title: Effect of paliperidone palmitate on hospitalisation in a naturalistic cohort - a four-year mirror image study.
abstract: Clinical trial outcomes are heavily influenced by the non-naturalistic clinical trial process. Observations of outcomes in clinical practice are a valuable adjunct to clinical trial results.
  
  
  
  Our null hypothesis was that clinically indicated switching to paliperidone palmitate had no effect on hospital admissions or hospital bed days.
  
  
  
  This was a part-prospective mirror image study examining outcomes 2years before starting paliperidone palmitate and 2years after. Sensitivity analyses examined the effect of different placings of the mirror in the mirror image design.
  
  
  
  We prospectively followed-up 225 patients prescribed paliperidone palmitate in clinical practice. At 2years, 41.8% of patients were still receiving paliperidone palmitate. In the primary analysis, the mean number of admissions fell from 1.80 in the two years before starting paliperidone palmitate to 0.81 in two years following the drug's initiation (outpatients) or two years following hospital discharge (inpatients) (P<0.001). More than half of patients were not admitted to hospital during two years follow-up. Mean total bed days was reduced from 79.6 in the two years before to 46.2 in the two years after paliperidone palmitate initiation or discharge (P<0.001). Sensitivity analyses gave broadly similar outcomes. Continuers demonstrated better outcomes than discontinuers in sensitivity analyses but not in the primary analysis.
  
  
  
  Paliperidone palmitate initiation is associated with a substantial reduction in hospital admissions and days spent in hospital. The reduction in costs associated with reduced use of health care facilities is likely to exceed the purchase and administration costs of the drug.
authors.affiliation: Maudsley Hospital, Pharmacy Department, Denmark Hill, London SE5 8AZ, UK; Institute of Pharmaceutical Science, King's College, 5th Floor, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK. Electronic address: david.taylor@slam.nhs.uk.
authors.forename: D M
authors.initials: DM
authors.lastname: Taylor
authors.affiliation: Maudsley Hospital, Pharmacy Department, Denmark Hill, London SE5 8AZ, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sparshatt
authors.affiliation: Maudsley Hospital, Pharmacy Department, Denmark Hill, London SE5 8AZ, UK.
authors.forename: M
authors.initials: M
authors.lastname: O'Hagan
authors.affiliation: Maudsley Hospital, Pharmacy Department, Denmark Hill, London SE5 8AZ, UK.
authors.forename: O
authors.initials: O
authors.lastname: Dzahini
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D000068882:Paliperidone Palmitate / Q000627:therapeutic use*; D011446:Prospective Studies; D012559:Schizophrenia / Q000628:therapy*; D006113:United Kingdom
chemical_list: D014150:Antipsychotic Agents; D000068882:Paliperidone Palmitate
keywords: Antipsychotics; Hospital admission; Long-acting injections; Paliperidone