Curtailing the progression of established chronic kidney disease (CKD) could contribute to controlling its costs. New data show a 2-fold increase in medical costs in patients whose CKD progresses to a higher stage. An estimated 12% of patients with type 2 diabetes progress to CKD, and approximately 40% have some form of diabetic nephropathy.
These new data, which were presented by Suma Vupputuri, PhD, Kaiser Permanente Center for Health Research, GA, at the 2012 ADA meeting, come from patients with type 2 diabetes and CKD in a real-world managed care setting, and reveal considerable worsening of CKD over time.
In this retrospective, observational, cohort study of patients in the Kaiser Permanente Northwest and Georgia health systems, 12% of 21,018 patients in stages 0 to 2 CKD progressed to a higher stage, with 327 patients reaching stage 4 and 76 reaching end-stage renal disease (ESRD). Approximately 27% of the 3885 patients in stage 3 CKD progressed, with 930 patients reaching stage 4 CKD and 217 reaching ESRD. Progression to ESRD was found in 30% of the 683 patients in stage 4 CKD.
The incidence of CKD progression from one stage to a higher stage, per 1000 person-years, was 26 in stages 0 to 2, 74 in stage 3, and 78 in stage 4. The rates were adjusted for age, sex, and duration of diabetes.
The costs for CKD and diabetes are increasing rapidly. The current annual expenditure for CKD and diabetes is approximately $18 billion, which is approximately 11 times higher than in 1993. Approximately 26% of the Medicare expenditure for diabetes is for patients (aged ≥65 years) who have CKD and diabetes, according to the US Renal Data System.
nd inpatient costs, by CKD stage, were $6551 for stages 0 to 1, $8206 for stage 2, $12,529 for stage 3, and $23,229 for stage 4. In each CKD stage, the outpatient nonpharmacy cost was predominant, at approximately 60% in stages 0 to 1 and 40% to 43% in the other stages. Pharmacy costs accounted for approximately 21% to 24% of the total costs, except in stage 4 CKD, for which it was 15%.
A nearly 2-fold increase for inpatient costs occurred when CKD progressed from stage 3 to stage 4. Costs were annualized and standardized to 2010 dollars.
Even when adjusted for demographics and clinical characteristics, disease progression was associated with significantly greater costs in each stage, stated Dr Vupputuri. Medical costs were 2 times higher in the patients with stage 2 CKD who progressed to a higher stage, 3 times higher for stage 3 CKD, and 4 times higher in patients who had ESRD at baseline. Compared with the patients who did not progress to CKD, the costs were $16,642 for stages 0 to 2 CKD, $34,698 for stage 3, and $57,509 for stage 4.
The study population of 25,586 patients, with a mean age of 60 years, had a 5.1-year duration of diabetes, and 51% were men. Men and blacks were less likely to be in the more severe stages of CKD, noted Dr Vupputuri. Age progressively increased across the CKD stages, from 53 years in stage 1 to 71 years in stage 4. Comorbidities also increased with higher CKD stages.
The medical costs of only the patients whose CKD worsened showed that their costs doubled, from $12,937 before progression to $23,233 after CKD progression.