Measuring the quality of health care is the basis for establishing accountability for providing good care. Yet although the science of quality measurement is steadily improving, the methods for setting a threshold for acceptable care are still rudimentary. In holding physicians accountable, when is care good enough to be acceptable? How good is good enough?
According to current practice, a payer judges a physician or a practice organization by the proportion of patients for which the physician adhered to the practice measure. “Good enough” therefore is an adherence rate that exceeds a threshold, which is typically expressed as a percentile of the distribution of adherence rates in a population of clinical practices. For example, in its recognition program, the National Committee for Quality Assurance sets the threshold for passing a measure according to the population-derived adherence rate for the corresponding Healthcare Effectiveness Data and Information Set (HEDIS) Health Plan measure (usually at the 70th percentile) (Gregory Pawlson, MD, National Committee for Quality Assurance, e-mail communication, April 2010).