de Jongste 2009.

Methods	Prospective, open‐label, randomised, multicentre, parallel‐group trial
Participants	151 children aged 6 to 18 years with stable mild/moderate asthma treated with 200 to 1000 microgram of inhaled budesonide or equivalent for 2 months before randomisation, recruited from 5 academic centres and 12 general hospitals. Children had RAST class 2 or higher or a positive skin prick test for at lease one airborne allergen.
Interventions	The intervention group received an nitric oxide airway inflammation monitor to perform measurements daily. Data were transmitted to the co‐ordinating centre. All children (intervention and controls)  recorded symptoms on a palmtop electronic diary. All parents were phoned every 3 weeks between visits and medication was adapted according to mean nitric oxide and cumulative symptom scores over the previous 3 weeks.
Outcomes	Children of both groups were seen at randomisation and at 3, 12, 21 and 30 weeks. All parents were phoned every 3 weeks between visits and medication (steroids) was adapted according to an algorithm which included symptoms and mean expired nitric oxide. 1. Expired nitric oxide was performed before and after salbutamol, as a measure of airways inflammation 2. Adverse events were recorded 3. Pediatric Asthma Caregiver Quality of Life Questionnaire with Standardized activities was administered at first and last visits 4. Primary end point was change from baseline of percentage symptom‐free days during the last 12 weeks 5. FEV1 and reversibility 6. Prednisone courses 7. Emergency visits 8. Hospitalisations
Notes	All nitric oxide analysers were checked for drift. Intention‐to‐treat analysis was performed for all subjects who were enrolled. In addition they performed a per protocol analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Children were randomised at their first visit, stratified by centre
Allocation concealment (selection bias)	Unclear risk	Insufficient information
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding
Incomplete outcome data (attrition bias) All outcomes	High risk	Four children, 2 for non‐compliance, 1 for inappropriate inclusion (no allergy) and 1 for moving abroad and being unable to transfer data. Therefore study population for evaluation was 147 children. "Only periods with at least 50% valid daily scores were analysed." Is later explained as 79% valid diary entries over the whole study period. It is not explained what is done for the remaining periods.
Selective reporting (reporting bias)	High risk	Full details of number of emergency department visits are not reported
Other bias	High risk	Children only recruited from academic centres or general hospitals therefore may not be receiving standard primary care