BACKGROUND
The authors have previously described the Unified Visual Function Scale (UVFS). Here we assessed intraobserver and interobserver reliability of the scale, and investigated correlations with patient quality of life (QoL).
METHODS
Eight healthcare practitioners independently applied the UVFS in 20 representative cases from our parasellar meningioma series. Scoring was compared to consensus grades assigned by lead authors. Inter- and intraobserver agreement was measured using intraclass correlation coefficient (ICC), Fleiss’s , and Cohen’s respectively. Patient QoL was assessed Visual Function Questionnaire (VFQ-25) or Activities of Daily Vision Scale (ADVS), and correlated with UVFS grades for each eye.
RESULTS
The interobserver ICC was 0.734 (95% CI, 0.652 to 0.811), with Fleiss’s of 0.758, 0.691, and 0.899 for grades A, B, and C respectively. The intraobserver ICC was 0.758 (95% CI 0.638 to 0.872), and Fleiss’s was 0.604, 0.268, and 0.910 for grades A, B, and C respectively. The Cohen’s for agreement between UVFS category grades and consensus grades was 0.816 (95 CI, 0.698 to 0.934). Survey response rate was 51% (27/53). The UVFS demonstrated strong correlation with VFQ-25 subdivisions general vision (r = 0.7712), near activities (r = 0.7262), peripheral vision (r = 0.6722), and driving (r = 0.6608), and also demonstrated strong correlation with the overall ADVS score (r = 0.5902).
CONCLUSION
This study shows that the UVFS is valid within a small subset of observers, and accurately reflects patient quality of life. It is robust and practical, which make it suitable for broad implementation.
Assessment of quality of life in patients with visual impairments using a new visual function questionnaire: the VFQ-J11
