Value-Based Medicine

VBM: Who Determines the “Value?”

By Melissa M. Brown, MD, MN, MBA

We are working our way through under standing what Value-Based Medicine is all about… and making progress. Having reviewed the pluses and mi nuses of evidence-based data and its use in evidence-based medicine, we are now maneuvering through the world of “value.”

In last month's column, I introduced the use of utility measurement in health care. This key assessment uses a time trade-off method, linking the improvement in utility with an effective intervention that leads to a more favorable health state.

Who Determines Quality of Life?

A fundamental question surrounding utility theory concerns the most appropriate source of respondents for determining utility.

There are two general groups from which to choose: those who have personally experienced the health state under study (patients with active disease or active in the past) and those who have not, also known as surrogate respondents. The surrogate respondent group might consist of the general public (community), people who are sick but who do not have the health condition in question, healthcare professionals, expert researchers and/or physicians and administrators.

Debating the pros and cons of each of these groups remains an ongoing topic in medical economic research. I believe, without reservation, that pa tients who have experienced the health state of interest are the appropriate respondents to quality-of-life questions pertaining to those issues. While more difficult to gather, more expensive and time consuming, it is a gold standard that must be demanded and is clearly obtainable.

Questions of usefulness in relation to the dollars spent for public health care often work their way into the topic. I concur that debating the use of public dollars for health care is clearly relevant; however, I will continue to maintain, and lobby to insist, that decision makers use the most relevant and true data obtained from patients on which to base their opinions and decisions for public health policy.

Utilities for vision are interesting; as we have two eyes, the quality of life conferred by an ophthalmic intervention varies depending upon whether pathology has affected one or both eyes. It has been noted widely that ocular utilities seem to be related to visual acuity in the better-seeing eye.

Anxiety Reduces Quality of Life

It is apparent that ocular diseases can substantially diminish quality of life. Although people with functional vision can usually perform activities of daily living, it is believed by many that the anxiety caused by the potential for further visual loss is reflected in their decreased overall quality of life. Therefore, even with relatively small visual loss, the utility value of patients with any ocular disease is less than 1.0. Recall that utility measurement ranges from 0.0 (the state of death) through 1.0 (perfect health indefinitely).

The methodology used at the Center for Value-Based Medicine to obtain utilities is standardized across all fields of medicine. Using time trade-off methodology, patient respondents experiencing the health state of interest are surveyed by direct interview.

Thousands of patient data points have been assimilated, allowing for narrow confidence intervals around the mean results. Recall that small confidence intervals give us assurance — and evidence — that if the questions were asked again of different folks, the mean utility would likely be the same or close to that of the original population interviewed.

Vision Loss vs. Other Health Issues

The degree of lessening of quality of life has been defined for many levels of vision and can be compared with that induced by other health-related states. Minimal visual loss in the presence of ocular disease seems to reduce the quality of life to the same degree as having diabetes mellitus or a mild stroke (0.88). With severe visual loss to the level of legal blindness (<20/200 bilaterally) the resultant quality-of-life assessment, or utility, is similar to someone with severe ulcerative colitis, severe angina or a moderately severe stroke (0.61).

Future columns will define more visual utilities and comparable health states, demonstrating the great value of vision and of those interventions that can improve it. OM

Value-Based Medicine is a registered trademark of the Center for Value-Based Medicine.

Melissa M. Brown, MD, MN, MBA, is president and CEO of the Center for Value-Based Medicine in Philadelphia, She can be reached via e-mail at mbrown@valuebasedmedicine.com