Marder 1994a.

Methods	Allocation: randomised. Blindness: double. Duration: 7‐day single‐blind placebo washout period plus 8‐week treatment period. Setting: inpatients, 20 centres in USA. Design: parallel‐group study.
Participants	Diagnosis: schizophrenia (DSM III‐R). N = 388*. Age: 18‐67 years. Sex: male and female. Inclusion criteria: total PANSS score between 60 and 120. Exclusion criteria: pregnant or lactating women or women without adequate contraception, mental disorders other than schizophrenia, neurological disorders, psychoactive substance use or alcohol abuse, and schizoaffective disorder.
Interventions	1. Risperidone: dose 2 mg/day, N = 63**. 2. Risperidone: dose 6 mg/day, N = 64**. 3. Risperidone: dose 10 mg/day, N = 65. 4. Risperidone: dose 16 mg/day, N = 64. 5. Placebo: N = 66. 6. Haloperidol: dose 20 mg/day, N = 66.
Outcomes	Mental state: PANSS*. Leaving the study early***. Global state: CGI*. Adverse effects: ESRS, UKU Side Effect Rating Scale*.
Notes	*Data from a subset of participating centre, where leaving the study early was not reported (risperidone N = 64; placebo N = 66). **Fixed dose. We included data only from the 6 mg/day arm, as this was the closest dose to what would be used in routine clinical practice. This arm had a differential leaving the study early rate with 45% in the risperidone arm leaving the study early compared to 68% in the placebo arm. ***Data from a wider set of participating centres (risperidone N = 86; placebo N = 88).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation in blocks of 12.
Allocation concealment (selection bias)	Unclear risk	No information available.
Blinding (performance bias and detection bias) All outcomes	Low risk	Double blind.
Incomplete outcome data (attrition bias) All outcomes	Low risk	ITT analysis was used.
Selective reporting (reporting bias)	Low risk	All outcomes measured were reported.
Other bias	High risk	Supported by a grant from the Janssen Research Foundation.