Methods | Allocation: random, no further details. Blindness: double, no further details. Duration: 28 weeks. Design: parallel. Location: multicentre. Setting: in- and outpatient. |
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Participants | Diagnosis: (DSM-IV) schizophrenia (n = 277), schizophreniform disorder or schizoaffective disorder, BPRS score of 42 or more. N = 339. Sex: 220 M, 119 F. Age: 18-65 years (mean = 36.21 years). History: duration ill not reported, age at onset mean = 23.7 years |
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Interventions |
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Outcomes | Leaving the study early: any reason, adverse events, inefficacy. Mental State: PANSS total score, BPRS total score, PANSS positive subscore, PANSS negative subscore, SANS total score. Quality of life: QLS total score. Adverse effects: open interviews, cardiac effects (ECG), death (any reason, suicide attempt), EPS (akathisia, akinesia, dyskinesia, dystonia, extrapyramidal symptoms, parkinsonism, tremor, use of antiparkinson medication), Prolactin associated side effects (abnormal ejaculation, abnormally high prolactin value, amenorrhea, decreased libido, galactorrhea, gynaecomastia, impotence), sedation, backache, blurred vision, breathing difficulties, early wakening, nightmares, seizures, weight gain, laboratory (glucose, white blood cell count) |
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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 |
High risk | The overall attrition was high 47.5 %. 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 |
Free of selective reporting? | High risk | Adverse effects were only reported in the case of a significant difference between groups. Important side effects may have been missed by this procedure |
Free of other bias? | High risk | The study was sponsored by the manufacturer of olanzapine. |