Association Between Screening for Suspected COVID-19 Cases and Outcomes of Patients Revisiting the Emergency Department

ABSTRACT

Objectives: Patients who revisit the emergency department (ED) shortly after discharge are a high-risk group for complications and death, and these revisits may have been seriously affected by the COVID-19 pandemic. Detecting suspected COVID-19 cases in EDs is resource intensive. We examined the associations of screening workload for suspected COVID-19 cases with in-hospital mortality and intensive care unit (ICU) admission during short-term ED revisits.

Study Design: We conducted a retrospective cohort study using electronic health record data from a tertiary teaching hospital.

Methods: We analyzed all 72-hour ED-revisiting patients at the Taipei Veterans General Hospital ED in Taiwan between January 27, 2020, and December 31, 2020. Screening workload for suspected COVID-19 cases was measured with the daily number of suspected COVID-19 cases. Multivariate logistic regression models were used after adjustment for patient characteristics to examine the associations of screening workload with in-hospital mortality and ICU admission.

Results: A total of 1107 patients were included. The mean number of daily suspected COVID-19 cases was 9.4. The rates of subsequent in-hospital mortality and ICU admission were 2.1% and 3.2%, respectively. The volume of daily suspected COVID-19 cases was significantly associated with increased subsequent in-hospital mortality (adjusted OR, 1.073 with each additional daily suspected COVID-19 case; P = .005).

Conclusions: This is the first study to our knowledge to identify that screening for suspected COVID-19 cases in EDs can adversely affect patient outcomes during short ED revisits. Identifying this association could enable ED providers and policy makers to optimize emergency service delivery during an epidemic and help patients.

Am J Manag Care. 2025;31(1):In Press

Takeaway Points

• The COVID-19 pandemic strained emergency departments (EDs), affecting quality of care and outcomes. Thus, increased workload due to COVID-19 screening may correlate with poorer outcomes for patients in the ED.
• Revisits to the ED shortly after discharge may indicate high risks for complications and deaths, which are influenced by various factors, including pandemic-related pressures.
• Monitoring ED revisits is crucial for adapting emergency care during epidemics, and we should consider other effective diversion strategies to ensure the safety of ED patients, whether they have COVID-19 or not.

Individuals who revisit the emergency department (ED) shortly after discharge are regarded as a high-risk group, and this metric is generally accepted as an ED quality measurement.^1,2 ED revisits—which can be caused by poor-quality care; possible diagnostic, cognitive, or logistical errors; adverse events; mismanagement of patient disposition; or other unexpected reasons—tend to raise health care utilization issues, such as quality of ED care and access to specialty care. The overall probability of ED revisit is approximately 3% in most studies, and patients who revisit are considered to have a high risk of complications and death.³ Conceivably, such a fragile and high-risk group would be more seriously affected when EDs experience overload and severe working conditions, such as during the COVID-19 pandemic.

The COVID-19 pandemic inevitably introduced additional complexities in delivering high-quality ED services, primarily because a significant portion of medical resources was redirected toward epidemic prevention efforts. EDs worldwide, serving as the front lines of health care systems, grappled with a substantial burden because of overwhelming workloads, including epidemic control, prevention of cross infection, notification of infectious diseases, mitigation of contagion risk, and screening for suspected COVID-19. Patients with COVID-19 symptoms should be isolated from other patients and immediately tested. Testing must be conducted for patients and health care providers who have been exposed to the virus and are experiencing mild to moderate symptoms, whether with fever or not. This is necessary to maintain safe provision of care to other patients in the ED. Identifying potential new SARS-CoV-2 infections within EDs places a significant demand on both personnel and resources.⁴ Under such strained circumstances, high-risk populations, such as ED-revisiting patients, would be highly vulnerable.

Emergency workers bore a significant responsibility to promptly triage and treat patients suspected or confirmed to have infections during the COVID-19 pandemic.⁵ However, patients with urgent emergencies, such as acute stroke, acute myocardial infarction, major trauma, or out-of-hospital cardiac arrest, must still rely on EDs for timely resuscitation. Unfortunately, patients with such emergencies experienced poorer outcomes during the pandemic.^6-9 Work overload of emergency systems, even with a decrease in total ED volume, and alterations in clinical protocols may be possible causes of this during the pandemic.⁴ However, few studies have examined the relationship between workload and care outcomes in the ED.

Since the outbreak of COVID-19, providing standard patient care in the ED has become challenging, causing extended wait times for triage screening when a suspected COVID-19 case is present. Determining whether a potential link exists between the volume of suspected cases and the quality of care in the ED necessitates additional investigations for confirmation. Therefore, we conducted this study to investigate the association between the workload of screening for suspected COVID-19 cases and the outcomes of patients revisiting the ED. Understanding the potential impact of COVID-19 screening executed in EDs on ED-revisiting patients during an epidemic will help care providers and policy makers properly adjust epidemic prevention strategies to accomplish both epidemic control and maintenance of emergency medical services.

