A cohort study to monitor the safety and use of prolonged-release quetiapine (OASIS)

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Drug utilisation
• Data collection methods:
  Primary data collection

Non-interventional study

• Non-interventional study design:
  Case-control

Study drug and medical condition

• Name of medicine, other:
  Seroquel XL
• Medical condition to be studied:
  Schizophrenia

  Mania

Population studied

• Short description of the study population:
  Patients with a clinical diagnosis of schizophrenia and the manic episodes associated with bipolar disorder in a mental health care trust setting in England.
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Special population of interest:
  Other
• Special population of interest, other:
  Schizophrenia or mania patients
• Estimated number of subjects:
  900

Study design details

• Main study objective:
  The study was requested by the MHRA for further clarification of safety at higher doses in the Seroquel XL (extendedrelease) formulation in the Mental Health Trust setting. The regulatory commitment is to conduct a study to monitorevents in the >600mg XL group and compare them to <600mg XL, with seroquel IR (immediate release preparation) as acomparator.</600mg></600mg>
• Data analysis plan:
  Drug utilisation characteristics will be described using summary statistics. Incidence Densities (IDs)will be calculated for the whole 12 week period, for all events reported in patients from the time they start high dose quetiapine (defined as receiving a dose > 600mg) until dose is reduced below 600mg, the patient stops treatment, leaves the care of the psychiatrist, or end of study period, which ever is the soonest. This will be repeated for the XL and IR cohort separately. For each four week period during the 12 week observational period IDs will be calculated for all events reported in patients receiving high dose quetiapine XL (excluding indication related events, which will be listed at analysis stage). Similarly, IDs will be calculated for patients receiving low dose XL. A time to event analysis will be performed in order to investigate the relationship between selected event(s) of interest and potential confounding factors for which information has been requested.