European Countries That Implemented Strict COVID-19 Mitigation Policies Saw Fewer Deaths

By Linda Carroll

January 15, 2021

(Reuters Health) - In Europe, countries that implemented strict COVID-19 mitigation policies early in the pandemic, including cancellation of public events, gathering restrictions, school closures and recommendations to stay at home, saw a lower death toll compared to those with less stringent policies, a new study finds.

An analysis of data from the spring of 2020 in 37 European countries showed that more than 75,000 deaths might have been averted had 26 of the nations adopted stricter policies once the death rate hit a specific threshold, according to the report published in the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.

"European countries that implemented more stringent mitigation policies by the time they reached an early mortality threshold in spring 2020 tended to report fewer COVID-19–associated deaths through the end of June," write the authors, led by James Fuller of the CDC. "Countries that implemented stringent policies earlier might have saved several thousand lives relative to those countries that implemented similar policies, but later. These findings suggest that earlier implementation, even by just a few weeks, might be important to preventing widespread transmission and large numbers of deaths."

The authors declined a request for comment.

To investigate the effectiveness of mitigation policies, Fuller and his colleagues turned to mortality data from the World Health Organization Coronavirus Disease Dashboard and data on mitigation polices from the CDC COVID-19 International Taskforce global mitigation database accessible through WHO and the University of Oxford's Coronavirus Government Response Tracker, specifically the Oxford Stringency Index (OSI).

The index is based on nine mitigation policies: "cancellation of public events, school closures, gathering restrictions, workplace closures, border closures, internal movement restrictions, public transport closure, recommendations to stay at home, and stay-at-home orders; mask requirements are not included."

The OSI ranges from 0 to 100 and it increases over time if more stringent policies are implemented and decreases over time if polices are canceled. The index is also weighted on the strictness of each policy.

The OSI was calculated for each nation when the country reached a threshold that was defined as a daily rate of 0.02 new COVID-19 deaths per 100,000 people based on a 7-day moving average.

The researchers used a linear regression to assess the association between the OSI on the day the country reached the mortality threshold and the cumulative mortality per 100,000 at the end of June 2020, which was chosen as the end point because that was when the rate of new deaths had dropped to relatively low levels for all 37 countries.

Fuller and his colleagues determined that the cumulative COVID-19–associated mortality on June 30 was lower in countries that had a higher OSI when reaching the mortality threshold. The association persisted after controlling for the calendar date the mortality threshold was reached, hospital beds per 1,000 population, median age of the population, population density, and gross domestic product per capita.

For each 1-unit increase in the OSI when the mortality threshold was reached, the cumulative mortality as of June 30 decreased by 0.55 deaths per 100,000. A 1-unit increase in the OSI standard deviation (22.9 unit increase in the OSI) was associated with a decrease of 12.5 deaths per 100,000.

Of the 37 countries, six had an OSI less than 80 when they reached the mortality threshold. The researchers determined that if the OSI had been 80 when the threshold was reached, 74,139 deaths could have been averted. The biggest impact would have been in the United Kingdom which would have averted 22,776 deaths, France, 13,365 deaths and Spain, 9,346 deaths.

The new study is "one of a cluster of papers all addressing the same issue in different ways, that is how effective are mitigation interventions," said Dr. Jeffrey Koplan, a former director of the CDC and currently vice president for global health at Emory University in Atlanta. "Nearly all have come to a similar conclusion: early implementation is better than later, even if it's just by a few weeks. And these interventions could play a role in diminishing the widespread transmission of the virus and the large numbers of deaths."

One thing missing from the study is the additive effect of masking, Dr. Koplan said. "They were focusing on government policies, but it would be interesting to look at the impact of encouraging or demanding masking," he added.

"One thing that needs to be expressed over and over again is we won't get economic success until there is decent control over the infectious threat," Dr. Koplan said. "It's not a case of one or the other."

Another limitation of the study is that it did not look at how effective each of the governments was at getting people to adopt the mitigation strategies, said Dr. Mark Roberts, a professor of health policy and management and director of the Public Health Dynamics Laboratory at the University of Pittsburgh Graduate School of Public Health.

"People keep talking about the virus as being the culprit," Dr. Roberts said. "But it's a combination of the virus and our response to it. And that's something we can control."

SOURCE: MMWR, online January 12, 2021.