Predicting adherence to diabetic eye examinations: development of the compliance withAnnual Diabetic Eye Exams Survey

Abstract

Objective: To identify variables that predict adherence with annual eye examinations using the Compliance with Annual Diabetic Eye Exams Survey (CADEES), a new questionnaire designed to measure health beliefs related to diabetic retinopathy and annual eye examinations.

Design: Questionnaire development.

Participants: Three hundred sixteen adults with diabetes.

Methods: We developed the CADEES based on a review of the literature, the framework of the Health Belief Model, expert opinion, and pilot study data. To examine content validity, we analyzed participant responses to an open-ended question asking for reasons why people do not obtain annual eye examinations. We evaluated construct validity with principal components analysis and examined internal consistency with Cronbach's α. To assess predictive validity, we used multivariate logistic regression with self-reported adherence as the dependent variable.

Main outcome measures: Associations with self-reported adherence (defined as having a dilated eye examination in the past year).

Results: The content analysis showed that CADEES items covered 89% of the reasons given by participants for not obtaining an annual eye examination. The principal components analysis identified 3 informative components that made up 32% of the variance. Multivariate logistic regression modeling revealed several significant predictors of adherence, including beliefs concerning whether insurance covered most of the eye examination cost (P < 0.01), whether there were general barriers that make it difficult to obtain an eye examination (P < 0.01), whether obtaining an eye examination was a top priority (P = 0.02), and whether diabetic eye disease can be seen with an examination (P = 0.05). Lower hemoglobin A1c levels (P < 0.01), having insurance (P = 0.01), and a longer duration of diabetes (P = 0.02) also were associated with adherence. A multivariate model containing CADEES items and demographic variables classified cases with 72% accuracy and explained approximately 24% of the variance in adherence.

Conclusions: The CADEES showed good content and predictive validity. Although additional research is needed before finalizing a shorter version of the survey, our findings suggest that researchers and clinicians may be able to improve adherence by (1) counseling newly diagnosed patients, as well as those with uncontrolled blood glucose, on the importance of annual eye examinations and (2) discussing perceived barriers and misconceptions.