Crump R Trafford, Peterson Alex, Charbonneau Camille, Carlson Kevin V, Sutherland Jason M, Baverstock Richard J
Department of Surgery, University of Calgary, Calgary, AB, Canada.
Centre for Health Services and Policy Research, University of British Columbia, Vancouver, BC, Canada.
Can Urol Assoc J. 2020 Apr;14(4):111-117. doi: 10.5489/cuaj.5997. Epub 2019 Oct 18.
We aimed to evaluate the psychometric properties of the 26-item Expanded Prostate Cancer Index Composite (EPIC-26) for measuring the quality of life in patients treated for localized prostate cancer. The EPIC-26 is a patient-reported outcome instrument recommended for use with patients treated for localized prostate cancer.
This study is based on data collected prospectively between September 2014 and February 2017 in Alberta, Canada. Men were treated with either radical prostatectomy or radiation therapy and administered the EPIC-26. Responses to the EPIC-26 were the primary outcome. Construct validity was measured using confirmatory factor analysis. Reliability was measured using Chronbach's alpha and item-total correlation. Ceiling and floor effects were also investigated.
EPIC-26 response data from 205 participants (prostatectomy =138; radiation=60; both=7) were used in this analysis. The EPIC-26 was administered an average of 33.8 weeks after treatment. The confirmatory factor analysis model did not meet the threshold for adequate fit. Several items had near-zero factor loadings and were non-significant. Four out of the EPIC-26's five domains met the acceptable reliability threshold based on Cronbach's alpha. Ceiling effects were observed in four out of five domains.
The EPIC-26 demonstrated poor construct validity, adequate reliability, and large ceiling effects. Several issues were observed, suggesting that the instrument's five domains were not well-defined by their respective items. The original EPIC's conceptual framework should be reviewed and the shortened instrument revised to improve its performance for measuring post-treatment quality of life.
我们旨在评估26项扩展前列腺癌指数综合量表（EPIC - 26）在测量局限性前列腺癌治疗患者生活质量方面的心理测量特性。EPIC - 26是一种推荐用于局限性前列腺癌治疗患者的患者报告结局工具。
本研究基于2014年9月至2017年2月在加拿大艾伯塔省前瞻性收集的数据。男性接受了根治性前列腺切除术或放射治疗，并接受了EPIC - 26评估。对EPIC - 26的回答是主要结局。使用验证性因子分析测量结构效度。使用克朗巴赫α系数和项目 - 总分相关性测量信度。还调查了天花板效应和地板效应。
本分析使用了205名参与者的EPIC - 26回答数据（前列腺切除术 = 138；放射治疗 = 60；两者都有 = 7）。EPIC - 26在治疗后平均33.8周进行评估。验证性因子分析模型未达到充分拟合的阈值。几个项目的因子负荷接近零且不显著。基于克朗巴赫α系数，EPIC - 26的五个领域中有四个达到了可接受的信度阈值。在五个领域中有四个观察到了天花板效应。
EPIC - 26表现出较差的结构效度、足够的信度和较大的天花板效应。观察到了几个问题，表明该工具的五个领域未通过各自的项目得到很好的定义。应审查原始EPIC的概念框架，并修订缩短后的工具以提高其测量治疗后生活质量的性能。
