Methods	Allocation: random, no further details. Blindness: double, no further details. Duration: 8 weeks. Design: parallel. Location: multicentre.
Participants	Diagnosis: (DSM-IV) schizophrenia (n = 149) or schizoaffective disorder (n = 26), PANSS between 50 and 120. N = 176. Sex: 62 M, 113 F (of intent-to-treat population). Age: 60 years or more (mean olanzapine = 71.4 years, mean risperidone = 70.9 years) (of intent-to-treat population). History: duration ill mean = 36.5 years, age at onset mean olanzapine = 33.4 years, mean risperidone = 36.0 years (of intent-to-treat population). Setting: in- and outpatient.
Interventions	Olanzapine: flexible dose. Allowed dose range: 5-20 mg/day. Mean dose: 11.1 mg/day. N = 89. Risperidone: flexible dose. Allowed dose range: 1-3 mg/day. Mean dose: 1.9 mg/day. N = 87
Outcomes	Leaving the study early: any reason, adverse events, inefficacy. Global State: CGI. Mental State: PANSS total score, PANSS positive subscore, PANSS negative subscore. Adverse effects: open interviews, cardiac effects (ECG), death (natural causes, suicide) EPS (akinesia, dystonia, extrapyramidal symptoms, parkinsonism, tremor, use of antiparkinson medication, ESRS), sedation, seizures, weight change, laboratory (cholesterol, glucose, prolactin)
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Random, no further details.
Allocation concealment?	Unclear risk	No further details.
Blinding? 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? 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 addressed? All outcomes	Unclear risk	Number of participants leaving the study early was moderate (23.9%). The LOCF method was used to account for people leaving the study early. It assumes that a participant who discontinued the study would not have had a change of his condition if he had remained in the study. This assumption can obviously be wrong. It is unclear whether this led to bias
Free of selective reporting?	High risk	Only those adverse events that occurred in at least 10% of the participants were reported. This procedure can miss rare, but important adverse events
Free of other bias?	High risk	The study was sponsored by the manufacturer of risperidone. The mean age of included subjects was about 71 years. Probably due to this reason the upper dose range limit of risperidone was rather low (3mg/day), compared to that of olanzapine (20mg/day)