Purpose:
To assess reliability (test-retest agreement) of a visual quality of life questionnaire (SREEQ) in Middle and High School students with a history of eyeglass wear.
Methods:
Subjects were 16 Middle and High School students who attend school on the Tohono O’odham Reservation, were enrolled in a study of refractive error development, and had a positive history of previous eyeglass wear (per parent report). Upon arrival for their eye exam, students were asked to complete a two-part questionnaire. Part A contained 15 questions and asked about their visual quality of life when they are NOT wearing their eyeglasses and Part B contained 23 questions and asked about their visual quality of life when they are wearing their glasses. For each question, the student was asked to choose one of four responses. Possible responses were "all the time", "most of the time", "some of the time", "none of the time" or "very much", "somewhat", "a little bit", or "not at all", depending on the question. Several weeks later, when students arrived to receive their new eyeglasses (prescribed at the eye exam), they were asked to complete the same questionnaires again. For each question, the percentage of students who responded with the exact same response on the 4 point scale on test and retest was calculated. Interclass correlations (ICC) for each question was also determined.
Results:
For Part A,the percentage of students with exact agreement on test-retest response ranged from 50 to 100%, depending on the question (mean 72%). For Part B,the percentage of students with exact agreement on test-retest response ranged from 33 to 87%, depending on the question (mean 57%). Summary of percentage of questions with various levels of agreement (ICC) are shown in the table below.
Conclusions:
Part A of the SREEQ, regarding visual quality of life without glasses, yielded better agreement on test-retest responses. Agreement on this part of the SREEQ may be better than on Part B (quality of life with glasses) because although all had a history of glasses wear, many of the students (56%) did not have glasses upon arrival for the examination. Thus poor test-retest agreement may be due to poor recall of visual experience with glasses on due to poor compliance.
Keywords: visual development • astigmatism • clinical research methodology