Trends in acute nonvariceal upper gastrointestinal bleeding in dialysis patients

Abstract

Impaired kidney function is a risk factor for upper gastrointestinal (GI) bleeding, an event associated with poor outcomes. The burden of upper GI bleeding and its effect on patients with ESRD are not well described. Using data from the US Renal Data System, we quantified the rates of occurrence of and associated 30-day mortality from acute, nonvariceal upper GI bleeding in patients undergoing dialysis; we used medical claims and previously validated algorithms where available. Overall, 948,345 patients contributed 2,296,323 patient-years for study. The occurrence rates for upper GI bleeding were 57 and 328 episodes per 1000 person-years according to stringent and lenient definitions of acute, nonvariceal upper GI bleeding, respectively. Unadjusted occurrence rates remained flat (stringent) or increased (lenient) from 1997 to 2008; after adjustment for sociodemographic characteristics and comorbid conditions, however, we found a significant decline for both definitions (linear approximation, 2.7% and 1.5% per year, respectively; P<0.001). In more recent years, patients had higher hematocrit levels before upper GI bleeding episodes and were more likely to receive blood transfusions during an episode. Overall 30-day mortality was 11.8%, which declined significantly over time (relative declines of 2.3% or 2.8% per year for the stringent and lenient definitions, respectively). In summary, despite declining trends worldwide, crude rates of acute, nonvariceal upper GI bleeding among patients undergoing dialysis have not decreased in the past 10 years. Although 30-day mortality related to upper GI bleeding declined, perhaps reflecting improvements in medical care, the burden on the ESRD population remains substantial.

Figure 1.

Lower and upper bounds of the occurrence rate of acute nonvariceal upper GI bleeding. Note: 95% confidence intervals not shown (essentially superimposed with rate estimates).

Figure 2.

Trends in the proportions of hospitalized and peptic ulcer disease–related acute nonvariceal upper GI bleeding episodes. (A) Proportion of hospitalized events. (B) Proportion of peptic ulcer disease–related events. Note: 95% confidence intervals not shown (essentially superimposed with rate estimates).

Figure 3.

Relative occurrence rates of acute nonvariceal upper GI bleeding (1998–2007). (A) Stringent criterion. (B) Lenient criterion. Note: The occurrence rates were 60 (stringent) and 294 (lenient) per 1000 person-years in 1998, which served as the referent for the estimated annual rate ratios and corresponding 95% confidence intervals. Model 1: adjusted for age, sex, and race. Model 2: also adjusted for Medicaid coverage, dialysis vintage, and modality. Model 3: also adjusted for history of kidney transplantation, history of acute nonvariceal upper GI bleeding and all comorbid conditions, alcohol dependence, tobacco use, drug dependence, ability to transfer, ability to ambulate, and baseline BMI.

Figure 4.

Crude 30-day mortality after acute nonvariceal upper GI bleeding, 1998–2007.

Figure 5.

Trends in the relative odds ratios and corresponding 95% confidence intervals for 30-day mortality after acute nonvariceal upper GI bleeding (1998–2007). (A) Stringent criterion. (B) Lenient criterion. Note: Fully adjusted model includes age, sex, race, dialysis vintage, modality, Medicaid coverage, peptic ulcer disease related, hospitalized and receiving transfusion or not, history of renal transplantation, history of acute nonvariceal upper GI bleeding, all comorbid conditions, alcohol dependence, tobacco use, drug dependence, ability to transfer, ability to ambulate, and baseline BMI.

Figure 6.

Trends in the most recent recorded hematocrit level and the proportion of patients receiving a transfusion during episodes of acute nonvariceal upper GI bleeding. (A) Hematocrit. (B) Proportion of patients receiving a transfusion. Note: 95% confidence intervals not shown (essentially superimposed with rate estimates).