The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected South Koreans since January 20, 2020. Reference Ryu and Chun1 To prevent the spread of SARS-CoV-2, the Korean government has implemented an unprecedented, large-scale home-quarantine for suspected or confirmed cases of coronavirus disease 2019 (COVID-19). Reference Ryu, Ali and Jang2 In the early epidemics of COVID-19, financial aids to the those quarantined cases and compensation for the employer for the wage loss were provided under the Korean Infectious Disease Control and Prevention Act (Table 1). Reference Namgoong3 In South Korea, to prevent seeding new SARS-CoV-2 infection, any individual who has traveled from a country with a high COVID-19 infection risk is also obliged to self-quarantine. Reference Lee, Kim and Choi4 The quarantined individuals are asked to comply with self-quarantine and are monitored for 14 days. Since April 1, 2020, all overseas travelers have been included in the self-quarantine program, which has greatly increased the number of quarantined individuals in South Korea (Figure 1A). The self-quarantine individuals have been actively monitored by a mobile application or phone-call twice a day and the public health workers sometimes randomly visit the quarantined place in person (Table 1). Reference Kim5 On April 5, 2020, the Korean government implemented a “1-strike out policy” and increased the penalty from a maximum of 3 million to 10 million Korean Won (8273 USD) in fines to further discourage quarantine violation. A previous study demonstrated that self-quarantine compliance for the case of COVID-19 is crucial for preventing local transmission Reference Kim, Hwang and Choi6 ; however, there is no literature measuring the exact noncompliance rate of self-quarantine for COVID-19 cases.
METHODS
This study did not require the institutional review board approval or informed consent, because the data had already been published by the Korean Ministry of Interior and Safety. 7 To obtain the noncompliance rate of self-quarantine for COVID-19 cases in South Korea, we collected the daily number of quarantine and quarantine violation cases from March 22 to June 10, 2020. To assess the impact of a 1-strike out policy and increased the penalty, the Poisson regression model incorporated with the additional sanctions were used to estimate the intervention effect with the confidence intervals on the daily rate (per 10,000 quarantined cases) and the daily number of quarantine violation. The established Poisson regression model is
Where, μ0 represents the count of quarantine violation at day t, β 0 and β 1 denote estimate for base level of the quarantine violation and multiplicative effect on the quarantine violation, and xt represents the additional sanctions (xt = 0 from March 22 to April 5, 2020; xt = 1 from April 6 to June 10, 2020). All statistical analyses were performed in R version 3.0.2 (R Foundation for Statistical Computing, Vienna, Austria).
RESULTS
The median number of individuals quarantined per day was 36,561 (interquartile range [IQR], 34,408-41,961; range, 8335-59,918). The median number of quarantined individuals, including those in contact with suspected and confirmed cases and those who have traveled overseas, was 5127 (IQR, 2451-7568; range, 846-11,053) and 32,041 (IQR, 28,923-37,819; range, 0-55,590), respectively (Figure 1A). The median number of daily self-quarantine violations was 6, with a range of 0-13 (Figure 1B). The median rate of self-quarantine violations was 1.6 per 10,000 quarantined individuals (range, 0.0-8.0 per 10,000) (Figure 1C). We identified a 1-strike out sanction and increased the amount of penalty had not a significant change on the daily violation rate (P = 0.99) (Table 2). Furthermore, it had not any significant impact on the number of violations among Koreans (P = 0.91) and foreigners (P = 0.81).
a rate: per 10,000 quarantined individuals
DISCUSSION
To limit the local transmission of SARS-CoV-2, public compliance with public health measures, such as self-quarantine for suspected or confirmed cases of COVID-19 is essential. Reference Kim, Hwang and Choi6,Reference Ryu, Ali and Lim8 A previous study demonstrated that a major obstacle to self-quarantine compliance was concern over the loss of income. Reference Bodas and Peleg9 To overcome this obstacle, the Korean government developed 3 specific plans early in the epidemic to reimburse, monitor, and sanction the individuals in self-quarantine for COVID-19 (Table 1).
The Korean government’s efforts to control the local transmission of SARS-CoV-2 has been positively evaluated among global public health experts; however, the implemented policies, particularly the forced control of people, is necessary to discuss. Our findings indicate that additional self-quarantine regulations did not significantly affect the violation rate of quarantine. This signifies the importance of a proper level of policy execution to control the number of violations and helps to decrease unnecessary costs and avoid time-consuming decision-making processes. Our findings also provide a proxy of the self-quarantine noncompliance rate under governmental regulation. However, this study is limited by a lack of demographic data and details on the reasons for violations, which make it challenging to identify the risk factors associated with breaches of self-quarantine rules. Furthermore, additional time-series data before our study period are required to improve the model fit and accuracy.
As of September 7, 2020, the two COVID-19 epidemic waves identified, Reference Ryu, Noh and Ali10 and the violations of self-quarantine are still being reported in South Korea. Further studies including the effective process for delivering comprehensive information about the self-quarantine to the public and appropriate level of policy for discouraging self-quarantine violations are warranted.
CONCLUSIONS
Our results identified the additional sanctions, including a 1-strike out policy and increased the amount of penalty, had no significant impact on reducing the violation rate of self-quarantine in South Korea. Additional studies are warranted to strengthen quarantine compliance for future epidemics.
Acknowledgments
The authors thank Dr Sheikh Taslim Ali (The University of Hong Kong) and anonymous reviewers for their constructive comments.
Funding
This study was financially supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Korean Ministry of Education (NRF-2020R1I1A3066471). The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Data availability Statement
The study data are available from the corresponding author upon reasonable request.
Ethics Committee Approval
Because this study was based on publicly available data, the institutional review board approval or informed consent was not required.
Conflict of Interest
The authors have no conflicts of interest to declare.