The COVID-19 pandemic disrupted access to routine medical care in community populations in Taiwan. The unmet needs should be emphasized as normal life resumes.
Objectives: Whether and how the COVID-19 pandemic affected utilization of routine medical care in areas with low infection risk, such as Taiwan, has not been widely addressed. We aimed to evaluate the impact of the COVID-19 pandemic on access to medical care.
Study Design: Before and after exposure (COVID-19 pandemic) design with a historical control group for comparison of clinical visits based on a retrospective cohort of 6722 customary patients of a community hospital in Zhunan, Taiwan.
Methods: Repeated measurements of medical utilization in 4-month periods (January to April) of 2019 and 2020 in light of the emerging COVID-19 pandemic were collected. Access to medical care was defined as the mean frequencies of clinical visits. The impacts of the COVID-19 pandemic on access in the overall and specific groups were quantified with a multivariable Poisson regression model.
Results: The overall outpatient visits per month declined by 39% (rate ratio [RR], 0.61; P < .0001) after adjusting for demographics. A notable reduction in visits was observed in foreign patients (RR, 0.50; P < .0001). The visits of the elderly (≥ 80 years) were the most frequent before the COVID-19 pandemic but were reduced by 44% (RR, 0.56; P < .0001) after it began. Most disease categories revealed a declining trend, but the size of reduction varied by International Classification of Diseases codes.
Conclusions: The COVID-19 pandemic prevented some individuals from keeping regular medical appointments even in an area with a low infection risk. Our findings imply that more research is required to mitigate the effects of delayed medical care for patients who infrequently utilized medical care during and after the long-lasting pandemic period.
Am J Manag Care. 2021;27(9):In Press
Access to routine medical care in Taiwan decreased after the COVID-19 pandemic began.
Since the start of the COVID-19 pandemic, caused by SARS-CoV-2, many medical systems have been severely strained.1-3 Due to the rapid surge of COVID-19 confirmed cases that kept many hospitalized patients and health care workers in quarantine and isolation, the workforce shortage has compelled medical communities not only to enlist support from recent medical school graduates, physician interns, and retired medical personnel but also to share tasks to maintain the medical capacity to cope with this public health emergency while maintaining routine health care services.4,5 In addition to the shortage of medical capacity, the containment measures involved with nonpharmaceutical interventions (NPIs) can be barriers to medical access for the patients of medical systems. This may impede the provision of both routine medical care and also preventive services such as cancer screening and health checkups, which will further result in declines in early detection of diseases, including cancer.6 Moreover, the elevated risk of nosocomial COVID-19 infection7-9 and the high fatality rate due to COVID-19–related pneumonia in vulnerable groups, especially those with cancer and chronic diseases,10-12 may also deter these patients from seeking routine medical care. The medical community has emphasized the development of coping strategies to strengthen the health care workforce to maintain essential health care in the era of COVID-19.13-15
The primary medical services provided by community hospitals in the health care system in Taiwan include regular clinical surveillance that is supposed to prevent disease from progressing to advanced status, confirmatory diagnosis for suspected cases of disease in population-based screening programs, and the administration of seasonal prophylaxis services such as vaccination for influenza. As per the vertical integration of medical care providers in Taiwan, community hospitals play pivotal roles in admitting patients who have been referred from primary care clinics to provide more specialized medical care and hospitalization for surgical procedures; they also admit patients who have been treated for severe disease at regional hospitals to receive routine follow-up care.16,17 Given the compromised medical access due to the resurgent and long-lasting COVID-19 pandemic,18,19 community residents with early-stage cancers could experience progression to advanced stages and might also be vulnerable to seasonal contagious diseases.
Although several studies have been conducted to highlight the impact of COVID-19 containment measures on the provision of medical care for certain diseases,6,13,14 few have focused on the accessibility of routine medical care, particularly in an area with low COVID-19 infection risk. The objective of this study is therefore to estimate the effect size of reduced access to routine medical care in Taiwan before and after the global COVID-19 pandemic. We further quantified the reduction among subgroups by demographic characteristics and also by disease-specific groups. Doing so enables us to identify the subpopulations vulnerable to low access to routine medical care under the threat of the COVID-19 pandemic.
