French version of FACT-G: validation and comparison with other cancer-specific instruments

The aim of this study was to assess the validity of the French version of the Functional Assessment of Cancer Therapy - General (FACT-G), and to compare its psychometric properties with those of two other cancer-specific quality of life questionnaires, European Organisation for Research and Treatment of Cancer Quality of Life - Core 30 (EORTC QLQ-C30) and Functional Living Index - Cancer (FLIC). Two hundred and twenty three patients with breast or colorectal cancer completed the FACT-G questionnaire in French followed by (in random order) the QLQ-C30 and FLIC. An additional 87 patients with head and neck (H&N) cancer completed the FACT-H&N followed by the QLQ-C30 and H&N-Besançon. The French version of FACT-G was internally consistent, and its reproducibility was excellent. FACT-G Physical Well-Being and global scores correlated with all QLQ-C30 subscales. There was evidence of discriminant validity. Compared with the other tools, FACT-G included a statistically significantly higher proportion of items patients considered to be confusing or upsetting. Patients with breast or colorectal cancer expressed a preference for QLQ-C30. Use of the specific H&N additional items increased the responsiveness to change of FACT-G. The French version of FACT-G is valid and has psychometric properties similar to those of FLIC and QLQ-C30.