Study	Reason for exclusion
Altman 1998	No co‐treatment with inhaled corticosteroids
Barnes 1996	Inconsistent co‐treatment with inhaled corticosteroids, and no tapering attempt Outcomes solely the result of provocation
Barnes 1997	No co‐treatment with inhaled corticosteroids
Basyigit 2001	No co‐treatment with inhaled corticosteroids
Baumgartner 1999	No co‐treatment with inhaled corticosteroids
Becker 2000	No co‐treatment with inhaled corticosteroids
Bisgaard 1999	No systematic co‐treatment with inhaled corticosteroids Intervention administered for < 4 weeks Outcomes were solely the results of provocation tests
Bisgaard 2000	No co‐treatment with inhaled corticosteroids Outcomes did not reflect chronic asthma control Intervention administered for < 4 weeks
Bjermer 2000	Planned (ongoing) trial Control intervention was not placebo (long‐acting beta2‐agonist)
Bjermer 2002	Use of other non permitted drug
Brabson 2002	No co‐treatment with inhaled corticosteroids
Brannan 2001	No co‐treatment with inhaled corticosteroids Intervention < 4 weeks Control intervention is not placebo (it is an anti‐histamine)
Brocks 1996	Subjects were not asthmatic
Bronsky 1997	Subjects were not asthmatic
Bruce 2002	Outcome measures did not reflect asthma control
Busse 1999	No systematic co‐treatment with inhaled corticosteroids Control intervention was not placebo (it's a long‐acting beta2‐agonist)
Cakmak 2000	Outcome measures did not reflect asthma control
Calhoun 1997	No co‐treatment with inhaled corticosteroids
Calhoun 2001	Use of other non permitted drug
Camargo 2002	Acute asthma setting
Capella 2001	Subjects not asthmatic
Chuchalin 2002	Intervention was not anti‐leukotrienes
Clifford 2000	Duplicate reference
Cloud 1989	No co‐treatment with inhaled corticosteroids
Currie 2003	Duplicate reference
Currie 2003 (B)	Use of other non permitted drug
Cylly 2003	Ongoing trial
Dahlen 2002	No consistent co‐treatment with inhaled corticosteroids. Merck Frosst unable to provide subgroup analysis.
Daikh 2003	Subjects were not asthmatics
Dempsey 1999	Intervention administered for < 4 weeks. No consistent co‐treatment with inhaled glucocorticoids
Dempsey 2000	Intervention administered for < 4 weeks (single dose study)
Dempsey 2000b	Control intervention was not placebo
Dempsey 2001	No co‐treatment with inhaled glucocorticoids
Dempsey 2002	Control intervention wase not placebo
Dessanges 1999	Intervention administered for < 4 weeks (single dose study) Outcomes did not reflect control of chronic or acute asthma (solely the results of exercise challenge) No consistent co‐treatment with inhaled corticosteroids
Diamant 1999	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes solely the result of provocation
Dicpinigaitis 2002	Outcome measures did not reflect asthma control
Dockhorn 2000	Intervention administered for < 4 weeks (single dose study) No co‐treatment with inhaled corticosteroids
Eliraz 2001	Tested intervention is not anti‐leukotrienes
Faul 2002	Outcome measures did not reflect asthma control
Findlay 1992	No co‐treatment of inhaled corticosteroids Intervention was administered for less than a four‐week period
Fischer 1995	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes were solely the result of provocation
Fischer 1997	No co‐treatment with inhaled corticosteroids
Fish 1997	No co‐treatment with inhaled corticosteroids
Flynn 2001	Duplicate Reference
Fujimura 1993	No co‐treatment with inhaled corticosteroids
Gaddy 1990	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period, intraveneously
Galant 2001	Duplicate reference
Geha 2001	Tested intervention is not anti‐leukotrienes
Georgiou 1997	No co‐treatment with inhaled corticosteroids Subjects were not asthmatic Intervention was administered for less than a four‐week period
Ghiro 2002	Outcome measures did not reflect asthma control
Gold 2001	Control intervention was not placebo
Green 2002b	Intervention was not anti‐leukotrien
Grossman 1995	No co‐treatment with inhaled corticosteroids
Grossman 1997	No co‐treatment with inhaled corticosteroids
Haahtela 1994	Intervention was not anti‐leukotrienes
Hamilton 1998	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes were solely the result of provocation
Hassall 1998	No co‐treatment with inhaled corticosteroids
Hood 1999	Control subjects not asthmatics (normal subjects)
Howland 1994	No co‐treatment with inhaled corticosteroids
Hsieh 1996	Intervention was not anti‐leukotrienes
Hughes 1999	No co‐treatment with inhaled corticosteroids
Hui 1991	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period
Israel 1990	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes were solely the result of provocation
