Table 4.
Generalized estimating equation estimates (95% confidence interval) of change in asthma-related emergency/urgent and hospitalization visit count as a function of particulate matter with a diameter less than 10 μm, (measured in μg/m3)
| Lag Structure for PM10* | Records Available for Analysis | Relative Increase in Hospital Count per IQR Increase in Pollutant† (%) | 95% CI | P Value |
|---|---|---|---|---|
| 3-d MA | 3,445 | 3.1 | 0.3 to 5.9 | 0.03 |
| 3-d MA‡ | 3,444 | 3.9 | 0.9 to 6.8 | 0.01 |
| 5-d MA | 3,512 | 3.1 | −0.1 to 6.4 | 0.06 |
| 1-d, lag 0 | 3,112 | 1.0 | −1.1 to 3.1 | 0.40 |
| 1-d, lag 1 | 3,112 | 1.5 | −0.6 to 3.4 | 0.17 |
| 1-d, lag 2 | 3,111 | 1.5 | −0.6 to 3.6 | 0.17 |
| 1-d, lag 3 | 3,111 | 0.0 | −2.2 to 2.3 | 0.99 |
| 1-d, lag 4 | 3,110 | −0.3 | −2.5 to 2.1 | 0.81 |
Definition of abbreviations: CI = confidence interval; IQR = interquartile range; MA = moving average; PM10 = particulate matter with a diameter less than 10 μm.
*
Averaged days starting from current day, for example, lagged 3-day MA includes current day plus previous 2 days.
†
IQR, 16, 14.7, and 14.4 for 1-day, 3-day, and 5-day moving averages, respectively.
‡
Without outlier (1 value that exceeded 300 μg/m3).