Tybura 2012.

Methods	Allocation: randomised, allocation concealed (see below). Blindness: open. Duration: 3 months. Raters: not stated to be independent of treatment. Design: two‐centre.
Participants	Diagnosis: paranoid schizophrenia according to "Composite International Diagnostic Interview" and ICD‐10. Excluded: serious neurological and/or somatic disorders (e.g. stroke, hepatic insufficiency, diabetes). N = 191. Sex: 89 men 102 women. Age: ˜ 36 years. History: duration ill ˜ 10 years. Setting: unclear.
Interventions	1. Perazine 300‐600mg/day. N = 60. 2. Olanzapine 10‐20mg/day. N = 72. 3. Ziprasidone 120‐160mg/day. N = 59.
Outcomes	Leaving the study early. General mental state: percentage PANSS change from baseline. No further outcomes were reported, the main focus of the study was genetics.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Personal communication from Jerzy Samochowiec: "Both recruiting centers had a simple program generating random allocations. The program was writen by our statistician (P.M.) and allowed random allocation of each patient meeting the study criteria. The program was a simple randomization tool, i.e. it allowed random (with a probability of 33,3%) allocation of each qualified patient to one of three treatment groups."
Allocation concealment (selection bias)	Low risk	Personal communication from Jerzy Samochowiec: "The processes of initial qualification and randomization were separated. Senior researchers in each center were asked for a random allocation by physicians willing to qualify a patient to the study. The patient was registered in the study database and allocation to one of the study groups was performed as described above. Database records and randomization was a duty of a senior researcher. Hence, the physician deciding to qualify a patient to the study could not predict to which group the patient will be allocated. The allocation was done by another person and was final. The whole system worked like with two 'randomization centers'."
Blinding of participants and personnel (performance bias) Objective outcomes	Low risk	"Open study". Lack of blinding would not be so important for objective outcomes.
Blinding of participants and personnel (performance bias) Subjective outcomes	High risk	"Open study".
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	"Open study". Lack of blinding would not be so important for objective outcomes.
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	"Open study".
Incomplete outcome data (attrition bias) All outcomes	High risk	Dropout rate 24%‐32%. Reasons for dropout not indicated. LOCF analysis.
Selective reporting (reporting bias)	Low risk	No indication of selective reporting.
Other bias	Low risk	No obvious other bias.