MATERIALS AND METHODS
Medical Care System in Taiwan
The medical care system in Taiwan has been transformed into a single-payer system on a national level, supported by the National Health Insurance (NHI) program since 1995.16,20-22 This universal medical care system, which covers 99% of Taiwan’s population and all foreigners with resident permission issued by the National Immigration Agency of Taiwan, seeks to provide high-quality, efficiently accessed medical care.22,23 Under the universal coverage of NHI, medical care services have been delivered through the vertical integration of medical providers: the primary care unit, local hospital, regional hospital, and medical center.
The community hospital for our study is located in Zhunan township, Miaoli County, Taiwan; Zhunan is the junction of the interior and coastal lines of the railroads in western Taiwan. Two industrial special districts, Zhunan Science Park and the National Health Research Institutes, are located within a 20-minute drive. For several reasons, this community hospital is the gateway to medical care from the township’s surrounding area. Many foreigners moved to the Zhunan area, attracted by the demand for a labor force, including in long-term care, the high-tech industry, projects to build the infrastructure, and the nearby Science Park. Outside the township, a resident may need to drive more than 1.5 hours to visit a medical center in their neighborhood metropolitan area. The provision of routine medical care and regular preventive services is therefore the major task of this hospital. This is also the only community-based facility in the township to care for patients of the Zhunan catchment area who have chronic disease, including arranging for routine follow-up and prescribing medications for disease control, at the hospital level.
In the Taiwanese medical care system, the main role of a local hospital, like the one in this study, is to act as a hub for primary care units (ie, clinics, local hospitals, and community health centers) and as the hinge to vertically integrate the primary care unit and regional hospital and medical centers. As such, medical care provided by our community hospital mainly includes preventive medicine services (with the International Classification of Diseases, Tenth Revision, Clinical Modification [ICD-10-CM] codes of Z00-Z99), care for chronic diseases (eg, diseases with the ICD-10-CM codes of E00-E89, I00-I99, and G00-G99), and care for acute medical and surgical conditions (eg, conditions with the ICD-10-CM codes of R00-R99, K00-K95, N00-N99, J00-J99, M00-M99, S00-T88, and L00-L99).
Study Subjects and Design
We used a retrospective cohort of our patients—not only from the catchment area of nearby townships but also those who have been directed to seek medical services from our hospital—as the basis for our study’s before-and-after design, corresponding to the time periods before and after the start of the COVID-19 pandemic. The historical control before the COVID-19 pandemic forms the comparator for the exposed group after COVID-19 emerged. Such before-and-after designs have been widely used in the evaluation of the effectiveness of health care services (such as the mortality reduction of breast cancer screening as indicated by Baker et al24); the structures of a randomized controlled trial or a nonrandomized study with a nonequivalent control group would have been impossible to adopt to evaluate the impact of COVID-19. The study cohort thus consisted of as many patients with customary visits as possible and did not exclude the community residents of our catchment area to ensure the representativeness of the study population. We identified 3 patterns of medical consultation for these customary patients:
Of these 3 types of customary patients, the intervals between successive visits were expected to span across the unit of months to years. Following this rationale, customary patients of our hospital with at least 3 medical visits between January 1, 2015, and December 31, 2019, were enrolled for analysis.
To assess the impact of COVID-19 on medical accessibility, we compared the frequencies of medical visits in 2 time periods: January 1 to April 30, 2019, and January 1 to April 30, 2020. We used a before-and-after design based on the previously mentioned retrospective cohort of customary patients with longitudinal follow-up to April 2020. The outsets of individuals’ follow-up person-month were assessed among the customary patients of our hospital (see eAppendix Figure for an illustration [eAppendix available at ajmc.com]).
We retrieved the data on medical visits from the hospital’s electronic health record. The mean number of clinical visits per month was used as a surrogate index of the intention to access medical service. The frequencies of clinical visits and the explanatory variables were treated and displayed under the data frame of repeated measurement. A total of 106,810 medical visits for 6722 individuals 18 years and older with information on date of birth, gender, nationality, and the relevant details of medical visits were retrieved from this retrospective cohort of customary patients.
