Clinical characteristics and outcomes of people with severe mental disorders hospitalized due to COVID-19: A nationwide population-based study

Objetive: Hospitalized COVID-19 patients with severe mental illness (SMI) have worse outcomes than counterparts without SMI. Barriers in access to acute care medical procedures among SMI patients may partially explain this phenomenon. Here, we examined differences in critical care admission and in-hospital mortality between hospitalized COVID-19 patients with and without SMI.Methods: This population-based study used Spain's nationwide electronic health records. Based on International Classification Diseases, Tenth Revision, ICD-10-CM codes, we identified all patients aged >15 years hospitalized due to COVID-19 between July 1st-December 31st, 2020, and compared patients with and without SMI in terms of (i) critical care admission and (ii) in-hospital mortality - overall and stratified by age. We used logistic regression models including sex, age, and comorbidity burden as measured by Charlson Comorbidity Index Score as covariates.Results: Of 118,691 hospital admissions due to COVID-19 of people aged >15 years, 1512 (1.3%) included a diagnosis of SMI. Compared to non-SMI patients, SMI patients had higher in-hospital mortality (OR,95%CI: 1.63,1.42-1.88) and were less frequently admitted to critical care (OR,95%CI: 0.70,0.58-0.85). Admission to critical care in SMI patients was lower than for non-SMI counterparts only among individuals aged >60 years. The magnitude of the difference in in-hospital mortality between SMI and non-SMI patients decreased as age increased.Conclusions: Individuals with SMI had reduced critical care admission and increased in-hospital mortality compared non-SMI counterparts, suggesting that differences in delivery of acute care medical procedures may partially explain higher risk of negative outcomes among COVID-19 patients with SMI.