Abstract: TH-OR092

Bio Impedance Measurements Taken Over a Period of Time May Be Better Predictors of Survival Than Baseline Measurements in Peritoneal Dialysis Patients

Session Information

  • Peritoneal Dialysis
    November 02, 2017 | Location: Room 290, Morial Convention Center
    Abstract Time: 05:18 PM - 05:30 PM

Category: Dialysis

  • 608 Peritoneal Dialysis

Authors

  • Dukka, Hari, University Hospital North Midlands, Stoke on Trent, United Kingdom
  • Lambie, Mark, Keele University, Crewe, United Kingdom
  • Davies, Simon J., University Hospital of North Midlands, Stoke-on-Trent, United Kingdom
Background

Numerous recent studies have shown that a single measure of body composition estimated from bioimpedance (BI) in dialysis patients is predictive of survival. However, fluid status varies with time and it is not known whether repeated measures improve predictions when compared to a single measure.

Methods

We analysed the long-term predictive value of baseline and longitudinal (5 measures over 12 months). BI measurements obtained from 289 patients enrolled into the UK and Shanghai BI trial (4 centres, 2009-2010). Patients were followed up until a censor date of 30 April 2016 and events such as death, Haemodialysis and transplantation were recorded. Analysis was performed using Cox model stratified for centre.

Results

On univariate analysis, increased extracellular water to total body water ratio (ECW/TBW) and lower phase angle (PA) predicted worse survival with HR’s of 1.063 (95% CI 1.030-1.097) and 0.792 (95% CI 0.671-0.933) respectively. In an analysis adjusted for age, co-morbid score, albumin and urine volume, baseline values of both ECW/TBW and PA provided estimated hazard ratios closer to 1 (HR 1.023, 95% CI 0.984-1.063, and HR 0.913, 95% CI 0.761-1.095 respectively). When time varying rather than baseline values were used in the same adjusted analysis, the goodness of fit statistics improved significantly (ECW/TBW Δ-2LL 7.7, PA Δ-2LL 6.2) and estimated HR’s were further from 1 (ECW/TBW HR 1.063, 95%CI 1.023-1.106, PA HR 0.726, 95%CI 0.577-0.913).

Conclusion

Our analysis demonstrates that repeated BI measurements over a period of time increases the predictive value compared to baseline measurements.

Survival analysis of Longitudinal ECW/TBW measures.

Survival analysis of longitudinal phase angle measures.