Development of a Quality-of-Life Questionnaire for Adults with Strabismus

Abstract

Purpose We report the development of a patient-derived, health related quality of life (HRQOL) questionnaire for adults with strabismus. Design Cross-sectional study. Participants 29 patients with strabismus in a first phase, and 32 patients with strabismus, 18 patients with other eye diseases, and 13 visually normal adults in a second phase. Methods Individual patient interviews generated 181 questionnaire items. For item reduction, we asked 29 patients with strabismus to complete the 181-item questionnaire, analyzed responses, and performed factor analysis. Two prominent factors were identified, and the 10 items with the highest correlation with each factor were selected. The final 20-item questionnaire (10 ‘psychosocial’ items, 10 ‘function’ items) was administered to an additional 32 patients with strabismus (22 with diplopia, 10 without diplopia), 13 visually normal adults, and 18 patients with other eye diseases. A 5-point Likert-type scale was used for responses (‘never’=100, ‘rarely’=75, ‘sometimes’=50, ‘often’=25, and ‘always’=0). Median overall questionnaire scores and psychosocial and function sub-scale scores, ranging from 0 (worst HRQOL) to 100 (best HRQOL), were compared across groups. Main Outcome Measures HRQOL questionnaire response scores. Results Median overall scores were statistically significantly lower (worse quality of life) for patients with strabismus (56) compared to visually normal adults (95; P<0.001) and patients with other eye diseases (86; P<0.001). Median scores on the psychosocial sub-scale were significantly lower for strabismus patients (69) compared to visually normal adults (99; P<0.001) and patients with other eye diseases (94; P<0.001). For the function sub-scale, median scores were again significantly lower for strabismus patients (43) compared to visually normal adults (91; P<0.001) and patients with other eye diseases (78; P<0.001). Conclusions We have developed a 20-item, patient-derived HRQOL questionnaire specific for adults with strabismus, with sub-scales to assess psychosocial and function concerns. This 20-item, condition specific questionnaire will be useful for assessing HRQOL in individual strabismus patients and also as an outcome measure for clinical trials.

We need to pay heed to the psychosocial aspects of strabismus

“…6 A new strabismus specific questionnaire was first reported in 2009. 7 The Appearance Scale 20 (AS20) was a patient-derived, health-related quality of life questionnaire for adults with strabismus. Patients (n ¼ 29) were interviewed in the initial phase followed by 32 strabismics, 18 with other eye disease and 13 normal adults for phase 2.…”

Improvement in patients' quality-of-life following strabismus surgery: evaluation of postoperative outcomes using the Adult Strabismus 20 (AS-20) score

“…The AS-20 is a freely available QoL questionnaire 10 developed specifically for strabismic adults. Development started with patients' interviews, which provided 181 questions derived from their unique statements.…”

“…These issues were addressed by the development of the strabismus-specific quality-of-life questionnaire (QoL), the Adult Strabismus 20 (AS-20), which assesses both the functional and psychosocial aspects of strabismus. 10 It has been shown to be superior in comparisons with existing QoL assessment tools, 7,11 with a high retest reliability. 12 The AS-20 provides a basis for assessing the holistic effects of squint surgery by comparing pre-and postoperative scores and relating these to the objective surgical success of the procedure.…”

The Italian version of the Adult Strabismus-20 (AS-20) questionnaire: translation validation and reliability

“…The AS-20 is a patient-derived instrument for use in patients with a diagnosis of strabismus [4]. Subjects with strabismus were interviewed and statements or phrases were used to generate a 181-item questionnaire.…”

“…When considering the application of HRQoL instruments within ophthalmology, there are concerns that generic measures are not sensitive to the recognised symptoms of vision loss or emotional aspects of a given ophthalmic condition, such as strabismus. Among the several specific measures, one instrument that may be used in the investigation and management of patients with strabismus is the Adult Strabismus-20 (AS-20) Questionnaire developed by Sarah R. Hatt et al [4].…”