End-stage renal disease-associated managed care costs among patients with and without diabetes.

OBJECTIVE To examine the direct costs of care before and after onset of end-stage renal disease (ESRD) for patients with and without diabetes based on analyses of retrospective healthcare claims data. RESEARCH DESIGN AND METHODS Patients with onset of ESRD between January 1998 though June 2002 were identified based on use of dialysis, renal transplantation, or other ESRD-related services. Continuous health plan enrollment > or =12 months before and > or =1 month after ESRD onset was required. The costs calculated include both observed and adjusted estimates; the latter were calculated using generalized linear models, controlling for demographic and clinical characteristics, "onset" period, and duration of follow-up. Analyses focus on the diabetic ESRD patient and include a comparison with ESRD patients without diabetes. RESULTS The study included 2,020 patients with diabetes and 2,170 without diabetes; 63% of patients were >50 years of age. Average costs were relatively stable before ESRD ($1,535 to $4,357 for diabetes, $1,082 to $2,447 for no diabetes) but more than doubled in the month preceding onset ($9,152 and $8,211, respectively). Postonset, average monthly per-patient costs escalated sharply in the 1st month ($26,507 and $26,789), declined steadily through month 6, and remained flat but elevated thereafter. Adjusted annual costs per patient pre- and postonset of ESRD were significantly higher for diabetes (P <0.0001); annual costs were 69% ($38,041 vs. $22,538) and 79% ($96,014 vs. $53,653) higher pre- and postonset, respectively. CONCLUSIONS The economic burden of ESRD in the year after onset is substantial, particularly among patients with diabetes.