Israel 1992	No co‐treatment with inhaled corticosteroids
Israel 1993	No co‐treatment with inhaled corticosteroids
Israel 1996	No co‐treatment with inhaled corticosteroids
Israel 2002	No co‐treatment with inhaled corticosteroids
Jayaram 2002	No co‐treatment with inhaled corticosteroids
Johnson 1999	No co‐treatment with inhaled corticosteroids
Juniper 1995	No co‐treatment with inhaled corticosteroids
Kalberg 1999	No co‐treatment with inhaled corticosteroids
Kanniess 2002 (B)	No co‐treatment with inhaled corticosteroids
Kemp 1995	No co‐treatment with inhaled corticosteroids
Kemp 1997	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes were solely the result of provocation
Kemp 1998	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period
Kemp 1999	Not a randomised controlled trial (meta‐analysis of RCTs) Subjects not all treated with inhaled corticosteroids
Kim 2000	No co‐treatment with inhaled corticosteroids
Kips 1991	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period, intravenously
Knorr 1997	Inconsistent co‐treatment with inhaled corticosteroids, and no tapering attempt
Knorr 1998	Inconsistent co‐treatment with inhaled corticosteroids, and no tapering attempt
Knorr 1999	Control intervention were not placebo
Korenblat 1998	No co‐treatment with inhaled corticosteroids
Kuna 1997	Inconsistent co‐treatment with inhaled corticosteroids, and no tapering attempt
Kylstra 1998	No co‐treatment with inhaled corticosteroids
Laitinen 1997	No co‐treatment with inhaled corticosteroids
Leff 1998	No co‐treatment with inhaled corticosteroids Outcomes solely the result of provocation
Leigh 2002	Tested intervention administrated for less than 4 weeks
Leigh 2002 (B)	Use of other non permitted drug
Lipworth 1999	Ongoing trial No co‐treatment with inhaled corticosteroids
Lipworth 2000	Planned (or ongoing) trial Control intervention is not placebo (anti‐histamine)
Liu 1996	No co‐treatment with inhaled corticosteroids
Lockey 1995	No co‐treatment with inhaled corticosteroids
Malerba 2002	No co‐treatment with inhaled corticosteroids
Malmstrom 1999	No co‐treatment with inhaled corticosteroids
Margolskee 1991	No co‐treatment with inhaled corticosteroids
Meltzer 2002	No co‐treatment with inhaled corticosteroids
Micheletto 1997	Interim report of an included eligible trial : Laitinen LA, Zetterstrom O, Holgate ST, Binks SM, Whitney JG. Effects of Accolate (zafirlukast: 20 mg bd) in permitting reduced therapy with inhaled steroids: a multicentre trial in patients with doses of inhaled steroids optimised between 800 and 2000 mcg per day. Allergy 1995: 50 suppl 26:320 (Abs)
Minkwitz 1998	No co‐treatment with inhaled corticosteroids
Miyamoto 1999	No co‐treatment with inhaled corticosteroids
Nathan 1998	No co‐treatment with inhaled corticosteroids
Nathan 2001	No co‐treatment with inhaled corticosteroids
Nelson 2001	Control intervention were not placebo
Nishizawa 2002	Intervention was not anti‐leukotrien
Noonan 1998	No co‐treatment with inhaled corticosteroids
Nsouli 2001	Control group were not placebo
O'Shaughnessy 1996	Subjects were not asthmatic Outcomes were solely the result of provocation
Obase 2001	Subjects received additional non‐permitted drugs (maintenance systemic steroids)
Overbeek 2002	No co‐treatment with inhaled corticosteroids
Paterson 1999	Tested intervention administrated for less than 4 weeks
Pearlman 1999	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes solely the result of provocation
Pearlman 2002	No co‐treatment with inhaled corticosteroids
Pizzichini 1999	No co‐treatment with inhaled corticosteroids
Pullerits 1999	Subjects non asthmatics (allergic rhinitis)
Pullerits 2001	Subjects were not asthmatics
Pullerits 2002	Subjects were not asthmatics
Ramsay 1997	No co‐treatment with inhaled corticosteroids
Ramsay 1998	No co‐treatment with inhaled corticosteroids
Reiss 1996	Inconsistent co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period
Reiss 1997a	Inconsistent co‐treatment with inhaled corticosteroids, and no tapering attempt
Reiss 1997b	Inconsistent co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period
Reiss 1998a	No co‐treatment with inhaled corticosteroids
Reiss 1998b	No co‐treatment with inhaled corticosteroids
Reiss 1998c	No co‐treatment with inhaled corticosteroids (Phase II) Not blinded (Phase IV)
Riccioni 2002 (B)	No co‐treatment with inhaled corticosteroids
Riccioni 2002 (c)	No co‐treatment with inhaled corticosteroids
Ringdal 1997	No co‐treatment with inhaled corticosteroids
Robinson 2001	Treatment for < 4 weeks
Rosenhall 2003	Intervention was not anti‐leukotrienes
Sahn 1997	No co‐treatment with inhaled corticosteroids No measure of efficacy or inflammatory markers.
