By Mary Gabb ([email protected])

The term “adherence” (or sometimes “compliance”) – the extent to which patients take their treatment as prescribed – has been understood to be a nagging clinical issue, but is now seen as a major cost driver in many therapeutic areas.

A recent report from the National Council on Patient Information and Education (NCPIE) in the United States reveals depressing statistics: 49% of those polled had forgotten to take a prescribed medication, 31% had not filled a prescription they were given, 29% had stopped taking a medicine before the supply ran out, and 24% had taken less than the recommended dosage.

A recent report in the Archives of Internal Medicine documents our failed efforts to improve adherence. Only about half of randomised controlled trials designed to improve medication adherence showed any consistent improvement in patient adherence, and less than one third of the studies demonstrated improvement in at least one clinical outcome. Non-adherence has even been referred to as the “other drug problem”.

How does the issue of adherence/compliance affect the field of health economics? The International Society for Pharmacoeconomic Outcomes and Research (ISPOR) has created the ISPOR Medication Compliance and Persistence Special Interest Group to study non-adherence in pharmacoeconomic evaluations.

JoAnne LaFleur, Research Assistant Professor at the Pharmacotherapy Outcomes Research Center, University of Utah College of Pharmacy (Salt Lake City, UT, USA) is a member of the ISPOR special interest group on adherence/compliance. She says there has been a surge in the last five years in measuring the cost outcomes of poor adherence.

She explains that medication costs are often much less expensive than the surgical or hospitalisation costs if the medications are not taken as directed and the clinical sequelae manifest. LaFleur also says that, in the US, a consistent problem has been that, with a few exceptions, the myriad health insurance plans don’t invest in programmes to improve adherence, in part because their pharmacy budgets are separate from the medical budgets. In fact, management of pharmacy coverage is often outsourced to other companies called pharmacy benefit managers. Thus, each group (pharmacy versus medical benefits) is not considering the ramifications of their decisions on the total healthcare cost, but rather only on their specific budgets.

According to David Nash, MD, MBA, Chairman of the Department of Health Policy at Jefferson Medical College (Philadelphia, PA, USA), who recently reviewed the Archives study, the only techniques that seem to have any impact on improving adherence are “once-a-day dosing and a rigorous reminder system to patients”.

For health economists, Dr. Nash sees three main issues regarding adherence and health economics:

  • a lack of programmatic progress in improving adherence, as evidenced in the Archives-published study and the NCPIE report
  • a lack of understanding of the downstream costs of poor adherence, which are “formidable”
  • the effect of co-payment (or “cost sharing”) on adherence.

In our next HOC article on adherence, we will discuss some of the challenges to including adherence in cost outcomes analyses, including effect of co-payment on adherence, as well as the use of accurate models of adherence in cost outcomes analyses – how closely do they reflect real life data?