Evaluation of outpatient COVID-19 patients’ readmissions to the emergency department

Abstract

AimIn this study, we aimed to analyze variables regarding emergency department (ED) readmissions of COVID-19 patients who were treated as outpatients.MethodsThis is a retrospective observational study. COVID-19 PCR- positive patients treated on an outpatient basis who were admitted to the ED during the treatment period or in the first week of the post-treatment period were analyzed. Demographic findings, complaints, comorbidities, vital parameters, laboratory, radiologic findings, and outcomes were analyzed by using the data registration system of the hospital.ResultsA total of 505 patients were evaluated, with the median age of 57 and 45% were female. Fever (%73), cough and dyspnea (%56 each) were the most common complaints. Two-thirds of the patients had two or more comorbidities. There was significant progress in radiologic and laboratory findings. Forty-one percent were hospitalized in inpatient clinics, and 15% in intensive care units on readmission to the ED. Fifty-one patients died.ConclusionIn COVID-19 patients with mild symptoms and favorable laboratory and radiological findings on index admission, followed up as outpatients, the disease might progress rapidly and readmission to ED, need for hospitalization and even death may occur. Thus, close follow-up of patients and being alert to new symptoms and signs that may develop is necessary.

Keywords

Introduction

The COVID-19 pandemic has placed a severe burden on health care systems over the past two years, especially the emergency departments (ED) of countries. Emergency admissions of outpatients with COVID constitute a significant part of this burden. The reason for the clinical deterioration of those patients might vary. The development or progression of ongoing pneumonia, cytokine storm, and systemic inflammatory response and complications are common reasons for hospital readmissions.^1-3
To reduce the number of readmissions, which significantly increase the burden on healthcare providers, the determination of risk factors is very important.⁴ Therefore, in this study, we aimed to analyze variables regarding readmissions of COVID-19 patients who were treated as outpatients to the emergency department.

Materials and Methods

This is a retrospective observational study conducted in a training and research hospital after approval of the local ethics committee of Keçiören Training and Research Hospital (Date: 2021-04-13, No: 2012-KAEK-15/2279). Patients, who already tested positive for COVID-19 by PCR and were treated on an outpatient basis and admitted to the ED during treatment period or in the first week of the post-treatment period were analyzed.
Demographic findings, complaints at admission, comorbidities, vital parameters, laboratory findings, complications if present, ventilatory support at ED, and outcomes were analyzed by using the data registration system of the hospital and recorded on study forms. Patients with missing data and patients younger than 18 years of age were excluded.
The first admission of patients to the hospital at which the COVID-19 was diagnosed was defined as an index admission. ED admission of the patients during ongoing treatment or post-treatment period, which is defined above, was the second admission. Radiological findings of the patients were evaluated according to local guidelines (available at: https://covid19.saglik.gov.tr/TR-66301/covid-19-rehberi.html). According to the distribution of lesions, radiographic findings were scored as 0: normal, 1:mild, 2:moderate, and 3: severe.Ethical ApprovalThis study was approved by the Ethics Committee of Keçiören Training and Research Hospital (Date: 13.04.2021, Decision No: 2012-KAEK-15/2279)Statistical Analysiswere performed by SPSS22.0 (Chicago, IL, USA). After analyzing the distribution of normality, data were presented as mean±SD or median and interquartile range (IQR)25-75. Categorical variables were presented as percentages. The Wilcoxon test was used for analyzes. A p-value <0.05 was considered statistically significant.

