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 Visual Functioning Index (VF-14), the Cataract Symptom Score (CSS) and two global measures of trouble and satisfaction with vision.

DESIGN

Survey by means of telephone interviews conducted 2 weeks apart.

SETTING

Ophthalmology clinic of a teaching hospital in Montreal.

SUBJECTS

Subjects 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 questionnaires and on the 36-Item Short-Form Health Survey (SF-36), a measure of perceived health status.

RESULTS

The integral consistency of the French-language versions of the VF-14 and the CSS was high, with Cronbach alpha values of 0.96 and 0.82 respectively. The fidelity with regard to the English-language version, the test-retest reproducibility and the interrater agreement were high (intraclass correlation coefficients > or = 0.80). The correlation between the visual acuity of the better eye and the mean score on all four vision-related measures was statistically significant (p < or = 0.05). The VF-14 scores were also correlated with the score on five of the eight SF-36 subscales (p < or = 0.05).

CONCLUSIONS

Our results show that French-language versions of the VF-14, CSS and global measures of trouble and satisfaction with vision are reliable and valid.