METHODS

Study Design and Setting

We conducted a retrospective cohort study using electronic health record data from Taipei Veterans General Hospital (TVGH), a 2900-bed tertiary care teaching hospital in Taipei, Taiwan. For early triage, isolation, and detection of patients with COVID-19 after the outbreak of the epidemic, a fever screening station (FSS) was immediately established outside the TVGH ED on January 27, 2020.¹⁰ The FSS assessed all individuals with fever, high potential for COVID-19 infection, or pertinent travel history, occupation, contact history, or cluster information. Individuals at significant risk of COVID-19 were not permitted to enter the ED. Infrared thermal imaging cameras and forehead thermometers were used to detect elevated body temperatures.

Study Population

Our study retrospectively enrolled patients with short ED revisits to the TVGH ED between January 27, 2020, and December 31, 2020. We excluded patients with incomplete data, those who left the ED without being seen by a provider, those who left against medical advice, and irrelevant revisits. We also excluded frequent ED users with more than 5 ED visits in the past year since their index ED visit¹¹; these patients represent a distinct group who appears to experience higher mortality and hospital admissions,^12,13 so their inclusion could have biased our outcomes of interest.

A short ED revisit was defined as the first unplanned ED visit less than 72 hours from an index treat-and-release ED visit discharge.^14-18 This study was approved by the TVGH Ethics Committee/Institutional Review Board (protocol No. 2021-06-027CC), which waived the requirement for informed patient consent because of the retrospective nature of the analysis.

Measures of Variables

Independent variables. Daily ED visits and suspected COVID-19 cases were documented during screening. To determine the workload volume from the FSS, each revisiting patient was linked to the number of patients with suspected COVID-19 and to the total ED encounters on their own index day.

Dependent variables. The primary outcome was in-hospital mortality after a short ED revisit. Secondary outcomes were hospital admission and intensive care unit (ICU) admission.

Covariates. Covariates included routine patient demographic data, triage level of the index visit and revisit, chief complaints, underlying comorbidities, Charlson Comorbidity Index (CCI) score, duration of ED stay during the index visit and revisit, and the interval between the 2 ED visits. The CCI score was used to calculate and estimate the severity of comorbid disease.¹⁹ The triage level was expressed on a scale of 1 to 5 (ie, immediate, emergency, urgent, semiurgent, and nonurgent) and based on the urgency and seriousness of the patient’s presentation. The change in triage score was computed as the difference in score between the return and index visits, and we documented escalation in triage score, with a negative value suggesting a deterioration of health status.

Two investigators (Y.H.M. and M.C.L.) collected the data using structured data collection forms. Data reliability was assessed at the beginning of the analysis and at random by 2 independent reviewers (C.T.C. and C.K.H.). Disagreements or uncertainties among the reviewers were resolved by introducing additional external experts (ie, assessment by a senior researcher or emergency physician) and concluded by a joint consensus.

Statistical Analysis

Normally distributed continuous variables are presented as mean and SD, and non–normally distributed continuous variables are presented as median and IQR. Continuous variables are summarized using medians with IQRs or means with SDs. Categorical data are expressed as frequencies and proportions. The Pearson χ² test with Yates correction or the Fisher exact test was used to compare discrete variables; the Student t test or the Mann-Whitney rank sum test was used to analyze continuous variables as appropriate. Multivariate logistic regression was used to determine independent predictors of primary and secondary outcomes. ORs and 95% CIs were determined. Predictors for logistic regression were selected based on significance in the univariate analysis (P < .05) and included daily suspected COVID-19 cases and ED encounters. Differences were considered to have reached a level of significance with a 2-tailed P value less than .05. All analyses were performed using IBM SPSS Statistics 20 software (IBM Corporation).

RESULTS

A total of 1107 patients were enrolled in our study (Figure); they had a mean (SD) age of 52.6 (25.9) years, and 48.5% were male (Table 1). No enrolled patients were diagnosed with COVID-19 during the initial visit or after returning to the ED. The mean (SD) index visit triage level was 3.03 (0.44) with a paired revisit triage level of 3.00 (0.54), and 12.5% of the patients experienced an escalation of triage level when revisiting. The most common chief complaint of patients revisiting the ED was fever, followed by abdominal pain and truncal or limb pain. The mean (SD) CCI score of patients was 3.1 (3.4); hypertension (33.0%), malignancy (19.9%), and diabetes (14.2%) were the most prevalent comorbidities. The mean (SD) ED lengths of stay of index visits and revisits were 385 (553) and 615 (969) minutes, respectively, and the interval between the 2 ED visits was a mean (SD) of 39 (17) hours. The mean (SD) number of daily suspected COVID-19 cases for screening was 9.4 (10.7), and the mean (SD) number of daily ED encounters was 198 (27). Regarding the outcomes of study patients, 497 (44.9%) experienced subsequent admission and 35 (3.2%) required ICU admission after revisiting. Among all the revisiting patients, 2.1% experienced subsequent in-hospital mortality.

