Validation of quality indicators for radical prostatectomy

Abstract

BACKGROUND: Radical prostatectomy is the surgical procedure performed on men with clinically localized prostate cancer. In recent years, radical prostatectomy quality indicators have been recommended, but the feasibility and validity for many of these listed surgical quality indicators have yet to be examined. We tested the convergent construct validity of these quality indicators by assessing their associations with hospital volume, a variable repeatedly associated with the quality of surgical care, for prostate cancer patients treated with radical prostatectomy. OBJECTIVES: (1) To assess variations in quality indicators by hospital volume; and (2) To investigate whether certain explanatory variables account for some of the variation observed in Objective 1. METHODS: This was a retrospective cohort study using medical chart review data that had already been collected as part of a parent study. The study population consisted of a stratified random sample of prostate cancer patients diagnosed between 1990 and 1998 in Ontario, who were treated by radical prostatectomy with curative intent within six months of diagnosis (n = 645). The feasibility of using this data to assess a number of quality indicators was explored, and where possible, variables were developed for analysis. Ultimately, detailed analyses were performed for the quality indicators: total blood transfusions of three units or greater, length of hospital stay, and use of non-nerve-sparing surgical technique. RESULTS: Even using high-quality chart data, it was not feasible to evaluate all of the quality indicators that were explored. For blood transfusions of three units or greater, length of hospital stay, and use of non-nerve-sparing surgical technique, worse outcomes were generally apparent with decreasing hospital volume, both before and after adjusting for the effect of explanatory variables. CONCLUSIONS: We demonstrated convergent construct validity for three quality indicators (blood transfusions, length of hospital stay, and non-nerve-sparing surgery). If their validity is further demonstrated in future studies, these indicators could be used for quality assessment and could provide feedback to surgeons, surgical department heads, hospital administrators, and quality councils by suggesting areas for quality improvement in surgical care, such that future outcomes can be optimized.