title: A risk-adjusted O-E CUSUM with monitoring bands for monitoring medical outcomes.
abstract: In order to monitor a medical center's survival outcomes using simple plots, we introduce a risk-adjusted Observed-Expected (O-E) Cumulative SUM (CUSUM) along with monitoring bands as decision criterion.The proposed monitoring bands can be used in place of a more traditional but complicated V-shaped mask or the simultaneous use of two one-sided CUSUMs. The resulting plot is designed to simultaneously monitor for failure time outcomes that are "worse than expected" or "better than expected." The slopes of the O-E CUSUM provide direct estimates of the relative risk (as compared to a standard or expected failure rate) for the data being monitored. Appropriate rejection regions are obtained by controlling the false alarm rate (type I error) over a period of given length. Simulation studies are conducted to illustrate the performance of the proposed method. A case study is carried out for 58 liver transplant centers. The use of CUSUM methods for quality improvement is stressed.
authors: Department of Biostatistics, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors: Rena Jie
authors: RJ
authors: Sun
authors: John D
authors: JD
authors: Kalbfleisch
mesh_terms: D003198:Computer Simulation; D006801:Humans; D016377:Organ Transplantation / Q000379:methods* / Q000592:standards; D017063:Outcome Assessment, Health Care / Q000379:methods*; D018570:Risk Assessment / Q000379:methods*; D015996:Survival Rate