Financial Toxicity of Nephrolithiasis: The First Assessment of the Economic Stresses of Kidney Stone Treatment.

OBJECTIVE: To investigate the financial toxicity (FT) related to kidney stone treatment. METHODS: We performed a cross-sectional cohort study with multi-institutional in-person and online cohorts of stone formers.  Participants were surveyed using the validated COST tool (COmprehensive Score for financial Toxicity). The maximum score is 44 and lower scores indicate increased FT. "Moderate FT" was defined by COST scores between 25 and 14 points and "severe FT" for scores <14. Descriptive statistics, X2 tests, T tests, Spearman correlation, and logistic regression were performed using SPSS v28. RESULTS: Two hundred and forty-one participants were surveyed, including 126 in-person participants and 115 online. A total of 60% of participants reported at least moderate FT (COST score <26) and 26% reported severe FT (COST score <14). Patients who reported moderate to severe FT were younger than those with low FT by a median difference of 8 years (95%CI = 4, 12). There was a significant correlation between out-of-pocket expense and COST scores, such that as out-of-pocket expenses increased, COST scores decreased, (Spearman's rho =-0.406, P = <.001). Participants with moderate to severe FT tended to miss more workdays (P = .002), and their caretakers tended to miss more workdays (P = .007) due to their stone disease. CONCLUSION: Most participants reported moderate to severe FT. As prior studies have shown that patients with "moderate FT" employ cost-coping strategies (i.e., medication rationing) and those with "severe FT" have worse health outcomes, urologists need to be sensitive to the financial burdens of treatment experienced by such patients undergoing kidney stone treatment.