Adherence to oral second-generation antipsychotic medications in patients with schizophrenia and bipolar disorder: physicians' perceptions of adherence vs. pharmacy claims.

OBJECTIVE: To compare physician-reported adherence of specific patients to oral second-generation antipsychotics vs. actual adherence rates determined from the patients' pharmacy claims. METHODS: Claims data from the HealthCore Integrated Research Database identified patients with schizophrenia or bipolar disorder with ≥ 1 oral second-generation antipsychotic prescription. The prescribing physicians were identified from the pharmacy claims and asked to complete an Internet survey assessing their perception of medication adherence for 1-2 of their patients and their beliefs regarding adherence to second-generation antipsychotics in general for a 1-year period. Adherence to second-generation antipsychotics was determined for each patient by pharmacy claims for the same period. Physician survey data were merged with patient claims data via unique patient identifiers, and physician-reported adherence rates were compared with claims-based rates as measured by the medication possession ratio. RESULTS: One hundred and fifty-three physicians responded to the survey, representing 214 patients (44 with claims for schizophrenia, 162 with bipolar disorder, 8 with claims for bipolar disorder and schizophrenia). Most physicians (60%) had no formal adherence training. More than two-thirds (68%) reported emphasising the importance of adherence and reported approximately 76% of their patients were adherent (≥ 71% of the time). In the schizophrenia group, 16 of 17 (94%) patients with low-to-moderate (≤ 70%) adherence levels had high (≥ 71%) physician-estimated adherence. In the bipolar disorder group, 62 of 92 (67%) patients with low-to-moderate adherence levels had high physician-estimated adherence. CONCLUSIONS/INTERPRETATION: These analyses suggest that, even when physicians are asked about specific patients in their practice, there is discordance between physician perceptions and adherence as measured through pharmacy claims. This disparity may delay appropriate interventions, potentially contributing to relapses.

The use of migraine preventive medications among patients with and without migraine headaches.

The aim was to describe the use of and adherence to migraine preventives among insured patients meeting the International Classification of Headache Disorders, 2nd edn (ICHD-II) criteria for migraine headaches. A retrospective, case-control study was conducted using data from a telephone interview linked with health insurance claims data. Subjects were health plan enrollees aged 18-55 years who had incurred at least one encounter between June 2000 and November 2001. Interview responses were used to identify cases meeting the ICHD-II criteria for strict and probable migraine and a random sample of controls. Pharmacy claims data were used to construct measures of use and adherence. Differences in outcomes by adherence status were evaluated using generalized linear models. We identified 2517 cases and 941 controls. Among cases, the prevalence of antidepressant use was 4%, anticonvulsant use was 1.9%, antihypertensive use was 8.9%. Combined use was 13.4% among cases and did not differ significantly from that observed among controls (12.4%). Mean adherence rate between the first and last dispensing during the year was high (88%) and did not differ by migraine status. When the entire 12-month period is considered, adherence was substantially lower (56%). Patients who were adherent between dispensings reported significantly less migraine-related disability and incurred higher prescription drug costs, but did not differ in their total medical care costs. Patients with migraine are unlikely to be users of preventive medications. Among users, few are taking preventive medications continuously. Patients with migraine-especially those without a medical diagnosis for migraine or headaches-are not receiving the benefits available from existing pharmacotherapy options.