Gowardman 1973.

Methods	Randomisation: “randomly allotted”. Blinding: double‐blind. Duration: 12 weeks. Design: parallel. Location: not indicated. Setting: inpatients.
Participants	Diagnosis: paranoid schizophrenia (N = 15 according to the main text, N = 14 according to table 1), hebephrenic schizophrenia (N = 3 according to the main text, N = 4 according to table 1), catatonic schizophrenia (N = 1), schizoaffective psychosis (N = 1). N = 20. Gender: not indicated.           Age: mean 48.6 years. History: duration stable: not indicated, duration of illness: mean 20.6 years, number of previous hospitalisations: not indicated, age at onset: not indicated, severity of illness: not indicated, baseline antipsychotic dose: not indicated.
Interventions	1. Haloperidol: fixed/flexible dose: not indicated, dose range: maximum dose 14 mg/day, mean dose: 10.15 mg/day. N = 10. 2. Pimozide: fixed/flexible dose: not indicated, dose range: maximum dose 6 mg/day, mean dose: 5.1 mg/day. N = 10.   “Having achieved a rapid control of psychotic symptoms, the drugs were suitably increased in individual cases to see if further benefit accrued, or until extrapyramidal side effects were noted.” Rescue medication: “patients exhibiting extrapyramidal side effects were treated with benztropine mesylate (Cogentin) 2 mg.”
Outcomes	Examined: Clinically important response to treatment: Global evaluation. Leaving the study early due to any reason. Leaving the study early due to inefficacy of treatment. Leaving the study early due to adverse effects. Adverse effects: at least one adverse effect, at least one movement disorder.
Notes	Study participants were 20 “chronic institutionalised and withdrawn schizophrenics”. “All patients had severe disorder of thinking, persecutory delusions, auditory hallucinations at some time, disturbed affect and social behaviour.” “short drug‐free interval” before the first administration of the study medications.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“Randomly allotted by the hospital pharmacist”. No further details.
Allocation concealment (selection bias)	Unclear risk	No further details.
Blinding (performance bias and detection bias) (performance bias)	Low risk	“Double‐blind”. “The drugs were supplied in identical capsules.” “The capsules were indistinguishable in outward appearance.” “The investigators did not know who was receiving which drug.”
Blinding (performance bias and detection bias) (detection bias)	Low risk	“Double‐blind”. “The investigators did not know who was receiving which drug.”
Incomplete outcome data (attrition bias) All outcomes	Low risk	“All patients completed the trial period of three months.”
Selective reporting (reporting bias)	Unclear risk	The adverse effects were not fully addressed. No information regarding the number of participants that received a medication with antiparkinson drugs.
Other bias	Unclear risk	Insufficient information to assess whether an important risk of bias exists.