Two prognostic scores for early mortality and their clinical applicability in elderly patients on haemodialysis: poor predictive success in individual patients

Abstract

Introduction: Few studies address the individual prognosis of an elderly patient beginning chronic haemodialysis (HD), despite the fact that doctors must frequently weigh the possible benefits and disadvantages of prescribing this treatment.

Objectives: Evaluate the usefulness of the REIN Registry’s prognosis score and the predictive index for early mortality proposed by the Catalan Registry of Renal Patients (RMRC, Registre de Malalts Renals de Catalunya) in elderly patients beginning HD by comparing indices with observed survival rates.

Methods: We studied patients aged 75 years and older who started and continued HD treatment in our Department between 2004 and 2009. Socio-demographic, clinical, co-morbidity and mortality data were recorded, in addition to whether or not initiating HD was planned. We calculated the REIN score and the RMRC probability of early mortality.

Results: We analysed 63 patients with a mean age of 80.4 +/- 3.9 years and a mean of 3.4 +/- 1.8 additional illnesses. Of these patients, 59% began HD with a catheter; 57.1% had cardiovascular disease, 15.9% neoplasia, 31.2% chronic obstructive pulmonary disease and 19% diabetic nephropathy. Survival rates observed at 6 and at 12 months were 79.4% and 73%, respectively. Patients who began HD on an emergency basis (47.7%) or who were unable to care for themselves (21%) had higher 6-month mortality rates. Analysis of ROC curves (Receiver Operating Characteristic) showed slight concordance between the observed mortality rates and both the REIN score (area 0.681, P=.046) and the RMRC index (area 0.594, P=.255).

Conclusions: The RMRC 1-year mortality probability model is not well adapted for individual prognoses in clinical practice. The REIN score only shows slight concordance with the mortality rates observed in the first 6 months of HD. Poor functional independence was the main risk factor for early mortality in elderly patients beginning HD treatment.