Table 3.
Quality of Spirometry Testing
| Outcome | Control | Intervention | Adjusted Difference of Differences | ||||
|---|---|---|---|---|---|---|---|
| Pre3 (n=410) | Post3 (n=884) | p-value1 | Pre3 (n=719) | Post3 (n=1103) | p-value1 | p-value2 | |
| Spirometry tests with passing grade (AB criterion): N (%) | 104 (25.4%) | 254 (28.7%) | 0.21 | 362 (50.4%) | 550 (49.9%) | 0.84 | 0.71 |
1
P-values are based on Chi-squared test comparing pre and post-intervention periods within each arm.
2
P-value is for the study group (intervention/control)-by-period interaction term in a mixed effects logistic regression model, controlling for age group (5–12 vs. 13–16 years), and gender. Within matched-pair correlations and within-site correlations were accounted for via random effects.
3
Pre-period for control practices: Jan–Apr, 2011; Pre-period for intervention practices Jan–Feb, 2011; Post-period for both control and intervention practices: Jul–Dec 2011.