Pilot study on a quality-of-life scale for school-age children with functional abnormalities in binocular vision

Abstract

Objective To develop and evaluate a quality-of-life scale(QOL)for school-age children with functional abnormalities in binocular vision, and to evaluate its validity, reliability and responsiveness. Methods This was an investigation study. We designed a scale to evaluate the quality of life of school-age children with functional abnormalities in binocular vision, based on the design principle of the QOL, by statistical analysis, and by a comprehensive analysis of the opinions of experts in the binocular vision and public health fields. One hundred sixteen school-age children with functional abnormalities in binocular vision and 100 with normal vision were evaluated with the scale. Filter items and evaluation of validity, reliability and responsiveness were analyzed with a coefficient of variation, correlation coefficient, factor analysis, stepwise regression analysis, stepwise discriminatory analysis, Krone Bach′s alpha coefficient, test-retest reliability and split half reliability. Results The 20-item scale covered four domains of QOL: binocular vision function, self-care ability, communication ability and psychology. The scale was rated for: Good format validity: Four common factors extracted by factor analysis were consistent with the four domains of the scale. Cumulative contribution rate: The cumulative contribution rate was 53.15%. Factor loading: Each item was above 0.50. Content validity: The correlation coefficient of the score for each item and its domain were more than 0.55. The correlation coefficient for the score of the four domains and the total score were 0.87, 0.48, 0.49, 0.54, respectively. Discriminant validity: The score for children with functional abnormalities in binocular vision differed significantly from the normal group(t= 1.97, P<0.01). The score after treatment was significantly different from before treatment(t=1.97, P< 0.01). Test-retest reliability: Test retest reliability was 0.98(P<0.01). Krone Bach′s alpha coefficient: The coefficient was above 0.70. Split-half reliability: The split-half reliability was 0.78(P<0.01). The effect size statistics: The result of the statistics was 0.53. Conclusion The scale has a satisfactory validity, reliability and responsiveness. It is suggested that the scale can be used in clinical trials. Key words: Children(6-12); Quality of life; Vision, Binocular; Scale