Clinical and Economic Impact of Hyperkalemia in Patients with Chronic Kidney Disease and Heart Failure.

Abstract

Hyperkalemia (HK) is a concern for patients with chronic kidney disease (CKD) and heart failure (HF), and for those receiving treatments that inhibit the renin-angiotensin-aldosterone system (RAASi). An analysis of 1.7 million medical records of patients in the United States revealed that among individuals with more than 2 potassium values during 2007 to 2012, HK was detected in 34.6% of patients with CKD and 30.0% of patients with HF. To evaluate the association of HK and use of RAASi therapies at optimal and suboptimal doses in patients with CKD and/or HF with health care resource utilization and overall cost of care in a diverse cohort of commercially insured patients. This retrospective cohort study was conducted using medical and pharmacy claims from multiple regional health plans. Qualifying patients were ≥ 18 years old, continuously enrolled for 6 months before and throughout the study period (January 1, 2014, to December 31, 2015) and had an ICD-9-CM or ICD-10-CM diagnosis code of CKD and/or HF. Health care resource utilization, including hospital visits, length of stay, office visits, and associated medical and pharmacy costs, were assessed according to the 3 cohorts (CKD alone, HF alone, and concomitant CKD and HF). For the 3 cohorts, the results were also compared between patients with and without HK and between patients with and without RAASi use at optimal and suboptimal doses. Generalized linear models were used to further examine the predictors of medical and overall costs. In this study, 15,999 patients met inclusion criteria. Among patients using RAASi therapy, 26.8% received the optimal dose. Optimal dosing of RAASi was associated with decreased median outpatient office visits (8, 10, and 15, respectively, for patients with CKD, HF, and both CKD and HF) compared with suboptimal dosing of RAASi (12, 15, and 23, respectively). Similarly, optimal dosing of RAASi was associated with decreased overall median medical costs ($2,092, $4,144, and $7,762, respectively, for patients with CKD, HF, and both CKD and HF) compared with suboptimal dosing of RAASi ($3,121, $8,289, and $12,749, respectively). Patients with CKD, HF, or both CKD and HF, all in combination with HK, had higher overall costs, compared with those without HK. The results of this real-world analysis suggest that HK and suboptimal dosing of RAASI were associated with a median increase in outpatient office visits as well as increased overall medical costs among patients with CKD and/or HF. This evaluation of median costs suggests effective HK management may potentially reduce costs in patients with CKD and/or HF, including those currently receiving RAASi therapy. This study was conducted by Magellan Rx Management and funded by Relypsa. Brenner, Alvarez, and Oestreicher were employed by Relypsa during the development of this study and the writing of this manuscript. Polson, Lord, Kangethe, Speicher, and Farnum are employees of Magellan Rx Management, which received funding from Relypsa for conducting the retrospective study and writing the manuscript. Study concept and design were contributed by Lord, Polson, Brenner, Alvarez, and Oestreicher. Data collection and interpretation were performed by Polson and Kangethe, with assistance from Lord. The manuscript was written by Farnum, with assistance from Kangethe and Speicher and revised by all authors.