Smith 2005.
| Methods | Randomised, placebo‐controlled, single‐blind study. This was a 2‐phase study, with phase 1 varying in duration (3 to 12 months), where the dose of inhaled fluticasone was titrated down in a stepwise manner until the optimal dose was deemed to have been achieved. During phase 2 (12 months), optimal dose from phase 1 was continued, and therapy was stepped up if asthma control was lost. Participants were blinded to which group they were assigned to. In phase 1 there were 16 dropouts, 13 during run‐in and 3 during follow‐up. Phase 2 had 5 dropouts during the 12 months |
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| Participants | 97 participants were randomised from 110 participants recruited, mean age of 44.8 years (range 12 to 73) and 41 males, 69 females. FeNO group N = 46 Control group N = 48 Inclusion criteria: Inhaled corticosteroids for 6 months with no dose change in previous 6 weeks. Exclusion criteria: > 4 courses of oral prednisolone in previous 12 months, admission to hospital in the last 6 months, any intensive care admissions, or cigarette smoking (current or past history of > 10 pack‐years) |
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| Interventions | Phase 1 Run‐in period was for 6 weeks, after 2 weeks fluticasone 750 ug/day was commenced. Visits were every 4 weeks until optimal dose was achieved. FeNO group: Adjustment of dose of ICS was based solely to keep FeNO < 15 ppb at 250 mL/sec. Control group: Dose adjustment based on asthma symptoms, nighttime waking, bronchodilator use, variation in PEFR and FEV1. Phase 2 Visits every 2 months. Upward adjustments made as per phase 1 but no downward adjustments would be made from optimal dose |
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| Outcomes | Primary outcome: Frequency of exacerbation. Secondary outcome: Mean daily dose of ICS |
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| Notes | Funding: This study was funded by the Otago Medical Research Foundation, the Dean’s Fund of the Dunedin School of Medicine, and a grant from the University of Otago. Supplies of fluticasone were provided by GlaxoSmithKline (New Zealand). Equipment for the analysis of nitric oxide in other studies was provided by Aerocrine | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Insufficient information of randomisation and sequence generation in published article |
| Allocation concealment (selection bias) | Unclear risk | Insufficient information of randomisation in published article |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Single blind. All treatment orders were verified independently by an investigator who was blinded to treatment group |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Single blind. All treatment orders were verified independently by an investigator who was blinded to treatment group |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Missing data has been imputed using appropriate methods |
| Selective reporting (reporting bias) | Unclear risk | Insufficient information provided in published article |
| Other bias | Unclear risk | Nil information provided in published article regarding success of measuring FeNO |