Interobserver reliability of Feline Dermatitis Extent and Severity Index (FEDESI) and Scoring Feline Allergic Dermatitis (SCORFAD) and the relationship between lesion scores and pruritus.

Background: Feline Dermatitis Extent and Severity Index (FEDESI) and Scoring Feline Allergic Dermatitis (SCORFAD) are scales used to assess lesion severity in cats with allergic dermatitis. Interobserver reliability has not been assessed for either.

Hypothesis And Objectives: To determine interobserver reliability for FEDESI and SCORFAD, and the relationship between lesion scores and pruritus.

Animals: Thirty-eight cats presenting for pruritus.

Methods And Materials: Each cat's lesions were scored by two observers at each visit using both FEDESI and SCORFAD (n = 117 paired observations). Spearman's rho was calculated to assess correlation between scales and between each scale and the owner-reported pruritus Visual Analog Scale (pVAS). Concordance correlation coefficients were calculated between observers for each scale, and Bland-Altman plots were used to visually represent the relationship between paired scores.

Results: FEDESI and SCORFAD were strongly positively correlated with one another (rho = 0.84, P < 0.001). Each scale showed fair correlation with pVAS (rho = 0.42, P < 0.001; rho = 0.38, P < 0.001, respectively). There was good concordance between observers for both scales, with a correlation coefficient of 0.77 for FEDESI and 0.80 for SCORFAD [intraclass correlation coefficient (ICC) 95%, confidence interval (CI) 0.69-0.83; ICC 95%, CI 0.72-0.86, respectively]. Median lesion score was low (FEDESI 20; SCORFAD 4), which may improve interobserver reliability.

Conclusions And Clinical Importance: There is good interobserver reliability for both FEDESI and SCORFAD. FEDESI and SCORFAD are positively correlated with one another and with pVAS. These findings support use of both scales in clinical research and assessment.