NONCOMPLIANCE IN HEMODIALYSIS - PREDICTORS AND SURVIVAL ANALYSIS

Noncompliance with hemodialysis (HD), depending on the definition, occ urs in 2% to more than 50% of patients. To better understand predictor s and outcomes of noncompliance, we evaluated patient characteristics associated with noncompliance and the impact of noncompliance on survi val. Using data from two USRDS special studies, we identified 6,251 pa tients who were on dialysis for more than 1 year for inclusion in this study. Noncompliance was defined in four ways: skipping one or more H D sessions in a month, shortening by 10 or more minutes one or more HD sessions in a month, an interdialytic weight gain (IWG) of more than 5.7% of dry weight, or a serum phosphate (PO4) of greater than 7.5 mg/ dL. Sociodemographic predictors of noncompliance were identified using logistic regression. Survival analysis was done using Cox proportiona l hazards models with adjustments for sociodemographics, comorbid cond itions, and dose of HD. Overall, 8.5% of patients skipped HD, 20% shor tened HD (7% three or more times), 10% had more than a 5.7% IWG, and 2 2% had a PO4 greater than 7.5. There was a significant correlation amo ng the measures of noncompliance. Blacks (adjusted odds ratio [AOR] = 2.10), patients aged 20 to 39 years (AOR = 1.62), and smokers (AOR = 1 .34) were significantly more likely to skip HD than whites, patients a ged 40 to 59 years, and nonsmokers, respectively (P < 0.01 for each). Similar results were seen for the other measures of noncompliance, exc ept for PO4, in which blacks were significantly less likely to be nonc ompliant (NC) (AOR = 0.85, P < 0.05). Compared with compliant patients , those who skipped one or more HD sessions in a month had a 25% highe r risk of death (P < 0.01). Those who had greater than a 5.7% IWG had a 35% higher risk of death (P < 0.001), whereas those with a PO4 > 7.5 had a 13% higher risk of death (P < 0.05). Overall, patients who shor tened HD sessions did not have a higher risk of death, but those who s hortened three or more in 1 month had a 20% higher risk of death (P < 0.05). Compliance with a medical regimen is a complex issue. Noncompli ance in HD often, but not always, is associated with a higher risk of an adverse outcome.