Comparing Adherence to and Persistence with Antipsychotic Therapy Among Patients with Bipolar Disorder

Auburn University, AUO, Alabama, United States
Annals of Pharmacotherapy (Impact Factor: 2.06). 11/2007; 41(11):1812-8. DOI: 10.1345/aph.1K205
Source: PubMed


Medication nonadherence is a significant problem among patients with bipolar disorder.
To compare adherence and persistence among patients with bipolar disorder initiated on antipsychotics in a state Medicaid system over a 12 month follow-up period.
Claims data for patients with bipolar disorder from a de-identified Medicaid database were examined. Patients were classified into 4 monotherapy treatment groups (risperidone, olanzapine, quetiapine, or typical antipsychotic) based on the first prescription filled between January 1, 1999, and December 31, 2001. Adherence and persistence were analyzed over a 12 month follow-up period. Adherence was measured using the Medication Possession Ratio (MPR). Persistence was defined as the total number of days from the initiation of treatment to therapy modification (ie, discontinuation, switching, or combination with another antipsychotic). Adjustment for confounding variables was undertaken using ordinary least-squares and Cox proportional hazard regression modeling.
The mean MPRs were 0.68 for risperidone (n = 231), 0.68 for olanzapine (n = 283), 0.71 for quetiapine (n = 106), and 0.46 for typical antipsychotics (n = 205). Patients initiated on typical antipsychotics were 23.6% less adherent than patients initiated on risperidone (p < 0.001). Mean persistence (days) was 194.8 for risperidone, 200.9 for olanzapine, 219.8 for quetiapine, and 179.2 for typical antipsychotics. Extended Cox regression modeling indicated no significant differences between antipsychotics in hazards of therapy modification within 250 days of initiation. However, patients initiated on typical antipsychotics were 5.2 times more likely to modify therapy compared with those initiated on risperidone after 250 days of antipsychotic therapy (p < 0.001).
Adherence and persistence were similar between atypical antipsychotic groups. The typical antipsychotic group, however, demonstrated lower adherence and a greater likelihood of patients modifying therapy compared with the risperidone cohort.

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    • "Compliance is the extent in accordance with prescribed dosage and schedule, which can be assessed with Medication Possession Rate (MPR) (i.e., total days a medication was actually dispensed to patients divided by treatment period in days). These two components represent different aspects of patients' behaviours and should be separately assessed, which has been reflected in recent studies in other physical and psychiatric diseases [6,7], including schizophrenia [5] and bipolar disorder [8]. However, surprisingly, there is only one report that has assessed these two components in antidepressant treatment [9]. "
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    ABSTRACT: Adherence has recently been suggested to be divided into these two components: persistence (i.e., whether patients continue treatment or not) and compliance (i.e., whether patients take doses as instructed). However, no study has yet assessed these two clinically relevant components at the same time in adherence to antidepressant treatment in the clinical outpatient setting. In this retrospective chart-review, 6-month adherence to antidepressants was examined in 367 outpatients with a major depressive disorder (ICD-10) (170 males; mean +/- SD age 37.6 +/- 13.9 years), who started antidepressant treatment from April 2006 through March 2007. Additionally, we evaluated Medication Possession Rate (MPR), defined as the total days a medication was dispensed to patients divided by the treatment period. Only 161 patients (44.3%) continued antidepressant treatment for 6 months. Among 252 patients who discontinued their initial antidepressant, 63.1% of these patients did so without consulting their physicians. Sertraline use was associated with a higher persistence rate at month 6 (odds ratio 2.59 in comparison with sulpiride), and the use of anxiolytic benzodiazepines had a positive effect on persistence to antidepressant treatment only at month 1 (odds ratio 2.14). An overall MPR was 0.77; 55.6% of patients were considered compliant (i.e., a MPR of > or = 0.8). Given a high rate of antidepressant discontinuation without consulting their physicians, closer communication between patients and their physicians should be encouraged. Although the use of anxiolytic benzodiazepines was associated with a higher persistence to antidepressant treatment at month 1, the use of these drugs should be avoided as a rule, given their well-known serious adverse effects.
    Full-text · Article · Jul 2009 · BMC Psychiatry
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    ABSTRACT: The STAndards for BipoLar Excellence (STABLE) Project was organized in 2005 to improve quality of care for bipolar disorder by developing and testing a set of evidence-based clinical process performance measures related to identifying, assessing, managing, and coordinating care for bipolar disorder. This article first briefly reviews the literature on the science of performance measurement and the use of performance measures as a tool for quality improvement. It then presents a detailed overview of the methodology used to develop the STABLE performance measures. Steps included choosing a clinical area to be measured, selecting key aspects of care for measurement, designing specifications for the measures, developing a data collection strategy, testing the scientific strength (validity, reliability, feasibility) of the measures, and obtaining, analyzing, and reporting conformance findings for the measures. Five of the STABLE measures have been endorsed by the National Quality Forum as part of their Standardizing Ambulatory Care Performance Measures project: screening for bipolar mania/hypomania in patients diagnosed with depression, assessment for risk of suicide, assessment for substance use, screening for hyperglycemia when atypical antipsychotic agents are prescribed, and monitoring change in level of functioning in response to treatment. Additional STABLE measures will be submitted to appropriate national organizations in the future. It is hoped that these measures will be used in quality assessment activities and that the results will inform efforts to improve care for individuals with bipolar disorder.
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