JMIR Publications

ABSTRACT

Background:

Background:

In the absence of an effective treatment method or vaccine, the outbreak of the COVID-19 pandemic elicited a wide range of unprecedented restriction policies aimed at mitigating and suppressing the spread of the SARS-COV-2 virus. These policies and their Stringency Index (SI) of more than 160 countries were systematically recorded in the Oxford COVID-19 Government Response Tracker (OxCGRT) dataset. The SI is a summary measure of the overall strictness of these policies. However, the OxCGRT SI may not fully reflect the stringency levels of the restriction policies implemented in Korea. Korea implemented 33 COVID-19 restriction policies targeting four areas: public facilities, public events, social gatherings, and religious gatherings.

Objective:

Objective:

We aimed to develop new Korea Stringency Indices (KSIs) reflecting the stringency levels of Korea’s restriction policies well and to determine which government-implemented policies were most effective in managing COVID-19 in Korea.

Methods:

Methods:

The random forest method was used to calculate the new KSIs using feature importance values and determine their effectiveness in managing daily COVID-19 confirmed cases. Five analysis periods were considered, including 2020.11.01 ~ 2021.01.20 (Period 1), 2021.01.20 ~ 2021.06.27 (Period 2), 2020.11.01 ~ 2021.06.27 (Period 3), 2021.06.27 ~ 2021.11.01 (Period 4), and 2021.11.01 ~ 2022.04.24 (Period 5).

Results:

Results:

Among the KSIs, public facilities in period 4, public events in period 2, religious gatherings in periods 1 and 3 and social gatherings in period 5 had the highest importance. Among the public facilities, policies associated with operation hour restrictions in cinemas, restaurants, PC rooms, indoor sports facilities, karaoke, coffee shops, night entertainment facilities, and baths/saunas had the highest importance across all analysis periods. Strong positive correlations were observed between public facilities, religious gatherings, and public events with daily confirmed cases in period 1 of the pandemic. From then, weaker and negative correlations were observed in the remaining analysis periods. The comparison with the OxCGRT SI showed that the SI had a relatively lower feature importance and correlation with daily confirmed cases than the proposed KSIs, making KSIs more effective than SI.

Conclusions:

Conclusions:

Restriction policies targeting public facilities were the most effective among the policies analyzed. Also, different periods call for enforcing different policies as their effectiveness varied during the pandemic.