Center-Specific Risk-Adjusted Standardized Mortality Rates on Continuous Ambulatory Peritoneal Dialysis in China

Abstract

Background The aim of this study was to determine if there were centers in China with unusually high levels of risk-adjusted mortality in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods We analyzed an inception cohort commencing CAPD between 1 January 2005 and 13 August 2015, followed until death, dropout defined as discontinuation of Baxter products, loss to follow-up, or 13 November 2015, whichever occurred first. We calculated standardized mortality ratios (SMRs) from Cox proportional hazards models, adjusting for age, gender, employment status, insurance status, primary renal disease, size of peritoneal dialysis (PD) program, and year of dialysis inception. We calculated 2 SMRs, 1 from models including a fixed effect for center of treatment, and 1 from stratified models. Results In this study, there was a 9.9% annual mortality rate in China, with decreasing mortality risk over time. There was significant variation of outcomes between Chinese centers, with up to 20% of facilities having SMRs indicating a higher risk-adjusted mortality rate than average. In particular, larger centers had better than expected mortality than smaller ones. There was significant misclassification of SMRs calculated using stratification versus fixed-effects models, although both showed directionally similar results. Conclusion Despite overall satisfactory and improving outcomes, our study showed a significant proportion of PD centers with higher than expected mortality. This is a signal for further assessment of these centers in China, after which there might be a range of actions taken depending on the results of the assessment and context, bearing in mind that the variation seen may be driven by factors unrelated to quality of care or beyond the control of hospital.