Clinical characteristics of patients with COVID-19 admitted to the COVID-19 Emergency Field Hospital of Bangkalan, Indonesia

Background: Following the surge of coronavirus disease 2019 (COVID-19) cases in the epicenter of East Java Province, this study aimed to determine the clinical characteristics of patients with COVID-19 at one of the emergency field hospitals in Indonesia. Methods: This was a single-centered, retrospective descriptive study of 763 patients admitted to the COVID-19 Emergency Field Hospital of Bangkalan from July 5 2021 to September 30 2021. The demographic data, clinical signs and symptoms, pre-existing comorbidities, therapy, and clinical outcomes of the patients were analyzed using SPSS. Results: The clinical characteristics of patients with COVID-19 at the emergency hospital were varied. A total of 763 patients were included. The most common age was between 40 and 49 years (31.1%), a slight majority were women (51.5%), and most had travelled abroad in the last 14 days (99.1%). Of the 763 patients, 70.9% had no comorbidities. Half of the patients were asymptomatic (49.4%), 46% were mild cases, 4.1% were moderate, and 0.5% severe. The most common symptoms were productive cough (15.7%) and headache (15.3%). Supportive and comorbidity therapy were given which showed excellent clinical outcomes. Conclusions: This study presents the description of the clinical characteristics of COVID-19 patients during high surge cases of COVID-19 that are mostly dominated by Indonesian migrant workers in a field hospital. majority of COVID-19 patients were asymptomatic and therapy without antibiotics or antivirals showed positive outcomes in COVID-19 patients.


Introduction
Coronavirus disease 2019 (COVID-19) is still a concern worldwide due to its rapid spread and enormous burden in all aspects. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1,2 . On March 12, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic 3 . The pandemic has already spread to several nations throughout the world, including Indonesia. Indonesia is a middle-income country with one of the lowest per capita health expenditures in the category 4 . Low-and middle-income countries (LMICs) are predicted to be affected most by the COVID-19 pandemic 5 . Physical distance and lockdown are nearly impossible due to the population's poor socioeconomic standing, which is characterized by congested living circumstances, limited access to daily basic requirements (e.g., food, clean water), and reliance on daily wages. Furthermore, caring for patients with COVID-19 is difficult since already limited health-care resources are soon exhausted.
The first COVID-19 case was reported in Indonesia in 2020, until early December 2021, the total number of cases in Indonesia was approximately 4,256,687 cases with a death amounting to 143,840 people 6 . Since March 2020, COVID-19 cases rapidly increased which made East Java, Indonesia's second most populous province, the epicenter of the pandemic from March to June 2020, where the highest number took place in this hospital area, Bangkalan. In response, the Indonesian government established the COVID-19 Emergency Field Hospital of Bangkalan in collaboration with the East Java Provincial Government, Regional Disaster Management Agency, and Regional Public Hospital Dr. Soetomo. This hospital was the epicenter of COVID-19 in Indonesia since the highest number of cases occurred in Bangkalan. From June 2021, the Emergency Field Hospital of Bangkalan conducted a study about the characteristics of patients with  in Indonesia since studies are still limited.
The COVID-19 Emergency Field Hospital of Bangkalanintended to treat a number of patients with COVID-19 with asymptomatic and mild-moderate symptoms to reduce community transmission. The study regarding the clinical characteristics of patients with COVID-19 in low-resource settings such as emergency field hospitals in Indonesia was limited, and particular studies of patients with COVID-19 in the Bangkalan area had not been established to date. This report will demonstrate the clinical characteristics of patients with COVID-19 in the Bangkalan area.
Clinical manifestations of COVID-19 are varied. Some patients are asymptomatic or have mild symptoms such as fever, cough, dyspnea, myalgia, and fatigue [7][8][9] . For severe cases, there are manifestations of acute respiratory distress syndrome and a combination of other complications that lead to death 10,11 . The characteristics of patients in this kind of emergency hospital in LMIC settings are still largely unknown, especially during the early phase of the pandemic. This study aimed to provide information regarding the clinical characteristics of patients with COVID-19 infection who have been hospitalized during high surge of COVID-19 ina field hospital of Indonesia.

