Table 3. Multivariable results for Pediatric Asthma Hospitalization Length of Stay, Charges, and Costs as predicted by Changes in Levels of Fine Particulate Matter¹.

PM_2.5 level²	Increment Change (95% CI) in Length of Stay³	Increment Change (95% CI) in Total Charges⁴	Increment Change (95% CI) in Total Costs⁴
1 month avg⁵	+0.6% (-0.3-1.5)	+$123 (40-249)^**	+$47 (15-93)^**
2 month avg	+0.9% (-0.2-2.1)^*	+$170 (67-321)^***	+$55 (20-110)^**
3 month avg	+1.1% (-0.2-2.4)^*	+$195 (82-362)^***	+$62 (24-121)^***
4 month avg	+1.2% (-0.1-2.6)^*	+$210 (93-386)^***	+$67 (29-126)^***
5 month avg	+1.1% (-0.3-2.6)^*	+$222 (100-404)^***	+$69 (30-127)^***

Increment changes for 1-unit (ug/m3) increase in particulate matter of diameter <2.5ug (PM_2.5)

Average level of PM_2.5 within a 10-mile radius of the hospital

Increment percent change calculated from exponentiating Poisson beta coefficient

⁴

Increment change in dollars calculated using Duan transformation for linear regression

p-value ≤ 0.1

^**

p-value ≤ 0.001

^***

p-value ≤ 0.0001

⁵

avg=average

Table 3. Multivariable results for Pediatric Asthma Hospitalization Length of Stay, Charges, and Costs as predicted by Changes in Levels of Fine Particulate Matter1.