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
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)
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
Outcomes	Primary outcome: Frequency of exacerbation. Secondary outcome: Mean daily dose of ICS
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