Development and Validation of Infantile Esotropia Quality of Life Questionnaire (IEQ): A Malay Version

Abstract

Introduction: Infantile esotropia, a prevalent strabismus problem among children, presents various challenges for both children and their parents. Despite this problem, an adequate instrument to evaluate the quality of life in our language is currently lacking. Hence, the objective of this study was to develop and validate a novel questionnaire that assesses the quality of life among children with infantile esotropia and their parents. Methods: The study was carried out from 2016 to 2019. The development of the questionnaire was grounded on existing literature, a survey, interviews, and expert brainstorming. Subsequently, a validation study was executed on both the children and their parents. Results: A novel questionnaire comprising three versions in Malay language targeting children aged 5-8 years (2 subthemes, 10 items), children aged 9-17 years (10 items, 2 subthemes), and their parents (25 items, 4 subthemes) was developed. Each item demonstrated satisfactory content evidence (scale level-content validity index, averaging method >0.8), and sound response process evidence (scale-level face validity index, averaging method >0.8). The questionnaires exhibited high internal consistency (Cronbach’s alpha: 0.84-0.87 (5-8 years old), 0.83-0.86 (9-17 years old), and 0.85-0.89 (parents)), acceptable intraclass correlation coefficients (r=0.497, p<0.01 (5-8 years old), r=0.728, p<0.01 (9-17 years old), and r=0.746, p<0.01 (parents)), and significant correlations with the IXTQ (r=0.780, p<0.01 (5-8 years old), r=0.602, p<0.01 (9-17 years old), and r=0.444, p<0.01 (parents) ). Conclusion: The IEQ has been proven to be a reliable and valid measure for evaluating the quality of life in children with infantile esotropia and their parents.