Johnson 1970.

Methods	Allocation: randomised. Blindness: double blind. Duration: 10 weeks (6 weeks of treatment + 4 weeks of drying out period). Setting: hospital.
Participants	Diagnosis: acute and chronic schizophrenia. N = 26. Age: 26‐59 years. Sex: male. History: not reported.
Interventions	1. Chlorpromazine (liquid form): minimum dose of 30 mg/day, maximum dose of 96 mg/day (N = 13). 2. Piperacetazine (liquid form): minimum dose of 15 mg/day, maximum dose of 60 mg/day (N = 13).
Outcomes	Adverse effects: general‐total number of events Leaving the study early. Unable to use: Global state: BPRS (no mean or SD). Mental state: CGI, NOSIE (no mean or SD).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Subjects were selected and/or assigned to treatment by random numbers".
Allocation concealment (selection bias)	Unclear risk	Further information regarding allocation concealment was not provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "This was a double blind, multidrug study"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information was provided regarding blinding of outcome assessors.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No attrition from trial
Selective reporting (reporting bias)	Unclear risk	Unclear if all data were reported as no information available regarding prespecified outcomes
Other bias	Unclear risk	Source of funding not reported