Study design
This is a retrospective descriptive, non-experimental study of patients with COVID-19 admitted to the COVID-19 Emergency Field Hospital of Bangkalan, Madura, Indonesia from July 5, to September 30, 2021. This date range was selected from the opening date of service of this Hospital until the lowest COVID-19 cases rate in this hospital. All data were obtained from hospital electronic medical records, including demographic data, clinical signs and symptoms, therapy, and clinical outcomes of the patients. Only researchers of this study have access to these data to protect patient confidentiality.

Patient criteria
Patients admitted to the COVID-19 Emergency Field Hospital of Bangkalan were diagnosed with COVID-19 infection according to the diagnostic criteria from the WHO Clinical management of COVID-19 interim guidance (27 May 2020) 12 . All patients were tested positive using reverse-transcription polymerase chain reaction (RT-PCR) and quarantined in this hospital. The patients were then classified based on the severity of COVID-19. Data for all patients with COVID-19 in the COVID-19 Emergency Field Hospital of Bangkalan were included in this study, and there were no exclusion criteria.

Data characteristics
All demographic data were collected from the electronic medical records, including basic information (age, sex, travel history within 14 days). Medical history including pre-existing comorbidities such as hypertension, diabetes, obesity, pregnancy, and cerebrovascular accident was recorded based on a clinical assessment or patient self-reporting in anamnesis. Clinical characteristics data including dry cough, productive cough, fever, anosmia and/or ageusia, cold, headache, nausea, vomiting, dyspnea, diarrhea, myalgia, COVID-19 RT-PCR data, treatment, and outcome were obtained from the medical records. An organized checklist was used when extracting the data from medical records to ensure complete information that was needed for this study. Microsoft Excel Version 2108 was used as a data cleaning tool in this study. A backup of original data was created before any changes. Data validation

Amendments from Version 1
The newest version has some changes in the abstract conclusion which we modified to a new sentence with the same old meaning of version 1. entails applying constraints to ensure the consistency of data. Any missing or invalid data was identified and analyzed during the data cleaning process. The medical record number was used to avoid duplicate data. The data was standardized to ensure that the dataset was consistent and valid.

Data analysis
The variables analyzed into categorical variables were described as frequencies and percentages. Because patients in this study were not derived from random selection, all statistical data are deemed to be descriptive only. The data were analyzed using SPSS version 23.0 (IBM SPSS Statistics, RRID:SCR_016479) and represented in the form of tables and text.

Ethical approval
This study received ethical approval from the Joint Ethics Committee of Dr. Soetomo Teaching Hospital and Faculty of Medicine Universitas Airlangga (Surabaya, Indonesia) with approval number 272/EC/KEPK/FKUA/2021. Written informed consent was obtained from all patients when admitted to the hospital for the usage of research purposes. Table 1 presents the characteristics of 763 patients that fit the research criteria during the research period from July 5, 2021 to September 30, 2021 as found in the underlying data 13 . Of these, 393 (51.5%) patients were female and 40-49 years (31.1%) was the most common age range (237 patients), whilst 27.1% were 30-39 years, 21.2% were 18-29 years, 16.1% were 50-64 years, 2.5% were above 64 years, and 0-17 years (2.0%) was the least common age range. As many as 756 (99.1%) patients admitted to this hospital had travelled abroad in the last 14 days, and the rest were local residents. Overall, 172 (22.5%) patients were recorded to have had at least one pre-existing comorbidity, 46 (6.0%) patients had two comorbidities, and 4 (0.5%) patients had three comorbidities. The most common comorbidity was grade 1 obesity found in 94 (12.3%) patients, followed by hypertension (11.0%), grade 2 obesity (5.9%), pregnancy (4.7%), diabetes mellitus (1.7%), and others (various comorbidities such as cerebrovascular accident, tuberculosis, and cardiovascular diseases).

