Aspirin prescription and outcomes in hemodialysis patients: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Abstract

Background: We investigated aspirin-prescribing patterns and potential benefits on cardiovascular morbidity and mortality in hemodialysis patients.

Study design: Cohort study.

Setting & participants: Data included 28,320 randomly selected hemodialysis patients from the Dialysis Outcomes and Practice Patterns Study I and II.

Predictor: Aspirin prescription at study baseline.

Outcomes & measurements: Prescription was investigated by means of logistic regression. All-cause mortality, all-cause hospitalization, cardiac event, myocardial infarction, cerebrovascular (CVA), gastrointestinal bleed, transient ischemic attack, and subdural hematoma were examined. Cox regression examined the risk of mortality and hospitalization. All models accounted for facility clustering and demographics and comorbid conditions.

Results: Wide variation was found in aspirin prescription, from 8% in Japan to 41% in Australia and New Zealand. Characteristics significantly associated with increased odds of prescription included coronary artery disease, cerebrovascular disease, diabetes, male sex, nonblack race, peripheral vascular disease, age, hypertension, and absence of gastrointestinal bleeding. Aspirin was associated with decreased risk of stroke in all patients (relative risk [RR], 0.82; P < 0.01) and increased risk of myocardial infarction (RR, 1.21; P = 0.01) and cardiac event (RR, 1.08; P < 0.01) in all patients, with similar results for patients with coronary artery disease. There was no increase in gastrointestinal bleeding.

Limitations: Observational studies are not protected from biases, despite adjustments. There is potential for aspirin use to be underreported because of its availability without prescription.

Conclusions: The hypothesis that prescribing aspirin to hemodialysis patients decreases cardiovascular disease risk is not supported. Aspirin might decrease CVA and appears not to increase hemorrhagic risk. This should be an incentive for randomized controlled trials.