The clinical variables associated with subsequent outcomes after revisiting the hospital are summarized in Table 2. Regarding the ED workload, the daily number of suspected COVID-19 cases was borderline significantly higher during the index visits of revisiting patients with subsequent in-hospital mortality vs those who survived (13.5 vs 9.3 cases; P = .061). Patients who experienced in-hospital mortality were older than patients who survived (69.5 vs 52.3 years; P = .002), had a lower revisit triage level (2.3 vs 3.0; P < .001), and had a higher rate of triage level escalation (47.8% vs 11.7%; P < .001). None of the patients who died were admitted due to fever, but they were more likely to have complained of shortness of breath (30.4% vs 2.4%; P < .001). Patients who experienced in-hospital mortality had a greater mean CCI score (8.2 vs 3.0; P < .001) and were more likely to have had the underlying comorbidities of hypertension (69.6% vs 32.2%; P < .001), malignancy (73.9% vs 18.7%; P < .001), cerebrovascular disease (17.4% vs 6.3%; P = .032), heart failure (13.0% vs 4.3%; P = .047), chronic obstructive pulmonary disease (17.4% vs 2.4%; P < .001), mild liver disease (13.0% vs 3.8%; P = .024), and moderate to severe liver disease (13.0% vs 2.2%; P = .001), and a longer index ED length of stay (752 vs 377 minutes; P = .001).

In the multivariable logistic regression model, the number of daily suspected COVID-19 cases was not an independent predictor of hospital admission (adjusted OR [AOR], 0.994; P = .413) or ICU admission (AOR, 0.973; P = .314) (eAppendix Tables 1 and 2 [eAppendix available at ajmc.com]); however, this was a significant predictor of in-hospital mortality (AOR, 1.073 with each additional daily suspected COVID-19 case; 95% CI, 1.021-1.128; P = .005) among patients with 72-hour ED revisits (Table 3). Additionally, revisit triage level (AOR, 0.318; P = .048), shortness of breath (AOR, 11.30; P = .001), and underlying malignancies (AOR, 4.996; P = .046) were all significant prognostic factors for in-hospital mortality among patients revisiting the ED.

DISCUSSION

In this retrospective study, we assessed patients with 72-hour ED revisits during the COVID-19 pandemic and investigated the association between screening for suspected COVID-19 cases and the outcomes of these revisiting patients. The in-hospital mortality of patients who revisited the ED within 72 hours increased when workload strain was exacerbated due to suspected COVID-19 cases. Specifically, the outcomes of short ED revisits were significantly affected by hospital workload pressures around epidemic prevention. Notably, daily ED encounters were not independent predictors of poor prognosis for short ED revisits, mortality, or ICU admission. Although a significant decrease in ED volume has been observed worldwide,^20,21 this cannot guarantee that ED pressure will be relieved from crowding or that the quality of emergency services will be improved. The influx of suspected or confirmed COVID-19 cases was a hazard to all individuals in need of emergency services in the ED, even those without COVID-19.

ED revisits within a short period have been used as a metric to assess and monitor the performance of ED services.¹ Short ED revisits may represent diagnostic inaccuracy,² medical errors or failures,²² or suboptimal care. Amid the COVID-19 pandemic, increasing demands related to delivering contagion surveys and relevant care undoubtedly exacerbated an already overfatigued ED, which may have placed high-risk patients, such as ED-revisiting populations, in increased danger. The occurrence of a short ED revisit comprises diverse and complex elements, including patient perspective, individual variations, disease nature, and hospital characteristics.^23-26 The short ED revisit rate may not be a perfect measure,²⁷ yet it remains a widely adopted ED performance index in quality metric research. Several scholars, however, have claimed that ensuing outcomes, such as subsequent hospital admissions, ICU admissions, or in-hospital mortality, are more persuasive.^4,28-30 Therefore, we assessed the outcomes of ED-revisiting patients as a more objective indicator of emergency service quality.

