Among Medicare Advantage Patients, Disparate Utilization Patterns for Hyperkalemia Medications

Among Medicare Advantage patients, disparate potassium binder utilization patterns were observed for patients treated in typical clinical practice.

Patiromer is a sodium-free, potassium-binding polymer approved for the treatment of hyperkalemia. Little research has been published about the real-world utilization of this medication. Sodium polystyrene sulfonate (SPS), was first approved for the treatment of hyperkalemia in 1958 and is frequently used alone or in conjunction with other medical therapies to lower serum potassium.

Researchers from University of Texas Southwestern Medical Center examined the utilization of potassium binder medications among patients with hyperkalemia who had Medicare Advantage insurance. Pharmacy dispensing claims data from a large, de-identified national health insurance claims database from January 1, 2016 to December 31, 2017 were evaluated for patiromer and SPS. Medicare Advantage patients were included who had at least one dispensing for patiromer/SPS. The index date was the first dispensing date in the study period. Patients were excluded who did not have a pre-index serum potassium level of ≥5.0 mEq/L or 6 months of continuous insurance enrollment with pharmacy and medical benefits. Follow-up began on the index date and ended at the first censoring event (ie, insurance disenrollment, death, or the end of the study period) or 6 months post-index.

The following utilization metrics were evaluated: initial dosing regimen, percentage of patients with a dose increase or decrease, proportion of days covered (PDC), and duration of continuous therapy.

At 6 months postindex, approximately 30% remained continuously exposed to patiromer, and approximately 2% remained continuously exposed to SPS. The study identified numerically higher proportion of days covered and longer duration of continuous patiromer use, potentially suggesting provider intent for chronic use of patiromer.

Among Medicare Advantage patients treated with a K+ binder in typical clinical practice, disparate utilization patterns were observed for patiromer and SPS exposed patients. Further research is warranted to fully elucidate these findings as patiromer use increases.

This study was sponsored by Relypsa.

Reference:

Toto R, Rowan CG, Alvarez P, Fogli J, Desai N. Real-world utilization of hyperkalemia management pharmacotherapy among Medicare Advantage patients. Presented at Academy of Managed Care Pharmacy Nexus 2018. J Manag Care Spec Pharm. 2018;24(10-a Suppl):S44.