Validation of Expert Opinion in Identifying Comorbidities Associated with Atopic Dermatitis/Eczema

Background: The use of expert opinion is widespread in economic studies of healthcare utilisation; however, few studies have attempted to assess the validity of assumptions derived from such sources. Objective: To examine the use of such expert opinion in determining comorbidities associated with atopic dermatitis/eczema (AD/E), which were assessed as part of a recent third-party payer cost-of-illness study. Design: To identify the disease-related comorbidities that would represent costs associated with AD/E, physicians on an expert panel were asked individually and then collectively to group all International Classification of Diseases, 9th Edition-Clinical Modification (ICD-9-CM) diagnosis codes as Results: The mean prevalence rate of any diagnosis code in the AD/E population was 0.65 +- 1.82% (SD) with a mean odds ratio of 1.81 +- 0.96. Comorbidities considered by the expert panel Conclusions: Comparing the result of consensus panels with actual claims histories validated the use of expert opinion in determining comorbidities associated with AD/E. Expert opinion yielded valid results in terms of identifying comorbidities that manifested frequently and disproportionately in the AD/E population. Limited statistical measurements of comorbidities would have been less specific than expert opinion. Future cost-of-illness studies should consider alternative data sources and methodologies to enhance the validity and importance of expert opinion and to corroborate their findings.