The Italian version of the Amblyopia and Strabismus Questionnaire: translation, validation, and reliability

To develop a culturally adapted Italian version of the Amblyopia and Strabismus Questionnaire (A&SQ) Health Survey and to test its acceptability, reliability, and validity in patients with strabismus.

The English A&SQ was translated into Italian after established cross-cultural adaptation procedures. The questionnaire was administered to 99 consecutive outpatients with strabismus and 39 normal adults and readministered after 2 weeks to 15 randomly selected patients and 26 adults with normal vision.

None of the participants had any problem in understanding the Italian A&SQ and 99% of the questionnaires were fully completed. The translated questionnaire has good discriminatory power between patients and healthy controls. Principal component analysis identified 7 factors, instead of the 6 in the original version. Cronbach's alpha coefficient ranged from 0.64 to 0.77, and the test-retest reliability ranged from 0.92 to 1 and was adequate for all scales. Correlations with other disease activity parameters were generally as expected.

The Italian A&SQ, with modified scales as principal component analysis suggest, appears to be an acceptable, reliable, and valid instrument for measuring health-related quality of life in Italian patients with strabismus.