Hossain 2013.

Methods	‐ Prospective, randomised, single‐centre study. ‐ Comparison of ipratropium bromide and salbutamol vs. salbutamol alone. ‐ Method of randomisation unclear. ‐ No information on allocation concealment provided.
Participants	‐ Patients who presented to the ED with an exacerbation of asthma. ‐ Set in Bangladesh. ‐ Asthma exacerbation was defined as PEF < 50% predicted. ‐ Ages: 18 to 65 years. ‐ Asthma exacerbation severity of presenting patients reported as severe. Unable to assess estimates of asthma severity based on control hospitalisation rates due to lack of information.
Interventions	‐ Multiple doses of combination inhaled therapy. Study interventions provided via nebuliser. ‐ Group one received three doses of salbutamol alone (2.5 mg diluted in 2 mL of normal saline) every 20 minutes. ‐ Group two received three doses of ipratropium bromide (250 μg in 2 mL solution) and salbutamol (2.5 mg diluted in 2 mL of normal saline) every 20 minutes. ‐ Additional co‐interventions provided in the ED included supplemental oxygen and injection hydrocortisone.
Outcomes	‐ The primary outcome was pulmonary function at 30 and 60 minutes after nebulisation. ‐ Outcome measurements were performed as baseline, as well as 30 and 60 minutes after treatment.
Notes	‐ Study authors contacted and provided clarification of some methodology and study results.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided on how patients were randomised. Quote (p. 347): A total of 80 patients were randomly assigned to two treatment groups,..."
Allocation concealment (selection bias)	Unclear risk	Study did not address allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Study did not address blinding of participants or personnel.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Study did not address blinding of outcome assessors.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient reporting of attrition/exclusions to permit judgement. Quote (p. 347): "A total 80 patients were randomly assigned to two treatment groups. Forty (40) received Salbutamol alone (Group A) and 40 received combination Ipratropium Bromide and Salbutomol (group B)..."
Selective reporting (reporting bias)	Unclear risk	No protocol available.
Other bias	Unclear risk	No source of funding provided.