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

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.

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.

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.

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.

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.