Study	Reason for exclusion
Becker 1985	Not acute asthma.
Carson 1985	Study comparison was a home‐made spacer vs. oxygen‐driven nebulizer, no commercial spacer involved.
Duarte 2002	Study comparison was a home‐made spacer vs. oxygen‐driven nebulizer, no commercial spacer involved.
El‐Kassimi 1987	Study included adult patients
Fowler 2001	Study included adult patients, and did not include outcomes of interest.
Henry 1983	Study comparison was salbutamol versus placebo via a home‐made spacer, no commercial spacer involved.
Kerac 1998	Not acute asthma
Kissoon 2001	No outcomes of interest in this study.
Lipworth 2002	Not a randomised controlled trial, not acute asthma, and absence of outcomes of interest.
Mazur 2000a	Not a randomised controlled trial, but a review and commentary of a previous published paper.
Mazur 2000b	Same study as Zar 1999.
Mazur 2000c	Same study as Zar 1999.
Motala 2000	Review article.
Obgaidze 2005	Non‐randomized trial
Quetulio 2004	Probably some patients included in Quetulio 2002, no outcomes presented in this abstract in a usable form, and no response from authors to request for clarification.
Rajkumar 2002	Not acute asthma.
Samaranayake 1998	Mixed population of patients (pediatric and adult participants), not possible to separate data from pediatric patients and no response from authors.
Schleufe 1998	Not a randomised controlled trial, design more suitable to before and after study. Not acute asthma. Probably adult patients, no response from authors to request for clarification.
Teo 1988	Study comparison was salbutamol versus placebo via a home‐made spacer, no commercial spacer involved.
Vichyanond 1992	Not acute asthma.
Willemse 2003	Study included adult patients. Not acute asthma.
Zar 1998a	Absence of outcomes of interest.
Zar 1998b	Absence of outcomes of interest.
Zar 2002a	Review article.
Zar 2002b	Review article.

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