Application of variables control charts to risk-adjusted time-ordered healthcare data

Qual Manag Health Care. Apr-Jun 2004;13(2):99-119. doi: 10.1097/00019514-200404000-00003.


In a previous article (M. K. Hart, Qual Manag Health Care. 2003;12(1):5-19), the authors presented risk-adjusted control charts applicable for attributes data. The present article discusses a similar class of control charts applicable for variables data that are often skewed. The key feature of these charts is their application of risk-adjusted data in addition to actual performance data. The resulting charts should decrease the occurrence of both type I and type II errors as compared to the unadjusted control charts. This article presents several control charts that vary in the data transformation and combination approaches. Data depicting hospital length of stay following coronary artery bypass graft procedures were used to illustrate the use of transformed and risk-adjusted control charts.

Publication types

  • Comment

MeSH terms

  • Confounding Factors, Epidemiologic
  • Coronary Artery Bypass / adverse effects
  • Coronary Artery Bypass / statistics & numerical data*
  • Data Interpretation, Statistical
  • Humans
  • Length of Stay / statistics & numerical data
  • Length of Stay / trends
  • Outcome and Process Assessment, Health Care / methods*
  • Outcome and Process Assessment, Health Care / statistics & numerical data
  • Reproducibility of Results
  • Research Design / statistics & numerical data
  • Risk Adjustment*
  • Time Factors
  • Total Quality Management / methods
  • Total Quality Management / statistics & numerical data*