title: Antipsychotic switching: results from a one-year prospective, observational study of patients with schizophrenia.
abstract: OBJECTIVE
  The Health Outcomes of a Canadian Community Cohort (HOCCC) study is a 1-year prospective observational study of outpatients with schizophrenia or related psychotic disorders. The purpose of the study was to compare effectiveness of antipsychotic treatment as measured by 1-year treatment completion rates.
  
  
  METHODS
  Patients (N = 929) were enrolled if in the course of usual clinical practice they switched to a second-generation antipsychotic (SGA). Observational data were collected for up to 1 year. The primary analysis compared 1-year treatment-completion rates for the olanzapine cohort with the other SGA cohort (quetiapine, risperidone, clozapine), using a chi-squared test.
  
  
  RESULTS
  Of 929 patients enrolled, 64.8% (516/796) of evaluable patients completed 1 year of treatment. There was no statistically significant difference in the proportion of treatment completers between the olanzapine cohort (67.4%, 256/380) and the other SGA cohort (62.5%, 260/416). Treatment-completion rates were risperidone 62.0% (127/205), quetiapine 63.7% (123/193) and clozapine 55.6% (10/18). Antipsychotic polypharmacy was common. Patients treated with olanzapine or risperidone had significantly higher increases in BMI than quetiapine-treated patients. There were no major differences between olanzapine monotherapy and pooled other SGA monotherapy groups in status of extrapyramidal symptoms from baseline to endpoint.
  
  
  CONCLUSIONS
  Olanzapine and other SGAs exhibited similar rates of 1-year treatment completion. Further study of medication combinations is needed, given their perceived clinical value, and the high frequency of antipsychotic polypharmacy in clinical practice.
  
  
  CONCLUSIONS
  As most patients received several psychotropics and power was reduced in monotherapy analyses, comparisons between cohorts must be interpreted cautiously. Comparisons between individual antipsychotics were post hoc and not powered a priori. Accuracy and completeness of adverse event information for drugs other than olanzapine is limited.
authors: Eli Lilly Canada Inc, Toronto, ON, Canada. karagianis_jamie@lilly.com
authors: Jamie
authors: J
authors: Karagianis
authors: Richard
authors: R
authors: Williams
authors: Lori
authors: L
authors: Davis
authors: Ric
authors: R
authors: Procyshyn
authors: Neerav
authors: N
authors: Monga
authors: James
authors: J
authors: Hanley
authors: Ranjith
authors: R
authors: Chandrasena
authors: Aruna
authors: A
authors: Thakur
authors: Ruth
authors: R
authors: Dickson
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001569:Benzodiazepines / Q000008:administration & dosage / Q000009:adverse effects; D003024:Clozapine / Q000008:administration & dosage / Q000009:adverse effects; D015331:Cohort Studies; D003987:Dibenzothiazepines / Q000008:administration & dosage / Q000009:adverse effects; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D000069348:Quetiapine Fumarate; D018967:Risperidone / Q000008:administration & dosage / Q000009:adverse effects; D012559:Schizophrenia / Q000188:drug therapy*; D028761:Withholding Treatment
chemical_list: D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D001569:Benzodiazepines; D000069348:Quetiapine Fumarate; D003024:Clozapine; D018967:Risperidone; D000077152:Olanzapine