Objective: The aim of this study was to develop and evaluate the psychometric properties of a new measurement tool, the Cancer Functional Assessment Set (cFAS).
Design: A total of 119 inpatients with cancer participated in this prospective cohort study. This study took place in three phases: (1) item generation, literature search, and a round-table discussion by 32 rehabilitation specialists; (2) item reduction and selection of appropriate items from the first item pool; and (3) evaluation of psychometric properties. Concurrent validity (Spearman correlation coefficients with existing scales), internal reliability (Cronbach coefficient alpha), interrater reliability (weighted kappa statistics and intraclass correlation coefficient), cross-validation, and responsiveness (standardized response mean values) were examined.
Results: The cFAS consisted of 24 items. Significant correlations were found between the cFAS and existing scales. Cronbach α for the total score was 0.92. Weighted κ values for each item ranged from 0.74 to 1.00. The intraclass correlation for the total score was 0.97. Concurrent validity and internal consistency were similar at two different hospitals. The cFAS was more responsive to changes than the other tools.
Conclusions: The cFAS has acceptable psychometric properties, supporting its broad generalizability. It can be a useful tool in clinical trials and can contribute to the development of cancer rehabilitation.