Costantini 1982.

Study characteristics
Methods	RCT. Duration: variable duration of course (mean (SD) 15 (3.4) days). Symptomatic regimen.
Participants	28 pulmonary exacerbations in 19 participants with CF. Age not given but stated that groups similar in age and disease severity. PsA colonised.
Interventions	Single antibiotic group 1: carbenicillin 675 mg/kg/day. Single antibiotic group 2: sisomycin 10.5 mg/kg/day. Combination antibiotic group: carbenicillin 590 mg/kg/day plus sisomycin 10 mg/kg/day.
Outcomes	CXR and symptom scores, bacteriology, development of resistant strains.
Notes	Abstract: no data. No withdrawals.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly assigned, but no further details given.
Allocation concealment (selection bias)	Unclear risk	Not directly discussed, but referred to as a controlled clinical trial.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not discussed.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not discussed, but appears to be no withdrawals.
Selective reporting (reporting bias)	Unclear risk	Not clear, only published as an abstract and protocol not available.
Other bias	Unclear risk	None identified, but limited information as only published as an abstract.