Schwartz 1998	No co‐treatment with inhaled corticosteroids
Sheth 2002	No co‐treatment with inhaled corticosteroids
Skalky 1999	No co‐treatment with inhaled corticosteroids
Smith 1993	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period
Smith 1998	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes solely the result of provocation
Spector 1992	No co‐treatment with inhaled corticosteroids
Spector 1994	No co‐treatment with inhaled corticosteroids
Spector 1995	No co‐treatment with inhaled corticosteroids
Stanford 2002	No co‐treatment with inhaled corticosteroids
Stelmach 2002	No co‐treatment with inhaled corticosteroids
Stelmach 2002 (b)	No co‐treatment with inhaled corticosteroids
Storms 2001	Duplicate reference
Suissa 1997	No co‐treatment with inhaled corticosteroids
Svensson 1994	No co‐treatment with inhaled corticosteroids
Tashkin 1998	No co‐treatment with inhaled corticosteroids
Terzano 2001	Intervention was not anti‐leukotrien
Townley 1995	No co‐treatment with inhaled corticosteroids
Tukiainen 2002	Intervention was not anti‐leukotrien
Verhoeven 2001	Subjects non‐asthmatics
Vethanayagam 2002	Tested intervention administrated for less than 4 weeks
Vidal 2001	No consistent co‐treatment with inhaled corticosteroids Intervention administered for < 4 weeks
Volovitz 1999	Subjects not all treated with inhaled corticosteroids
Von Berg 2002	Intervention was not anti‐leukotrien
Wahedna 1991	Intervention was administered for less than a four‐week period Outcomes solely the result of provocation challenge
Weinberg 1998	No co‐treatment with inhaled corticosteroids
Welch 1994	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period
Wenzel 1994	No co‐treatment with inhaled corticosteroids
Wenzel 1995	Control subjects were not asthmatic Intervention was administered for less than a four‐week period
Wenzel 1997	No co‐treatment with inhaled corticosteroids
Westbroek 1998	No co‐treatment with inhaled corticosteroids
Westbroek 2000	Intervention administered for < 4 weeks Subjects not all treated with inhaled corticosteroids
Williams 2000	3 studies: Study A :No co‐treatment with inhaled corticosteroids Study B: No consistent co‐treatment with inhaled corticosteroids Study C: No consistent co‐treatment with inhaled corticosteroids
Wilson 1999	Ongoing trial Subjects not asthmatics (allergic rhinitis)
Wilson 1999 (b)	Control intervention were not placebo
Wilson 2001	Outcome measures did not reflect asthma control
Wilson 2001 (c)	Subjects were not asthmatics
Wilson 2001a	No co‐treatment with inhaled corticosteroids control intervention is not placebo treatment < 4 weeks
Wilson 2001b	Control intervention is not placebo (it's a long‐acting beta2‐agonist)
Xiang 2001	Use of other non permitted drug
Yamamoto 1994	No co‐treatment with inhaled corticosteroids Intervention was administered for less than a four‐week period Outcomes solely the result of provocation
Yamauchi 2001	No co‐treatment with inhaled corticosteroids
Yoo 2001	Inconsistent co‐treatment with inhaled corticosteroids
Yoshida 2000	Tested intervention asministrated for less than 4 weeks
Yoshida 2002	Tested intervention asministrated for less than 4 weeks
Zhang 1999	No co‐treatment with inhaled corticosteroids
Zorc 2003	Intervention was not anti‐leukotrienes