Changing medication use in managed care: a critical review of the available evidence

To review the effectiveness of strategies to improve the quality and efficiency of medication use in managed care organizations (MCOs).

Systematic review of published intervention studies.

Studies were identified by using computerized and manual literature searches and personal contacts, and were categorized by intervention type and adequacy of research design according to commonly accepted criteria. Reported significance and magnitude of the changes in key outcomes were used to summarize the effects of studies with adequate research designs.

The searches identified 105 studies, 70 of which were reported since 1996. Overall, 46% of the studies met the minimum criteria for methodologic adequacy (n = 48). Consistently effective interventions included dissemination of educational materials with drug samples, participatory clinical guideline development, group or one-to-one educational outreach, and enhanced patient-specific feedback. Disease management (primarily for depression and diabetes) showed promise in improving short-term outcomes. Dissemination of educational materials and aggregated feedback alone were ineffective. Interventions in staff-model health maintenance organizations were more effective than those conducted in group-model health maintenance organizations.

High-quality studies of interventions to improve drug use in MCOs are increasing in frequency. There is evidence for the effectiveness of several strategies to change drug use, but little is known about longer-term clinical outcomes. Few well-designed, published studies have assessed the efficacy or safety of financial incentives for physicians, tiered copayments for patients, or formularies--despite their widespread use.