Bachmann 2003.

Methods	Allocation: randomised. Blindness: double. Duration: 16 weeks. Setting: inpatients and outpatients, USA. Design: parallel groups.
Participants	Diagnosis: people with schizophrenia or schizoaffective (DSM‐IV). N = 69 Age: 18‐65 years. Sex: male and female (data only available for completers). Inclusion criteria: Those who met DSM‐IV criteria for schizophrenia or schizoaffective disorder were selected for study entry. BPRS total score of > 45 or CGI severity of illness item score of > 4; and BPRS positive symptom item total score of > 8, with 1 or more item rated > 4. They were required to have had an adequate clozapine trial, defined as clozapine treatment for > 6 months on a dose that produced a clozapine plasma level of X350 ng/ml or a clozapine + norclozapine plasma level of X450 ng/ml. Exclusion criteria: Participants who met DSM‐IV diagnosis of alcohol or substance abuse (other than nicotine) within the past month, alcohol or substance dependence (other than nicotine) within the past 6 months, mental retardation, unstable medical condition, or those treated previously with adjunctive risperidone at X8 mg/day for at least 6 weeks.
Interventions	1. Risperidone (dose 4 mg) plus clozapine (dose not reported). N = 33. 2. Placebo plus clozapine (dose not reported). N =36.
Outcomes	Mental state: BPRS, SANS. Leaving the study early (the week that participants left the study early were reported; all left before 12 weeks). Adverse effects: metabolic, extrapyramidal, haematological.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomization was stratified by in‐patient status" (p2276).
Allocation concealment (selection bias)	Unclear risk	No information available.
Blinding (performance bias and detection bias) All outcomes	Low risk	"All raters were blind to treatment assignment" (p2275). "Risperidone 4mg (two 2mg capsules) or placebo (two capsules)" (p2276).
Incomplete outcome data (attrition bias) All outcomes	Low risk	ITT analysis and completers‐only analysis undertaken.
Selective reporting (reporting bias)	Low risk	Outcomes listed in paper all reported.
Other bias	High risk	Double‐blind medications were provided by Ortho‐McNeil‐Janssen Scientific Affairs, LLC. Authors have associations with Eli Lilly, Astra‐Zeneca, Pfizer, GlaxoSmithKline, Cephalon, Otsuka, Bioscience, Abbott, Cypress, Merck, Organon, Sanofi‐Aventis, Bristol‐Myers Squibb, Janssen, Solvay, Wyeth, Zeneca, and Roche either as employees, stockholders, or members of advisory boards.