Death during the first 90 days of dialysis: A case control study

Abstract

Comparison of survival data among centers may be used to assess performance, but may be influenced by the number of patients who die during the first 90 days of renal replacement therapy (RRT). Data published by registries in Europe do not detail these deaths, and US data generally exclude them from analysis for financial reasons. To study factors influencing such deaths we compared 42 patients who died within 90 days of first commencing RRT in one Scottish renal unit (group A) between 1971 and 1992 with 42 age- and sex-matched controls who started RRT over the same period and survived longer (group B). Patients who died within 90 days of RRT ranged in age from 25.3 to 83.7 years and had a mean age of 65.2 (SEM, 1.6; 95% confidence interval, 61.9 to 68.4). The proportion of patients who died during the first 90 days of RRT increased from 2% of all patients treated before 1981 to 12% in subsequent years. Thirty-three patients in group A received emergency dialysis via temporary venous access compared with only nine in group B ( P < 0.055). There were more patients in group A with a diagnosis of arteriosclerotic renal artery stenosis (14 v 1) and with a history of smoking (15 v 2) than in group B ( P < 0.0005). Median renal or nonrenal follow-up before RRT was 1.1 month in group A and 10.6 months in group B ( P < 0.0001). Fewer patients in group A had no coexisting disease (1 v 17; P < 0.0001). Group A patients had a significantly lower mean serum albumin concentration at the time of commencing RRT than group B patients (31.4 g/ L v 37.1 g/ L) ( P = 0.0006). Blood pressure and serum concentrations of creatinine and potassium were comparable in both groups. We conclude that 90-day mortality in our center was associated with the presence of coexisting disease, renal artery stenosis, smoking, hypoalbuminaemia, and presentation with advanced renal failure. Furthermore, since such heterogeneous patients are difficult to classify, valid survival data can be obtained from different centers only when such early mortality is excluded from analysis.