Therapy
The therapy given to all patients were isolation, supportive drugs (vitamin, antipyretic, antitussive, decongestant, antidiarrhea, antiemetic), encourage patient to getting enough rest and staying well hydrated, adequate nutrition, based on Table 3. Moreover, patients with comorbidity were given therapy according to their condition. Approximately 759 (99.5%) patients received multivitamins, 163 (21.3%) patients received antipyretic therapy (such as paracetamol), 155 (20.3%) patients received cough medicine (such as N-acetylcysteine, Ambroxol, Codeine), 59 (7.7%) patients received decongestant therapy (such as Allerfed, Demacolin), and a small number of patients received anti-diarrhea (1.0%) and antiemetic therapy (0.7%). Therapy according to each patient's comorbidity was also given in conjunction with symptomatic therapy; 112 (14.7%) patients received antihypertensive therapy, and 14 (2.8%) patients received antidiabetic therapy. Furthermore, 9 (1.3%) patients received supplemental oxygen therapy. No antiviral or corticosteroid therapy was given to any of the patients admitted to Bangkalan Emergency Field Hospital.

Clinical outcomes
Out of a total of 763 patients, 692 (90.7%) patients recovered from COVID-19 with 14 days isolation from the first PCR swab, and 43 (5.6%) patients continued self-quarantine. There were 28 (3.7%) patients referred to a more equipped health facility due to desaturation (SpO 2 <94%). No patient died during the research period. Based on the average length of stay (LOS), the largest number was in groups with less than 10 days LOS with as many as 753 (98.7%) patients, LOS for 10 days was 3 (0.4%) patients, and LOS for more than 10 days was 7 (0.9%) patients. LOS varies because based on the hospital policy, patients must be quarantined for at least ten days based on the first date of PCR test results. But some patients came with positive PCR results from external laboratories 2 or 3 days prior to their hospital admission. That explains LOS of less than ten days. Furthermore, the discharge criteria for asymptomatic patients were ten days quarantine from the first positive PCR date, and for symptomatic patients were at least ten days quarantine plus 3 additional symptom-free days. The clinical outcomes data are presented in Table 4.

