TABLE 3.
Associations of PM2.5 and O3 With Fatal Exacerbations of Asthma Among Children in North Carolina, With Results Generated From Five Sensitivity Analyses
| Lag Period, in Days | OR (95% CI) | |
|---|---|---|
| Sensitivity analysis 1: Main model, adjusted for continuous measures of same-day temperature and relative humidity | ||
| PM2.5, in μg/m3 | 3–5 | Referent |
| 0.7 (0.3, 1.5) | ||
| 2.5 (1.2, 5.2) | ||
| O3, in ppb | 3–5 | Referent |
| 1.4 (0.7, 2.8) | ||
| 1.7 (0.6, 5.1) | ||
| Temperature, in °F | 0 | 1.0 (0.9, 1.0) |
| Relative humidity, % | 0 | 1.0 (1.0, 1.1) |
| Sensitivity analysis 2: Main model, adjusted for continuous measures of temperature and relative humidity, lagged by 3–5 days | ||
| PM2.5, in μg/m3 | 3–5 | Referent |
| 0.7 (0.3, 1.4) | ||
| 2.1 (1.0, 4.5) | ||
| O3, in ppb | 3–5 | Referent |
| 1.2 (0.6, 2.6) | ||
| 1.2 (0.4, 4.2) | ||
| Temperature, in °F | 3–5 | 1.0 (1.0, 1.1) |
| Relative humidity, % | 3–5 | 1.0 (0.9, 1.0) |
| Sensitivity analysis 3: Main model, with tertiles replaced by continuous measures of PM2.5 and O3 | ||
| PM2.5, in μg/m3 | 3–5 | 1.0 (0.9, 1.1)a |
| O3, in ppb | 3–5 | 1.0 (1.0, 1.1)a |
| Sensitivity analysis 4: Sensitivity analysis 1, with tertiles replaced by continuous measures of PM2.5 and O3 | ||
| PM2.5, in μg/m3 | 3–5 | 1.0 (0.9, 1.1)b |
| O3, in ppb | 3–5 | 1.0 (1.0, 1.1)b |
| Temperature, in °F | 0 | 1.0 (0.9, 1.0) |
| Relative humidity, % | 0 | 1.0 (1.0, 1.1) |
| Sensitivity analysis 5: Sensitivity analysis 2, with tertiles replaced by continuous measures of PM2.5 and O3 | ||
| PM2.5, in μg/m3 | 3–5 | 1.0 (0.9, 1.1)c |
| O3, in ppb | 3–5 | 1.0 (1.0, 1.1)c |
| Temperature, in °F | 3–5 | 1.0 (1.0, 1.1) |
| Relative humidity, % | 3–5 | 1.0 (0.9, 1.0) |
ORs shown are per unit increase. Converting to ORs per 10-unit increase generates an OR per 10 μg/m3 of PM2.5: 1.0 (95% CI = 0.4, 2.3) and an OR per 10 ppb of O3: 1.5 (95% CI = 1.0, 2.3).
ORs shown are per unit increase. Converting to ORs per 10-unit increase generates an OR per 10 μg/m3 of PM2.5: 1.1 (95% CI = 0.5, 2.5) and an OR per 10 ppb of O3: 1.5 (95% CI = 1.0, 2.3).
ORs shown are per unit increase. Converting to ORs per 10-unit increase generates an OR per 10 μg/m3 of PM2.5: 1.0 (95% CI = 0.4, 2.2) and an OR per 10 ppb of O3: 1.4 (95% CI = 0.9, 2.4).
CI indicates confidence interval; PM2.5, particulate matter ≤2.5 μm; ppb, parts per billion; O3, ozone; OR, odds ratio.