Validation of a glaucoma knowledge assessment in glaucoma patients

SUMMARY To develop metrics to identify knowledge deficits and barriers to learning in glaucoma patients, this study seeks to validate a glaucoma knowledge assessment to use in the evaluation of knowledge in glaucoma patients. PURPOSE Glaucoma treatment adherence appears to improve when patients demonstrate a greater knowledge of the disease and its treatment. This study seeks to validate a glaucoma knowledge assessment in a glaucoma patient population to assist in patient educational assessments and interventions. PATIENTS AND METHODS The National Eye Health Education Program's (NEHEP) glaucoma knowledge assessment has previously been suggested as a useful measure to assess glaucoma patient's knowledge. This questionnaire was administered in glaucoma patients along with a more comprehensive 49-question examination. Demographic data and health literacy were assessed. Statistical analyses were performed to assess the validity of the assessments. RESULTS A total of 12 glaucoma patients completed the knowledge assessments. The mean ± standard deviation age of the patients was 69±14 years, and the duration of glaucoma was 14±13 years. The participants' mean score on the NEHEP assessment was 7.3±0.8 (of 10, 73% correct) vs 29.3±7.3 (of 49, 60% correct) on the comprehensive assessment. The value of coefficient α was 0.592 for NEHEP and 0.872 for the cumulative assessment. The P-value (proportion of examinees answering correctly) ranged from 0 to 1 for individual questions. Item point-biserial correlation values for each question ranged from -0.402 to 0.813. DISCUSSION The NEHEP quiz may be a good starting point for the development of a reliable knowledge assessment tool to measure and monitor glaucoma knowledge, due to its concise nature and reasonable level of difficulty. This study suggests that questions included in the currently available questionnaires vary widely in difficulty and ability to differentiate knowledge level, which may ultimately compromise reliability and utility of existing examinations. Further examination of individual questions and teaching points included in the current assessments may help to construct increasingly reliable and useful knowledge assessments in the future.