Quality of Life Research, 19 (suppl 1), 49, Abstract #13/1247.

Poster presented at ISOQOL 17th Annual Conference: October 27-30, 2010 London, UK.

AIMS: To develop UK English and German versions of the EyeTSQ, design based on the DTSQ for diabetes, the MacTSQ for macular disease (MD) and the RetTSQ for diabetic retinopathy (DR) and interviews with patients with cataract, glaucoma, MD, DR.

METHODS: The EyeTSQ included 14 items about aspects of treatment and an open-ended question about any other sources of satisfaction/dissatisfaction. Data were collected from intervention studies of a) intraocular anti-VEGF injections for DR or MD, n=50, b) cataract surgery in patients with MD, n=103. Principal components analysis identified factor structure, Cronbach’s alpha assessed internal consistency. Rasch analyses examined targeting, unidimensionality and differential item functioning (DIF). Construct validity was examined by testing expected relationships of EyeTSQ scores with visual acuity (VA). Content validity was explored using the open-ended question.

RESULTS: Scores for cataract surgery were extremely positively skewed, those for anti-VEGF injections more normally distributed; Rasch analyses relied on anti-VEGF data. A one-factor solution (all loadings >0.45) had high internal consistency (alpha=0.89), a possible pain/side effects subscale was not sufficiently supported. The full scale was well-targeted; item response options also covered a more negative range than participants’ evaluations of treatments studied. Several items displayed disordered thresholds, no DIF was shown across the sex differences found. Women were more apprehensive and less satisfied with risks and side effects. Three items were dropped from the scale to reduce redundancy and improve unidimensionality. As expected, worse VA correlated with worse EyeTSQ scores in the anti-VEGF study (r=0.4). Open-ended question responses (all from UK) indicated no need for new EyeTSQ items but a need for a service satisfaction measure such as the MacSSQ for MD patients.

CONCLUSIONS Satisfaction with cataract surgery had a strong ceiling effect in this study. The EyeTSQ is a valid and reliable single-scale measure of satisfaction with anti-VEGF injections for patients with MD or DR.