The impact of varying patient populations on the in-control performance of the risk-adjusted CUSUM chart

• Published in: International journal for quality in health care 2015-02, Vol.27 (1), p.31-36
• Main Authors: TIAN, WENMENG, SUN, HONGYUE, ZHANG, XIANG, WOODALL, WILLIAM H.
• Format: Article
• Language: English
• Subjects: Age Factors; Bias; Computer Simulation; Health Status; Humans; Models, Statistical; Quality of Health Care; Risk Adjustment - methods; Risk Adjustment - standards; Risk Factors
• ISSN: 1353-4505; 1464-3677
• DOI: 10.1093/intqhc/mzu092

This research is designed to examine the impact of varying patient population distributions on the in-control performance of the risk-adjusted Bernoulli CUSUM chart. The in-control performance of the chart is compared based on sampling the Parsonnet scores with replacement from five realistic subsets of a given distribution. Five patient mixes with different Parsonnet score distributions are created from a real patient population. The outcome measures for this research are the in-control average run lengths (ARLs) given varying patient populations. Our simulation results show that the in-control ARLs of the risk-adjusted Bernoulli CUSUM chart with fixed control limits and a given risk-adjustment equation vary significantly for different patient population distributions, and the in-control ARLs decrease as the mean of the Parsonnet scores increases. The simulation results imply that the control limits should vary based on the particular patient population of interest in order to control the in-control performance of the risk-adjusted Bernoulli CUSUM method.