Cardiotoxicity is a leading cause of mortality among breast cancer patients treated with chemotherapy. Therefore, an early risk assessment is vital for the clinical prevention and treatment of cardiotoxicity in breast cancer patients treated with chemotherapy, although a recognized tool is scant in our country.

To develop a cardiotoxic risk assessment scale for breast cancer patients undergoing chemotherapy and to test its reliability and validity.

Through reviewing relevant domestic and international literatures, a pool involving items to assess the risk of cardiotoxicity in breast cancer patients treated with chemotherapy was created. Semi-structured interviews with healthcare providers at Jiangsu Cancer Hospital from September to October 2022 were performed by purposive sampling, thus primarily forming a tool of items for the cardiotoxic risk assessment scale. In addition, breast cancer patients treated with chemotherapy in Jiangsu Cancer Hospital were randomly selected for a pre-survey and validation of the reliability and validity of the scale. Ranked by the score of the cardiotoxic risk assessment scale, the top 27% of participants were assigned into the high-score group, and the remaining were in the low-score group. Cronbach's α coefficient was used to evaluate the internal consistency of the scale. Validity of the scale was verified by measuring the item-level content validity index (I-CVI) and scale-level content validity index (S-CVI). Exploratory factor analysis was performed to assess the structural validity. Receiver operating characteristic (ROC) curves were plotted, and the area under tcurve (AUC) was calculated to determine the predictive validity.

Twenty healthcare providers were included in the semi-structured interviews. After two rounds of expert consultations, a 19-item cardiotoxic risk assessment scale in breast cancer patients treated with chemotherapy was developed. In this study, there were 79 patients in the low-score group and 83 in the high-score group. No significant differences in the history of smoking, endocrine treatment and immunotherapy were detected between the two groups (P>0.05). Correlation analysis showed that the history of smoking and immunotherapy was not significantly correlated with the total scores (P>0.05). Eventually, three items of smoking history, history of endocrine treatment and history of immunotherapy were removed, forming a 16-item scale. The Cronbach's α coefficient, test-retest reliability and inter-rater reliability were 0.739, 0.983 and 0.984, respectively. Content validity results showed that I-CVI ranged from 0.83 to 1.00, and S-CVI was 0.98. Predictive validity results showed the AUC of 0.887 (95%CI=0.827-0.947, P<0.001), with a cut-off value of 32.50 points, Youden's index of 0.649, specificity of 89.1%, and sensitivity of 75.9%. Exploratory factor analysis results showed a Kaiser-Meyer-Olkin (KMO) value of 0.700. Bartlett's sphericity test showed the χ² value of 1 037.898 (df=120, P<0.001). Five common factors were extracted, with a cumulative variance contribution rate of 61.991%. Risk stratification results indicated a low risk at 32-38 points, medium risk at 39-56 points, and high risk at 57 points and above.

The cardiotoxic risk assessment scale for breast cancer patients undergoing chemotherapy has good reliability and validity. It can better predict the high-risk population of cardiotoxicity and provide an effective assessment tool for clinicians and nurses to effectively identify the high-risk population of breast cancer patients undergoing chemotherapy.

乳腺癌化疗患者心脏毒性是乳腺癌幸存者及患者死亡的主要原因，而早期风险评估发现心脏毒性对临床预防和治疗心脏毒性具有重要意义，但目前国内缺乏公认的乳腺癌化疗患者心脏毒性风险评估工具。

编制乳腺癌化疗患者心脏毒性风险评估量表，并检验其信效度。

通过查阅国内外相关文献构建条目池，采用目的抽样法，于2022年9—10月在江苏省肿瘤医院选取医护人员进行半结构式访谈，初步形成乳腺癌化疗患者心脏毒性风险评估条目池，并选取江苏省肿瘤医院就诊的乳腺癌化疗患者进行预调查与量表的信效度检验，将所有乳腺癌化疗患者心脏毒性风险评分进行排序，以前27%为低分组，后27%为高分组。采用Cronbach's α系数评价量表的内部一致性，采用条目水平的内容效度指数（I-CVI）与量表水平的内容效度指数（S-CVI）进行效度检验，运用探索性因子分析的方法对量表的结构效度进行评价，绘制受试者工作特征曲线（ROC曲线），计算ROC曲线下面积（AUC）确定预测效度。

半结构式访谈纳入医护人员9名，经过2轮专家函询后，形成19个条目的乳腺癌化疗患者心脏毒性风险评估量表。本研究患者低分组共79例，高分组共83例，两组吸烟史、内分泌治疗史、免疫治疗史临界比值比较，差异无统计学意义（P>0.05）。相关性分析结果显示，吸烟史、免疫治疗史与总分无相关性（P>0.05）。最终删除"吸烟史""内分泌治疗史""免疫治疗史"3个条目，形成含有16个条目的量表。量表的Cronbach's α系数为0.739；重测信度为0.983；评定者间信度为0.984。本量表内容效度结果示：I-CVI为0.83~1.00；S-CVI为0.98。预测效度结果示：量表的AUC为0.887（95%CI=0.827~0.947，P<0.001），截断值为32.50分，约登指数为0.649，特异度为89.1%，灵敏度为75.9%。探索性因子分析结果显示，KMO值为0.700，Bartlett's球形检验的χ²值为1 037.898（df=120，P<0.001）。本研究共提取5个公因子、累计方差贡献率为61.991%。危险程度分级结果显示，得分为32~38分为低危，39~56分为中危，≥57分为高危。

乳腺癌化疗患者心脏毒性风险评估量表具有良好的信效度，能够较好预测心脏毒性的高危人群，可为临床医生护士有效识别乳腺癌化疗患者心脏毒性高风险人群提供有效的评估工具。