Factors associated with the prevalence of arteriovenous fistulas in hemodialysis patients in the HEMO Study

Background. Arteriovenous (AV) fistulas are the vascular access of choice f or hemodialysis patients, but only about 20% of hemodialysis patients in th e United States dialyze with fistulas. There is little information known ab out the factors associated with this low prevalence of fistulas. Methods. Multiple logistic regression analysis was used to evaluate the ind ependent contribution of factors associated with AV fistula use among patie nts enrolled in the HEMO Study. The analysis was conducted in 1824 patients with fistulas or grafts at 45 dialysis units (15 clinical centers). Results. Thirty-four percent of the patients had fistulas. The prevalence o f fistulas varied markedly from 4 to 77% among the individual dialysis unit s (P < 0.001). Multiple regression analysis revealed five demographic and c linical factors that were each independently associated with a lower likeli hood of having a fistula, even after adjustment for dialysis unit. Specific ally, the prevalence of fistulas was lower in females than males [adjusted odds ratio (AOR) 0.37, 95% CI, 0.28 to 0.48], lower in patients with periph eral vascular disease than in those without (AOR 0.55, 95% CI, 0.38 to 0.79 ), lower in blacks than in non-blacks (AOR 0.64, 95% CI, 0.46 to 0.89), low er in obese patients (AOR per 5 kg/m(2) body mass index, 0.76, 95% CI, 0.65 to 0.87), and lower in older patients (AOR per 10 years, 0.85, 95% CI, 0.7 8 to 0.94). The differences in the prevalence of fistulas among the dialysi s units remained statistically significant (P < 0.001) after adjustment for these demographic and clinical factors. Finally, there were substantial va riations in the prevalence of fistulas even among dialysis units in a singl e metropolitan area. Conclusions. Future efforts to increase the prevalence of fistulas in hemod ialysis patients should be directed at both hemodialysis units and patient subpopulations with a low fistula prevalence.