Arata 1994a.

Study characteristics
Methods	A randomised, double‐blind, multicentre clinical trial
Participants	Country: Japan Setting: hospitals (35 centres) Study period: July 1991 to July 1992 Inclusion criteria: Aged between 16 and 80 years  With superficial skin infection (Group I to VI) Exclusion criteria: Severe infectious disease considered insufficient under oral antibiotics therapy Allergy to beta‐lactam antibiotics Patients with with severe liver or kidney function disorder Pregnant women, breastfeeding, and possibly pregnant women The pathogenic bacterium was resistant to test drug The disease had resolution before treatment Patients with severe underlying diseases, complications, difficulty in judging the efficacy and safety of test drugs Patients whose symptoms were already improving due to antibiotic administration just before the start of the study Patient had received S‐1108 just before the start of the study A total of 193 participants received the drugs (98 in the S‐1108 group and 95 in the cefaclor group); 183 (94.8%) (95 in the S‐1108 group and 88 in the cefaclor group) were included in the efficacy analysis. Focusing on folliculitis and boils, 132 participants were included in the efficacy analysis, including 68 receiving S‐1108 and 64 receiving cefaclor. 189 (97.9%) (96 in the S‐1108 group and 93 in the cefaclor group) were included in the safety analysis.
Interventions	S‐1108 group: S‐1108 150 mg and cefaclor placebo 3 times per day for 7 days Cefaclor group: cefaclor 250 mg and S‐1108 placebo 3 times per day for 7 days The active medicines and matching placebo used in this study were manufactured by Shionogi Pharmaceutical Co Ltd.
Outcomes	Clinical efficacy: based on the degree of general improvement at the end of dosing by physicians as excellent (considered cure), good, fair, and poor (efficacy rate: excellent + good) Bacteriological examination Safety: divided as safe (no symptoms or abnormal clinical data whilst taking medication); almost safe (with symptoms or abnormal clinical data, but treatment or discontinuing the medication was not necessary); safety slightly doubted (with treatable symptoms or abnormal clinical data, but discontinuation of medication was not necessary); not safe (severe adverse events leading to withdraw of treatment)
Funding source	Shionogi Research Laboratories, Shionogi & Co Ltd
Declarations of interest	Not reported
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Method of administration: participants were allocated to assigned medications according to the sequence of numbers." (author's translation) Comment: method of random sequence generation not explicitly reported.
Allocation concealment (selection bias)	Low risk	Quote: "Assignment of agents: the control (Koi Nakajima) were allocated through the probabilistic operation." (author's translation)
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "By the same drug appearance, it could not be identified exteriorly; we kept the dummy double‐blind method." (author's translation)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded physicians assessed the outcomes.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	The intention to treat data were unavailable, and the outcome efficacy analysis was according to pre‐protocol data.
Selective reporting (reporting bias)	Low risk	Both efficacy and safety outcomes were prespecified and reported.
Other bias	Unclear risk	There was insufficient information to assess whether an important risk of bias existed.