Table 1.
Pre-specified predictor variables for modeling the Asthma Prediction Rule
| Variable | Type | d.f. |
|---|---|---|
| Age | Continuous | 2 |
| BMI | 2 | |
| Race | Dichotomous | 1 |
| Gender | 1 | |
| Gina chronic control | ||
| Daytime sx > 2/wk | 1 | |
| Nocturnal sx > 1/wk | 1 | |
| Activity limitation | Dichotomous | 1 |
| Need for albuterol > 2/wk | 1 | |
| Asthma exacerbation tx with CCS (prior yr) |
1 | |
| SpO2 | Continuous | 1 |
| Accessory muscle use | ||
| SCM | 1 | |
| Intercostal | Dichotomous | 1 |
| Subcostal | 1 | |
| Inspiratory to expiratory ratio | Ordinal | 2 |
| Wheezing | 2 | |
|
|
||
| Total d.f. | 19 | |
d.f. = Degrees of freedom; BMI = Body mass index; sx = symptoms; tx = treatment; SpO2 = oxygen saturation on room air; SCM = sternocleidomastoid