Study	Reason for exclusion
Anonymous 1978	Non‐experimental study (not randomized controlled clinical trial).
Arnaud 1977	Not randomized controlled clinical trial.
Beswick 1975	Not randomized controlled clinical trial..
Blumenthal 1979	Letter, not a clinical trial.
Boe 1985	Not randomized controlled clinical trial. Intravenous beta‐agonists use was not the primary research question (no control; compared 2 doses of terbutaline ‐ dose response curve).
Bohn 1984	Not randomized controlled clinical trial.
Bruguerolle 1991	Not randomized controlled clinical trial.
Crompton 1990	Review.
Downes 1973	Not randomized controlled clinical trial.
Edmunds 1981	Not randomized controlled clinical trial.
Evans 1980	Not randomized controlled clinical trial ‐ cohort study.
Fitchett 1975	Not randomized controlled clinical trial ‐ cohort study.
Grant 1976	Letter to editor.
Greif 1985	Not randomized controlled clinical trial ‐ cohort study.
Herman 1983	Not randomized controlled clinical trial ‐ cohort study.
Hetzel 1976	Not randomized controlled clinical trial ‐ cohort study.
Hirsch 1979	Case report.
Iodice 1980	Not randomized controlled clinical trial ‐ cohort study.
Janson 1992	Not randomized controlled clinical trial.
Marlin 1975	Chronic asthma.
May 1975	Not randomized controlled clinical trial ‐ cohort study.
Nogrady 1977	Case series.
Noseda 1989	Review.
O'Connell 1990	Not randomized controlled clinical trial ‐ cohort study.
Parry 1976	Not randomized controlled clinical trial ‐ cohort study.
Pierce 1981	Patients were not seen in an emergency setting (study done in a lab setting).
Salmeron 1995	Letter to editor.
Schiavi 1987	Not randomized controlled clinical trial.
Smith 1986	Non‐experimental study (not randomized controlled clinical trial).
Spiro 1975	Non‐experimental study (not randomized controlled clinical trial). Patients were not seen in an emergency setting (study done in a lab setting).
Subias 1989	Not randomized controlled clinical trial.
Teoh 1979	Non emergency patients. Not randomized controlled clinical trial ‐ cohort study.
Thiringer 1976	Non‐experimental study (not randomized controlled clinical trial). Patients were not seen in an emergency setting (study done in a lab setting).
Ting 1991	Not randomized controlled clinical trial.
Tirot 1992	Not randomized controlled clinical trial.
Tripathi 1989	Not randomized controlled clinical trial.
Williams 1977	Non‐experimental study (not randomized controlled clinical trial).
Wood 1972	Not randomized controlled clinical trial.
Wood 1973	Not randomized controlled clinical trial.