TABLE 3.

Hysteresis effect of different concentration grade of PM2.5.

Hysteresis (day)	PM2.5 ≤ 50	50 < PM2.5 ≤ 100	PM2.5 > 100
	OR (LI, UI)	OR (LI, UI)	OR (LI, UI)
2019
0	0.680 (0.226, 2.051)	0.684 (0.194, 2.415)	0.841 (0.176, 4.027)
1	1.405 (0.589, 3.352)	2.822 (0.887, 8.977)	1.744 (0.499, 6.098)
2	0.889 (0.318, 2.487)	0.919 (0.276, 3.058)	0.442 (0.116, 1.682)
3	0.774 (0.281, 2.133)	1.320 (0.401, 4.342)	0.989 (0.248, 3.946)
4	0.368 (0.106, 1.276)	0.895 (0.217, 3.693)	0.590 (0.128, 2.727)
5	0.980 (0.383, 2.508)	1.359 (0.437, 4.230)	1.882 (0.417, 8.502)
6	1.336 (0.535, 3.336)	1.131 (0.384, 3.332)	0.875 (0.230, 3.327)
7	1.112 (0.395, 3.134)	0.606 (0.199, 1.842)	0.811 (0.188, 3.494)
2020
0	1.664 (0.878, 3.157)	2.014 (0.953, 4.254)	3.115 (1.137, 8.536)
1	0.963 (0.500, 1.855)	1.197 (0.556, 2.579)	2.726 (0.918, 8.091)
2	0.816 (0.414, 1.608)	0.833 (0.374, 1.859)	2.057 (0.631, 6.703)
3	0.888 (0.439, 1.796)	1.021 (0.449, 2.321)	0.973 (0.339, 2.790)
4	1.135 (0.553, 2.329)	0.645 (0.282, 1.475)	0.362 (0.127, 1.034)
5	1.052 (0.526, 2.101)	0.967 (0.436, 2.145)	0.871 (0.303, 2.502)
6	0.969 (0.488, 1.925)	1.034 (0.462, 2.311)	1.619 (0.538, 4.876)
7	0.965 (0.496, 1.877)	1.108 (0.498, 2467)	1.051 (0.527, 4.326)

PM2.5, particulate matter 2.5; OR, odd ratio; LI, lower interval of 95% confidence interval; UI, upper interval of 95% confidence interval.