Association of air quality index (AQI) with incidence of atopic dermatitis in Taiwan: A nationwide population-based cohort study

Chen-Yi Wu; Chun-Ying Wu; Meng-Chieh Li; Hsiu J Ho; Chon-Kit Ao

doi:10.1016/j.jaad.2024.01.058

Association of air quality index (AQI) with incidence of atopic dermatitis in Taiwan: A nationwide population-based cohort study

J Am Acad Dermatol. 2024 Feb 2:S0190-9622(24)00207-X. doi: 10.1016/j.jaad.2024.01.058. Online ahead of print.

Authors

Chen-Yi Wu¹, Chun-Ying Wu², Meng-Chieh Li³, Hsiu J Ho⁴, Chon-Kit Ao⁵

Affiliations

¹ Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Dermatology, Faculty of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan; Institute of Public Health and Department of Public Health, National Yang Ming Chiao Tung University, Taipei, Taiwan; Health Innovation Center, National Yang Ming Chiao Tung University, Taipei, Taiwan. Electronic address: chenyiok@gmail.com.
² Health Innovation Center, National Yang Ming Chiao Tung University, Taipei, Taiwan; Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan; Division of Translational Research and Center of Excellence for Cancer Research, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Public Health, China Medical University, Taichung, Taiwan.
³ Department of Medical Education, Chang-Gung Memorial Hospital, Taoyuan, Taiwan.
⁴ Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁵ Department of Economics, National Cheng Kung University, Tainan, Taiwan. Electronic address: chonao@ncku.edu.tw.

PMID: 38311242
DOI: 10.1016/j.jaad.2024.01.058

Abstract

Background: Air pollutants may aggravate atopic dermatitis (AD). However, the association between Air Quality Index (AQI) and incidence of AD remains unknown.

Objective: To investigate association between AQI and incidence of AD, using the nationwide cohort in the Taiwan National Health Insurance Research Database (NHIRD).

Methods: We included 21,278,938 participants from the NHIRD not diagnosed with AD before 2008. Long-term average AQI value, obtained from the Taiwan Air Quality Monitoring System Network, before AD diagnosis was calculated and linked for each participant.

Results: 199,205 incident cases of AD were identified from 2008 to 2018. Participants were classified into 4 quantiles (Q) by AQI value. With the lowest quantile, Q1, as reference, the AD risk increased significantly in the Q2 group (adjusted hazard ratio [aHR]: 1.29, 95% confidence interval [CI]: 1.04-1.65), Q3 group (aHR: 4.71, 95% CI: 3.78-6.04), and was highest in the Q4 group (aHR: 13.20, 95% CI: 10.86-16.60). As AQI treated as a continuous variable, an increase of 1 unit of AQI value added 7% of AD risk (aHR, 1.07, 95% CI: 1.07-1.08).

Limitations: The NHIRD lacks detailed information on individual subjects.

Conclusions: The results demonstrated a significant positive association between AQI and incidence of AD with a clear dose-response relationship.

Keywords: air pollution; air quality index; atopic dermatitis; cohort study.