Patterns and predictors of early mortality in incident hemodialysis patients: new insights

Abstract

Background: Incident hemodialysis patients have the highest mortality in the first several months after starting dialysis treatments. We hypothesized that the patterns and risk factors associated with this early mortality differ from those in later dialysis therapy periods.

Methods: We examined mortality patterns and predictors during the first several months of hemodialysis treatment in 18,707 incident patients since the first week of hemodialysis therapy and estimated the population attributable fractions for selected time periods in the first 24 months.

Results: The 18,707 incident hemodialysis patients were 45% women and 54% diabetics. The standardized mortality ratios (95% confidence interval) in the 1st to 3rd month of hemodialysis therapy were 1.81 (1.74-1.88), 1.79 (1.72-1.86), and 1.34 (1.27-1.40), respectively. The standardized mortality ratio reached prevalent mortality only by the 7th month. No survival advantage for African Americans existed in the first 6 months. Patients with low albumin <3.5 g/dl had the highest proportion of infection-related deaths while patients with higher albumin levels had higher cardiovascular deaths including 76% of deaths during the first 3 months. Use of catheter as vascular access and hypoalbuminemia <3.5 g/dl explained 34% (17-54%) and 33% (19-45%) of all deaths in the first 90 days, respectively.

Conclusions: Incident hemodialysis patients have the highest mortality during the first 6 months including 80% higher death risk in the first 2 months. The presence of a central venous catheter and hypoalbuminemia <3.5 g/dl each explain one third of all deaths in the first 90 days.

Figure 1

Monthly standardized mortality ratios (SMRs) during the first 2 years for the incident dialysis pts (n=18,707). SMRs are standardized by age, gender, diabetes and race using the reference cohort of 57,456 hemodialysis patients who started DaVita cohort within 30 days after starting dialysis treatment (see text)

Figure 2

Primary causes of ESRD for incident hemodialysis patients who died within 24 months after dialysis initiation from 5 year DaVita Cohort 07/01-06/06; N= 6,507

Figure 3

Causes of death by the mortality periods for incident hemodialysis patients from 5 year DaVita cohort, excluding pts with missing causes of death; N=5,026 (1841 deaths that occurred after month 24 and 2,236 cases with no documented cause of death were excluded)