Calhoun 2012.
| Methods | Randomised, parallel, 3‐group, placebo‐controlled, double‐blinded multicentred trial comparing 3 strategies to adjust inhaled corticosteroids in adults with mild to moderate asthma. The 3 strategies were: a strategy based on National Heart, Lung, and Blood Institute guidelines (PABA group), measurement of exhaled nitric oxide (BBA), or occurrence of symptoms prompting rescue use of albuterol (SBA group) | |
| Participants | 363 participants were enrolled with 342 randomised. PABA group N = 114; mean age 34 (SD 12), 42 male, 72 female. BBA group N = 115; mean age 35 (SD 11), 33 male, 82 female. SBA group N = 113; mean age 36 (SD 12), 30 male, 83 female. Participants were recruited with a concurrent Asthma Clinical Research Network trial, but it was unclear as to where study visits occurred. Inclusion criteria: Physician diagnosis of asthma and either reversible airflow limitation (≥ 12% improvement in FEV1 after 360 ug albuterol) or airway hyper‐responsiveness (provocative concentration of methacholine (< 8 mg/mL) causing a 20% drop in FEV1) |
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| Interventions | The adults with mild to moderate asthma on inhaled corticosteroids had their medications adjusted using 1 of 3 strategies:
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| Outcomes | Primary outcome: Time to first treatment failure, a clinically important worsening of asthma Secondary outcomes: Spirometry, albuterol reversibility, methacholine responsiveness, sputum eosinophils, daytime and nighttime symptom and rescue beta‐agonist diaries, ACT, Asthma Symptom Utility Index, and AQLQ. |
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| Notes | The control group used for the analysis was the PABA group, which utilised guidelines. Funding: The study was conducted with the support of the Institute for Translational Sciences at the University of Texas Medical Branch, supported in part by a Clinical and Translational Science Award from the National Center for Advancing Translational Sciences, National Institutes of Health and by National Institutes of Health Grants awarded by the National Heart, Lung, and Blood Institute. Teva Pharmaceuticals provided the study drug and matching placebo. The National Heart, Lung, and Blood Institute had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | No description of how sequence was generated. Protocol from Asthma Clinical Research Network also had no details of sequence generation |
| Allocation concealment (selection bias) | Unclear risk | Concealment not described in the publication. Protocol states that "the module set up by DCC" will be used |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Study states multiblinded study and puffers labelled A, B, C. However, it is unclear if the puffers could be recognised by participants or physicians or both, i.e. whether they identical in appearance |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | As for blinding of participants, this is also unclear |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Primary outcome was time to treatment failure (asthma exacerbation) and secondary outcomes reported |
| Selective reporting (reporting bias) | High risk | Some secondary outcomes are reported incorrectly, with label not correlating with the results published |
| Other bias | Unclear risk | Days from school lost was reported, but unsure of age used in the inclusion criteria. The mean ages of the groups ranged from 34.2 to 36 years old |