Discrepancy Between Real-World Objective Functioning and Subjective Quality of Life in Visually Impaired Adults

PRÉCIS: Discrepancy between objective measures of functioning and self-reported quality of life is predicted by depressive symptoms, females, and advanced field loss, while significant variability between these measures remains unexplained. PURPOSE: To determine the degree to which functional metrics and self-reported quality of life agree in glaucoma, and identify factors associated with discrepancies between the two. PATIENTS AND METHODS: Individuals with glaucoma or suspected glaucoma (n=227) were evaluated. Subjective functioning was assessed with the Glaucoma Quality-of-Life-15 (GQL-15) questionnaire. Objective metrics of functioning included balance (total sway), gait (cadence), and reading speed, which were compiled into a z- scored composite measure of function. Discrepancy scores were defined as the difference between composite functioning and GQL-15 z -scores. Linear regression models were computed to identify patient-level and neighborhood-level factors associated with discrepancies between objective functioning and self-reported quality of life. RESULTS: Composite functioning and GQL-15 z -scores were poorly correlated (the Pearson coefficient r =0.15, P =0.024). In multivariable analyses, positive discrepancy (greater function than self-report) was associated with female gender (β=0.53, P <0.001), depressive symptoms (β=0.19, P <0.001), and greater visual field damage (β=0.28, P =0.001). The multivariable model, including gender, depressive symptoms, and visual field sensitivity, accounted for 20% of the variance in discrepancy scores. CONCLUSIONS: Female gender, depressive symptoms, and greater visual field damage are associated with greater subjective vision-related disability than predicted by objective functional impairment. The overall ability of the studied measures to predict agreement between function and self-report was poor, highlighting the complexity of both self-reported impairment and functional evaluation.