Chouinard 1995.

Methods	Allocation: "randomly assigned", not described Blindness: "double blind", partially described Design: post hoc analysis of parallel, 6‐group RCT Setting: inpatients, Canada Duration: 8 weeks
Participants	Diagnosis: chronic schizophrenia (DSM‐III R criteria) N = 135 Age: mean 39 years, range 19‐60 years Sex: 34 men and 14 women History: duration TD not reported; the most common pre‐study medications were haloperidol, procyclidine, lorazepam, benztropine and chlorpromazine; the most commonly used depot antipsychotic agents were haloperidol decanoate, fluphenazine decanoate, flupenthixol decanoate and pipothiazine palmitate.
Interventions	Mean duration of washout phase 6 days. 1. Risperidone: dose 2 mg/d for 8 weeks. N = 8 2. Risperidone: dose 6 mg/d for 8 weeks. N = 6 3. Risperidone: dose 10 mg/d for 8 weeks. N = 6 4. Risperidone: dose 16 mg/d for 8 weeks. N = 11 5. Haloperidol: dose 20 mg/d. N = 6 6. Placebo: N = 11 "At the time of selection, all psychotropic and antiparkinsonism medications were discontinued"; "no other psychotropic medication was administered except for chloral hydrate or a benzodiazepine if a sedative/hypnotic was required.", "An antiparkinsonian medication (biperiden or procyclidine) was given in case of the emergence of clinically significant drug‐induced parkinsonism and dystonia"
Outcomes	Adverse events: use of antiparkinsonism medication Unable to use (data does not have variability measures, and only reports differences from baseline to worst scores) ‐ ESRS: dyskinesia symptoms total score, CGI severity dyskinesia, buccolinguomasticatory factor, choreoathetoid factor
Notes	Sponsorship source: not reported. Study author kindly replied to our request for data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomly assigned", details not reported
Allocation concealment (selection bias)	Unclear risk	Allocation concealment not reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"identical tablets"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of raters not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	33% of participants terminated the study early due to insufficient therapeutic response. All early terminations were included in the ITT analysis
Selective reporting (reporting bias)	High risk	Outcomes not fully reported
Other bias	High risk	Subgroup with TD