed during the subsequent 5-year period. Multivariable survival models adjusted for sociodemographic variables, Charlson comorbidity index, admission diagnostic category, and number of ICU and non-ICU exposures. ICU cohort had a 14.5% (95% CI, 14.0-15.0) and 42.7% (95% CI, 42.0-43.5) age- and sex-standardized incidence of any diagnosed mental disorder at 1 and 5 years post-ICU exposure, respectively. In multivariable analysis, ICU cohort had increased risk of any diagnosed mental disorder at all time points versus the hospitalized cohort (year 5: adjusted hazard ratio, 2.00; 95% CI, 1.80-2.23) and the general population cohort (year 5: adjusted hazard ratio, 3.52; 95% CI, 3.23-3.83). A newly diagnosed mental disorder was associated with younger age, female sex, more recent admitting years, presence of preexisting comorbidities, and repeat ICU admission. Conclusions: ICU admission is associated with an increased incidence of mood, anxiety, substance use, and personality disorders over a 5-year period.