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Oxford study:  Quick, stringent lockdown flattens curve sooner

Geogrande.com / Published April 21, 2020

OXFORD, UNITED KINGDOM - An ongoing study being performed by the University of Oxford shows that virus control measures such as stay-at-home orders significantly slow the spread of COVID-19 within about three weeks after significant implementation. The study estimates the level of stringency of control measures (a stringency index level) in each country for each day throughout the time period extending from 50 days before the 100th case was recorded in a country, to the present day.

A stringency index level ranging between 0 and 100 (with 100 being the most stringent) was assigned to each country based on the stringency of control measures in force on each day (see accompanying world map of index levels from a recent day).

Seven factors went in to determining stringency, including closures of schools, workplaces, and public transportation, as well as travel/movement restrictions and public information campaigns.

Plotting a country’s daily stringency index level on a graph, along with the country’s daily new cases, enables visualization of the relationship over time between the start of control measures and the resulting growth of new cases (see accompanying graphs for six countries)

Graphs - Six countries- Number of cases vs Stringency

The six graphs show the curve of total cases in each country flattened within three weeks after the stringency index level reached 60. South Korea’s curve flattened within about a week after the stringency index level reached 60. In contrast, the curves for the United Kingdom and the United States did not flatten until approximately three weeks after the stringency index level passed 60 in those two countries.

South Korea had implemented strict control measures early in its virus outbreak, reaching a stringency index level of 60 when less than 1,000 cases had been reported in that country. The U. K. and the U. S., however, did not implement control measures of stringency index level 60 until about 2,000 total cases had been reported in each of those two countries

The data appear to suggest that early ramp-up of control measures when the number of cases is relatively low, may result in a much slower spread of the virus.