Disparities in Intensive Care Unit Admission and Mortality Among Patients With Schizophrenia and COVID-19

A National Cohort Study

Guillaume Fond; Vanessa Pauly; Marc Leone; Pierre-Michel Llorca; Veronica Orleans; Anderson Loundou; Christophe Lancon; Pascal Auquier; Karine Baumstarck; Laurent Boyer


Schizophr Bull. 2021;47(3):624-634. 

In This Article


To our knowledge, we report the largest series of SCZ patients with COVID-19 to date, including 823 SCZ patients hospitalized for COVID-19 infection with a nationwide geographical distribution. In this large population-based cohort study, we reported the existence of disparities in health and health care between hospitalized COVID-19 SCZ patients and patients without a diagnosis of severe mental illness. These disparities differed according to the age and clinical profile of SCZ patients.

SCZ patients under 55 years of age had 14% more ICU admissions than patients without a diagnosis of severe mental illness, suggesting more severe COVID-19 infection in SCZ patients.

SCZ patients under 55 years were mostly male, were more frequently smokers, were more overweight and obese, and had more multiple somatic comorbidities, including chronic obstructive pulmonary disease, than patients without a diagnosis of severe mental illness. Although the results are contradictory, smoking seems more likely to be associated with the negative progression and adverse outcomes of COVID-19.[9] Obesity in patients younger than 60 years has been reported as a risk factor for COVID-19 hospital admission and worse outcomes.[10] Chronic obstructive pulmonary disease has been also reported to worsen the progression and prognosis of COVID-19.[11] A delay in access to hospital care may be evoked to explain the severity of SCZ patients although we do not have any prehospital data. The existence of barriers in access to somatic care for SCZ patients has been described in previous studies.[2,10,12,13] Altogether, these findings suggest that young SCZ patients with the risk factors listed above should be targeted as a high-risk population for early intervention.[14,15]

These discrepancies in severity are apparently compensated by the important increase in ICU admissions that prevented increased mortality in SCZ patients. However, depression, anxiety, post-traumatic stress disorder, and cognitive dysfunction are increasingly recognized among patients who survive an ICU admission and these consequences have a significant impact on the patient's long-term quality of life.[16] Rehabilitation following critical illness has shown its efficacy to improve both physical and nonphysical recovery,[17] and SCZ patients should benefit from these programs.

SCZ patients between 65 and 80 years had a higher risk of death (+7.89%), and SCZ patients between 65 and 80 years and over 80 years old had less ICU admissions than patients without a diagnosis of severe mental illness (−15.44% and −5.93%, respectively).

SCZ patients between 65 and 80 years were mostly female, had more dementia, and had more cerebrovascular disease than patients without a diagnosis of severe mental illness. Previous studies have confirmed the relationship between SCZ and dementia risk, especially in women.[18,19] The diagnosis of dementia has been reported as an important risk factor for mortality in COVID-19 patients.[20,21] Dementia has also been associated with increased aggressive behavior in institutionalized patients who may affect the care of these patients at the hospital.[22] In addition, a new environment can lead to increased stress and behavioral problems.[23] Delirium caused by hypoxia could complicate the presentation of dementia.[24] Dementia as a preexisting condition may in part explain the lower ICU admissions in SCZ patients. All these elements demonstrate the importance of reinforcement of inpatient support for SCZ patients with dementia. To date, psychogeriatric teams remain insufficiently developed while demand in the aging population is growing.

SCZ patients between 65 and 80 years were more frequently referred from hospitals or institutions than patients without a diagnosis of severe mental illness, which can explain the poor health outcomes in SCZ patients. A French study reported that most psychiatric inpatients with a COVID-19 diagnosis were kept in dedicated psychiatric departments and not in general hospitals.[25] The division between physical and psychiatric medicine results in confusion about which sector of the health service (ie, primary, mental health, or acute care levels) should take responsibility for the management of patients with complex health needs.[10] We lack national data on the rate of elderly SCZ patients who are institutionalized, yet we can reasonably hypothesize that institutionalization is a risk factor for COVID-19 severe infection in elderly patients with SCZ. Our results support a strategy of systematic detection in institutionalized SCZ patients and early intervention in this population. This has already been done in a homeless shelter in Boston where 36% of the residents tested positive.[26]

The lower ICU admission rate in SCZ patients than in patients without a diagnosis of severe mental illness is a perfect illustration of the debate between utility- and equity-based arguments.[27] SCZ patients had one of the poorest prognosis indicators justifying ICU triage. However, this triage based solely on prognosis exacerbates existing health inequities, leaving disadvantaged patients worse off. Factors consistently found in the literature to be associated with a decision to admit or refuse a patient to the ICU are age, severity of illness and functional status at baseline, initial ward or team the patient was referred from, bed availability, and do-not-resuscitate order status/patient preference.[28] Although some factors are not modifiable (eg, age, functional status), others can be improved so as not to penalize SCZ patient ICU admission. The first one is to guarantee respect for the SCZ patient's wishes and values expressed directly by the patient via advance directives or reported by relatives. However, the overrepresentation of institutionalized SCZ patients and dementia patients suggests an autonomy loss and probably increased social isolation of these patients. The absence of relatives may have impacted medical decisions of do-not-resuscitate orders, and a previous study has suggested that patients with severe mental illness may be more prone to ask for do-not-resuscitate orders than those without psychiatric disorders.[29] Previous works have reported that implementation of advance directives is difficult in patients with psychiatric disorders.[30] Efforts should be undertaken to embed the use of advance directives in routine mental health care.[31] Second, the link between the hospital and/or the ICU team and the initial ward or team the patient was referred from needs to be strengthened. A psychiatrist on call must be reachable 24/7 to participate, if necessary, in a collegial decision to not admit the patient to the ICU. Third, as previously noted, the time of access to the hospital is a major issue and must be kept to a minimum as a condition to prevent patients from being admitted with very serious conditions. Finally, mental illness stigma may also play a specific role in the lower ICU admission rate of SCZ patients from nursing homes and psychiatric departments.[32] ICUs may be less prone to admit a patient referred by a psychiatric department due to potential behavioral/aggressive disturbances of SCZ patients and the inability to monitor them properly. Some ICU staff report being unprepared to care for patients with severe mental illness.[33] ICU staff should be specifically trained for the care of patients with severe mental illness.

Geographical areas of hospitalization did not influence the relationship between SCZ and mortality or ICU admission. We could have expected that access to care and health outcomes would be influenced in SCZ patients according to hospital overcrowding. However, our data may have been insufficiently accurate, and further studies will need to work with more accurate indicators such as bed occupancy rates at the hospital or ICU level.

Limits and Perspectives

The worldwide absolute mortality data suggest that COVID-19 infection may have different impacts across countries due to multiple factors (climate, facility organization, COVID-19 public management strategies). Thus, our results may not be extrapolated to other countries and should be replicated. Some data are known to be insufficiently coded in the medicoadministrative databases (eg, smoking, overweight, and obesity). We have no information on the contamination rate of SCZ patients[34] and the delay between the onset of infection and hospitalization. Treatment variables including psychotropics and repurposed or experimental anti-COVID-19 treatments were not available in the PMSI database. Some experimental anti-COVID-19 treatments may have been contraindicated in SCZ patients because of potential interactions with psychotropics.[35–38] No biological data are available in the PMSI database and SCZ has been shown to have different immune-inflammatory profiles[39] that may also partly explain the observed differences. Further studies should be carried out to explore the influence of these data on the prognosis of COVID-19 in SCZ patients. Finally, we do not know if our results are specific to COVID-19 or if they would be similar in other urgent pathologies. Future studies should explore this issue.