Tuesday, January 29, 2008

A Clintonesque Examination of Quality in Disease Management

Everyone is aware that millions of Americans are being stymied by suboptimal healthcare quality, but the Disease Management Blog has been pondering just what “is” quality? Assuming it is expressed as a fraction of a group defined by a condition that achieves a desired outcome, the higher that fraction, the better. What’s more, with continued interventions, innovations and incentives we should be blessed with 100% quality. One example is NCQA, HEDIS and beta blockers.

But is that realistic in other sectors of chronic illness care?

Those of us who have worked in the trenches know the answer is sadly no. High blood pressure is a good example. As the heart squeezes down and pushes blood out into the arteries, the pressure goes up until the heart reaches its maximum degree of contraction. The maximum pressure in the arteries at that point in time is the “top number” (systolic pressure). As the heart relaxes or dilates (it needs to fill up with blood again), the pressure falls until the heart stops the relaxation and starts to squeeze again. That point of low pressure in the arteries is the bottom number (diastolic pressure). With the contraction and relaxation of the heart, the pressure in the arteries bounces between the systolic and diastolic, typically 120 millimeters of mercury on top and 80 mm of mercury on the bottom.

No one really knows what causes high blood pressure (usually defined as 140 or more systolic, or 90 or more diastolic) but whoever figures it out will likely deserve the Nobel Prize for Medicine, since that kind of discovery can lead to a cure. Absent that cure, we’re stuck with treatments consisting of weight loss, salt restriction, other lifestyle modifications and of course, drugs. Just how well do these treatments work?

To answer that question, the intrepid disease management blog blew tanks and dove into some of the peer review literature. Trials of hypertension therapy are a good window into the topic because in research settings, motivated volunteers agree to fully comply with treatment, have close follow-up by doctor and typically have a research assistant (such as a nurse) provide direction to the patient under protocol as part of a registry. It’s not too dissimilar from disease management or the chronic care model. That was also the approach used in the landmark HOT study.

In that study, patients with hypertension were randomly assigned to one of three targeted treatment protocols. While much has been made of the outcomes in the study, what is not widely appreciated is that only 85% of those assigned to a diastolic blood pressure less than 90 actually achieved it. In other words, even in high intensity research settings, the achievement of blood pressure control is not 100%.

How do I know this? Because I was one of the investigators in HOT and despite nuclear powered education and suitcase loads of pills, some of the participants in my clinic never got to target blood pressure.

And this phenomenon is not confined to high blood pressure. Outcomes less than “perfect” are typical in other clinical trial research reports involving chronic conditions like chronic heart failure, diabetes mellitus and high cholesterol. The HEDIS beta blocker success story will probably turn out to be the exception and not the rule.

Therefore, based on what the science is telling us, even with fully motivated patients who are carpet bombed with disease management (or the advanced medical home), ideal healthcare quality cannot be expressed as 100%. However, absent an adequate comparator, clinically reported clinical trials can yield up a “best of class” success rate of what can be accomplished under optimum conditions involving an optimum population. That puts a new perspective on press releases like this, where the results (compared to published trials) probably ain’t bad, but fail to tell us what is – and what isn’t – possible.

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