No substitute for quality
It was just yesterday that we noted the excellent paper, "Redefining Quality--Implications of Recent Clinical Trials ," published in the June 12 issue of the New England Journal of Medicine. Doctors Harlan Krumholz and Thomas Lee challenged their medical colleagues to design medical strategies that affect overall patient health outcomes - not simply isolated risk factors. Reluctantly, we stated that it was unlikely the article would get most of their colleagues to move away from the risk factor fixation.
It did not take long for that unfortunate prediction to be realized. It appeared in the supplement to the article "Cutting salt intake saves lives and money ". The Abstract which appears halfway down the page under the title, "The 2008 Canadian Hypertension Education Program recommendations for the management of hypertension: Part 2 - therapy" describes a project to update the evidence-based recommendations for the prevention and management of hypertension in adults. It goes on to state:
"For lifestyle and pharmacological interventions, evidence was preferentially reviewed from randomized controlled trials and systematic reviews of trials. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field."
The very same crowd that have always protested that a large scale study to determine the impacts of low salt diets on health outcomes would be too costly, turns around and justifies the use of surrogate risk factors as outcomes because there is no data on health outcomes. How duplicitous is that? This approach is precisely what Krumholz and Lee were referring to.
The main article describes a set of model projections that predict the number of cardiovascular events that will be prevented if salt consumption is decreased. Using blood pressure as the sole marker, this is the same sort of mathematical manipulation that resulted in the statements made by the Center for Science in the Public Interest that 150,000 lives per year would be saved by reducing salt. It is difficult to understand how such work can receive any credibility in the face of our achievement of significantly improved cardiovascular and stroke performance, while consuming the same levels of salt we always have.
C'est curieux, n'est-ce pas?
