COVID-19 Prevalence and Mortality Among Schizophrenia Patients

A Large-Scale Retrospective Cohort Study

Dana Tzur Bitan; Israel Krieger; Khalaf Kridin; Doron Komantscher; Yochai Scheinman; Orly Weinstein; Arnon Dov Cohen; Assi Albert Cicurel; Daniel Feingold

Disclosures

Schizophr Bull. 2021;47(5):1211-1217. 

In This Article

Abstract and Introduction

Abstract

Objective: Individuals with schizophrenia may be at an increased risk for COVID-19 morbidity due to the disease characteristics. In this study, we aimed to explore the odds of significant COVID-19 morbidity and mortality among schizophrenia patients while controlling for potential sociodemographic and medical confounders.

Methods: Schizophrenia patients and age-and-sex matched controls (total n = 51 078) were assessed for frequency of COVID-19 positivity, hospitalizations, and mortality. The odds for COVID-19-associated hospitalization and mortality were calculated using logistic regression models, while controlling for age, sex, marital status, sector, socioeconomic status, diabetes, ischemic heart disease, hypertension, hyperlipidemia, obesity, smoking, and chronic obstructive pulmonary disease.

Results: Individuals with schizophrenia were less likely to test positive for COVID-19; however, they were twice as likely to be hospitalized for COVID-19 (OR 2.15 95% CI 1.63–2.82, P < .0001), even after controlling for sociodemographic and clinical risk factors (OR 1.88 95% CI 1.39–2.55, P < .0001). Furthermore, they were 3 times more likely to experience COVID-19 mortality (OR 3.27 95% CI 1.39–7.68, P < .0001), compared to controls.

Conclusions: We found evidence of associations between schizophrenia and increased COVID-19 morbidity and mortality compared to controls regardless of sociodemographic and medical factors. As these patients present with a combination of potential risk factors for mortality, efforts should be made to minimize the effects of the pandemic on this vulnerable population.

Introduction

The social, economic, and health-related consequences of the novel coronavirus (COVID-19) pandemic, caused by the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have been documented extensively. Studies exploring the consequences of the pandemic have demonstrated its effects on the general population,[1,2] as well as on at-risk groups such as individuals with racial, ethnic, and income disparities.[3] Nonetheless, the effect of the pandemic on vulnerable groups such as individuals with severe mental illness has not been fully delineated thus far. Kozloff et al[4] recently suggested that individuals with schizophrenia may be considered an at-risk group, as some clinical (ie, cognitive impairment and poor insight) and sociodemographic (ie, living in congregate housing) characteristics may increase the risk of infection among this population. Furthermore, they suggested that these patients may be more prone to premature death due to their poor physical health. Indeed, many studies have demonstrated that individuals with schizophrenia and other severe mental illnesses have an excess of physical comorbidities and consequent reduced life expectancy,[5,6] as well as a higher prevalence of deaths from pneumonia and influenza.[7] Nonetheless, only a few studies have systematically evaluated whether schizophrenia patients are indeed at risk for either infection or premature death due to COVID-19.

Empirical studies examining the association between psychiatric disorders and COVID-19 infections and complications have only recently begun to emerge. Merzon et al[8] suggested that patients with attention-deficit/hyperactivity disorder (ADHD) may be more prone to become infected with COVID-19 due to their limited ability to comply with COVID-19 prevention recommendations. They assessed the prevalence of ADHD patients among 14,022 cases of COVID-19 positive patients and found significantly higher rates of ADHD patients in this population. Reilev et al[9] performed a population-based study to assess factors that might contribute to a higher risk of severe and fatal COVID-19 disease among Danish individuals, and found that a major psychiatric disorder increased the odds of mortality by 2.4–2.7. To the best of our knowledge, only one study has assessed the association between schizophrenia diagnosis and severity of COVID-19 illness: Fond et al[10] performed a case-control study of 1092 patients admitted to acute care hospitals due to COVID-19 illness in Marseille, France, and found increased mortality rates among patients with schizophrenia (26.7%) compared to patients without schizophrenia (8.7%). Nonetheless, the authors stated that the sample of schizophrenia patients included only 15 cases, and the database suffered from missing data and potential inaccuracies, precluding strong conclusions.[10] Thus, the association between schizophrenia and prevalence of infections, as well as with severity of illness, remains to be examined.

In this study, we aimed to bridge the gap in the epidemiological literature related to the prevalence of COVID-19 morbidity and mortality among individuals with schizophrenia. Specifically, we aimed to address the following empirical research questions: (1) Are patients with schizophrenia more prone to COVID-19 infections? (2) Do patients with schizophrenia have a more severe course of COVID-19 illness, as manifested by higher rates of hospitalization and mortality? To address these research questions, we updated a validated database of schizophrenia patients and their age-and-sex matched controls (total n = 51 078) with recent data pertaining to the current epidemic. COVID-19 data included number of COVID-19 tests, COVID-19 hospitalizations, and COVID-19 mortality rates. Sociodemographic and medical risk factors were entered as covariates and included age, sex, marital status, sector, socioeconomic status, obesity, smoking, diabetes, hyperlipidemia, chronic obstructive pulmonary disease (COPD), and ischemic heart disease (IHD). Based on the reviewed literature, we hypothesized that schizophrenia patients would show higher positive results, as well as higher rates of hospitalization and mortality.

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