# The impact of less restrictive quarantine for exposed COVID-19 patients in inpatient psychiatric settings: a cohort analysis

## TL;DR

A study found that relaxing quarantine rules for COVID-19 exposed patients in psychiatric hospitals led to higher transmission rates.

## Contribution

This study quantifies the increased risk of SARS-CoV-2 transmission when less restrictive quarantine policies are applied in psychiatric inpatient settings.

## Key findings

- Relaxing quarantine policies increased SARS-CoV-2 conversion rates per admission and per patient-day.
- Vaccination rates among patients remained low during the study period.
- Transmission risk per exposure did not significantly change between the two periods.

## Abstract

To quantify the impact of a changing cohort strategy on COVID-19 transmission in an acute inpatient behavioral health facility.

Cohort study.

Behavioral health inpatients exposed to COVID-19.

This cohort project compared COVID-19 conversion rates during two periods. In the first period (July 2020–April 2022), exposed patients (regardless of vaccination status) were cohorted separately from unexposed individuals. In the second period (May 2022–September 2022), exposed vaccinated patients remained with unexposed patients. COVID-19 conversion was identified through post-exposure asymptomatic testing or test-confirmed symptom development, with rates quantified per all admissions, per 10,000 patient days at risk, and per patient-specific exposure.

The 27-month project included 11,761 admissions and 164,762 patient days of care. The proportion of patients up-to-date on COVID-19 vaccination at admission and discharge ranged from 11%–19%. The second period showed an increased risk of SARS-CoV-2 conversion per admission (1.87% vs 0.36%, P < 0.001) and per 1,000 patient-days at risk (1.44 vs 0.27 conversions per 1,000 patient days, P < 0.001), but not per exposure (3.44% vs 3.13%, P = 0.68).

Reducing the population of patients cohorted after a SARS-COV-2 exposure is associated with increased risk of SARS-COV-2 transmission in inpatient psychiatric settings.