Real-world burden of primary hyperoxaluria with chronic kidney disease in the United States: a retrospective administrative claims analysis

Abstract

Background: Primary hyperoxaluria (PH) is a family of three rare, autosomal recessive genetic disorders that can result in recurrent kidney stones, progressive chronic kidney disease (CKD), and kidney failure. PH prevalence is underestimated due to its varying presentation and lack of awareness; delays in diagnosis can lead to substantial burdens on the healthcare system.

Methods: This retrospective, observational claims analysis evaluated disease burden and cost of care in patients who had PH, PH with CKD, or CKD alone. Data from the Merative MarketScan Commercial Claims and Encounters databases and the Centers for Medicare and Medicaid Services Medicare Fee-for-Service Limited Data Set were assessed during the study period of January 1, 2017, to December 31, 2021. PH prevalence was calculated based on the sample population within each data source.

Results: The study sample included 326 patients who had PH; applying projection factors to the US population, an estimated 4500 patients had a diagnosis of PH in 2021. Among these patients, 37% were estimated to have PH with CKD (65% of whom had early CKD, 33% had advanced CKD, and 2% had stage reported as unknown). Patients who had CKD alone (n = 845) were matched with patients who had PH with CKD (n = 169). Patients who had PH with CKD were significantly more burdened with kidney stones (p < 0.01) than patients who had CKD alone. Higher rates of pharmacotherapy and medical treatments were observed in patients who had PH with CKD versus patients who had CKD alone. Median semi-annual total all-cause healthcare costs were greater in patients who had PH with CKD than in patients with CKD alone, regardless of CKD stage ($54,154 in patients who had PH with advanced CKD vs. $35,016 in patients with advanced CKD alone; $9,784 in patients who had PH with early CKD vs. $5,572 in patients with early CKD alone).

Conclusions: CKD stage progression among patients who had PH is associated with increasing all-cause costs, suggesting that early diagnosis and treatment of PH to limit the progression to advanced CKD could represent an opportunity to alleviate not only PH symptoms, but also the healthcare cost burden.

Keywords: Disease burden; Healthcare resource utilization; Kidney stones; Nephrolithiasis; Urolithiasis.

Fig. 1

Projected demographics of patients who had PH and PH with CKD. ^aEarly CKD includes patients who had CKD stages 1–3. ^bAdvanced CKD includes patients who had CKD stages 4–5 or end stage kidney disease. CKD = chronic kidney disease; FFS = fee for service; PH = primary hyperoxaluria

Fig. 2

Matched analysis of PH comorbidities in patients who had PH with CKD and CKD alone. **p < 0.01; *p < 0.05. ^aEarly CKD includes patients who had CKD stages 1–3. ^bAdvanced CKD includes patients who had CKD stages 4–5 or end stage kidney disease. Adv = advanced; CKD = chronic kidney disease; PH = primary hyperoxaluria; UTI = urinary tract infection

Fig. 3

Matched analysis of treatment in patients who had PH with CKD and CKD alone. **p < 0.01; *p < 0.05. ^aEarly CKD includes patients who had CKD stages 1–3. ^bAdvanced CKD includes patients who had CKD stages 4–5 or end stage kidney disease. Adv = advanced; CKD = chronic kidney disease; PH = primary hyperoxaluria

Fig. 4

Matched analysis of resource utilization in patients who had PH with CKD and CKD alone. (A) Proportions of patients who had at least one healthcare visit for any cause within the 6-month observation window (all-cause healthcare visits). (B) Proportions of patients who had at least one specialty visit for any cause within the 6-month observation window (all-cause specialty visit). (C) Mean number of all-cause healthcare visits within the 6-month observation window. **p < 0.01; *p < 0.05. ^aEarly CKD includes patients who had CKD stages 1–3. ^bAdvanced CKD includes patients who had CKD stages 4–5 or end stage renal disease. ^cOther includes home health, independent labs, and skilled nursing facilities. Adv = advanced; CKD = chronic kidney disease; PH = primary hyperoxaluria

Fig. 5

Median total all-cause costs and costs associated with specific visits for six-month period, per patient, in patients who had PH with CKD and matched cohort of patients who had CKD alone. Bar graph represents the median (Q1, Q3) costs, with mean costs in italics. *p < 0.05 for mean values. ^aEarly CKD includes patients who had CKD stages 1–3. ^bAdvanced CKD includes patients who had CKD stages 4–5 or end stage kidney disease. ^cOther includes home health, independent labs, and skilled nursing facilities. CKD = chronic kidney disease; PH = primary hyperoxaluria