Jonasson 1998.

Methods	DESIGN: a randomised, double‐blind, placebo‐controlled trial
Participants	SYMPTOMATIC PARTICIPANTS RANDOMLY ASSIGNED: N = 83 INTERVENTION: ICS (budesonide 100 μg/d o.d.): 41 CONTROL: ICS (budesonide 200 μg/d o.d.): 42 WITHDRAWALS: reported AGE: mean (years) (range): INTERVENTION: ICS (budesonide 100 μg/d o.d.): 10.0 CONTROL: ICS (budesonide 200 μg/d o.d.): 9.8 GENDER: N (male %): INTERVENTION: ICS (budesonide 100 μg/d o.d.): 23 (54.7) CONTROL: ICS (budesonide 200 μg/d o.d.): 31(75.6) ASTHMA SEVERITY: mild asthma ASTHMA DURATION: not reported MEAN (± SD) β2‐AGONIST USE (puffs/d): not reported DOSE OF ICS AT STUDY ENTRY AND AT RUN‐IN: none within 2 months ATOPY: N (% of participants): INTERVENTION: ICS (budesonide 100 μg/d o.d.): 25 (59.5) CONTROL: ICS (budesonide 200 μg/d o.d.): 31 (75.6) ELIGIBILITY CRITERIA Diagnosis of asthma, based on definition in the International Consensus report and in the Nordic Consensus report Patients had three previous obstructive episodes or one previous obstructive episode with atopy; at least one of these episodes had to have occurred within the year before the first visit EXCLUSION CRITERIA Patients used ICS within 2 months, or cromoglycate and/or nedocromil within 4 weeks, of entry Patient had a lower respiratory tract infection or exacerbation of asthma requiring an emergency department visit and/or hospitalisations in the 4 weeks before entry
Interventions	PROTOCOL DURATION Run‐in = 2 weeks Intervention = 12 weeks DEVICE: Turbuhaler inhalers DOSE OF ICS INTERVENTION: budesonide 100 μg/d o.d. CONTROL: budesonide 200 μg/d o.d. CRITERIA FOR WITHDRAWAL FROM STUDY: reported
Outcomes	ANALYSIS: intention to‐treat; analysis of variance (ANOVA). Missing values were handled by applying the last value extended principle. For diary variables, this was accomplished by extending the period means OUTCOMES GROWTH MEASUREMENT TECHNIQUE: not reported PULMONARY FUNCTION TESTS Mean maximum fall in FEV1 (% fall from pre‐exercise value) after the exercise test measured at baseline and after 12 weeks of treatment Mean percentage increase in PD20 (μmol) from baseline to end of treatment Change in PEFR (% pred) (lung function measured every 4 weeks); the difference FEV1, FEF25%, FEF50% and FEF75% at all visits throughout the study period FUNCTIONAL STATUS Mean values for asthma symptoms BIOMARKERS: not done ADVERSE EVENTS: reported WITHDRAWALS: reported
Notes	PUBLICATION: full paper (1998) FUNDING: not provided CONFIRMATION OF METHODOLOGY: not received
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information on sequence generation: "patients were randomised into four parallel groups in balanced blocks"
Allocation concealment (selection bias)	Unclear risk	Insufficient information
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinding of participants and key study personnel ensured
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of participants and key study personnel ensured
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	Low risk	Study protocol not available but published reports include all expected outcomes, including those that were prespecified
Other bias	Low risk	Study appears to be free of other sources of bias