Worldwide, mortality risk is high soon after initiation of hemodialysis

Abstract

Mortality rates for maintenance hemodialysis patients are much higher than the general population and are even greater soon after starting dialysis. Here we analyzed mortality patterns in 86,886 patients in 11 countries focusing on the early dialysis period using data from the Dialysis Outcomes and Practice Patterns Study, a prospective cohort study of in-center hemodialysis. The primary outcome was all-cause mortality, using time-dependent Cox regression, stratified by study phase adjusted for age, sex, race, and diabetes. The main predictor was time since dialysis start as divided into early (up to 120 days), intermediate (121-365 days), and late (over 365 days) periods. Mortality rates (deaths/100 patient-years) were 26.7 (95% confidence intervals 25.6-27.9), 16.9 (16.2-17.6), and 13.7 (13.5-14.0) in the early, intermediate, and late periods, respectively. In each country, mortality was higher in the early compared to the intermediate period, with a range of adjusted mortality ratios from 3.10 (2.22-4.32) in Japan to 1.15 (0.87-1.53) in the United Kingdom. Adjusted mortality rates were similar for intermediate and late periods. The ratio of elevated mortality rates in the early to the intermediate period increased with age. Within each period, mortality was higher in the United States than in most other countries. Thus, internationally, the early hemodialysis period is a high-risk time for all countries studied, with substantial differences in mortality between countries. Efforts to improve outcomes should focus on the transition period and the first few months of dialysis.

Figure 1

Mortality After the Start of Dialysis Countries were ordered by mortality rate at ≤120 days. ANZ=Australia and New Zealand; BE= Belgium; CA= Canada; FR= France; GE= Germany; IT: Italy; JPN= Japan; SW= Sweden; UK= United Kingdom; US= United States Error bars correspond to 95% confidence intervals calculated using the Byer approximation

Figure 2

Mortality in Each DOPPS Country vs. the US by Time on HD Model adjusted for age, sex, race and diabetes as cause of ESRD, stratified by study phase (N=86,886 HD patients from DOPPS census [2002–2008])

Figure 3

Figure 3a: Association of mortality with age and vintage ^†One model was fitted to each patient subgroup based on age at study enrollment (<45, 45–55, 55–64, 65–74, ≥75 years) Models were adjusted for age, sex, race, and diabetes as cause of ESRD, stratified by countries and study phase, and accounted for facility clustering. *Mortality rate: unadjusted number of deaths per 100 patient-years. Error bars correspond to 95% confidence intervals calculated using the Byer approximation. Figure 3b: Association of mortality with sex, diabetes status, and vintage ^†One model was fitted to each patient subgroup based on sex or diabetes status at study enrollment Models were adjusted for age, sex, race, and diabetes as cause of ESRD, stratified by countries and study phase, and accounted for facility clustering. *Mortality rate: unadjusted number of deaths per 100 patient-years. Error bars correspond to 95% confidence intervals calculated using the Byer approximation.

Figure 3

Figure 3a: Association of mortality with age and vintage ^†One model was fitted to each patient subgroup based on age at study enrollment (<45, 45–55, 55–64, 65–74, ≥75 years) Models were adjusted for age, sex, race, and diabetes as cause of ESRD, stratified by countries and study phase, and accounted for facility clustering. *Mortality rate: unadjusted number of deaths per 100 patient-years. Error bars correspond to 95% confidence intervals calculated using the Byer approximation. Figure 3b: Association of mortality with sex, diabetes status, and vintage ^†One model was fitted to each patient subgroup based on sex or diabetes status at study enrollment Models were adjusted for age, sex, race, and diabetes as cause of ESRD, stratified by countries and study phase, and accounted for facility clustering. *Mortality rate: unadjusted number of deaths per 100 patient-years. Error bars correspond to 95% confidence intervals calculated using the Byer approximation.

Figure 4

Overall mortality rate by age at study enrollment *Mortality rate: number of deaths per 100 patient-years

Figure 5

Proportion of Deaths due to Withdrawal from Dialysis by Dialysis Period and Country Countries were ordered by percent of deaths due to withdrawal from dialysis.