For Determining Atopic Dermatitis Prevalence, Questionnaires May Yield Fickle Results

Among adults who reported having dermatologist-diagnosed atopic dermatitis in a questionnaire in 2018, more than a third claimed they were never diagnosed with atopic dermatitis when they completed the same questionnaire again 2 years later, according to a study that examined the validity of questionnaires for measuring psoriasis and atopic dermatology prevalence published in JAMA Dermatology.

“Asking people about a history of psoriasis may be useful for assessing psoriasis prevalence, but a questionnaire does not appear to be a reliable method for assessing atopic dermatitis prevalence among adults,” researchers advised.

For the study, which took place in Denmark, 2333 adults completed questionnaires on psoriasis, and another 2312 adults completed questionnaires on atopic dermatitis, in 2018 and in 2020.

Even though the same participants answered the same questions at both time points, agreement between individual responses for those reporting a history of atopic dermatitis was low, according to the study. The overall prevalence of atopic dermatitis in the cohort changed from 8.2% to 7.6% between 2018 and 2020, and 36.9% of those who reported being diagnosed with atopic dermatitis in the first survey said in the second survey that they never had atopic dermatitis.

For psoriasis, however, agreement between individual responses on the first and second questionnaire administrations was high. Between 2018 and 2020, psoriasis prevalence showed minimal change, from 7.8% to 8%.

“This cohort study found considerable agreement between responses over time when participants were asked about a history of psoriasis. When asked about a history of atopic dermatitis, responses over time were inconsistent,” researchers wrote. “This inconsistency suggests that questionnaires on a history of atopic dermatitis will confer considerable risk of bias and misclassification.”

Reference:
Nymand LK, Andersen YMF, Thyssen JP, Egeberg A. Limitations of Using Questionnaires for Assessing the Prevalence of Psoriasis and Atopic Dermatitis Among Adults. JAMA Dermatol. 2021;157(8):971-977. doi:10.1001/jamadermatol.2021.2307