Associations between comorbidities, treatment choice and outcome in the elderly with end-stage renal disease

BACKGROUND: New patients treated for end-stage renal disease are increasingly elderly: in France, 38% are 75 years or older. The best treatment choices for the elderly are still debated. METHODS: We studied case-mix factors associated with choice of initial dialysis modality and 2-year survival in the 3512 patients aged 75 years or older who started dialysis between 2002 and 2005 and were included in the French REIN registry. RESULTS: Overall, 18% began with peritoneal dialysis (PD), 50% with planned haemodialysis (planned HD) and 32% with unplanned HD, that is, HD that started on an emergency basis. At least one comorbid condition was reported for 85%, and three or more for 36%, but case-mix varied with age. PD was chosen significantly more often than planned HD for the oldest (> or =85) compared with the youngest (75-79) patients: odds ratio 2.1 (95% confidence interval, 1.5-2.8), in those with congestive heart failure: 1.8 (1.5-2.3) and severe behavioural disorder: 2.2 (1.3-3.5), but less often for obese patients: 0.5 (0.3-0.8) and smokers: 0.4 (0.2-0.9). Two-year survival rates were 58, 52 and 39% in patients aged 75-79, 80-84 and > or =85, respectively. Compared with planned HD, unplanned HD was associated with a risk of mortality 50% higher, and PD with a risk 30% higher, independent of patient case-mix. CONCLUSION: PD is a common treatment option in French elderly patients, but our study suggests the need for caution in the long-term use. The high frequency of unplanned HD would require further attention.