Abstract: This retrospective, longitudinal study was conducted to identify drivers of chronic kidney disease (CKD) stage progression and associated health care costs. We queried the Humedica electronic medical records database for adult patients in the United States with new, sustained, or progressive CKD (stage 2, 3a, 3b, 4, or 5) with ≥ 1 year preindex and ≥ 3 years postindex data. Data were analyzed for 212,920 CKD stages among 189,799 patients (age < 65 years, n = 52,280; age ≥ 65 years, n = 137,519). On Poisson regression, diabetes, heart failure, cardiovascular disease, and preindex hyperkalemia predicted CKD progression. The highest progression rates occurred among patients with stage 3a or 3b disease (between 38% and 43% at 3 years). Progressing patients averaged 12 to 16 months in their index stage. Incremental cost increased with each successive stage (all P < .001, except stage 3a vs stage 2 in Medicare patients, and was higher in commercially insured patients vs Medicare patients. Hyperkalemia and the well-known comorbidities were associated with CKD progression. Incremental costs with CKD progression are substantial, especially in younger patients.
Acknowledgements: Writing and editorial support services were provided by Impact Communication Partners Inc, and funded by Relypsa Inc, a Vifor Pharma Group Company.
Chronic kidney disease (CKD) affects 13.6% of the adult population of the United States, with a projected increase to 16.7% expected by 2030.1,2 Risk factors for progression of CKD include diabetes, albuminuria, and various cardiovascular comorbidities, which provide the targets for current CKD management.3-6 Adverse cardiovascular events and mortality increase with CKD progression.7-11 The associations between decreased estimated glomerular filtration rate (eGFR) and risk for major cardiovascular events and death appear independent of concomitant chronic diseases (eg, cardiovascular disease or heart failure).7
Prevalence estimates of CKD, based on cross-sectional analyses,12,13 provide a snapshot with little information about CKD progression over time. Most information on effects of CKD progression on health care costs were also derived from cross-sectional studies. Notwithstanding these limitations, a direct association between progression and cost was demonstrated in Australia, where annual health care costs increased from $1829 for patients without CKD to $14,545 for those with stage 4 or stage 5 CKD.14 In a Japanese cohort, medical expenditures increased with CKD stage.15,16 In our previous study of CKD patients with a prescription history of renin-angiotensin-aldosterone system inhibitor (RAASi) therapy, all-cause costs per patient were exponentially higher at each successive CKD stage.17 We further hypothesized that other factors, such as hyperkalemia, may contribute to cost independently through increased provider-driven hospitalization.
Longitudinal analyses of real-world clinical practice are needed to evaluate the rate of CKD stage progression, explore the risk factors driving progression, and assess how CKD progression affects health care costs. Identifying cost drivers of CKD progression may help uncover cost-reducing strategies. We report a retrospective longitudinal study of a large electronic medical database evaluating the rates and risk factors for progression by CKD stage over 3 years, and the related impact on health care costs.