Davies 1993.

Methods	Parallel‐group RCT
Participants	95 participants recruited with allergic conjunctivitis
Interventions	Three treatment arms: levocabastine 0.5 mg/ml; sodium cromoglycate 20 mg/ml; placebo eye drops. Duration of treatment 28 days
Outcomes	Investigators' and participants' assessment of ocular symptoms (4‐point qualitative scale: excellent, good, moderate, poor) Time points: at baseline, day 14 and 28 after treatment
Country	United Kingdom
Number randomised, gender (male:female)	95 participants randomised. M:F 40:49
Age mean (SD), median, range	Mean (range) levocabastine 30 years (7‐66); sodium cromoglycate 31 years (10‐69); placebo 30 years (13‐61)
Notes	Not reported when study was conducted. Source of funding not stated. Declaration of interest by the authors was not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The method used to generate the allocation sequence was not described.
Allocation concealment (selection bias)	Unclear risk	The method used to conceal the allocation sequence was not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	Percentages given (numerators/denominators unclear)
Selective reporting (reporting bias)	High risk	P values given for selected outcomes
Other bias	Unclear risk	No apparent evidence of other risk of bias
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐masked (p.520 ‐ methods): "…95 patients participated in this double‐blind, parallel group trial."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Double‐masked (p.520 ‐ methods): "…95 patients participated in this double‐blind, parallel group trial."