The COVID-19 pandemic was one of the most devastating in history, highlighting the critical importance of swift responses and early detection from individual EDs to the global level to contain the rapid spread of the virus. ED demand is influenced by a combination of factors, including physical and social environments, as well as the epidemiology of the injuries and illnesses being treated. The unprecedented COVID-19 pandemic severely affected emergency care in most countries. Consequently, many resources typically dedicated to emergency care were disproportionately redirected toward patients with COVID-19, either suspected or confirmed. Although a decrease in ED volume and modification in the use of medical services were observed worldwide after the outbreak,^31-35 surges in febrile patients will be inevitable if infection numbers grow again and clinical challenges ensue. Screening for suspected COVID-19 is an essential measure and an important public health issue; however, the majority of screened cases may not necessarily be critically ill patients.¹⁰

EDs are the front lines for dealing with time-sensitive emergencies and delivering lifesaving management, so maintaining a functional ED with durable capacity and an emergency medical system with prompt response for time-sensitive emergencies during a pandemic should take priority over serving mainly as a screening station. With the increased number of febrile patients following the outbreak of an epidemic, it is necessary to integrate other measures, such as initiating community screening stations, to avoid jeopardizing regular emergency service capacity. Meeting optimal or acceptable COVID-19 screening thresholds can help reduce poor outcomes for ED-revisiting patients. The COVID-19 pandemic warrants a reevaluation of numerous aspects of previous strategies for epidemic control. To appropriately preserve emergency medical capacity, the regional integration of emergency care resources from nearby medical institutions should also be considered for primary diverting or secondary transfer of suspected COVID-19 cases.

An effectively structured operational emergency care network is crucial for mitigating the overwhelming effects of an epidemic and ensuring the continuation of critical treatment. Although EDs worldwide were largely tasked with screening for COVID-19 cases during the pandemic, the appropriateness of this arrangement should be reexamined. Most ED workers were not originally trained to perform epidemic prevention–related tasks. After the outbreak of COVID-19, the sudden placement of this responsibility on ED workers not only caused substantial psychological pressure but also hindered routine ED duties, thus endangering patients in the ED.³⁶

Limitations

This study has some limitations. First, the inherent constraints of medical chart reviews exist when precisely assessing the quality of care. Second, because our data were collected exclusively from one specific facility, the findings may have limited generalizability and may not be directly transferable to hospitals in diverse regions of varying sizes. In addition, ED revisits of patients may have been underestimated based on our using a single medical center. We also had minimal information about events that occurred during ED visits, such as consultations, investigations, and therapies. Finally, quality of care is undeniably a multifaceted concept, so the outcomes of ED revisits would only encompass certain aspects of the quality of services provided in EDs.

CONCLUSIONS

Our study found that the volume of daily suspected COVID-19 cases was demonstrated to be an independent predictor for in-hospital mortality of patients with 72-hour ED revisits. Given the emergent nature of COVID-19 and the complexity of the true disease burden, it is crucial to emphasize the importance of effective diversion strategies and public health interventions to curb the spread of COVID-19 and associated spillover effects. To improve our ability to combat the next unknown epidemics, sustained investment in public health infrastructure and preparedness in EDs is required to protect lives. More specifically, we propose considering the following strategies to close the gap in ED care: developing streamlined triage procedures to prioritize patients efficiently, establishing risk stratification protocols to identify patients at higher risk of adverse outcomes, improving communication channels between institutions with efficient transferring systems to prevent EDs from collapsing due to overloading, and fostering a multidisciplinary approach to patient care via collaboration between emergency physicians, infectious disease specialists, critical care specialists, and other relevant health care professionals.

We believe this is the first study to identify the impact of screening for suspected COVID-19 in the ED, which affected the outcomes of short ED revisits during the epidemic. Identifying such an association could help patients and enable ED providers and policy makers to modify and optimize the delivery of emergency services during large-scale epidemics such as COVID-19. As an epidemic continues to fluctuate, the outcomes of short ED revisits should continue to be monitored, and strategies should be developed to maintain the quality of emergency care.

Author Affiliations: Emergency Department (CTC, YHM, CKH) and Nursing Department (MCL), Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Health Policy and Management (CTC, YCT) and Master of Public Health Program (YCT), College of Public Health, National Taiwan University, Taipei, Taiwan; School of Medicine, National Yang Ming Chiao Tung University (CTC, YHM, CKH), Taipei, Taiwan.

Source of Funding: This study was supported by the Population Health and Welfare Research Center from the Featured Areas Research Center Program within the framework of the Higher Education SPROUT Project by the Ministry of Education in Taiwan (grant No. NTU-113L900401).

Author Disclosures: The authors report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (CTC, YHM, YCT); acquisition of data (CTC, YHM, MCL); analysis and interpretation of data (CTC, YHM, MCL, YCT); drafting of the manuscript (CTC, MCL, YCT); critical revision of the manuscript for important intellectual content (CTC, CKH, YCT); statistical analysis (CTC, YCT); administrative, technical, or logistic support (CTC, CKH, YCT); and supervision (CKH, YCT).

Address Correspondence to: Yu-Chi Tung, PhD, Institute of Health Policy and Management and Master of Public Health Program, College of Public Health, National Taiwan University, No. 17 Xu-Zhou Road, Taipei 100, Taiwan. Email: yuchitung@ntu.edu.tw.

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