The Good, the Bad, and the Different: A Primer on Aspects of Heterogeneity of Treatment Effects


Each person is unique thanks to a multitude of factors, such as racial and ethnic backgrounds, age, genetics, chronic conditions, disease severity, gender, environment, and even personal preferences. These and other factors make patients different and affect how they may respond to a certain treatment. 

When there are differences in how different patients respond to treatments it is known as individual treatment effects (or heterogeneity). Because not all patients respond the same way to the same treatment, health care decisions that are made based on a "one-size-fits-all" model could lead to “substantial benefits for some patients, little benefit for many and harm for a few patients.”

But when are these differences meaningful? When is more flexibility needed in coverage policies and when are fewer treatment choices appropriate to provide quality health care and manage health care costs? What information is needed to evaluate when individual treatment effects or heterogeneity exists?  This concept of heterogeneity is explained and further explored via four articles published in the June 2014 issue of the Journal of Managed Care & Specialty Pharmacy:

The Good, the Bad, and the Different: A Primer on Aspects of Heterogeneity of Treatment Effects
Authors: Malone DC; Hines LE, Graff JS.
This article explains the concept of heterogeneity and its importance, especially for clinicians and pharmacy and therapeutics committee members who are making clinical, coverage and reimbursement decisions at a population level. The article also presents a variety of tools and resources to aid decision-makers as they evaluate studies to determine when clinically relevant differences exist. In particular, the article outlines two checklists, one to help decision-makers review patient differences within a study, and the other to help decision-makers understand patient differences across studies.

Managing Heterogeneity in Prescription Drug Coverage Policies
Author:  Teagarden JR.
Necessity and fairness require that health plans limit the products and services they cover, and the basis for plans’ decisions refers to population averages and related population parameters. However, individuals vary and may not be accurately represented by the parameters used to establish coverage policies. Health plans, therefore, are obligated to anticipate and manage heterogeneity among their member groups. This commentary offers considerations for managing heterogeneity in prescription drug benefits.

Medical and Pharmacy Coverage Decision Making at the Population Level
Authors: Mohr PE, Tunis SR.
Medicare is one of the largest health care payers in the United States. As a result, its decisions about coverage have profound implications for patient access to care. In this commentary, which includes a case study, the authors describe how Medicare used evidence on heterogeneity of treatment effects to make population-based decisions on health care coverage for implantable cardiac defibrillators. This case study is discussed in the context of the rapidly expanding availability of comparative effectiveness research. While there is a potential tension between population-based and patient-centered decision making, the expanded diversity of populations and settings included in comparative effectiveness research can provide useful information for making more discerning and informed policy and clinical decisions.

Evaluation of an Educational Program on Deciphering Heterogeneity for Medical Coverage Decisions
Authors: Warholak TL, Hilgaertner JW, Dean JL, Taylor AM, Hines LE, Hurwitz J, Brown M, Malone DC.
The University of Arizona College of Pharmacy conducted an evaluation of its seminar series, funded by NPC, on the important role of heterogeneity in influencing treatment outcomes and in evaluating evidence for making critical drug therapy decisions. This study found that this educational program was effective in improving participants’ knowledge of heterogeneity concepts and methods to evaluate heterogeneity.

To illustrate the challenges with heterogeneity, NPC has developed two infographics, one to help patients understand the concept, and the other to help health professionals in their evaluation of studies.