To assess the impact of the COVID-19 outbreak on medical utilization, an indicator variable was applied and defined as 1 if the outpatient visiting date occurred on or after January 1, 2020, and 0 otherwise. The episodic effect of the Chinese New Year holiday was also considered in the analysis due to its possible effect on the frequency of medical visits and its proximity to the onset of the pandemic in 2020. In addition, the residential areas of the study subjects were included in the analysis to have a proxy for the residents’ determination and intention to access medical care during the pandemic.
The primary outcome of interest was outpatient visit counts. The data collected for each visit included patient gender, age, resident area, nationality (foreigner or not), and date. Rate ratios (RRs) to compare the frequency of visits after vs before COVID-19 for the overall group and subgroups (eg, sex, nationality, age groups) were estimated by using a series of Poisson regression models wherein the generalized estimating equation (GEE) was used to calculate intraindividual correlation. Subgroup analysis by ICD diagnosis codes was applied to evaluate the reduction in medical accessibility in each category. Each patient could have more than 1 diagnosis code in a single visit, and in such a circumstance, more than 1 ICD category was used for the visit. The correlation structure due to multiple diagnosis codes used in a single visit for a patient was taken into account by using the Poisson regression model with GEE. By using such a disease group–based outcome measurement, the impact of the COVID-19 pandemic on medical utilization for each category of disease can be quantified.
Of the 6722 individuals enrolled in the analysis, 63.97% were women; 2.32% were foreigners. All demographic measures, except for sex, were significantly associated with the visiting frequency. All demographic results are summarized in eAppendix Table 1. Figure 1 shows the estimated results on the frequencies and RRs of medical visits before and during the pandemic (see eAppendix Table 2 and eAppendix Table 3 for descriptive statistics). The overall crude reduction of visiting frequency was 21% (RR, 0.79; 95% CI, 0.77-0.83) (eAppendix Table 1). After adjusting for demographics, the reduction was elevated to 39% (RR, 0.61; 95% CI, 0.49-0.76) (Figure 1). Both genders showed significant reduction in the frequencies of outpatient visits after the pandemic had begun (declining from about 0.25 to about 0.15 times per month) (Figure 1).
Both foreigners and domestic residents reduced their visiting frequencies, foreigners significantly more so (50% and 25% reductions, respectively). All age groups significantly reduced their visiting frequencies after the COVID-19 outbreak. Notably, reductions were observed not only in the elderly group (≥ 80 years: 44% reduction; RR, 0.56; 95% CI, 0.43-0.74) but also in the youngest adults (≤ 40 years: 43% reduction; RR, 0.57; 95% CI, 0.45-0.71).
Figure 2 shows the results of subgroup analysis for outpatient diagnosis by ICD classification. Compared with the 4-month period in 2019, almost all of the disease classes showed a significant declining trend in clinic visiting frequencies (Figure 2 and eAppendix Table 4). The diagnosis subgroups of skin and subcutaneous tissue disorders (–62%) and respiratory system disorders (–56%) had the largest visit reductions. In contrast, the ICD classification groups of hypertension (–8%) and diabetes mellitus (–14%) had the least change.
The impact of COVID-19 on health equity and accessibility for vulnerable groups6,14 and races25 has been addressed in recent studies. By using empirical data in an area with a low infection risk of COVID-19, our results show that the reduction in medical utilization attributable to COVID-19 outbreak in community residents was substantial, regardless of demographics and the categories of clinical diagnosis. The vertical integration of medical care providers established by the NHI program in Taiwan guides the patient flow of medical utilization in the system. However, due to the consideration of accessibility and equity, the ultimate right to visit any medical institute in the NHI program has been preserved for the insured. Patients who seek medical care at community hospitals include community dwellers referred from primary care clinics and those being discharged from regional hospitals.16,17 The number of patients seeking care at the community hospital level is thus a key indicator of medical care accessibility, given the bidirectional patient flow both from primary care clinics and regional hospitals. Therefore, to evaluate the impact of the COVID-19 pandemic on overall medical care utilization in Taiwan’s NHI medical care system, evaluating the patterns of patient usage at a community-based hospital makes sense.
