Medication adherence and utilization in patients with schizophrenia or bipolar disorder receiving aripiprazole, quetiapine, or ziprasidone at hospital discharge: A retrospective cohort study
BMC Psychiatry, 08/03/2012

Berger A et al. – Medication compliance is poor in patients with schizophrenia or bipolar disorder who initiate treatment with aripiprazole, quetiapine, or ziprasidone at hospital discharge.

• Using a database linking hospital admission records to health insurance claims, the authors identified all patients hospitalized for schizophrenia or bipolar disorder between January 1, 2001 and September 30, 2008 who received aripiprazole, quetiapine, or ziprasidone at discharge.
• Patients not continuously enrolled for 6months before and after hospitalization ("pre–admission" and "follow–up", respectively) were excluded.
• They examined patterns of use of these agents during follow–up, including adherence with treatment (using medication possession ratios [MPRs] and cumulative medication gaps [CMGs]) and therapy switching.
• Analyses were undertaken separately for patients with schizophrenia and bipolar disorder, respectively.

• The authors identified a total of 43 patients with schizophrenia, and 84 patients with bipolar disorder.
• During the 6–month period following hospitalization, patients with schizophrenia received an average of 101 therapy–days for the second–generation antipsychotic agent prescribed at discharge; for patients with bipolar disorder, the corresponding figure was 68 therapy–days.
• Mean MPR at 6 months was 55.1% for schizophrenia patients, and 37.3% for those with bipolar disorder; approximately one–quarter of patients switched to another agent over this period.