A prospective survey of comprehensive score for financial toxicity in Japanese cancer patients: report on a pilot study

Background: Financial toxicity (FT) has a negative impact on the quality of life and survival of patients with cancer. The comprehensive score for FT (COST) questionnaire is a tool to measure FT which has already been validated in patients with cancer in the United States. However, the feasibility and validity of assessing FT using the COST questionnaire have not been established in non-US healthcare settings, including that in Japan. Methods: This is a prospective pilot survey to ascertain the feasibility of using the COST questionnaire to evaluate FT in Japanese patients with advanced solid cancer who had been receiving chemotherapy for at least 2 months. The COST Japanese using Functional Assessment of Chronic Illness Therapy methodology. Results: Of the 12 patients approached, 11 (92%) responded to the questionnaire. The median COST score was 22 (range, 6-29; mean +/- SD, 20.18 +/- 8.17). Five (45%) and two (18%) patients suffered grade 1 (COST score 14-25) and grade 2 (COST score 1-13) FT, respectively. The COST measure demonstrated good internal consistency with a Cronbach a of 0.87. Conclusions: The COST measure demonstrated good feasibility in measuring FT in the Japanese healthcare setting. Despite the existing universal health insurance system and ceiling amount for high-cost medical expenses, some Japanese patients experienced meaningful FT during chemotherapy. A prospective study is already underway to confirm the preliminary results (UMIN: 000025043).