To assess the impact of the COVID-19 pandemic on medical utilization, we used a retrospective study design to examine the cohort of customary patients in the catchment area of our community hospital, comparing the frequencies of medical visits to the hospital in two 4-month periods: January 1 to April 30, 2019, and January 1 to April 30, 2020—namely, before and after the COVID-19 outbreak. Although the use of a historical control in such a before-and-after design may have other threats to internal validity, such as maturation (aging), regression toward the mean, history effect, and practice effect, these threats may be irrelevant to the exposure of the COVID-19 pandemic, and some of them can be ameliorated by Poisson regression analysis with adjustment for extraneous factors such as age, gender, nationality, and the type of medical visits. Because of the equal-length periods used for comparison, the exposed group would be rendered closer to the historical control except for the exposure to COVID-19, to remove other confounding factors such as maturation and seasonal variation in medical utilization.
The compromised access to outpatient care in community hospitals in an area with a low COVID-19 infection rate, as observed in our study, could be the result of the psychosocial impact of the pandemic.18,19 The substantial decline in the frequency of medical visits for the elderly group could also result from the widely propagated messages regarding the high risk of being infected by SARS-CoV-2 and the elevated odds of unfavorable outcomes for elderly patients with COVID-19.10 These messages were conveyed by mass media and transmitted through conventional and digital platforms, leading to the delays in seeking care by elderly individuals. This possibility, taking into account the highest visiting frequency for the elderly group before the COVID-19 outbreak, should be scrutinized for the risk of delayed and unmet medical needs in the pandemic and postpandemic period for this vulnerable group.
The decrease in access to health care services noted in foreign workers has been omnipresent worldwide,26,27 with the pandemic exacerbating the vulnerability in health equity of this marginalized group.28,29 The substandard living environment (eg, crowdedness, shared bedroom, poor hygiene), relatively closed social networks, economic vulnerability, and language barriers of foreign workers may preclude them from being updated on the pandemic’s local impact and on the NPIs implemented in the community, which can result in reduced medical access. Concerns around deportation, either as a result of being infected by SARS-CoV-2 or because of identity documents that have expired, can further impede their access to medical care. Furthermore, foreign workers living in dormitories provided by employers may be dissuaded from making visits to hospitals to prevent introducing this pathogen to their neighbors. These obstacles may jointly explain the decline in the frequency of medical visits in foreign workers to the level of near zero (0.09 per month) after the pandemic began, as observed in our study. More importantly, our finding shows the need to address the issue of medical accessibility for this marginalized population during the COVID-19 pandemic and also in the postpandemic era.
Although almost all of the ICD categories showed a decreasing trend in medical access after the outbreak of COVID-19, the ICD groups of diseases of skin and subcutaneous tissue, diseases of the respiratory system, and diseases of the digestive system were the most severely affected. In contrast, the subgroups associated with the chronic disease of hypertension and preventive medical services showed nonsignificant reductions and that of hyperlipidemia and diabetes showed modest reductions in the frequency of medical visits. Although hospital visits may increase the risk of contracting contagious diseases such as COVID-19, especially among patients with chronic diseases, an important issue for hospitals providing essential medical care to these subgroups during the pandemic has been to ensure the balance between harms and benefits for these high-risk patients.
The provision of routine medical services, including disease surveillance and preventive medicine, is among the major roles of community-based hospitals in the medical care system designed by NHI in Taiwan. As the pandemic persists, the reduction in access to routine medical care is expected and will affect both short- and long-term outcomes—for instance, unmonitored fluctuations in blood pressure could lead to subsequent end-organ damage due to compromised control of hypertension. Our results provide an insight into the groups who are the most vulnerable to and most affected by the reduced medical accessibility associated with the COVID-19 outbreak: the elderly and foreigners. The second implication of our study is to recognize that there will likely be a resurgence in demand for routine medical services. As the pandemic ebbs, the surge in demand for services, due to needs that were left unmet during the pandemic, can pose a threat to medical care systems unless they are well prepared in advance.
