Using comparison charts to assess performance measurement data.
BACKGROUND: In 1997 the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) announced the ORYX initiative, which integrates outcomes and other performance measurement data into the accreditation process. JCAHO uses control and comparison charts to identify performance trends and patterns that are provided to JCAHO surveyors in advance of a health care organization's (HCO's) survey. During the survey, the HCO is asked to explain its rationale for its selection of performance measures, how the ORYX data have been analyzed and used to improve performance, and the outcomes of these activities. CONSTRUCTING COMPARISON CHARTS: A comparison chart, a graphical summary of the comparison analysis, consists of actual (or observed) rates, expected rates, and expected ranges (upper and lower limits) for a given time frame. The expected range describes the degree of certainty that a given point is different from the average score (population). THE USE OF COMPARISON CHARTS: Comparison charts are primarily useful for telling an HCO whether one of its selected performance measures may be evidencing one of the three types of measurement outcomes: exemplary performance, average performance, or substandard performance (indicating an opportunity for improvement). The comparison charts compare an HCO's outcomes to those of its comparison group or to its risk-adjusted data. The charts provide guidance to an HCO about whether it should continue to monitor a process so as to maintain its current level of performance or whether it should try to improve its current performance.