The Concept of Risk When Time is a Crucial Factor: How to Understand and How to Communicate? Theoretical Considerations and Empirical Findings

Please note: All research in progress seminars are off-the-record. Any information about methodology and/or results are embargoed until publication.

Ivar Sønbø Kristiansen

Professor MD PhD MPH

Department of Health Management and Health Economics, University of Oslo, Institute of Public Health, University of Southern Denmark, visiting scholar, Stanford Center for Health Policy

Chronic diseases (cardiovascular, cancer, diabetes, psychiatric, etc.) account for the majority of the costs of health care. It is therefore essential that patients, policy makers and providers understand measures of prognosis and effectiveness for interventions for chronic diseases. Typical measures of prognosis is 10-year survival, while absolute risk reduction, relative risk reduction, number-needed-to-treat and odds ratio are measures of effectiveness. However, for chronic diseases prognosis may also be expressed as life expectancy and effectiveness as postponement of adverse outcomes such as heart attack or death.

Odense Risk Group in Denmark is an informal network of physicians, economists, pharmacists, psychologists and others who have conducted a range of studies to explore the following hypothesis: Lay-people and professionals are better able to understand information on effectiveness when presented as postponement of adverse outcomes than risk reduction.

We have undertaken a range of experiments by telephone interviews, web-interviews and in-person interviews to test the hypothesis. Currently, a clinical trial in primary care is ongoing using absolute risk reduction or prolongation of life as measures of effectiveness.

I will present results of some of the studies and how the measures of effectiveness can be taught in an easier way.