Results

The number of patients admitted to the ED during their outpatient COVID treatment period or in the first week of the post-treatment period was 505. Forty-five percent of them were female, and the median age was 57 years. Only 25 of those patients were hospitalized during their index visit (hospital visit when the diagnosis was made). The time period between PCR positivity and readmission to ED was 7 (IQR 5-10) days. The most common symptoms during readmission were fever, cough, and dyspnea. One-third of the patients had two or more comorbid conditions. Nearly all patients were taking favipiravir, and one-fourth were using enoxaparin sodium. The general characteristics of patients are summarized in Table 1.
Laboratory parameters of the patients showed that lactate dehydrogenase, ferritin, D-dimer, troponin, fibrinogen, C reactive protein and lactate levels were significantly higher at the second admission of the patients compared to their index admission. There was also a significant decrease in their lymphocyte counts (Table 2).
Radiological findings of the patients were analyzed. At the index admission, the number of radiologic imaging was less, and most of the images were regarded as normal or mild pneumonia. At the second admission, most of the patients were evaluated with thorax tomography (CT), and lesions showed progression with a quarter of thorax CT’s having severe lesions (Table 2).
All values were given as median (Interquartile range 25 – 75). Wilcoxon test was used, p-value <0,05 was considered statistically significant.
Nearly all patients needed oxygen support during their second visit. Seven percent of the patient were intubated. Forty-three percent of the patients were discharged at their ED admission; 41% admitted to inpatient clinics and 15% admitted to the intensive care unit. In total 51 patients died (Table 3).

Discussion

This study demonstrated that COVID-19 patients who had mild symptoms at index admission with favorable laboratory and radiologic findings, might progress during their outpatient follow-up, and readmissions to ED occur mostly between the 5th-10th days of PCR positivity.
In the past two years, the COVID-19 pandemic has taken up much of the academic agenda. With the rapidly increasing number of cases that exceed the health care capacity, outpatient follow-up of mild cases and discharge of inpatients as soon as possible were planned. Thus, since readmission of these patients would cause a severe health burden, many studies have been conducted to examine the rates and risk factors of readmission.^5,6
Studies demonstrated that among discharged patients, the rate of re-hospitalization was 5-15%.⁷ It is shown that the male gender is a risk factor for the readmission, similar to our results.⁷ Cough and dyspnea were found to be the most frequent reasons for return visits.⁸ Another important risk factor for readmissions is comorbid conditions. Nematshahi et al. demonstrated that diabetes and high creatine levels were the most important predictors of readmissions.⁹ On the other hand, there were also studies showing especially cardiac and pulmonary conditions as important risk factors for revisits.^10,11 In our study group, comorbid conditions were present, but creatine levels were normal. Also, those studies included patients who were hospitalized at their index visits. There are limited studies about the readmission characteristics of mild/ outpatient COVID-19 patients.
Among return visits, when the ED representations are evaluated, it was found that, revisit rates might be as high as 20% or more.¹² Haag et al. showed in their study which was conducted with outpatient COVID-19 patients, similar to ours, the median ED readmission occurred on day 9, and nearly 45% of them need hospitalization on their second visit.¹³ According to a study from Argentine, previous smoking, fever, and oxygen saturation were determined as risk factors for ED readmission of mild COVID patients who were discharged at index hospital visits and followed at home.¹⁴ Supporting this study, our study showed that the most common reasons for ED readmissions were fever, cough, and dyspnea. Our study showed that laboratory parameters such as CRP, WBC, ferritin, troponin, D dimer, lactate, fibrinogen were significantly higher at second admission. Those markers were evaluated at COVID-19, those changes were predictable and were similar to the literature.⁸ In another study Somani et al. claimed that lower in-hospital anticoagulation rates were associated with ED readmissions.¹⁵ In our study, only onefourth of the patients were treated with anticoagulants but our data are not appropriate for detecting an association between anticoagulation and readmissions.

Limitations

Our study has some important limitations. First, this was a single-centered study, and we could not evaluate patients who might revisit different health centers. Since we did not have a control group, we could not analyze the difference between readmitted and not-readmitted patients. Due to the retrospective nature of the study and the use of only the data registration system, we could not reach information such as smoking habits, which might be a risk factor for readmission.

Conclusion

In COVID19 patients with mild symptoms and favorable laboratory and radiological findings during index hospital admission, followed up as outpatients, the disease may progress rapidly and readmission to the ED, the need for hospitalization and even death may occur. Thus, close follow-up of patients and being alert to new symptoms and signs that may develop, is necessary.

