UNC Dry Eye Management Scale: Spanish Language Translation and Validation Study
Creators: name: Ellis, Jane Reeves
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: BACKGROUND: Dry eye disease (DED) is a common, chronic ocular surface disease that diminishes the quality of life (QOL) of millions of Americans. DED is poorly managed because of the poor correlation of patient-reported symptom severity and clinician-observed disease severity. Our colleagues developed the UNC Dry Eye Management Scale (DEMS) in an effort to improve the management DED. The primary aim of this study was to translate the UNC DEMS to Spanish and to conduct a feasibility and comprehensibility study of a Spanish language version of the DEMS (Spanish DEMS) in a Spanish-speaking population. A secondary aim of our study was to perform initial validity and reliability testing of the Spanish DEMS, alone and as it compares to the original English instrument. This study helps meet the urgent need for valid, reliable patient reported outcomes measures in languages other than English. METHODS: We developed the Spanish DEMS by using a cross-cultural adaptation method similar to the universal translation methodology recommended by proponents of PROM translation. We recruited native bilingual speakers to perform forward, back, and forward translations. I then reconciled these different versions of the Spanish DEMS with the help of an expert translator, after which we put the Spanish DEMS through pre-testing and cognitive interviewing in a pilot sample population. After receiving approval from the UNC and Duke IRBs, I recruited 13 Spanish-speaking DED patients from a UNC ophthalmology cornea clinic in Chapel Hill, NC in May 2014 and June 2014 to participate in the first test of the Spanish DEMS. I administered the Spanish DEMS questionnaire to these patients, and then using cognitive interviewing techniques, I asked them several questions about the comprehensibility of the questionnaire and its utility to them as an indicator of the effect of their symptoms on their quality of life. I obtained clinical assessments of disease severity, (Schirmer's test, Tear Break-Up Time, Oxford Grade of corneoconjunctival fluorescein staining, and clinician-reported overall assessment of disease severity) to be used in statistical analysis of validity and reliability. RESULTS: Cognitive interviewing validated the accuracy and appropriateness of the translation. Patients generally understood, related to, and agreed with the wording of the questionnaire, including descriptions of symptom severity and effects on daily life. Analysis of validity and reliability is strictly illustrative, as sample size is too small for stable statistical data analysis (n=13). As a test of internal validity, I compared Spanish DEMS scores to these patients' measures of disease severity. Spearman's correlation coefficients showed non-significant weak degrees of correlation, as expected given the fact that DED symptom severity does not correlate well with disease severity, and the sample was extremely small. While the magnitude of these correlations was not strong, the direction of the correlations was appropriate, and is promising for the further validation of the instrument. As a test of external validity, I compared performance on the Spanish language DEMS to performance on the English language instrument for patients of similar disease severity using the Mann-Whitney test. While performance on the two language versions was not statistically comparable within the overall population or for the normal disease category, it was significantly similar in the mild-to-moderate and severe disease categories, which is promising for the equivalence of the two PROMs. This early validity and reliability testing, while statistically inconclusive, is promising for the future validation of the Spanish DEMS. CONCLUSIONS: The early stages of our research confirm that the Spanish UNC DEMS is an easy to use and easy to understand, one-item questionnaire that can improve the management and monitoring of Spanish-speaking DED patients.