Table 1.

 Characteristics of included trials

Trials	No of patients	Publication status	Industry sponsored trials	Mean age (years)	% male	Baseline FEV1 (mean % predicted)	Atopy	Dose optimisation before randomisation	Drug (dose) of anti- leukotrienes‡		Inhaled glucocorticoids				Duration of treatment (weeks)	Intention to treat analyses		Reported outcomes
											Drug	Intervention group	Control group					Exacerbations requiring systemic steroids	Steroid dose reduction
Anti-leukotrienes versus placebo as add-on therapy to inhaled glucocorticoids
Laviolette et al9	393	Yes	Merck	40	54	72	75		Montelukast (10 mg once daily)		Beclomethasone diproprionate	400 μg	400 μg		16	Yes		No
Simons et al14†	279	Yes	Merck	10	67	78	72		Montelukast (5 mg once daily)		Budesonide	400 μg	400 μg		4	Yes		Yes
Tamaoki et al7	79	Yes	No	48	43	80*	Not reported		Pranlukast (450 mg twice daily)		Beclomethasone diproprionate	750 μg	750 μg		6	Not reported		Yes
Tomita et al18	41	Yes	Not reported	50	60	88*	66		Pranlukast (450 mg once daily)		Beclomethasone diproprionate	400 μg	400 μg		8	Not reported		No
Virchow et al8	368	Yes	Astra-Zeneca	48	51	64	46		Zafirlukast (80 mg twice daily)		Beclomethasone diproprionate	1598 ± 381 μg	1650 ± 456 μg		6	Yes		Yes
Wada et al15	80	Yes	No	50	50	74	53		Pranlukast (225 mg twice daily)		Beclomethasone diproprionate	1048 ± 237 μg	1127 ± 307 μg		4	Not reported		No
Anti-leukotrienes as add-on therapy to inhaled glucocorticoids versus double dose of inhaled glucocorticoids
Nayak et al17	394	No	Astra-Zeneca	39	38	67	94		Zafirlukast (40 mg or 80 mg twice daily)		Beclomethasone diproprionate	400 μg	800 μg		13	No		Yes
Ringdal et al16	440	No	Astra-Zeneca	41	49	85	Not reported		Zafirlukast (20 mg or 80 mg twice daily)		Beclomethasone diproprionate	400-500 μg	800-1000 μg		12	No		Yes
Anti-leukotrienes versus placebo as add-on therapy to tapering doses of inhaled glucocorticoids
Baba et al21	24	No	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Pranlukast (not reported)		Beclomethasone diproprionate	Not reported	Not reported		Not reported		Not reported	No	No
Bateman et al19	359	No	Astra Zeneca	42	45	2.6L	48	0	Zafirlukast (20 mg twice daily)		Beclomethasone diproprionate or Budesonide	400-750 μg	400-750 μg		20	Yes		No	Yes
Laitinen et al20	262	No	Astra Zeneca	44	42	2.5L	43	2 weeks to 3 months	Zafirlukast (20 mg twice daily)		Beclomethasone diproprionate or Budesonide	800-2000 μg	800-2000 μg		12	No		No	Yes
Lofdahl et al6	226	Yes	Merck	40	43	83	Not reported	⩽7 weeks	Montelukast (10 mg once daily)		Various‡	300-3000 μg	300-3000 μg		12	Yes		No	Yes
Shingo et al22	22	No	Merck	39	41	84	Not reported	0	Montelukast (10 mg once daily)		Various§	1600 μg	1350 μg		8	Yes		Yes	No

FEV₁=forced expiratory volume in one second. Anti-leukotriene licensed doses for adults: Montelukast: 10 mg once daily (5 mg for children aged 5 to 14 years), Pranlukast 225 mg twice daily, Zafirlukast 20 mg twice daily. No trial reported use of inhaled glucocorticoids propelled by hydrofluorocarbons. ^*Reported spirometry before abrupt reduction by half of maintenance dose of inhaled glucocorticoids.^† Cross over study. ^‡Reported use of beclomethasone dipropionate (16%), budesonide (22%), flunisolide(15%), fluticasone propionate (7%), and triamcinolone acetonide (40%). Corticosteroids dose reduction not been provided in μg of “chlorofluorocarbon propelled beclomethasone diproprionate equivalent” (T R Reiss, personal communication, 2000). ^§Reported use of triamcinolone acetonide (72%), flunisolide (18%), and beclomethasone dipropionate (9%).