In light of the possible emergence of contagious diseases with contact and airborne transmission modes30 and given the anticipation that COVID-19 will not be the last pandemic, 2 other issues are crucial for community hospitals to recognize. One is the urgent need for novel care modalities, such as remote consultation31 or home-based medical care and prescription; with these, patients who are at increased risk of being infected and having an unfavorable prognosis11,12 could reduce their frequency of visiting hospitals in person without compromising health care quality. The second pertains to nosocomial infection prevention.7-9 For patients who require essential in-hospital medical care, automated devices that can perform disinfection on a large scale can reduce their risk (and staff members’ risk) of being infected.32
The lack of direct and valid measurements of individuals’ intention to routinely access medical care is a study limitation. However, by comparing the frequencies of medical visits for the 4-month periods in 2019 and 2020 based on the cohort of customary patients of our hospital, we demonstrate that the reduction in medical visits can serve as a surrogate index for the intention to access medical care. Although the public policy decisions regarding the implementation of NPIs can be a reason for the decrease in the frequency of medical visits, the results in our study were less likely to be affected by this factor because the risk of infection in the study area, unlike other regions worldwide, was so low as not to require strict containment strategies to bar medical visits in Taiwan, even for the elderly or those with chronic diseases. Another limitation is that our study is based on data from 1 hospital. Although similar results may be applied to the community hospitals of the same level in the NHI system in Taiwan, this can be validated by using empirical data from other hospitals.
Although the COVID-19 pandemic is currently a global disaster, it will eventually be controlled with the effort of international research groups and organizations. As the postpandemic era approaches, most medical care systems will be confronted with not only the direct impacts resulting from the COVID-19 pandemic but also the sequelae of compromised access to routine medical care. Community hospitals can play a crucial role in this postpandemic phase. Given the characteristics of the universal health care system and the relatively low risk of COVID-19 infection during 2020 in Taiwan, our results on the variation of medical accessibility can inform the balance among needs, demands, and accessibility in the upcoming months and years when the COVID-19 pandemic will, presumably, be contained.
Furthermore, given how long the pandemic has lasted, our results provide even more insight as the decision makers of each country will need to monitor their populations’ medical needs and evaluate how to handle the medical care that patients, particularly those with chronic diseases, have delayed.
Yachung Jeng, PhD, and Feng-Hsi Chen, MD, contributed equally to this work and are listed as co–first authors.
The authors would like to express their gratitude to Mr Kuang-Chun Ku for his helpful assistance on preparing for research discussion meetings, to Mr Yi-Hung Wang and Miss Yu-Chun Lin for their kindly assistance with data collection, to Mr Chun-Sheng Tsai for performing careful data cleaning, and to vice-superintendent Mrs Hui-Lan Chen for her support and impetus to establish the clinical research database.
Author Affiliations: Department of Internal Medicine, National Taiwan University Hospital Yunlin Branch (YJ), Yunlin, Taiwan; Department of Medical Affairs (YJ), Superintendent Office (FHC), Department of Pharmacy (HCC), Department of Family Medicine (CDC), and Department of Emergency (CYH), Daichung Hospital, Miaoli, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University (GHHJ, CYH), Taipei, Taiwan; School of Oral Hygiene, College of Oral Medicine, Taipei Medical University (AMFY), Taipei, Taiwan; Department of Family Medicine, Far Eastern Memorial Hospital (CDC, HWK), New Taipei, Taiwan; Department of Family Medicine, School of Medicine, College of Medicine, Taipei Medical University (STW), Taipei, Taiwan; Department of Family Medicine and Health Management Center, Taipei Medical University Hospital (STW), Taipei, Taiwan.
Source of Funding: Ministry of Science and Technology (MOST 108-2118-M-002-002-MY3; MOST 108-2118-M-038-001-MY3; MOST 109-2327-B-002-009).
