Penfluridol 1975.

Study characteristics
Methods	Randomisation: random, no further details. Allocation: procedure not described. Blinding: double‐blind, identical capsules. Duration: 12 weeks. Design: parallel. Location: single‐centre. Setting: inpatient.
Participants	Diagnosis: chronic schizophrenia (clinical diagnosis). N = 35. Gender: 19 men, 16 women. Age: mean 43.9 years. History: duration stable‐ maintained on neuroleptic for at least 3 months, prospective 12 week stabilisation phase during which participants were switched to penfluridol, duration ill‐ n.i., number of previous hospitalisations‐ mean 1.34, age at onset‐ n.i., severity of illness‐ n.i., baseline antipsychotic dose‐ mean 64.1 mg/week penfluridol.
Interventions	1. Drug: penfluridol ‐ Flexible dose. Allowed dose range: 20 mg to 120 mg/week. Mean dose:n.i.. N = 18. 2. Placebo: duration of taper: 0 days. N = 17. Rescue medication: antiparkinson medication, it seems that haloperidol was not allowed in the double‐blind phase.
Outcomes	Examined Relapse: psychiatric decompensation that could not be controlled by dose increase. Leaving the study early. Adverse effects (at least one movement disorder). Unable to use/Not included Global state: Clinical Global Impression Scale (no usable data for remission). Mental state: BPRS (no numbers/no predefined outcomes of interest). Behaviour: NNOSIE (no numbers/no predefined outcomes of interest). Physiological measures: vital signs (weight, pulse, blood pressure, respiratory frequency, temperature ‐ no numbers/no predefined outcomes of interest).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised, no further details.
Allocation concealment (selection bias)	Unclear risk	Procedure not described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Double‐blind, identical capsules.
Blinding (performance bias and detection bias) Subjective outcomes	Unclear risk	Double‐blind, identical capsules.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Double‐blind, identical capsules.
Incomplete outcome data (attrition bias) All outcomes	High risk	12 of 35 participants left the study early (34%), 11 of them were in the placebo group. As all participants in the placebo group discontinued due to relapse, the primary outcome is not affected. But the results of all other outcomes are biased by this effect.
Selective reporting (reporting bias)	Low risk	Results on rating scales have not been reported, but these were not outcomes of interest in our review.
Other bias	Low risk	No clear other bias