Background: Hospital clinicians may identify the presence of a patient’s comorbid conditions, overall severity of illness, and clinical status at discharge as risk factors for readmission after COVID-19 hospitalization. Objective data are lacking to support reliance on these factors for discharge decision-making. Objectives included examination of risk factors for readmission to hospital after COVID-19 hospitalization and the impact of vital sign abnormalities, within 24 hours of discharge, on 30-day readmission rates.
Methods: 2,557 COVID-19 related hospital admissions within a large multicenter health system (Rhode Island, USA) in 2,230 unique patients aged 18 years and older, occurring from April 1, 2020 to December 31, 2020 were analyzed. All patients identified tested positive for presence of SARS-CoV-2 coronavirus via nasopharyngeal swab or serum serology testing. Clinical variables including demographics, comorbid conditions, functional status, laboratory testing, hospital complications occurring during admission, pharmacologic treatments, and vital signs within 24 hours of discharge were identified. The primary outcome was readmission to hospital within 30 days of discharge after COVID-19 hospitalization.To identify the patient groups who may be more susceptible to intervention, moderation analysis was used. Possible moderation by patient vital signs at discharge was included for all variables.
Results: The sample had a wide distribution of ages, with about half of patients over 65 years old (48.81%), and about a third of the sample identified of Hispanic primary racial identity (31.87%) (Table 1). Clinical factors associated with readmissions included existing cardiovascular conditions (risk ratio = 0.84, p = 0.0279, odds ratio = 2.32) and pulmonary disease (risk ratio = 1.18, p = 0.0000, odds ratio = 3.25). The absence of abnormal vital signs within 24 hours of discharge was associated with decreased 30-day readmission rates (risk ratio = -0.35, p = 0.0191, odds ratio = 0.70). In moderation analysis, the presence of normal vital signs within 24 hours of discharge was associated with decreased readmission risk in patients who had primary risk factors for readmission including pulmonary disease (risk ratio = -0.22, p = 0.0424, odds ratio = 0.80), psychiatric disorders and substance use (risk ratio = -0.35, p = 0.0191, odds ratio = 0.70).
Conclusions: Normalization of vital signs at discharge was associated with a reduced risk of 30-day readmission after COVID-19 hospitalization. A moderation analysis revealed that patients with high-risk primary factors including behavioral health conditions, immunocompromised status, and pulmonary disease may be at greatest need for stable clinical condition, as represented by vital signs, before discharge. The clinician, who must balance the potential risks and benefits of discharge timing, may incorporate the normalization of vital signs within 24 hours of discharge as a criterion in decision-making during COVID-19 hospitalization.
