Psychometrics properties of a new scale to evaluate the impact of dry eye on daily life and the patient satisfaction using eye drops.

Purpose: Dry eye disease (DED) impacts quality of life. Ocular Surface Disease Index (OSDI) and Dry Eye questionnaire (DEQ‐5) are 2 frequently used tools. OSDI is psychometrically sound but its 12 items do not cover all the patient experience. Validity of DEQ‐5 is questioned and the 1‐month recall period may introduce a memorization bias1. Aim of this study was to check the psychometrics properties of a new scale capturing a wider picture of patient perception. Methods: Baseline data were from the TEARS cohort of 312 DED patients (Spain and UK) treated by a combination of sodium hyaluronate + trehalose. Apart of OSDI, DEQ‐5, and a global satisfaction, patients completed new questions (9 on impact of dry eye and 10 on satisfaction with eye drops) identified through a literature review and expert committee. These 19 items have a 4–5‐point Likert answers, and recall period is the last 3 days. Results: Mean age of patients was 57.9 ± 15.2 years, 82.4% were women. Iterative factorial analyses were performed. 4 items were deleted (high inter‐item correlation, or no factor loading). A 4‐factor structure was found robust, ranked by their cumulative variance, and named by their content analysis: 1/DED impact on daily activities (n = 6); 2/perception of relief/being comfortable/duration with eye drops (n = 4); 3/DED impact on mood/sleep (n = 3); 4/easiness with eyes drops (n = 2). Reliability of the dimensions was confirmed by Cronbach alpha ranging from 0.67 to 0.86. Scores were calculated (range: 0–100 worst), e.g. 35.8 ± 20.6 for global score. Logical correlations between the 4 dimensions and OSDI, DEQ‐5 and global satisfaction ranged from 0.088 (Easiness vs OSDI) and 0.715 (impact on daily activities vs DEQ‐5). Correlation between global score versus OSDI was 0.440. 4 of the 5 DEQ‐5 items were highly inter‐correlated (>0.8) challenging its validity. Conclusions: This 15‐item 4‐dimension scale has robust psychometrics properties. The next step is to quantify its responsiveness to change. Reference 1. Okumura Y, Inomata T, Iwata N, Sung J, Fujimoto K, Fujio K, Midorikawa‐Inomata A, Miura M, Akasaki Y, Murakami A. A Review of Dry Eye Questionnaires: Measuring Patient‐Reported Outcomes and Health‐Related Quality of Life. Diagnostics (Basel). 2020;10(8):559. [ABSTRACT FROM AUTHOR]