Changing risk factor demographics in end-stage renal disease patients entering hemodialysis and the impact on long-term mortality

Abstract

Patient survival on hemodialysis has previously been shown to be associated with the presence of comorbid conditions on entrance. Significant comorbid conditions are atherosclerotic heart disease (ASHD), cerebral vascular disease (CVD), nonskin malignancies, chronic obstructive pulmonary disease, diabetes mellitus, and age on entrance to dialysis. Changes in annual mortality have been noted in the United States and at the Regional Kidney Disease Program. The increase in annual mortality was analyzed to determine the impact of risk factors during the time intervals 1976 to 1982 and 1983 to 1987. Patients with no major risk factors have longer survival rates and lower deaths per 1,000 treatment-months from 1983 to 1987 compared with 1976 to 1982. Diabetics have survival rates and deaths per 1,000 treatment-months that are comparable up to age 75. However, over age 75, diabetics have lower survival rates and higher death rates. The presence of comorbid conditions in the diabetic group is high and may account for the increased death rate. The percent of diabetics entering the program has increased from 29% to 48% over the intervals. Nondiabetics with comorbid conditions on entrance had higher deaths per 1,000 treatment-months from 1983 to 1987 compared with 1976 to 1982 across all age categories. Risk factor analysis shows that nondiabetics with major risks are entering with increasing numbers and continuation of comorbid conditions that impact death rates. Peripheral vascular disease, originally not significantly associated with death on dialysis, has dramatically increased from 18% to 60% in nondiabetics with comorbid conditions. In the patients over age 60 with comorbid conditions, 75% of patients now entering dialysis have peripheral vascular disease (PVD). In summary, major shifts in the hemodialysis population have occurred. Diabetics entering dialysis now account for almost 50% of all patients, with the older group having more comorbid conditions. This change alone would increase the annual mortality rate. Patients with comorbid conditions now enter with a higher prevalence of multiple comorbid conditions, which would increase the annual mortality rate. Nondiabetics without comorbid conditions now have better survival across all age categories compared with the previous data. PVD, with its current high prevalence, needs to be reevaluated as a significant risk factor for death on hemodialysis. Therefore, the increase in the annual gross mortality rate is highly predicted based on the change in the diabetic population and the increase in single and multiple comorbid conditions in the nondiabetic population.