Statin effect sizes adjusted for confounders
| Statin effect size | p Value* | Favours | Final model | |
|---|---|---|---|---|
| Primary endpoint† | ||||
| Δ Adjusted mean ACT score | 2.2±0.94 | 0.02 | Statin user | Statin use, obesity, GERD, h/o smoking and FVC predict ACT score |
| Secondary endpoints | ||||
| Lung function† | ||||
| ΔFEV1 (L) | 0.036±0.06 | 0.56 | Statin user | Age, FEV1% predicted and FVC predict FEV1 |
| ΔFVC (L) | 0.026±0.18 | 0.88 | Statin user | Age and ethnicity predict FVC |
| ΔFEF25–75% (L) | 0.088±0.16 | 0.59 | Statin user | Age, FEV1% predicted, FVC and montelukast predict FEF25–75% |
| ΔPEFR (L/min) | −26.8±25.7 | 0.92 | Non user | Systemic steroid use, PPI or H2-blockers, and FVC predict PEFR |
| Symptoms‡ | ||||
| Corticosteroid burst | 0.93 | 0.84 | Statin user | FEV1% predicted, h/o smoking and DM predict the need for a steroid burst in clinic |
| Albuterol inhaler use | 0.46 | 0.41 | Statin user | ICS use strongly predicts albuterol inhaler use |
| Ipratropium inhaler use | 0.83 | 0.71 | Statin user | Age, h/o smoking, and FVC predict ipratropium inhaler use |
| Limited physical activity | 1.09 | 0.91 | Non user | Aspirin use and FVC predict limited physical activity |
| Nocturnal symptoms | 1.71 | 0.39 | Non user | Obesity predicts nocturnal symptoms/awakening |
| Peripheral blood counts† | ||||
| Δ Total WCC (K/mm3) | −0.77±0.72 | 0.29 | – | Systemic steroid use predicts change in WCC |
| Δ Absolute eosinophil count | 0.024±0.06 | 0.68 | Non user | No variable in the model predicts the change in absolute eosinophil count (see online supplement) |
| Δ% Eosinophil count | 0.28±0.64 | 0.66 | Non user | Systemic corticosteroid and aspirin use predict the % eosinophil count |
Δ This symbol represents ‘delta’ or the change due to the statin's effect, hence, ‘statin effect size’.
*p Values represent the significance of statin use in the final model.
†Statin effect sizes are listed as the model estimate ± SE. ACT was adjusted for the confounders of obesity, GERD, h/o smoking and FVC.
‡Statin effect sizes are listed as ORs.
ACT, Asthma Control Test questionnaire; DM, diabetes mellitus; FVC, forced vital capacity; GERD, gastro-oesophageal reflux disease; h/o, history of; H2, histamine receptor-2; ICS, inhaled corticosteroid; PEFR, peak expiratory flow rate; PPI, proton-pump inhibitor; WCC, white cell count.