Table 1.

Baseline characteristics of the COVID-19 and non-COVID-19 groups before and after propensity score matching.

	Before PS matching (overall group)			After PS matching*
	COVID-19 (N = 18,278)	Non-COVID-19 (N = 5,501,604)	aSD	COVID-19 (N = 17,401)	Non-COVID-19 (N = 17,401)	aSD
Age, years	50.0	51.2	0.068	48.8	48.6	0.016
Charlson Comorbidity Index	1.923	1.523	0.194	1.650	1.768	0.055
Sex (%)
Male	47.4%	49.5%	0.043	47.6%	47.5%	0.003
Female	52.6%	50.5%	0.043	52.4%	52.5%	0.003
Index date (%)
February 2020–May 2020	18.0%	47.8%	0.298	18.9%	20.1%	0.012
June 2020–September 2020	17.3%	49.6%	0.323	18.0%	17.8%	0.020
October 2020–February 2021	66.8%	5.3%	0.615	65.3%	64.3%	0.010

Values are numbers (percentages) unless stated otherwise. PS, propensity score; aSD, absolute standardized difference.

*Balance in covariate distribution between two groups was assessed using the absolute standardized mean difference.