Wenzel 1998.

Methods	STUDY DESIGN: Parallel group, multicentre, 40, USA. 12 weeks. RANDOMISATION: Yes, no method stated. BLINDING: double blind, double dummy, matching devices. WITHDRAWALS/DROP OUTS: 15 described after randomization. COMPLIANCE:. Not assessed / reported. CONFOUNDERS: Groups well balanced by characteristics QUALITY: Jadad 4. Cochrane B
Participants	N = 539 ENROLLED/ RANDOMISED, ADULT/ADOLESCENT , M = 272 F = 266 Mean age: 35.4 (range 12 to 83) BASELINE SEVERITY: Mild to moderate persistent asthma INCLUSION : Diagnosis asthma by ATS criteria, requiring daily bronchodilator treatment > 6 weeks. Baseline FEV1 40 to 80% predicted, > 15% FEV1 reversibility to SABA. EXCLUSION: CF, COPD, current smokers, hospitalized by exacerbation asthma < 6 weeks. Use of theophyllines or cromones.
Interventions	LONG ACTING BETA AGONIST: Salmeterol 42 mcg BD SHORT ACTING BETA AGONIST: Albuterol 180mcg QDS PLACEBO: placebo BD DEVICE: MDI. TREATMENT PERIOD: 12 weeks RESCUE: Albuterol 90 mcg PRN CO‐INTERVENTIONS: ICS 46%,
Outcomes	OUTCOMES: FEV1, FVC, PEF, Rescue use, asthma symptom score, adverse events, AQOL scores.
Notes	Symptom Score‐ Night‐time 0‐3 (none ‐ woke > 3 times). Day‐time 0‐3 (no symptoms ‐ significant discomfort)
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Information not available (Cochrane Grade B)

ICS = Inhaled corticosteroids. OS = oral corticosteroids. LABA = long‐acting beta2 agonist. SABA = Short‐acting beta 2 agonist. Short acting beta 2 agonist salbutamol known in USA as albuterol‐ dose measured at mouthpiece 90 mcg = 100mcg from inhaler . Bronchial hyperreactivity = BHR, measured as PD20 or PC20 in methacholine or histamine. BDP = beclomethasone dipropionate, BUD = budesonide , FP = fluticasone propionate. Cromones = sodium cromoglycate, nedocromil sodium . 
 MDI = Metered dose inhaler. Dosages: QDS= 4 times daily, TDS= 3 times daily, BD= twice daily. 
 AQOL score = Asthma quality of life score, based on Juniper 1992 (Juniper EF, Guyatt GH. Evaluation of impairment of health related quality of life in asthma: development of a questionnaire for use in clinical trials. Thorax 1992;47:76‐83) value of 1 = maximum impairment, value 7 = no impairment. Results 0.5 = small change, 1.0 = moderate change, 1.5 = large change. 
 LWAQ = Living with asthma questionnaire (Hyland M. The living with asthma questionnaire. Respir Med 1991;85 supp:13‐16.), lower score indicates better quality of life.