Measurement of body surface area involvement in atopic eczema: an impossible task?

Estimation of the area of skin involvement is an important part of atopic e czema severity scoring systems, We examine the variation seen when six derm atologically trained observers assessed disease extent in six patients with atopic eczema using the rule of nines, The median scores ranged from 4.8% to 37.2%. The level of agreement for the classification of scores into quin tile categories was 55%, with a chance-corrected agreement (kappa statistic ) of 0.09, representing very poor interobserver agreement. To measure the e ffects of health care intervention accurately, reliable methods of assessme nt should be used. Scoring methods in which reliability cannot be demonstra ted may be misleading and should be interpreted with caution.