EXHIBIT 4.

Adjusted relative risks (RRs) and adjusted semimonthly rates of 30-day COVID-19-related mortality among residents in a sample of US nursing homes, 2020

	Full sample		Symptomatic residents		Asymptomatic residents
Date of diagnosis (2020)	30-day mortality rate	RR	30-day mortality rate	RR	30-day mortality rate	RR
March 16–31	19.3	0.92	27.3	1.01	8.3	0.49
April 1–15	20.9	Ref	27.0	Ref	16.8	Ref
April 16–30	16.5	0.79**	22.6	0.84**	11.2	0.67**
May 1–15	15.5	0.74**	20.9	0.77**	10.9	0.65
May 16–31	13.3	0.64**	19.5	0.72**	8.2	0.49**
June 1–15	10.2	0.49**	14.2	0.53**	6.9	0.41**
June 16–30	10.9	0.52**	16.2	0.60**	7.0	0.42**
July 1-15	10.3	0.49**	16.7	0.62**	6.3	0.38**
July 16–31	11.7	0.56**	15.7	0.58**	8.4	0.50**
August 1–15	7.2	0.35**	7.4	0.27**	7.0	0.42**
August 16–31	10.7	0.51**	13.5	0.5**	7.8	0.46**
September 1–15	11.4	0.54**	15.4	0.57**	8.1	0.48**
September 16–30	13.3	0.64**	18.4	0.68**	9.0	0.53**
October 1–15	11.4	0.55**	12.7	0.47	8.5	0.51**
October 16–31	14.0	0.67**	13.6	0.50**	11.4	0.68
November 1–15	11.2	0.53**	9.3	0.34**	10.4	0.62**

SOURCE Authors’ analysis of resident-level data from 282 nursing homes operated by a large long-term care provider.

NOTES Adjusted mortality rates and relative risks were derived from a robust Poisson regression model. Covariates were age, sex, race (categorized as White, Black, and other), Morris activities of daily living score, Cognitive Function Scale score, baseline comorbidities, postacute versus long-stay status, and presence of COVID-19-related symptoms (see the Study Data And Methods for details). Referent = 1.00.

^**p < 0.05