HPI faculty have established a national and global reputation for pharmaceutical policy research, including investigating the impacts of changes in insurance coverage on use of medicines, affordability, and clinical outcomes. We conducted the first well-controlled studies of the effect of strict state Medicaid drug coverage limits, which demonstrated reductions in use of both nonessential and essential medications, as well as increases in acute and institutional care. HPI investigators showed that requiring drug prior authorization and step therapy for expensive antipsychotics in Medicaid increased use of less expensive medications, but reduced treatment initiation and adherence among patients with schizophrenia and produced minimal savings. We also determined that the creation of the Medicare Part D drug benefit led to substantially increased access to medications and reductions in cost-related nonadherence in a wide range of patient groups. Globally, we have collaborated with WHO and others on the development and publication of some of the standard methods for investigating medication use in health facilities, examining end-user prices in public and private pharmacies, and evaluating access to medicines through household surveys. We have supported evaluations of interventions in the pharmaceutical sectors of low and middle-income countries and have initiated a portfolio of evidence on impacts of expanding health coverage on medicines utilization in middle-income countries.
Our ongoing research examines the effects of Part D on medication utilization for specific clinical conditions and on health outcomes, as well as the impacts of policy developments within Part D. We are evaluating the impacts of employers offering zero-copay Preferred Drug Lists linked to high deductible health plans with Health Savings Accounts. And we are studying the health and economic impacts for patients and insurers of increased coverage of highly-priced medicines for conditions like hepatitis C and cancers.