Table 2.

Comparison between epidemic wave in COVID-19 pandemic and control periods.

		Prepandemic	1st Wave	2nd Wave	3rd Wave	Total Wave a	Inter-Wave
LAD	ED visit change, %	29.42	−52.44	−58.1	−60.38	−56.47	−48.58
	Deaths change, %	20.00	11.11	−31.43	84.62	4.00	24.32
	Fatality rate change, %	0.00	0.04	0.03	0.08	0.05	0.04
	p-Value	0.03 *	<0.01 **	0.14	<0.01**	<0.01 **	<0.01 **
SARI	ED visit change, %	33.61	−66.05	−63.14	−89.67	−77.06	−66.89
	Deaths change, %	−3.64	−11.29	18.03	−2.11	−1.77	−2.03
	Fatality rate change, %	−0.28	2.40	4.47	6.62	4.00	3.87
	p-Value	<0.01 **	<0.01 **	<0.01**	<0.01**	<0.01 **	<0.01 **
AHS	ED visit change, %	−7.66	0.08	10.48	−5.81	0.83	−0.07
	Deaths change, %	−30.53	6.56	25.18	−5.62	7.31	14.67
	Fatality rate change, %	−2.73	0.65	1.35	0.02	0.65	1.46
	p-Value	0.14	0.54	0.33	0.99	0.36	0.13
AIS	ED visit change, %	18.87	−1.53	1.74	1.33	0.29	5.52
	Deaths change, %	33.33	23.21	2.94	−15.29	5.66	33.33
	Fatality rate change, %	0.25	0.54	0.02	−0.36	0.11	0.49
	p-Value	0.66	0.14	0.95	0.36	0.92	0.08
AMI	ED visit change, %	10.69	−1.57	−0.90	−7.06	−3.07	1.77
	Deaths change, %	6.90	11.6	−6.56	−7.44	0.94	5.70
	Fatality rate change, %	−0.22	0.93	−0.39	−0.03	0.28	0.27
	p-Value	0.87	0.29	0.70	0.98	0.62	0.71
CA	ED visit change, %	14.56	8.23	15.00	12.48	11.37	17.05
	Deaths change, %	9.61	6.48	19.00	13.12	11.84	19.57
	Fatality rate change, %	−3.84	−1.41	2.96	0.50	0.37	1.86
	p-Value	0.08	0.30	0.09	0.74	0.67	0.12

Changes in incidence of ED visits, deaths, and fatality by epidemic wave in 2020 compared to the average of corresponding periods in 2018 and 2019. ^a Total wave: February, March, April, August, September, November, and December. * p < 0.05, ** p < 0.01. ED = emergency department, LAD = low-acuity disease, SARI = severe acute respiratory infection, AHS = acute hemorrhagic stroke, AIS = acute ischemic stroke, AMI = acute myocardial infarction, CA = cardiac arrest.