Declarations

References

1. Wang D, Hu B, Hu C, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA. 2020;323(11):1061-1069. doi:10.1001/jama.2020.1585
   Article · PubMed · Google Scholar
2. Mangalmurti N, Hunter C. Cytokine storms: understanding COVID-19. Immunity. 2020;53(1):19-25. doi:10.1016/j.immuni.2020.06.017
   Article · PubMed · Google Scholar
3. Atak Yücel A, Bayrakal V, Baskın H. Sitokin fırtınası ve COVID-19 (Cytokine storm and COVID-19). In: İmmünoloji ve COVID-19. 1st ed. Türkiye Klinikleri; 2020:15-21.
   PubMed · Google Scholar
4. Sulaiman SS, Felix R, Valentin F, et al. Characterization of patients who return to hospital following discharge from hospitalization for COVID-19. J Gen Intern Med. 2020;35(10):2838-2844.
   PubMed · Google Scholar
5. Sotoodeh Ghorbani S, Taherpour N, Bayat S, et al. Epidemiologic characteristics of cases with reinfection, recurrence, and hospital readmission due to COVID-19: a systematic review and meta-analysis. J Med Virol. 2022;94(1):44-53. doi:10.1002/jmv.27281
   Article · PubMed · Google Scholar
6. Verna EC, Landis C, Brown RS, et al. Factors associated with readmission in the United States following hospitalization with coronavirus disease 2019. Clin Infect Dis. 2022;74(10):1713-1721. doi:10.1093/cid/ciab464
   Article · PubMed · Google Scholar
7. Akbari A, Fathabadi A, Razmi M, et al. Characteristics, risk factors, and outcomes associated with readmission in COVID-19 patients: a systematic review and meta-analysis. Am J Emerg Med. 2022;52:166-173. doi:10.1016/j.ajem.2021.12.012
   Article · PubMed · Google Scholar
8. Alanli R, Kucukay MB, Yalcin KS. Readmission rates of patients with COVID-19 after hospital discharge. Rev Assoc Med Bras (1992). 2021;67(11):1610-1615. doi:10.1590/1806-9282.20210675
   Article · PubMed · Google Scholar
9. Nematshahi M, Soroosh D, Neamatshahi M, Attarian F, Rahimi F. Factors predicting readmission in patients with COVID-19. BMC Res Notes. 2021;14(1):374. doi:10.1186/s13104-021-05782-7
   Article · PubMed · Google Scholar
10. Finn A, Tanzer JR, Jindal A, Selvaraj V, Collins B, Dapaah-Afriyie K. Readmission risk after COVID-19 hospitalization: a moderation analysis by vital signs. South Med J. 2022;115(11):842-848. doi:10.14423/smj.0000000000001472
    Article · PubMed · Google Scholar
11. Kirkegaard C, Falcó-Roget A, Sánchez-Montalvá A, et al. Incidence and risk factors for early readmission after hospitalization for SARS-CoV-2 infection: results from a retrospective cohort study. Infection. 2022;50(2):371-380. doi:10.1007/s15010-021-01662-1
    Article · PubMed · Google Scholar
12. Peiris S, Nates JL, Toledo J, et al. Hospital readmissions and emergency department re-presentation of COVID-19 patients: a systematic review. Rev Panam Salud Publica. 2022;46. doi:10.26633/rpsp.2022.142
    Article · PubMed · Google Scholar
13. Haag A, Dhake SS, Folk J, et al. Emergency department bounceback characteristics for patients diagnosed with COVID-19. Am J Emerg Med. 2021;47:239-243. doi:10.1016/j.ajem.2021.04.050
    Article · PubMed · Google Scholar
14. Pedretti A, Marquez Fosser S, Pasquinelli R, et al. Risk of readmission to the emergency department in mild COVID-19 outpatients with telehealth follow-up. Rev Fac Cien Med Univ Nac Cordoba. 2021;78(3):249-256. doi:10.31053/1853.0605.v78.n3.32414
    Article · PubMed · Google Scholar
15. Somani SS, Richter F, Fuster V, et al. Characterization of patients who return to hospital following discharge from hospitalization for COVID-19. J Gen Intern Med. 2020;35(10):2838-2844. doi:10.1007/s11606-020-06120-6
    Article · PubMed · Google Scholar

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