Regional Cancer Centre Stockholm-Gotland, Region Stockholm, Box 6909, SE-102 39, Stockholm, Sweden.
Department of Medical Sciences, Division of Clinical Diabetology and Metabolism, Uppsala University, Uppsala, Sweden.
Qual Life Res. 2021 Sep;30(9):2663-2670. doi: 10.1007/s11136-021-02839-9. Epub 2021 Apr 12.
To psychometrically evaluate the hypothesized four-factor structure of the 19-item Functional Assessment of Cancer Therapy-Kidney Symptom Index (FKSI-19) health-related quality of life (HRQoL) instrument in a sample of surgically treated renal cell carcinoma (RCC) patients and examine if an alternative factor structure with good psychometric properties may be derived from the available items.
The model fit of the hypothesized four-factor structure was examined using confirmatory factor analysis on cohort data from 1731 individuals included in the National Swedish Kidney Cancer Register who had undergone surgery for RCC during the three years 2016-2018 and answered the FKSI-19 instrument within 6-12 months after surgery. Exploratory factor analysis was applied to the same dataset to derive a possible alternative factor solution.
The four-factor structure did not reach the thresholds for good model fit using the normed χ-value or the Comparative Fit Index, although the Standardized Root Mean Square Residual and Root Mean Square Error of Approximation measures indicated good and acceptable model fits, respectively. An alternative 14-item trimmed FKSI version (FKSI-14) with a two-factor structure derived from the available FKSI-19 items was found to measure the same aspects of HRQoL as the full FKSI-19 instrument.
The present study is the first to use psychometric methods for examining the factor structure of the FKSI-19 instrument. The hypothesized four-factor structure of FKSI-19 provided a barely acceptable model fit. The two-factor FKSI-14 structure may be used as an alternative or complement to the four-factor structure when interpreting the FKSI-19 instrument.
在接受手术治疗的肾细胞癌 (RCC) 患者样本中，对假设的 19 项癌症治疗功能评估-肾脏症状指数 (FKSI-19) 健康相关生活质量 (HRQoL) 量表的 19 项进行心理测量评估，考察是否可以从现有项目中推导出具有良好心理测量特性的替代因素结构。
使用来自全国瑞典肾脏癌登记处的队列数据，对假设的四因素结构进行验证性因子分析，该队列包括 1731 名在 2016-2018 年三年内接受 RCC 手术且在手术后 6-12 个月内回答 FKSI-19 量表的个体。对同一数据集进行探索性因子分析，以推导出可能的替代因素解决方案。
尽管标准化均方根残差和近似误差均方根的测量值分别表示良好和可接受的模型拟合，但使用规范化 χ 值或比较拟合指数，四因素结构均未达到良好模型拟合的标准。从可用的 FKSI-19 项目中推导出具有双因素结构的 14 项简化 FKSI 版本 (FKSI-14)，该版本被发现与完整的 FKSI-19 仪器一样可以衡量 HRQoL 的相同方面。
本研究首次使用心理测量方法来检验 FKSI-19 仪器的因素结构。FKSI-19 的假设四因素结构提供了勉强可接受的模型拟合。当解释 FKSI-19 仪器时，FKSI-14 的两因素结构可能作为替代或补充四因素结构使用。
