Development and Validation of a Questionnaire to Assess Parent Reported Quality of Life Pre and Post Vision Therapy in a Population with Autism Spectrum Disorder

Abstract

Background: Autism spectrum disorder is characterized in part by atypical behavior in the communication, social, and visual domains. Success in vision therapy is judged not only by changes in optometric findings, but through improvement in quality of life involving communication, social behavior and visual behavior. It would therefore be beneficial to have a validated questionnaire to assess parent reported quality of life pre and post vision therapy specific to patients with autism spectrum disorder. To our knowledge, a questionnaire of this nature has not been previously published in the literature. Methods: Questionnaire items were generated through surveying medical literature based on symptoms in three different categories: visual behavior, social behavior and communication. A pool of 34 questions was developed initially and then with thorough discussion with other experts, a 20-point questionnaire was developed with each item reflected in the construct concept. A draft of 20 questions was then sent to 10 subject experts with clinical experience in the field for more than 20 years, to review the pooled items. Validity and reliability was established prior to assessing the psychometric properties of the ASD/QOL-VT. Prospective observational study was conducted for a duration of 18 months. The study included individuals undergoing vision therapy in the age range of 3 to 15 years who had been diagnosed with ASD. The questionnaire was administered to parents of these children prior to the start of vision therapy. All subjects completed a minimum of 60 vision therapy sessions. The questionnaire was readministered after completing 60 sessions of vision therapy. Results: Cronbach’s alpha value for this questionnaire was 0.93, which reflected very good internal consistency. Factorial analysis yielded four factors with an Eigen value exceeding 1.0 which accounted for 68% variation in the model. The Cronbach alpha value for subscales identified by factorial analysis is 0.97 indicating excellent internal reliability. The mean pre vision therapy social behavior, communication and visual behavior score was 12.0±3.21, 17.07±4.57 and 26.97±6.41 respectively. The mean post vision therapy scores for social behavior, communication and visual behavior was 8.27±4.16, 11.33±5.27 and 17.93±6.52 respectively. On paired t test, the mean difference in score was statistically significant with P<0.001 in all three subcategories. Conclusions: Our study presents the development of a valid and reliable parent questionnaire, the ASD/QOL-VT, that judges communication, social behavior, and visual behavior in autism. Results of the study conducted indicate that vision therapy can result in significant improvements in the quality of life of patients with ASD as judged by their parents. This is evidenced by statistically significant changes in psychometric properties of the ASD/QOL-VT in social behavior, communication and visual behavior.