Erlandsen 1977 (H).

Methods	Allocation: randomised. Blindness: double. Duration: 40 days. Setting: inpatients.
Participants	Diagnosis: schizophrenia (no diagnostic criteria). N=40. Sex: male. Age: range 22 to 75 years, average 43 years. History: mean duration of illness 15 years.
Interventions	1. Clozapine: dose 50 to 400 mg/day. N=19. 2. Haloperidol: dose 1 to 8 mg/day. N=21.
Outcomes	Leaving the study early. Global assessment. Laboratory tests. Unable to use ‐ Mental state: BPRS (no SDs).
Notes	Jadad score 1. No wash‐out period before trial reported. Low haloperidol doses may not have been comparable to clozapine doses.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Randomised ‐ no further details
Allocation concealment?	Unclear risk	No details
Blinding? All outcomes	High risk	Double blind, but investigators were able to guess correctly in all patients after two to three days, due to the sedating and relaxing effect of clozapine
Incomplete outcome data addressed? All outcomes	Low risk	Study attrition reported
Free of selective reporting?	Unclear risk	No details
Free of other bias?	Unclear risk	Unclear