Risk-adjusted control charts for health care assessment

The recent Joint Commission on Accreditation of Healthcare Organization requirement that hospital accreditation be based upon a Total Quality Management approach has focused the attention of health care administrations on the use of techniques such as control charts. However, control charts are not typically adjusted for severity of illness. This adjustment is needed because, unlike industrial organizations, hospitals are not able to control all of their inputs and must accept variances in their patients. In this paper, the authors present a methodology for adjusting a health care organization’s control charts to reflect their patient population’s severity of illness during different time intervals. They then demonstrate that risk-adjusting expected patient outcomes can change the present assessments of the relative quality of care offered by a health care organization in different time periods.