The Increased Clinical and Economic Burden of Hyperkalemia in Medicare Patients Admitted to Long-Term Care Settings

Abstract

Introduction: Older patients are at increased risk for hyperkalemia (HK). This study describes the prevalence, recurrence, and clinical and economic burden of HK in Medicare patients admitted to a long-term care (LTC) setting. Methods: Retrospective cohort study using 100% Medicare Fee-for-Service (FFS) claims identified patients aged ≥ 65 years with index admission between 2017 and 2019 to a LTC setting (skilled nursing, home health, inpatient rehabilitation, or long-term acute care). Beneficiaries were required to have 12 months continuous medical and pharmacy coverage prior to index LTC admission and ≥ 30 days after LTC discharge (follow-up). Patient characteristics, healthcare resource utilization, and costs were assessed. HK was defined as ICD-10 diagnosis code E87.5 in any claim position or Medicare Part D fill for oral potassium binder. Results: Of 4,562,231 patients with a LTC stay, the prevalence of HK was 14.7% over the full study period (pre-index, index stay, and follow-up). Excluding those with HK only during the follow-up period resulted in 4,081,103 patients. Of these, 290,567 (7.1%) had HK and 3,790,536 (92.9%) did not have HK during or within 14 days prior to index LTC stay. The HK recurrence rate during index stay and follow-up was 48.3%. Unmatched HK versus non-HK patients were more often male (43.0% vs. 35.4%), Black (13.5% vs. 8.0%), dual eligible for Medicaid (34.2% vs. 25.0%), with higher mean Charlson Comorbidity Index scores (6.2 vs. 3.9) (all p < 0.0001). After propensity matching, HK patients were 2.2 times more likely to be hospitalized, with higher mortality (30.8% vs. 21.5%) and higher total healthcare costs during both index stay (US$26,520 vs. $18,021; p < 0.0011) and follow-up ($57,948 vs. $41,744 (p < 0.0011) versus matched non-HK patients. Conclusion: Prevalence and recurrence of HK was high among LTC patients, and HK was associated with significantly greater clinical and economic burden during and post-LTC.