Purpose: Impairment of cognitive function, a common complaint in patients receiving chemotherapy, is usually measured through neuropsychological tests. Patient self-evaluation of cognitive difficulties is an important complement to those tests. The Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) is a self-report questionnaire with potential to be used in standard clinical practice as a tool for evaluating patient's cognitive function before, during, and after chemotherapy. The purpose of our study was to conduct linguistic validation of the French version of the FACT-Cog.
Methods: Both qualitative and quantitative methods were used in this study. After undergoing a rigorous translation methodology, the French FACT-Cog version was pretested in France with 35 cancer patients undergoing chemotherapy treatment. Interviews were conducted with all patients to ascertain their understanding of each item. The validation of the final version was conducted among 63 cancer patients, and sociodemographic information was collected as well as brief measure of cognitive function and depression score.
Results: Patient comments obtained through the cognitive debriefing interviews indicated that patients understand the French FACT-Cog items as they are intended and that the measure is culturally appropriate. Internal consistency reliability of the subscales, evaluated using Cronbach's coefficient alpha, was high for all four subscales: Perceived Cognitive Impairments = 0.93, Impact On QOL = 0.85, Comments From Others = 0.70, and Perceived Cognitive Abilities = 0.89. All item-total correlations for each subscale were greater than 0.20, and most were greater than 0.50.
Conclusions: Results from this study effectively demonstrate that the French FACT-Cog is a reliable instrument for the self-reporting of cognitive abilities in patients undergoing chemotherapy.