Clinical and economic impact of primary hyperoxaluria: a retrospective claims analysis

BACKGROUND: Primary hyperoxaluria (PH) is a family of rare, life-threatening genetic liver disorders characterized by elevated production and excretion of oxalate. To date, the clinical and economic burden associated with PH has not been well characterized due to the rarity of the disease and previous challenges with diagnostic coding that prevented proper identification of patients with PH in claims data. OBJECTIVE: To characterize the clinical and economic costs, as well as health care resource utilization (HCRU), associated with PH relative to a matched cohort of patients without PH. METHODS: Data from the IQVIA PharMetrics Plus Database were used to conduct a retrospective matched-cohort study to compare differences in clinical characteristics, HCRU, and pharmacy and medical costs in patients with PH compared with a matched cohort of patients without PH from January 2014 to December 2019. RESULTS: Overall, 324 patients were included in the PH cohort and 1,620 patients were in the non-PH cohort. The mean age of PH patients was 48.1 years, and approximately 58% of the sample were male. Significantly more patients in the PH cohort than the non-PH cohort were diagnosed with stage 2 chronic kidney disease (CKD; 3.1% vs 0.4%, respectively; P < 0.001), stage 3 CKD (4.6% vs 0.5%; P < 0.001), stage 4 CKD (2.5% vs 0.1%; P < 0.001), and stage 5 CKD or end-stage renal disease (ESRD; 2.2% vs 0.1%; P < 0.001). PH patients had a significantly higher mean Charlson Comorbidity Index composite score than patients in the non-PH cohort (0.79 vs 0.37; P < 0.001). HCRU was significantly higher in patients with PH. The PH cohort had a significantly higher proportion of patients with at least 1 visit to clinicians specializing in nephrology (19% vs 0.4%, respectively; P < 0.001), cardiology (22% vs 12%; P < 0.001), ophthalmology (16% vs 7%; P < 0.001), general surgery (9% vs 6%; P = 0.011), and urology (65% vs 6%; P < 0.001) compared with patients without PH. Mean total annual health care costs in the PH cohort were 65% higher than in the non-PH cohort ($22,549 vs $7,852, respectively; P < 0.001). Similar results were found for total prescription drug costs ($4,125 vs $2,464; P = 0.012). CONCLUSIONS: Despite the rarity of PH, patients with this disease incur substantial clinical and economic burden and may cause financial strain on the health care system. Additional research is warranted to understand the economic and clinical burden of PH stratified by the 3 subtypes of the disease.