Predicting Tree-Year Clinical Outcomes Using the Baseline and Trajectories of Serum Albumin in Patients on Peritoneal Dialysis

Abstract

Background: The change and trend in serum albumin levels after initiation of peritoneal dialysis may be a crucial determinant for clinical outcomes. Objectives: The current study aimed at determining the association between the trajectory of serum albumin and the 3-year clinical outcomes using a novel approach joint modeling longitudinal and survival data. Furthermore, the current study was performed to compare the impact of baseline and trajectory serum albumin on predictability of 3-year outcomes. Methods: The current retrospective longitudinal study reviewed all of the available files of the patients undergoing continuous ambulatory peritoneal dialysis (CAPD) in Al-Zahra hospital, Isfahan, Iran, from May 2005 to March 2015. A total of 183 patients with at least 3 years follow-up were selected for the study. The independent variables of interest were baseline and the trajectories of serum albumin, age, gender, history of previous hemodialysis (HD), body mass index (BMI), baseline serum creatinine, and comorbidity including cardiovascular disease and diabetes. The outcomes of interest were death from all causes, transfer to HD and transplantation during the first 3 years of CAPD. Results: The patient and technique survival rates at 36 months were 71% and 77%, respectively. C-indexes (prediction errors) of mortality, transfer to HD, and transplantation for joint modeling with trajectories of serum albumin were higher (lower) than those of the Cox regression with baseline albumin. Hazard ratios of mortality, transfer to HD, and transplantation for trajectories of serum albumin were 0.409, 0.273, and 3.394, respectively. Conclusions: The current study indicated that the predictability of 3-year clinical outcomes using trajectories of serum albumin was higher than those of the baseline. According to the findings of the current study, it seems that controlling serum albumin over time in patients undergoing CAPD, particularly the ones with the history of diabetes and HD, can help to prevent or modify the clinical outcomes during the PD period.