One of the odder results of Barack Obama's attempts to reform US Medicare has been an eloquent if troubling assault by his critics of the use of "quality metrics" in health care.

Prevention science has spent the year refining its interest in fidelity, manualization, dosage and so on; some medical writers have been going into print regardless, alluding to "disturbing data on the unintended consequences of coercive regulation".

That particula phrase comes from the Wall Street Journal, and an article published in the spring by Jerome Groopman and his partner, Pamela Hartzband, about the risks they associate with rigid treatment protocols.

Groopman is a staff writer for the New Yorker, and both are on the faculty of Harvard Medical School. But he is best known for How Doctors Think, an analysis of the mixture of factors enmeshed in good and bad diagnosis.

They reported how the US federal government had piloted Medicare projects at more than 260 hospitals since 2003 to reward physicians and institutions for meeting quality metrics. Many private insurers had followed suit with similar incentive programs.

They acknowledged the value of simple quality improvement initiatives – hygiene protocols for hand-washing, for example, and for the insertion of intravenous catheters.

But they argued that clinicians had been driven by insurance regulators to turn "guidelines for complex diseases into iron-clad rules” – too often with counter-productive result.

"Analysis of Medicare pay-for-performance for hip and knee replacement by orthopedic surgeons at 260 hospitals in 38 states published in the most recent issue of Health Affairs showed that conforming to or deviating from expert quality metrics had no relationship to the actual complications or clinical outcomes of the patients,” they wrote.

"Similarly, a study led by UCLA researchers of over 5,000 patients at 91 hospitals published in 2007 in the Journal of the American Medical Association found that the application of most federal quality process measures did not change mortality from heart failure.

They concluded by putting into ambiguous context lines from one of the pioneers of "evidence-based medicine," David Sackett.

"Half of what you'll learn in medical school will be shown to be either dead wrong or out of date within five years of your graduation; the trouble is that nobody can tell you which half – so the most important thing to learn is how to learn on your own," Sackett had said.

From Groopman and Hartzband’s perspective, such plain speaking reinforced their conviction that: “science depends upon such a sentiment, and honors the doubter and iconoclast who overturns false paradigms.

All these threads were picked up by the New York Times magazine’s and their writer David Leonhardt in an account of “delivery research” activity in Salt Lake City.

That centered on the work of former Harvard cancer specialist Brent James, now executive director of Intermountain Healthcare and architect of a training program that combines statistical methods, management theory and, arguably, elements of open design.

“The debate between intuition and empiricism is as old as Plato,” David Leonhardt reflected. “The argument has seemed especially intense lately, as one field after another has struggled to define the role of human judgment in a data-saturated society.

"These disagreements can sometimes be exaggerated, because everyone agrees that intuition and empiricism both have a role to play. But the fight over how to balance the two is a real one.

And by Brent James's reckoning the balance is secured by improving the flow of knowledge and understanding back and forth between one state and the other. “Groopman’s right at one level,” he told Leonhardt. “You cannot write a protocol that perfectly fits any patient. Humans that come to us for care are just too variable.”

“But James pulled out a graph that showed a steep fall in mortality after Intermountain put in place a heart-failure protocol,” Leonhardt continued. “The changes appear to save about 450 lives a year.

“Graphs like that one are the reason he believes in evidence-based medicine. It must be done right - with hospitals monitoring outcomes at every step, quickly sharing that data with doctors and altering the guidelines as necessary… He is not defending protocols per se. He is defending measurement. ‘Don’t argue philosophy,’ he told me. ‘Show me your mortality rates, and then I’ll believe you.’”

[See also: Unfold my blanket next to the bench]

• Useful historical additions to the Sackett anecdote are to be found on the website of the Information Resources Group at the School of Health and Related Research (ScHARR) at the University of Sheffield, UK. It records, for example, an exchange between “two giants of epidemiology,” Kerr White and Archie Cochrane (after whom we named the collaboration): “Kerr had just suggested that ‘only about 15-20% of physicians' interventions were supported by objective evidence that they did more good than harm’ when Archie interrupted him with: ‘Kerr, you're a damned liar! you know it isn't more than 10%’.”