Measurement has long been a cornerstone of quality improvement, whether it's on the factory floor or the hospital ward.
And making the quality scores of doctors and hospitals publicly available is central to the idea that health care can become a service that patients shop for intelligently. The results can also ratchet up professional peer pressure for improvement.
But does public reporting lead doctors and hospitals to game the system by withholding care from the sickest patients?
Some researchers turned to Medicare data to compare treatment of acute heart attack patients using angioplasty and stents in three states that have led the way on public reporting with other states that don't report the results.
The upshot: New York, Pennsylvania and Massachusetts had lower rates of angioplasty — about 20 percent lower — than other nearby states that didn't publicly report the findings. Overall, the death rates at a month after treatment were no different, however, and the rates of bypass surgery for heart attack treatment were comparable.
Outcomes scores typically include factors to account for the condition of patients, but some doctors have questioned whether those adjustments for sicker people are adequate.
But the biggest drop in treatment was seen for some of the very sickest patients, those with a so-called STEMI heart attacks, cardiac arrest and cardiogenic shock in the reporting states.
The results appear in JAMA, the Journal of the American Medical Association.
Now there are a couple of possible explanations for the findings, but the study, which looked backward at patients treated between 2002 and 2010, can't prove exactly what's happening.
One possibility is that doctors, patients and their families chose to forgo futile treatment or treatment that wasn't necessary. It's also possible that doctors skipped appropriate treatment of patients who were at the highest risk of dying to avoid the possibility of a lower quality score.
Adjustments to the measures are supposed to take care of that problem, but the formulas have their limitations.
"The concern has been that if you don't give people credit for how sick their patients are, you might be penalizing hospitals of last resort," cardiologist Karen Joynt, lead author of the study tells Shots.
She accepts that measurement and public disclosure are here to stay. "We can't improve without measuring our quality," says Joynt, who works at Brigham and Women's Hospital in Boston and the Veterans Administration Medical Center in West Roxbury.
But public reporting could have unintended consequences. "We need to understand just how this policy is playing out — not just in policy world — but in clinical world," she says in a video accompanying the study. Something that looks good on paper may not be so great in the hospital.