Effect of Ambient PM2.5-Bound BbFA and DahA on Small Airway Dysfunction of Primary Schoolchildren in Northeast China

Table 3

OR for the incidence of PVD and SAD in students of schools A and B in Harbin.

	Incidence of PVD (%)		Incidence of SAD (%)
	School A	School B	School A	School B
Heating season	49.67	47.02	17.64	29.14^#
Nonheating season	26.79	28.48	11.76	16.56
OR (95% CI)	2.696 (1.672–4.348)	2.229 (1.384–3.590)	1.607 (0.844–3.060)	2.073 (1.190–3.608)

OR, odds ratio; 95% CI, 95% confidence interval. vs. schoolchildren in the nonheating season; ^# vs. schoolchildren A in the heating season.