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 (YJ, FHC, CDC, STW, CYH); acquisition of data (FHC, GHHJ, HCC, HWK); analysis and interpretation of data (YJ, GHHJ, AMFY, CDC, HWK, CYH); drafting of the manuscript (YJ); critical revision of the manuscript for important intellectual content (STW, CYH); statistical analysis (YJ, GHHJ, AMFY, HWK); provision of patients or study materials (FHC, HCC); obtaining funding (GHHJ, AMFY); administrative, technical, or logistic support (FHC, HCC, AMFY); and supervision (CDC, STW, CYH).
Address Correspondence to: Chen-Yang Hsu, MD, Daichung Hospital, No. 304, Guangfu Rd, Zhunan Township, Miaoli, Taiwan. Email: firstname.lastname@example.org.
1. Sharma S, Sharma M, Singh G. A chaotic and stressed environment for 2019-nCoV suspected, infected and other people in India: fear of mass destruction and causality. Asian J Psychiatr. 2020;51:102049. doi:10.1016/j.ajp.2020.102049
2. Pasquariello P, Stranges S. Excess mortality from COVID-19: a commentary on the Italian experience. Int J Public Health. 2020;65(5):529-531. doi:10.1007/s00038-020-01399-y
3. Faust JS, Del Rio C. Assessment of deaths from COVID-19 and from seasonal influenza. JAMA Intern Med. 2020;180(8):1045-1046. doi:10.1001/jamainternmed.2020.2306
4. Larkin PJ Jr. COVID-19 and the provisional licensing of qualified medical school graduates as physicians. Wash Lee Law Rev. 2020;76(2):81. https://scholarlycommons.law.wlu.edu/wlulr-online/vol76/iss2/1
5. DeWitt DE. Fighting COVID-19: enabling graduating students to start internship early at their own medical school. Ann Intern Med. 2020;173(2):143-144. doi:10.7326/M20-1262
6. Kansagra AP, Goyal MS, Hamilton S, Albers GW. Collateral effect of Covid-19 on stroke evaluation in the United States. N Engl J Med. 2020;383(4):400-401. doi:10.1056/NEJMc2014816
7. Ong SWX, Tan YK, Chia PY, et al. Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient. JAMA. 2020;323(16):1610-1612. doi:10.1001/jama.2020.3227
8. Zhou Q, Gao Y, Wang X, et al; COVID-19 Evidence and Recommendations Working Group. Nosocomial infections among patients with COVID-19, SARS and MERS: a rapid review and meta-analysis. Ann Transl Med. 2020;8(10):629. doi:10.21037/atm-20-3324
9. Gao S, Yuan Y, Xiong Y, et al. Two outbreaks of SARS-CoV-2 in department of surgery in a Wuhan hospital. Infect Prev Pract. 2020;2(3):100065. doi:10.1016/j.infpip.2020.100065
10. Liu K, Chen Y, Lin R, Han K. Clinical features of COVID-19 in elderly patients: a comparison with young and middle-aged patients. J Infect. 2020;80(6):e14-e18. doi:10.1016/j.jinf.2020.03.005
11. Pal R, Bhansali A. COVID-19, diabetes mellitus and ACE2: the conundrum. Diabetes Res Clin Pract. 2020;162:108132. doi:10.1016/j.diabres.2020.108132
12. Fang L, Karakiulakis G, Roth M. Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? Lancet Respir Med. 2020;8(4):e21. doi:10.1016/S2213-2600(20)30116-8
13. Holstein SA, Vose JM. Oncology treatment in the era of COVID-19: we cannot afford to hit the pause button. Clin Pharmacol Ther. 2020;108(3):422-424. doi:10.1002/cpt.1920
14. Mayor S. COVID-19: impact on cancer workforce and delivery of care. Lancet Oncol. 2020;21(5):633. doi:10.1016/S1470-2045(20)30240-0
15. Garg M, Wray CM. Hospital medicine management in the time of COVID-19: preparing for a sprint and a marathon. J Hosp Med. 2020;15(5):305-307. doi:10.12788/jhm.3427
