Date Published: June 15, 2006
Publisher: BioMed Central
Author(s): Ane Nødtvedt, Kerstin Bergvall, Ulf Emanuelson, Agneta Egenvall.
A cross-sectional study of insured Swedish dogs with a recorded diagnosis of canine atopic dermatitis (CAD) was performed. In order to validate the correctness of this specific diagnosis in the insurance database, medical records were requested by mail from the attending veterinarians. All dogs with a reimbursed claim for the disease during 2002 were included in the original study sample (n = 373). Medical records were available for 335 individuals (response rate: 89.8%). By scrutinizing the submitted records it was determined that all dogs had been treated for dermatologic disease, and that 327 (97.6%) could be considered to have some allergic skin disease. However, as information regarding dietary trial testing was missing in many dogs the number that were truly atopic could not be determined. The clinical presentation and nature of test diet for dogs with or without response to dietary trial testing was compared for a subset of 109 individuals that had undergone such testing. The only significant difference between these two groups was that the proportion of dogs with reported gastrointestinal signs was higher in the group that subsequently responded to a diet trial. In conclusion, the agreement between the recorded diagnosis in the insurance database and the clinical manifestations recorded in the submitted medical records was considered acceptable. The concern was raised that many attending veterinarians did not exclude cutaneous adverse food reactions before making the diagnosis of CAD.
Canine atopic dermatitis (CAD) is a genetically-predisposed inflammatory and pruritic allergic skin disease, most commonly associated with IgE antibodies to environmental allergens . Among humans, the prevalence of allergic diseases has been increasing in industrialized countries over the past decades, and this has been related to factors regarding lifestyle and environment . Many similarities exist between human and canine atopy, and it is of interest to investigate whether this increase is seen among dogs as well. The available knowledge on the epidemiology of CAD is limited, and more studies within this area are in demand according to the International Task Force on Canine Atopic Dermatitis .
A previous study was performed utilizing a Swedish insurance database to estimate the incidence of and risk factors for canine atopic dermatitis . Before any inferences can be drawn about the target population of insured Swedish dogs, or an even broader external population, one must assure that the internal validity of a study is acceptable . The purpose of the current analysis was to validate the diagnosis of CAD in the insurance database against medical records. The next step in assuring the accuracy of the diagnosis in the insurance database would be to validate the claims records versus clinical observations performed by a diplomate in veterinary dermatology. However, this was not feasible due to the retrospective nature of the study.
Overall, the agreement between the recorded diagnosis in the insurance database and the collected medical records was considered acceptable. However, it appears that many practitioners diagnose CAD without ruling out AFR hence for a large group of dogs it could not be determined whether or not they were truly atopic.
“Atopisk dermatitt hos hund: validering av registrert diagnose mot kliniske journaler fra 335 forsikrede hunder i Sverige”