Healthcare utilization and expenditures associated with hyperkalemia management: a retrospective study of Medicare Advantage patients

Abstract

Aims This study aimed to estimate the association of patiromer exposure vs no potassium (K+) binder (NoKb) exposure with healthcare utilization and expenditures among a cohort of Medicare Advantage patients with hyperkalemia (HK). Methods Using Optum’s Clinformatics® Data Mart (study period 2016–2019), the authors assessed propensity score—matched patients (1:1) with a serum K+ concentration ≥5.0 mmol/L and a HK diagnosis that were exposed to patiromer or NoKb on baseline characteristics. The following outcomes were compared: (1) inpatient/emergency department (ED) encounters, (2) inpatient costs greater than or equal to mean Medicare Advantage inpatient cost (ie, $14,900), and (3) the relative healthcare spending rate. Logistic regression and zero inflated negative binomial regression were used to analyze the outcomes. Results The study cohort included 1,539 patiromer and NoKb matched pairs. Baseline characteristics were (patiromer/NoKb): age 74/75 years; female 42/40%; serum K+ 5.6/5.6 mmol/L; eGFR rate 36/36 mL/min/1.73m2; low-income subsidy 42/41%, chronic kidney disease 96/96%; end-stage renal disease 12/12%; and congestive heart failure 37/36%. A total of 253 matched pairs (506 patients) remained uncensored and were analyzed at 6 months. Inpatient/ED encounters were observed for 25% (patiromer) and 37% (NoKb) (odds ratio [OR] 0.58, 95% confidence interval [CI]: 0.38–0.89). The relative odds of having inpatient costs ≥$14,900 were ∼50% less for patients exposed to patiromer vs NoKb (OR [95% CI]: 0.47 [0.25–0.89]). The relative total healthcare spending rate (including inpatient, outpatient, ED, and pharmacy costs) was 19% less for patients exposed to patiromer vs NoKb (spending rate ratio [95% CI]: 0.81 [0.67–0.98]). Conclusion and Limitations Among Medicare Advantage patients with HK, patiromer exposure (vs NoKb) was associated with statistically significant reductions in the proportion with inpatient/ED encounters, inpatient costs ≥$14,900, and lower total healthcare spending. Further research, with a larger sample size, is warranted to fully validate these findings.