title: Adherence to treatment guidelines in clinical practice: study of antipsychotic treatment prior to clozapine initiation.
abstract: BACKGROUND
  Clozapine is the only antipsychotic drug licensed for treatment-resistant schizophrenia but its use is often delayed. Since previous studies, national guidelines on the use of clozapine and other antipsychotics have been disseminated to clinicians.
  
  
  OBJECTIVE
  To determine the theoretical delay to clozapine initiation and to quantify the prior use of antipsychotic polypharmacy and high-dose antipsychotic treatment.
  
  
  METHODS
  Clinico-demographic data were extracted from the treatment records of all patients commencing clozapine in our centre between 2006 and 2010.
  
  
  RESULTS
  Complete records were available for 149 patients. The mean theoretical delay in initiating clozapine was 47.7 months (s.d. = 49.7). Before commencing clozapine, antipsychotic polypharmacy and high-dose treatment was evident in 36.2 and 34.2% of patients respectively. Theoretical delay was related to illness duration (β = 0.7, P<0.001) but did not differ by gender or ethnicity.
  
  
  CONCLUSIONS
  Substantial delays to clozapine initiation remain and antipsychotic polypharmacy and high doses are commonly used prior to clozapine, despite treatment guidelines.
authors.affiliation: Department of Psychosis Studies, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. oliver.howes@kcl.ac.uk
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Howes
authors.forename: Francis
authors.initials: F
authors.lastname: Vergunst
authors.forename: Siobhan
authors.initials: S
authors.lastname: Gee
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
authors.forename: Shitij
authors.initials: S
authors.lastname: Kapur
authors.forename: David
authors.initials: D
authors.lastname: Taylor
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D003024:Clozapine / Q000627:therapeutic use*; D004351:Drug Resistance; D057915:Drug Substitution; D005260:Female; D019983:Guideline Adherence / Q000592:standards; D006801:Humans; D008297:Male; D019338:Polypharmacy; D017410:Practice Guidelines as Topic / Q000592:standards; D012559:Schizophrenia / Q000188:drug therapy*; D061665:Time-to-Treatment
chemical_list: D014150:Antipsychotic Agents; D003024:Clozapine