A proposed methodology for the assessment of glaucoma awareness in Greece: introduction of the EIT-8G scale

Abstract

Purpose: To develop a reliable and practical questionnaire for glaucoma awareness and evaluate the impact of potential determinants.

Methods: Patients with primary open-angle, pigmentary, and exfoliation glaucoma, as well as healthy controls, were recruited. The instrument included questions about demographic characteristics, as well as 8 questions assessing the participant's familiarity with glaucoma. Rasch analysis was used for the validation of the questionnaire. The effect of demographics as potential determinants of awareness was examined with a multivariate logistic regression analysis. Bonferroni-corrected statistical significance was tested with the Mann-Whitney U test or one-way analysis of variance. Association between demographics and questionnaire scores was examined with Spearman correlation.

Results: As indicated by power analysis, responses from 175 patients (mean age 65.5 years) and 314 controls (mean age 43.3 years) were analyzed. Rasch analysis indicated no multidimensionality and good item-person targeting. Mean ± SD awareness scores for the glaucoma and control groups were 4.43 ± 2.10 and 4.20 ± 2.11, respectively (p=0.207). Sex and residence were not predictors of disease awareness, whereas educational level was only a determinant in the control group (p<0.001). Income was a predictor only for patients (r=0.357, p<0.001), whereas family history was predictive for both groups (p<0.001). Logistic regression analysis revealed that only family history was associated with increased awareness (Chi(2)=4.61, p=0.03, odds ratio 1.98).

Conclusions: This study introduces a practical and valid instrument for the assessment of glaucoma awareness.