Table 3. Primary and Secondary Asthma Outcomes and Lung Function Assessmenta.
| Observed outcomes after the intervention | Adjusted effect (95% CI)b | Observed outcomes after the intervention | Adjusted effect (95% CI)b | |||
|---|---|---|---|---|---|---|
| IPM | No IPM | HEPA filter | Sham HEPA filter | |||
| Primary outcome | ||||||
| No. of students | 97 | 105 | 105 | 97 | ||
| No. of symptom-days with asthma, 2-wk mean (SD) | 1.5 (2.9) | 1.9 (3.3) | IRR, 0.71 (0.38 to 1.33) | 1.6 (3.0) | 1.8 (3.3) | IRR, 1.47 (0.79 to 2.75) |
| Prespecified secondary outcomes | ||||||
| No. of students | 97 | 105 | 105 | 97 | ||
| No. of missed school days due to asthma, 2-wk mean (SD) | 0.11 (0.50) | 0.17 (0.75) | IRR, 0.20 (0.04 to 0.96) | 0.15 (0.68) | 0.13 (0.59) | IRR, 0.74 (0.17 to 3.28) |
| Asthma-related health care use, 2-mo mean (SD)c | 0.04 (0.21) | 0.08 (0.29) | IRR, 0.94 (0.38 to 2.31) | 0.07 (0.27) | 0.06 (0.24) | IRR, 1.01 (0.43 to 2.38) |
| Composite Asthma Severity Index, mean (SD)d | 2.9 (2.2) | 3.0 (2.4) | MD, –0.2 (–0.7 to 0.3) | 3.0 (2.3) | 2.8 (2.3) | MD, 0.1 (–0.5 to 0.6) |
| Lung function | ||||||
| No. of students | 111 | 107 | 109 | 109 | ||
| FEV1, mean (SD), % predicted | 95.2 (17.5) | 98.0 (15.5) | MD, –3.8 (–6.8 to 0.8) | 96.2 (16.7) | 96.9 (16.5) | MD, –0.2 (–3.2 to 2.8) |
| FEV1:FVC, mean (SD), % | 82.8 (8.8) | 83.2 (7.1) | MD, –1.5 (–3.2 to 0.2) | 83.8 (7.9) | 82.2 (8.1) | MD, 1.6 (–0.1 to 3.4) |
| FEF25%-75%, mean (SD), % predicted | 88.4 (28.5) | 93.3 (32.0) | MD, –5.8 (–12.0 to 0.5) | 90.8 (31.1) | 90.6 (29.6) | MD, 4.7 (–1.6 to 10.9) |
Abbreviations: FEF25%-75%, forced expiratory flow between the 25% and 75% of FVC; FEV1, forced expiratory volume in first second of expiration; FEV1:FVC, ratio of FEV1 to percent of FVC; FVC, forced vital capacity; HEPA, high-efficiency particulate air; IPM, integrated pest management; IRR, incidence rate ratio; MD, mean difference.
The test for interaction between the 2 interventions yielded null results; therefore, pooled results are presented. Details of the 4 mutually exclusive treatment groups appear in eTable 3 in Supplement 2.
Adjusted for between-group differences prior to the intervention, visit, effect of the other intervention, and student and school random effects.
Defined as sum of unscheduled clinic visits, emergency department visits, and overnight hospitalizations.
No. of symptoms during the day and albuterol use and No. of symptoms during the night and albuterol use, controller treatment, lung function, and exacerbations (defined as need for systemic corticosteroids for asthma).