The Financial Burden of Nephrolithiasis and Predictors of Disease-specific Financial Toxicity

Abstract

Objective: To characterize stone-related financial toxicity among US adults with kidney stones through validated questionnaires for financial toxicity and disease-specific health-related quality of life.

Materials and methods: We performed a cross-sectional survey of adults with kidney stone disease from the general population ascertained through a national registry of volunteers (ResearchMatch). A computer-based survey queried stone event history and related costs for medical care, disease-specific quality of life (WISQOL), and an 11-item measure of stone-related financial toxicity (COST-11 score). Multivariable logistic regression was performed to evaluate predictors of financial toxicity, defined as having a COST-11 score ≤20.

Results: Of 942 responses, median COST-11 score was 29 (IQR 21-38), and 24.7% (N = 233) met criteria for disease-specific financial toxicity. Stone-formers with financial toxicity spent more out of pocket on stone-treatment in the previous year than patients with lower financial burden (P <.001) and were more likely to defer or delay recommended treatment due to anticipated cost (27% vs 3%; P <.001). Stone-specific financial toxicity was associated with poorer disease-specific health-related quality of life across all WISQOL domains (each P <.001). Multivariable logistic regression showed that female gender (OR 1.81; 95% CI 1.24-2.67), Medicaid compared to private insurance (OR 3.91; 95% CI 2.34-6.94), and stone passage in the previous year (OR 2.00; 95% CI 1.41-2.86) were independently associated with financial toxicity.

Conclusion: Approximately 1 in 4 individuals with kidney stone disease report disease-specific financial toxicity. These data suggest the financial burden of the condition may influence decision-making and associates with poorer disease-specific quality of life.