Table 5.

Percentage changes with 95% CIs in hospitalization for CHF associated with a 10 μg/m³ increase in PM_2.5.

Variables	df a	Percentage Change	95% CI	p
Calendar time	4	0.33	0.07–0.60	0.0142
	5	0.35	0.07–0.62	0.0148
	6	0.33	0.06–0.61	0.0171
	7 b	0.35	0.06–0.64	0.0191
	8	0.40	0.10–0.70	0.00804
Temperature	2	0.35	0.06–0.64	0.0191
	3 b	0.35	0.06–0.64	0.0191
	4	0.47	0.20–0.74	0.000609
	5	0.46	0.19–0.73	0.000874
	6	0.45	0.18–0.72	0.00101
Relative humidity	2	0.35	0.06–0.64	0.0191
	3 b	0.35	0.06–0.64	0.0191
	4	0.33	0.04–0.63	0.0238
	5	0.33	0.04–0.63	0.0239
	6	0.34	0.05–0.63	0.0211

^a df notes degree of freedom. ^b The df values used in this study model.