There are plenty of good reasons why thoughtful physicians are often unhappy with the current approach to measuring the quality of care they provide. Some, of course, object to the whole notion of quality measurement, but I believe they are in a shrinking minority clinging to an anachronistic mental model in which each physician defines for himself what constitutes high quality care. I have addressed this previously. But even those, who like me, believe it is essential (and possible) to measure quality, can point to legitimate shortcomings in the way it is done.
Among these shortcomings is the imperfect process by which individual physicians’ “results” are “adjusted” to account for differences in the patients they care for. In the simplest case, when the quality of care is judged by looking at patient outcomes, this risk-adjustment is meant to reflect the fact that clinical outcomes reflect both the baseline characteristics of the patients being treated and the treatment they get. For example, if one were to use in-hospital mortality rates to assess the quality of care for acute myocardial infarction, it would be essential to know “how sick” the patients, on average, were on presentation. A 50 year-old man with a small inferior wall MI is likely to live even in the absence of good care (or any care for that matter), whereas a 90 year-old woman with cardiogenic shock from an anterior wall MI is likely to die even with state-of-the art care. Any attempt to assess the quality of care for a population of MI patients must take this into consideration.