Demographic and clinical characteristics
This study included a total of 16838 patients (mean age 30.94 years, SD
± 24.08 years) with AD enrolled
from 205 hospitals across China from August, 2021 to September, 2022.
The patients’ demographic characteristics are summarized in Table 1.
Among all included patients with AD, the stratification criteria
resulted in a high percentage of moderate (49.51%) AD patients with
smaller proportions of mild (35.72%) and severe (14.77%) AD patients.
In terms of gender distribution, 9156 patients were men (54.91%) and
3768 patients were women (45.09%). Females comprised a lower percentage
of severe (12.14%) AD patients when compared to males (16.91%). The
majority of patients included belong to the 18-60 years old age group.
The age distribution of AD according to age was as follows: 0-2 years:
5.13%; 2-6 years: 12.74%; 6-12 years: 12.90%; 12-18 years: 7.91%;
18-60 years: 44.84%; and >60 years: 15.32%; In terms of
severity, the proportion of patients with severe AD within each age
group increased with age: from <10% in infants (0–2 years
old) and preschoolers (2–5 years old) to 10–20% in children (6–11
years old), adolescents (12–17 years old), and adults (18–59 years
old), to 26.56% in older adults (>60 years old). The
proportion of patients with severe AD was the highest in patients with
onset of AD at ≥60 years (26.73%). In terms of gender, the proportion
of severe AD patients increased with the age of AD onset more
drastically in males than females (Figure 1). There was a comparable
proportion of moderate AD patients in males and females. There were less
mild AD patients with older age of AD onset in males than females. In
the entire study population, less AD patients included from rural areas
of habitual residency. There was no significant difference in AD
severity distribution between urban and rural areas of habitual
residency. The proportion of AD severity group was similar across
different levels of education. Overall, there was a higher proportion of
patients with severe AD from northern China (north China 20.75%,
northeast China 19.94%), while there was a lower proportion of patients
with severe AD from western China (southwest China 10.72%, northwest
China 10.93%) (Table 1). In the total population, the EASI score (mean
6.7, IQR 2.9–15) increased with AD severity; patients with severe AD
had higher EASI scores than patients with mild and moderate AD (Table
1).