Ocular Surface Disease Index (OSDI) Versus the Standard Patient Evaluation of Eye Dryness (SPEED): A Study of a Nonclinical Sample

Purpose:To compare the Standard Patient Evaluation of Eye Dryness (SPEED) and the Ocular Surface Disease Index (OSDI) questionnaires, and to further validate the SPEED questionnaire using the OSDI in a nonclinical sample.Methods:This was a cross-sectional study involving 657 undergraduate students aged 18-34 years. Subject selection was by systematic random methods.Results:The Cronbach alphas of the SPEED and OSDI questionnaires were 0.895 and 0.897, respectively. Classification of participants based on OSDI grading of severity indicated that the total mean SPEED score were 2.2, 5.0, 6.6 and 9.9 for the asymptomatic, mild, moderate and severe dry eye groups respectively (F-(3,F-653) = 141.3 P < 0.001,(2)=0.394). Post hoc testing for all between-group differences was statistically significant (P < 0.05; Tukey test of multiple comparisons). There was a significant correlation between the total scores of the OSDI and SPEED questionnaires (r(s) = 0.68 P < 0.001). The receiver operating characteristic curve (ROC) of the SPEED questionnaire was plotted, and the area under the curve (AUC) was estimated to be 0.82 (95% CL: 0.79-0.85; P < 0.001). Factor analysis revealed 3 dimensions as responsible for the substantial amount of variance in the data generated by the SPEED questionnaire.Conclusions:The SPEED questionnaire was good in separating asymptomatic and symptomatic participants in comparison with the OSDI. This indicates that the SPEED questionnaire is a valid measure for dry eye symptoms even in a nonclinical sample and would be useful in epidemiological studies and clinical practice for dry eye symptom assessment.