Heterogeneity in aripiprazole diffusion for bipolar disorder treatment in the Veterans Health Administration

The objectives of this study were to ascertain the relative importance of scientific "approval" versus U.S. Food and Drug Administration (FDA) regulatory approval regarding changes in aripiprazole prescribing rates for treating bipolar disorder and to identify system-level covariates associated with faster regional uptake of aripiprazole.

Medication use data for 2002–2009 were obtained from the Veterans Health Administration (VHA) National Psychosis Registry for 106,547 patients with diagnoses of bipolar disorder, aggregated at the level of the Veterans Integrated Service Network (VISN). VISN-level independent variables were obtained from several VHA organizational databases. Interrupted time-series analysis was used to examine changes in rates of prescribing aripiprazole, and logistic regression was used to model above- versus below-median growth in aripiprazole prescribing across VISNs.

Three inflections were observed, corresponding to the publication of two positive studies and FDA approval of aripiprazole for the treatment of bipolar mania. No significant VISN-level policy, administrative, or staffing predictors of the growth rate in aripiprazole prescribing were identified. Exploratory analyses showed that access to care may play a role in uptake, whereas competing demands, such as substance abuse treatment needs, may retard adoption.

Early published evidence may have a strong impact on practice for low-barrier innovations, such as newly marketed medications or changes in indication for approved medications. Regional targeting of prescriber behavior interventions may maximize efficiency in efforts to change prescribing; further delineation of factors associated with regional heterogeneity in prescribing would support such efforts.