Methods	Allocation: random, no further details. Blindness: double, no further details. Duration: six weeks. Design: parallel. Location: multicentre.
Participants	Diagnosis: (DSM-IV) acute schizophrenia (n=170) or schizoaffective disorder (n=99). CGI-S score ≥4, CGI-I score ≥3. N=269. Age: 18-55 years (mean olanzapine=37.6 years, mean ziprasidone=37.7 years). Gender: 176 M, 93 F. History: duration of illness mean olanzapine=14.0, mean risperidone=15.4, age at onset mean olanzapine=23.7 years, mean ziprasidone=22.2 years. Setting: inpatient.
Interventions	Olanzapine: flexible dose, allowed dose range: 5-15 mg/day, mean dose=11.3 mg/day. N=133. Ziprasidone: flexible dose, allowed dose range: 80-160 mg/day, mean dose=129.9 mg/day. N=136
Outcomes	Leaving the study early: any reason, adverse events, inefficacy. Global State: CGI. Mental State: BPRS total score, depression Calgary depression scale for schizophrenia. Adverse effects: open interviews, EPS (use of antiparkinson medication, ESRS) cardiac effects (ECG), weight gain, laboratory Unable to use- Laboratory (no usable data).
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random, no further details.
Allocation concealment (selection bias)	Unclear risk	No further details.
Blinding (performance bias and detection bias) Subjective outcomes	Unclear risk	Double, no further details. Whether blinding was successful has not been examined, but the compounds differ quite substantially in side-effects. This can be a problem for blinding
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Objective outcomes such as laboratory measures or death are unlikely to have been much affected by problems of blinding
Incomplete outcome data (attrition bias) All outcomes	High risk	The overall attrition was high (42.8%).The last observation carried forward method was used to account for people leaving the study early
Selective reporting (reporting bias)	High risk	The study focused on acutely ill schizophrenic or schizoaffective patients but data on the positive symptom subscore were not provided
Other bias	High risk	The study was sponsored by the manufacturer of ziprasidone. The upper dose limit of olanzapine was 15 mg/day which is below the maximum dose for this medication