Table 2.

Stringency Index levels and their median constitutent non-pharmaceutical intervention levels

Restriction type	$51-{60}^{†}$	$41-{50}^{\diamond }$	$31-{40}^{\circ }$	Description of $31-{40}^{\circ }$ levels
school closing	2	1	1	recommend closing
workplace closing	2	1	1	recommend closing (or work from home)
cancellation of public events	2	1	1	recommend cancelling
gatherings restrictions	3	3	2	restrictions on gatherings of 100–1,000 people
transport closing	0	0	0	no measures
stay-home restrictions	1	0	0	no measures
internal mobility restrictions	0	0	0	no measures
international mobility restrictions	3	3	3	quarantine arrivals from high-risk regions
information campaigns	2	2	2	coordinated public information campaign

${}^{†}$ upper bound of optimal Stringency Index level for confirmed case growth rate, ${}^{\diamond }$ upper bound of optimal Stringency Index level for death growth rate, ${}^{\circ }$ achieves at least 90% of the effectiveness for both case and death growth rates