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. Author manuscript; available in PMC: 2014 Sep 19.
Published in final edited form as: Cochrane Database Syst Rev. 2010 Mar 17;(3):CD006654. doi: 10.1002/14651858.CD006654.pub2
Methods Allocation: random, no further details.
Blindness: double, no further details.
Duration: 8 weeks.
Design: parallel.
Location: single centre.
Country: Germany.
Participants Diagnosis: (DSM-IV) schizophrenia, acute episode, CGI of more than 4, PANSS total score of more than 60.
N=52.
Age: 18-65 years (mean olanzapine=34.47 years, mean quetiapine=36.69 years) (of completers).
Sex: 21 M, 12 F (of completers, here defined as participants who completed cognitive assessments at two or more time points out of three (baseline, week 4, weeks 8)).
History: duration ill mean olanzapine=4.71 years, mean quetiapine=8.44 years (of completers), age at onset mean olanzapine=29.76 years, mean quetiapine=28.25 years (of completers).
Setting: inpatient.
Interventions
  1. Olanzapine: flexible dose. Allowed dose range: 10-20 mg/day. Mean dose: 15.82 mg/day. N=26.

  2. Quetiapine: flexible dose. Allowed dose range: 400-800 mg/day. Mean dose: 586.86 mg/day. N=26

Outcomes Leaving the study early: any reason, adverse events.
Global state: CGI.
Mental State: PANSS total score, PANSS positive subscore, PANSS negative subscore.
Adverse effects: open interviews, UKU, EPS (akathisia, use of antiparkinson medication, BAS, ESRS), sedation, headache, dizziness, obstipation, weight gain
Unable to use -
Global state: no data.
BAS: no data.
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?
Objective outcomes
Low risk Whether blinding was successful has not been examined, but both compounds differ quite substantially in side-effects. This can be a problem for blinding
Blinding?
Subjective outcomes
Unclear risk Double, no further details. 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 attrition rate was high (61.5%). The last-observation-carried-forward 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, given the high number of attrition
Free of selective reporting? High risk Data on global state have not been presented.
Free of other bias? High risk The study was sponsored by the manufacturer of olanzapine.