The Clinical and Economic Burden of Hyperkalemia on Medicare and Commercial Payers

Abstract

Background: Hyperkalemia (serum potassium >5.0 mEq/L) may be caused by reduced kidney function and drugs affecting the renin-angiotensin-aldosterone system and is often present in patients with chronic kidney disease (CKD).

Objective: To quantify the burden of hyperkalemia in US Medicare fee-for-service and commercially insured populations using real-world claims data, focusing on prevalence, comorbidities, mortality, medical utilization, and cost.

Methods: A descriptive, retrospective claims data analysis was performed on patients with hyperkalemia using the 2014 Medicare 5% sample and the 2014 Truven Health Analytics MarketScan Commercial Claims and Encounter databases. The starting study samples required patient insurance eligibility during ≥1 months in 2014. The identification of hyperkalemia and other comorbidities required having ≥1 qualifying claims in 2014 with an appropriate International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code in any position. To address the differences between patients with and without hyperkalemia, CKD subsamples were analyzed separately. Mortality rates were calculated in the Medicare sample population only. The claims were grouped into major service categories; the allowed costs reflected all costs incurred by each cohort divided by the total number of member months for that cohort.

Results: The prevalence of hyperkalemia in the Medicare and commercially insured samples was 2.3% and 0.09%, respectively. Hyperkalemia was associated with multiple comorbidities, most notably CKD. The prevalence of CKD in the Medicare and the commercially insured members with hyperkalemia was 64.8% and 31.8%, respectively. After adjusting for CKD severity, the annual mortality rate for Medicare patients with CKD and hyperkalemia was 24.9% versus 10.4% in patients with CKD without hyperkalemia. The allowed costs in patients with CKD and hyperkalemia in the Medicare and commercially insured cohorts were more than twice those in patients with CKD without hyperkalemia. Inpatient care accounted for >50% of costs in patients with CKD and hyperkalemia.

Conclusion: Hyperkalemia is associated with substantial clinical and economic burden among US commercially insured and Medicare populations.

Keywords: Medicare; chronic kidney disease; commercially insured; comorbidities; cost; fee for service; hyperkalemia; mortality; prevalence; utilization.

Figure 1. Patients with CKD, by Severity Level, with and without Hyperkalemia^a

Figure 2. Annual Mortality Rate in Medicare Patients with CKD with and without Hyperkalemia

Figure 3. Cost Summary for Patients with CKD with and without Hyperkalemia (CKD Severity Adjusted)

Figure 4. Hospital Admissions Incurred in Patients with CKD and with or without Hyperkalemia in 2014 (CKD Severity Adjusted)