Quality-of-life questionnaire developed for adults with strabismus

Researchers at the Mayo Clinic College of Medicine, Rochester, MN, have developed a quality-of-lifequestionnaire for adults with strabismus. This 20-question patient-derived, health-related questionnaire hassubscales for assessment of psychosocial and functional concerns and should be useful for assessing the impactof strabismus in patients and as an outcome measure for clinical trials, said Sarah R. Hatt, DBO, of theOphthalmology Department at the Mayo Clinic College of Medicine.

"As we all know, strabismus can affect psychosocial and emotional functioning in adults, and strabismusmanagement often aims to address these and other effects of strabismus on the quality of life," Dr. Hatt said."Yet, formal assessment of the quality-of-life impact of strabismus is rarely performed in clinical settings, sowe aimed to develop and validate a health-related quality-of-life questionnaire for adults with strabismus.Specifically, we wanted the questionnaire to be patient-derived because it's been shown that it's moreappropriate to use the patient's perspective than the clinician's or the researcher's."

The developers also wanted the questionnaire to be specific to strabismus so that it would be more sensitive tochange than generic instruments, include only generalizable questions, and be practical and easy to administerin clinical settings.

The group began by interviewing individual patients to derive their concerns about quality of life and thenturned each concern into a question. This process resulted in 181 questions, which was reduced to a moremanageable number of core questions. This was accomplished by asking 29 adult strabismus patients to completethe questionnaire and evaluate the items. The responses were reviewed with factor analysis and redundancyanalysis; this eventually enabled the developers to whittle down the questionnaire to 49 questions. Thetop-scoring 10 questions pertaining to psychosocial concerns and to functional concerns then were chosen for thenext version of the questionnaire.

Additional testing with patients was performed, and scores for the questionnaire overall and for the functionand psychosocial subscales were determined. Comparing the scores of control groups with normal vision or othereyes diseases with those of strabismus patients, the functional and psychosocial scores of the strabismuspatients were statistically significantly lower, reflecting a poorer quality of life, Dr. Hatt said.

In future studies, the developers hope to address test-retest reliability and the responsiveness of thequestionnaire.