Discussion
Between March and June 2020, Jakarta Special Capital Region Jakarta and East Java Province were the epicenters of COVID-19 cases in Indonesia with the highest number of  (Table 1). This finding was consistent with the previous study in Indonesia stating that the incidence correlates with adult people being engaged in many daily activities and actively working; therefore, it is easier for them to be infected while not strictly adhering to COVID-19 prevention protocols 16 . This may have allowed COVID-19 to spread more greatly contributing to the sudden outbreak in East Java. In this study, the prevalence of COVID-19 was slightly higher in women (51.5%), in concordance with the East Java population where the female population was slightly higher (50.1%) and in contrast to many previous studies in which more men were infected [15][16][17][18]  Among 763 patients included in this study, 377 (49.4%) patients were asymptomatic. Moreover, 120 (15.7%) patients complained of productive cough, followed by headache in 117 (15.3%) patients, cold (8.7%), dry cough (5.9%), fever (5.9%), and sore throat (4.7%). Less common symptoms were dyspnea, nausea, abdominal pain, myalgia, diarrhea, vomiting, anosmia, and/or ageusia. These findings support the earlier studies that fever and cough were the dominant symptoms and gastrointestinal symptoms were uncommon 18-22 . Anosmia and/or ageusia stated to be the single strongest predictor of COVID-19 infections (by 10.2-fold higher than those with COVID-19-like illness) were found at the least number in our study. For its reliability, this symptom was used as the empiric signal for symptom-based public health surveillance in areas with fewer facilities available; however, several hypothesized that anosmia and/or ageusia mechanisms still require future studies 23,24 .
Overall, 172 (22.5%) patients were recorded to have at least one pre-existing comorbidity, 46 (6.0%) patients have two comorbidities, and 4 (0.5%) patients have three comorbidities. The most common comorbidity was grade 1 obesity found in 94 (12.3%) patients, followed by hypertension (11.0%), grade 2 obesity (5.9%), pregnancy (4.7%), diabetes mellitus (1.7%), and others. Previous studies also mentioned risk factors contributing to more severe disease and poorer outcomes with COVID-19 infections such as age >60 years, obesity, hypertension, diabetes, cardiovascular diseases, cerebrovascular diseases, chronic kidney disease, and chronic obstructive pulmonary disease 25,26 . This study also collected data on patients' comorbidities, with obesity becoming the most common (12.3%). Evidence from a previous study involving 4,265 patients with COVID-19 in Jakarta stated that the risk of death across all ages was higher for patients with more than one comorbidity than for those without; the risk among patients <50 years was notably increased by six-fold 25 . In addition, pregnancy is widely considered as a comorbidity; the most common comorbidity in this study was obesity. It correlates with this study finding since a large number of patients present with fewer comorbidities, mostly asymptomatic, and therefore come with great clinical outcomes.
When this study was conducted, several drugs had been repurposed for COVID-19 treatment, yet no effective treatment against the virus had been proven 23 . Supportive therapy and monitoring remain the mainstay treatment of mild and asymptomatic COVID-19 infections. Suspected or confirmed mild COVID-19 should be isolated, given treatment such as antipyretics for fever and pain, adequate nutrition, appropriate rehydration, without antibiotic therapy or prophylaxis based on the latest WHO clinical management living guidance 27 .
The clinical outcomes of this study showed that 692 (90.1%) patients recovered, 43 (5.6%) patients self-quarantined, 28 (3.7%) patients referred to a more equipped health facility, and no patients died. No patient admitted to this hospital received antiviral, antibiotics, or corticosteroids. A study involving 500 patients observed disadvantages of the use of antiviral drugs for patients with COVID-19 with mild symptoms. The study concluded that antiviral treatment did not provide superior clinical outcomes to supportive care, since patients with mild COVID-19 who had received antiviral medication had significant LOS at the hospital compared with those without 28 . Effective COVID-19 drugs were not available at the moment during our research time. Approximately 1.3% of patients receive O 2 therapy during their stay in the hospital. This is differs with a study in Japan where 61.6% of patients did not receive respiratory support during hospitalization 29 . The clinical outcomes were excellent; 90.1% of patients recovered.
In the current study, there were 753 (98.7%) patients with an LOS of less than 10 days, 3 (0.4%) patients with an LOS of 10 days, and 7 (0.9%) patients with an LOS of more than 10 days. Although the clinical symptoms of patients are similar to the data reported from previous studies 17,18 , the mortality rates reported were significantly different (no deaths reported in this study) as most study subjects had either mild or asymptomatic COVID-19 infection, and those with moderate to severe infection were referred to a more equipped health facility.
This study had some limitations. First, recall bias was inevitable based on the nature of the retrospective study. Second, the data were collected from the electronic health record database. This precluded the level of detail possible with a manual medical record review. Third, the subjects either were asymptomatic or had mild symptoms and there was no comparison to patients who had been treated with antiviral therapy. Finally, this was a small study that only covers one area where the majority of patients are Madurese and Javanese, so it falls short to represent the whole country. A further multi-center study covering more areas and patients will give a more comprehensive finding of the characteristics as well as the management of COVID-19 in Indonesia.

Conclusion
Most patients with COVID-19 were asymptomatic with an age range between 40 and 49 years, dominated by women. Most patients had a history of travel abroad and had no comorbidities. Supportive therapy without antibiotics or antivirals was given to patients with an LOS of fewer than 10 days, and most of the cases showed excellent clinical outcomes. Findings from the data reported that our population originated from a single geographic area and may not reflect risk factors associated with clinical outcomes associated with SARS-CoV-2 infection in the general population. Accordingly, our data should be interpreted with caution as the risk factors associated with these health outcomes may differ elsewhere. Our study is a retrospective study based on electronic medical records collected during high surge cases of COVID-19 that are mostly dominated by Indonesian migrant workers. More clinical and basic research for the assessment, risk factors, and treatment of patients with COVID-19 with a wider population is needed in the future. This section only provides descriptive analysis. Since one purpose of your study is risk stratification, you need to build a prediction model for this.

Is the work clearly and accurately presented and does it cite the current literature? Yes
Is the study design appropriate and is the work technically sound? Yes

If applicable, is the statistical analysis and its interpretation appropriate? Yes
Are all the source data underlying the results available to ensure full reproducibility? Partly

Are the conclusions drawn adequately supported by the results? Yes
Therapy -relaxation? What is the relaxation? I suggest you omit. 4. 43 (5.6%) patients continued self-quarantine -why was this so? It is not clear to me the intention of this self-quarantine and why?

