AUTHOR=Li Fei , Zhou Jiali , Wan Chonghua , Yang Zheng , Liang Qilian , Li Weiqiang , Chen Huanwei 

TITLE=Development and Validation of the Breast Cancer Scale QLICP-BR V2.0 Based on Classical Test Theory and Generalizability Theory

JOURNAL=Frontiers in Oncology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.915103

DOI=10.3389/fonc.2022.915103

ISSN=2234-943X

ABSTRACT=[Abstract] 
Objective: The aim of this study was to develop and validate the breast cancer scale among the system of quality of life instruments for cancer patients (QLICP-BR V2.0).
Methods: Programmed decision procedures and theories on instrument development were applied to develop QLICP-BR V2.0. A total of 246 breast cancer inpatients were investigated using QLICP-BR V2.0 from hospital admission until discharge. The reliability, validity and responsiveness of QLICP-BR V2.0 scale were evaluated by using the classical test theory combined with the generalizability theory (GT), including correlation analysis, multi-trait scaling analysis, factor analyses, t-tests and also multivariate generalizability theory analysis. 
Results: The test-retest reliability of the total scale is 0.79, the Cronbach coefficient is 0.85, and the Intra-class correlations (ICC) coefficient is 0.88. Item-domain correlation analysis showed that the correlation coefficient between items and their own domain is greater than that with other domains except of item GSO4. Exploratory factor analysis showed that three principal components are obtained in the specific module. The outcome of the factor analysis coincides substantially with our theoretical conception. The score difference of each domain of the scale and the total scale before and after treatment is statistically significant (P<0.05) with the SRM (standardized response mean) of the total scale being 0.61. According to GT, the generalization coefficient of scores in 5 domains is between 0.626 and 0.768, the reliability index is between 0.557 and 0.695.
Conclusion: The QLICP-BR V2.0 exhibited reasonable degrees of validity, reliability, and responsiveness according to classical test and generalizability theory. The number of items in the scale is appropriate.