财务毒性是指由于癌症诊断和护理的负担而对患者的财务状况造成的损害。 COST：慢性病治疗财务毒性指标的功能评估 (FACIT-COST) 是最广泛使用的癌症特异性主观财务毒性指标，已在多种语言中得到验证，但尚未在印度尼西亚语中得到验证。本研究旨在验证印度尼西亚版本的 FACIT-COST 在乳腺癌样本中的作用。在印度尼西亚进行了一项单中心前瞻性队列研究。邀请基线时接受治疗的年龄≥18岁的女性乳腺癌患者参与并随访长达六个月。该调查包括由访谈员向患者实施的 FACIT-COST (v2) 官方印度尼西亚版本。根据医疗记录提供临床信息（例如转移状态、疾病持续时间）。测试了 FACIT-COST 的以下测量属性：分布特征、结构有效性（主成分 [PCA] 和验证性因子分析 [CFA]）、内部一致性可靠性（Cronbach's alpha 和 McDonald's omega）、已知群体有效性（Mann-Whitney） U 或 Kruskal-Wallis H 检验）、重测可靠性以及对变化的响应能力。总体而言，基线时有 300 名女性患者参与。没有患者报告可能最好或最差的 FACIT-COST 总分。 PCA提出了仪器的双因素模型结构，并得到了CFA的确认（RMSEA = 0.042，SRMR = 0.049，CFI = 0.99，TLI = 0.99）。两个因素的内部一致性信度被认为是足够的（Cronbach's alpha = 0.774-0.882，McDonald's omega = 0.786-0.888）。 FACIT-COST 总分在以下已知群体中存在显着差异：年龄、教育、居住环境、收入、就业、转移状态、症状数量和财务应对策略。 FACIT-COST 表现出出色的重测可靠性（组内相关系数 = 0.96）和令人满意的变化响应能力（标准化响应平均值和效应大小范围=|0.39| 至 |0.92|）。这是第一项验证 FACIT-乳腺癌患者的 COST 并介绍印尼版 FACIT-COST 的测量特性。印度尼西亚 FACIT-COST 表现出可接受的心理测量性能，并显示出作为主观财务毒性有效衡量标准的潜力。该工具可以作为为卫生政策提供信息的宝贵工具，重点是提供资源支持以改善印度尼西亚的癌症护理。© 2024。作者。

Financial toxicity describes the impairment of financial wellbeing in patients due to the burden of cancer diagnosis and care. The COST: A Functional Assessment of Chronic Illness Therapy Measure of Financial Toxicity (FACIT-COST) is the most widely used cancer-specific measure of subjective financial toxicity, having been validated in multiple languages, but not in Indonesian. This study aimed to validate the Indonesian version of FACIT-COST in a breast cancer sample.A single-center prospective cohort study was performed in Indonesia. Female breast cancer patients aged ≥ 18 undergoing treatment at baseline were invited to participate and followed for up to six months. The survey included the official Indonesian version of FACIT-COST (v2) which was administered to the patients by interviewers. Clinical information (e.g., metastasis status, disease duration) was provided based on medical records. The following measurement properties of FACIT-COST were tested: distributional characteristics, structural validity (principal component [PCA] and confirmatory factor analyses [CFA]), internal consistency reliability (Cronbach's alpha and McDonald's omega), known-groups validity (Mann-Whitney U or Kruskal-Wallis H test), test-retest reliability, and responsiveness to change.Overall, 300 female patients participated at baseline. No patients reported the best or worst possible FACIT-COST total scores. The PCA proposed a two-factor model structure for the instrument, which was confirmed by the CFA (RMSEA = 0.042, SRMR = 0.049, CFI = 0.99, TLI = 0.99). The internal consistency reliability of the two factors was considered adequate (Cronbach's alpha = 0.774-0.882, McDonald's omega = 0.786-0.888). The FACIT-COST total score significantly discriminated across the following known-groups: age, education, residential setting, income, employment, metastasis status, number of symptoms, and financial coping strategies. The FACIT-COST demonstrated excellent test-retest reliability (intraclass correlation coefficient = 0.96) and satisfactory responsiveness to change (standardized response mean and effect size ranges=|0.39| to |0.92|).This is the first study to validate the FACIT-COST in patients with breast cancer and to present the measurement properties of the Indonesian version of FACIT-COST. The Indonesian FACIT-COST demonstrates acceptable psychometric performance and shows potential as a valid measure of subjective financial toxicity. The instrument may serve as a valuable tool for informing health policies that focus on providing resource support to improve cancer care in Indonesia.© 2024. The Author(s).