5.
Largest number was in groups with less than 10 days LOS with as many as 753 (98.7%) patients, LOS for 10 days was 3 (0.4%) patients, and LOS for more than 10 days was 7 (0.9%) patients -it is not clear to me why some were less than 10 days and some stayed longer than 10 days? What is the reason? What is the discharge criteria -that should be stated earlier?

6.
Mostly asymptomatic, and therefore come with great clinical outcomes -I suggest changing this to 'and therefore had good clinical outcomes'.

7.
There is no proven effective treatment against the virus to date approved by WHO -I think the timing of this sentence is misplaced as we all know there are fantastic medicines for this in 2022… so suggest rewording to mention that during that time drugs were not available?

8.
A study involving 500 patients observed disadvantages of the use of antiviral drugs for patients with COVID-19 with mild symptoms. The study concluded that antiviral treatment did not provide superior clinical outcomes to supportive care, since patients with mild COVID-19 who had received antiviral medication had significant LOS at the hospital compared with those without -again I would not use this reference with what we know with Paxlovid etc. in the year 2022.
9. Approximately 1.3% of patients receive O 2 therapy during their stay in the hospital. This is consistent with a study in Japan where 61.6% of patients did not receive respiratory support during hospitalization. The clinical outcomes were excellent; 90.1% of patients recovered. The word 'consistent' may be too strong here considering less than 2% in this paper cohort progressed but 40% in the Japanese cohort progressed. I would use the word 'differs' instead.

10.
Moderate to severe infection were referred to in a more equipped health facility -it would be nice to know what happened to this group if it's possible.

Are sufficient details of methods and analysis provided to allow replication by others? Yes
If applicable, is the statistical analysis and its interpretation appropriate? Partly (98.7%) patients, LOS for 10 days was 3 (0.4%) patients, and LOS for more than 10 days was 7 (0.9%) patients -it is not clear to me why some were less than 10 days and some stayed longer than 10 days? What is the reason? What is the discharge criteriathat should be stated earlier?-> Our hospital policy was to quarantine patients at least for ten days based on the first date of PCR test results. Sometimes, we received patients who already had positive PCR test results from the external lab for 2 or 3 days before going to the hospital. That was why there were LOS of less than ten days. The discharge criteria were ten days quarantine for the asymptomatic patient (the first day was counted based on the first PCR date) and at least ten days quarantine + 3 additional days without symptoms for symptomatic patients.
Mostly asymptomatic, and therefore come with great clinical outcomes -I suggest changing this to 'and therefore had good clinical outcomes'.-> Yes, we agree with your suggestion. We will revise the word. Thank you.

7.
There is no proven effective treatment against the virus to date approved by WHO -I think the timing of this sentence is misplaced as we all know there are fantastic medicines for this in 2022… so suggest rewording to mention that during that time drugs were not available?-> Yes, we agree with your suggestion. We will revise it. Thank you.

8.
A study involving 500 patients observed disadvantages of the use of antiviral drugs for patients with COVID-19 with mild symptoms. The study concluded that antiviral treatment did not provide superior clinical outcomes to supportive care, since patients with mild COVID-19 who had received antiviral medication had significant LOS at the hospital compared with those without -again I would not use this reference with what we know with Paxlovid etc. in the year 2022.-> Yes, we agree with your suggestion. We will revise it. Thank you.

9.
Approximately 1.3% of patients receive O 2 therapy during their stay in the hospital. This is consistent with a study in Japan where 61.6% of patients did not receive respiratory support during hospitalization. The clinical outcomes were excellent; 90.1% of patients recovered. The word 'consistent' may be too strong here considering less than 2% in this paper cohort progressed, but 40% in the Japanese cohort progressed. I would use the word 'differs' instead.-> Yes, We will revise the word. Thank you for your suggestion.

10.
Moderate to severe infection were referred to in a more equipped health facility -it would be nice to know what happened to this group if it's possible.-> Unfortunately, we did not have a follow-up record after referring those patients to a more equipped health facility.

11.
Competing Interests: No competing interests were disclosed.
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