Supplementary Material for: Cumulative Life Course Impairment in Moderate-to-Severe Atopic Dermatitis: A Cross Sectional Study in Singapore

Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin disease with lifelong consequences for patients’ well-being. Quality-of-life tools such as DLQI and POEM assess disease burden at a specific time point but do not capture long-term life course impairment. The Cumulative Life Course Impairment (CLCI) model describes the multidimensional, cumulative effects of a chronic condition over an individual’s life course, influencing their trajectory and fulfillment. Two instruments to assess CLCI were recently developed. The CLCI-R assesses retrospective, irreversible cumulative damage since disease onset, while the CLCI-P identifies patients at risk of future life course impairment. Both tools measure the psychosocial impact of chronic skin disease over time, extending beyond conventional cross-sectional quality-of-life measures. This study aims to quantify the extent of CLCI in adult patients with moderate-to-severe AD seen at an academic medical center.

Methods: A cross-sectional study was conducted at Singapore General Hospital among 82 adults with moderate-to-severe AD. Participants completed CLCI-R and CLCI-P questionnaires, while EASI, DLQI, POEM, Itch and sleep Visual Analogue Scale (VAS) scores were collected in the same visit. Spearman’s correlation, Mann-Whitney U tests, and multiple linear regression were used to analyse associations and predictors of CLCI.

Results: Mean CLCI-R score was 29.4±1.9, with no significant difference between moderate and severe AD (p=0.907), indicating substantial retrospective impairment in both. CLCI-P scores were significantly higher in severe AD patients (Mean: 28.4±5.5 vs. 15.9±2.0; p=0.007), highlighting greater future impairment’s association with severe disease. CLCI-P correlated significantly with DLQI (r=0.611) and disease severity (r=0.489). In multivariable analysis, greater prospective impairment was associated with higher DLQI, CLCI-R and disease duration ≥ 21 years.

Conclusion: This study underscores the substantial cumulative burden faced by patients with AD, particularly in those with longer disease duration and more severe disease. Integrating CLCI into dermatology assessments may help identify patients at higher risk of life course impairment and offers an opportunity to mitigate future cumulative burden with treatment.