Comparison of the performance of the dry eye questionnaire (DEQ-5) to the ocular surface disease index in a non-clinical population.

OBJECTIVE

To compare the performance of the dry eye questionnaire (DEQ-5) with the Ocular Surface Disease Index (OSDI) and further validate the DEQ-5 questionnaire.

METHODS

A population-based cross-sectional study conducted in Ghana. OSDI and DEQ-5 questionnaires were administered to participants. Cronbach's alpha was used to evaluate the reliability of the OSDI and DEQ-5 questionnaires. Analysis of variance was used to evaluate the discriminant validity of DEQ-5. Concurrent validity was evaluated using the Spearman correlation analysis. A receiver operating characteristic (ROC) curve was generated to describe the sensitivity and specificity of the DEQ-5 questionnaire for diagnosis of dry eye symptoms. Cohen Kappa was used to evaluate agreement between the two questionnaires.

RESULTS

The reliability of the overall OSDI and DEQ-5 scores were 0.919 and 0.819 respectively. The mean (SD) DEQ-5 scores for asymptomatic, mild, moderate and severe dry eye symptoms as defined by the OSDI grading were 3.05 (2.73), 5.13 (3.69), 7.65 (3.30) and 9.77 (4.16) respectively. There was a statistically significant correlation between total OSDI and total DEQ-5 scores (r = 0.649, p < 0.0001). The area under the curve (AUC) of the ROC curve for DEQ-5 was 0.835 (95 % CI: 0.796 - 0.875). A DEQ-5 threshold of 5.5 yielded maximum sensitivity (0.712) and specificity (0.827). The Cohen kappa using a the DEQ-5 total score threshold of 5.5 was K = 0.539 (p < 0.0001).

CONCLUSION

In conclusion, performance of the DEQ-5 questionnaire in discriminating symptoms of dry eye is comparable to the OSDI questionnaire. The DEQ-5 questionnaire is a valid measure of dry eye symptoms and can be used as a dry eye symptoms assessment tool in both clinical and epidemiological studies.