Virchow 2000.

Methods	DESIGN ‐parallel‐group ‐multicentre (82 centres) ‐ALLOCATION ‐Random ‐Computer‐ generated BLINDING ‐double‐blind ‐placebo controlled ‐identical placebo ‐number coded solutions/boxes WITHDRAWAL/DROPOUT ‐described JADAD's Quality Score = 5 ‐Confirmation of methodology obtained
Participants	SYMPTOMATIC PARTICIPANTS RANDOMISED N = 368 Zafirlukast = 180 Control = 188 WITHDRAWALS: Zafirlukast = 18% Control = 18% AGE: Zafirlukast: 49.2 ±12.9 (SD) years Control: 47.4 ± 12.6 years GENDER (% male) Zafirlukast : 48% Control: 53% SEVERITY: moderate/severe asthma BASELINE FEV1 (% pred): Zafirlukast: 64.3 ± 7.5 (SD) Control: 63.5 ±8.0 ALLERGEN TRIGGERS (%) Zafirulast: 41% Control:51% DURATION OF ASTHMA: Zafirlukast: 15.7 ± 12.61(SD) years Control: 17.5 ± 13.63 years ICS DOSE: Zafirlukast: 1598 ± 381 mcg/day (SD) Control: 1650 ± 456 mcg/day of beclomethasone‐equivalent ELIGIBILITY CRITERIA ‐50 to 75% FEV1 Pred ‐ICS dose >= 1200 mcg/day beclomethasone‐equivalent ‐mean FEV1/PEF reversibility >= 15% after salbutamol ‐symptomatic asthma ‐no smoking in preceding 6 months
Interventions	PROTOCOL: AL + ICS vs SAME dose ICS DURATION: ‐Run‐in Period: not described ‐Dose optimisation period: NONE ‐Intervention Period: 6 weeks TEST GROUP ‐Zafirlukast 80 mg bid p.o. + Beclomethasone >= 1200 ug/day CONTROL GROUP ‐Placebo + Beclomethasone >= 1200 ug/day DEVICE ‐various devices used ‐CO‐TREATMENT: none reported
Outcomes	INTENTION‐TO‐TTREAT (ITT) ANALYSIS (some per‐protocol (PP) analyses) ‐results used at 6 weeks PULMONARY FUNCTION TESTS ‐ ITT ‐Change from baseline FEV1 ‐**Change from baseline Am PEF FUNCTIONAL STATUS ‐ITT ‐Change in night wakings (episodes/week)‐Number of patients with exacerbations requiring additional treatment ‐Number of days off work ‐Change in use of rescue beta2‐agonist (puffs/day) INFLAMMATORY MARKERS ‐not reported ADVERSE EFFECTS ‐elevated liver enzymes, headache, nausea, death, etc. WITHDRAWALS ‐reported (** denotes primary outcomes)
Notes	‐Full Text (2000) ‐Funded by Astra‐Zeneca ‐Confirmation of methodology and data extraction received from M. Christopher Miller and Ms. Susan Shaffer, Astra‐Zeneca, Oct 2000 ‐User‐defined order: 165 (mean intervention ICS dose of 1650 mcg/ day X 0.1)
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	Study investigators unaware as to order of treatment group assignment (Cochrane Grade A)