Of the many different medical conditions for which treatment is sought, chronic ones are by far the most common and the most costly. They are also among the most preventable. Persuading people to modify the health behaviors that put them at risk for developing a chronic disease is no small task, but Karen Glanz, a Penn Integrates Knowledge Professor, has found that grounding health behavior programs in theory is a highly effective approach.

Glanz, who holds appointments in the Perelman School of Medicine and the School of Nursing, began teaching health behavior theory in the 1980s, when no comprehensive textbook on the subject existed. When approached by a publisher in 1987 to write a textbook on a topic of her choosing, she talked with her colleague, Barbara Rimer, currently a dean at the University of North Carolina, knowing just what gap they needed to fill.

“Health Behavior and Health Education: Theory, Research, and Practice” has gone on to sell more than 250,000 copies in five languages over the course of its first four editions. This year saw the release of its fifth edition, “Health Behavior: Theory, Research, and Practice,” written with Rimer and co-editor K. Viswanath, a health communications expert at Harvard University.

So how has Glanz, founding director of Penn’s Center for Health Behavior Research, been able to anticipate the issues students should know in such a rapidly changing field?

“Every six years, we go through areas of the field that we think have really changed, and look for contributors who are the leaders in these areas,” Glanz says. They then ask each contributor to write an updated chapter on the health behavior theory within their expertise, its history and core components, and how it can be applied in research and practice.

Glanz says that research methods have grown more sophisticated since she published the first edition in 1990, with more complex statistical approaches and new ways of analyzing data. She also notes a significant expansion in the book’s audience, growing from public health and some nursing students with the first edition to include professionals in postgraduate medical education and a wide range of other disciplines.

“The theories themselves don’t change that much,” Glanz says, “but their applications change, as do the critical issues, among which, currently, are behavioral economics, health disparities, and the cross-cultural application of health behavior theories.

“Every time we write the introduction of a new edition, we reflect on the global issues and events over the prior six years. For this latest edition, we considered the spread of pandemics such as Ebola. We have to know how to solve these problems,” she says, “and changing health behavior is a critical part of this work.”