VALIDATION OF FRENCH-LANGUAGE VERSIONS OF THE VISUAL FUNCTIONING INDEX (VF-14) AND THE CATARACT SYMPTOM SCORE

Objective: To produce and validate French-language versions of the Vis ual Functioning Index (VF-14), the Cataract Symptom Score (CSS) and tw o global measures of trouble and satisfaction with vision. Design: Sur vey by means of telephone interviews conducted 2 weeks apart. Setting: Ophthalmology clinic of a teaching hospital in Montreal. Subjects: Su bjects were recruited among patients with ocular media opacities, such as cataracts and corneal opacities. Of the 71 subjects recruited, 66 (41 French-speaking and 25 French- and English-speaking) completed the study. Outcome measures: Visual acuity, scores on vision-related ques tionnaires and on the 36-Item Short-Form Health Survey (SF-36), a meas ure of perceived health status. Results: The internal consistency of t he French-language versions of the VF-14 and the CSS was high, with Cr onbach alpha values of 0.96 and 0.82 respectively. The fidelity with r egard to the English-language version, the test-retest reproducibility and the interrater agreement were high (intraclass correlation coeffi cients greater than or equal to 0.80). The correlation between the vis ual acuity of the better eye and the mean score on all four vision-rel ated measures was statistically significant (p less than or equal to 0 .05). The VF-14 scores were also correlated with the score on five of the eight SF-36 subscales (p less than or equal to 0.05). Conclusions: Our results show that the French-language versions of the VF-14, CSS and global measures of trouble and satisfaction with vision are reliab le and valid.