16. Kreng VB, Yang CT. The equality of resource allocation in health care under the National Health Insurance System in Taiwan. Health Policy. 2011;100(2-3):203-210. doi:10.1016/j.healthpol.2010.08.003
17. Yan YH, Kung CM, Yeh HM. The impacts of the hierarchical medical system on National Health Insurance on the residents’ health seeking behavior in Taiwan: a case study on the policy to reduce hospital visits. Int J Environ Res Public Health. 2019;16(17):3167. doi:10.3390/ijerph16173167
18. Asmundson GJG, Taylor S. Coronaphobia: fear and the 2019-nCoV outbreak. J Anxiety Disord. 2020;70:102196. doi:10.1016/j.janxdis.2020.102196
19. Amin S. Why ignore the dark side of social media? a role of social media in spreading corona-phobia and psychological well-being. Int J Ment Health Promot. 2020;22(1):29-38. doi:10.32604/IJMHP.2020.011115
20. Cheng SH, Chiang TL. The effect of universal health insurance on health care utilization in Taiwan. results from a natural experiment. JAMA. 1997;278(2):89-93. doi:10.1001/jama.278.2.89
21. Peabody JW, Yu JC, Wang YR, Bickel SR. Health system reform in the Republic of China. formulating policy in a market-based health system. JAMA. 1995;273(10):777-781. doi:10.1001/jama.1995.03520340033032
22. Lu JFR, Hsiao WC. Does universal health insurance make health care unaffordable? lessons from Taiwan. Health Aff (Millwood). 2003;22(3):77-88. doi:10.1377/hlthaff.22.3.77
23. Wu TY, Majeed A, Kuo KN. An overview of the healthcare system in Taiwan. London J Prim Care (Abingdon). 2010;3(2):115-119. doi:10.1080/17571472.2010.11493315
24. Baker SG, Kramer BS, Prorok PC. Comparing breast cancer mortality rates before-and-after a change in availability of screening in different regions: extension of the paired availability design. BMC Med Res Methodol. 2004;4:12. doi:10.1186/1471-2288-4-122
25. McCormack G, Avery C, Spitzer AKL, Chandra A. Economic vulnerability of households with essential workers. JAMA. 2020;324(4):388-390. doi:10.1001/jama.2020.11366
26. Karim AHMZ, Diah NM. Health seeking behavior of the Bangladeshi migrant workers in Malaysia: some suggestive recommendations in adjustive context. Asian Soc Sci. 2015;11(10):348-357. doi:10.5539/ass.v11n10p348
27. Loganathan T, Rui D, Ng CW, Pocock NS. Breaking down the barriers: understanding migrant workers’ access to healthcare in Malaysia. PLoS One. 2019;14(7):e0218669. doi:10.1371/journal.pone.0218669
28. Bagdasarian N, Fisher D. Heterogenous COVID-19 transmission dynamics within Singapore: a clearer picture of future national responses. BMC Med. 2020;18(1):164. doi:10.1186/s12916-020-01625-7
29. Haley E, Caxaj S, George G, Hennebry J, Martell E, McLaughlin J. Migrant farmworkers face heightened vulnerabilities during COVID-19. J Agric Food Syst Community Dev. 2020;9(3):1-5. doi:10.5304/jafscd.2020.093.016
30. Peeri NC, Shrestha N, Rahman MS, et al. The SARS, MERS and novel coronavirus (COVID-19) epidemics, the newest and biggest global health threats: what lessons have we learned? Int J Epidemiol. 2020;49(3):717-726. doi:10.1093/ije/dyaa033
31. Bekelman JE, Emanuel EJ, Navathe AS. Outpatient treatment at home for Medicare beneficiaries during and after the COVID-19 pandemic. JAMA. 2020;324(1):21-22. doi:10.1001/jama.2020.9017
32. Nardell EA, Nathavitharana RR. Airborne spread of SARS-CoV-2 and a potential role for air disinfection. JAMA. 2020;324(2):141-142. doi:10.1001/jama.2020.7603