Identifying Mild-to-Moderate Atopic Dermatitis Using a Generic Machine Learning Approach: A Danish National Health Register Study

Authors

  • Mie Sylow Liljendahl Department of Dermatology and Allergy, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark
  • Kristina Ibler Department of Dermatology, Bispebjerg Hospital, Copenhagen University Hospital, Denmark
  • Christian Vestergaard Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
  • Lone Skov Department of Dermatology and Allergy, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
  • Pavika Jain Market Access, Sanofi Denmark A/S
  • Jan Håkon Rudolfsen EY, Frederiksberg, Denmark
  • Ann Hærskjold Department of Dermatology, Bispebjerg Hospital, Copenhagen University Hospital, Denmark
  • Mathias Torpet Medical Affairs, Sanofi Denmark A/S

DOI:

https://doi.org/10.2340/actadv.v105.42250

Keywords:

atopic dermatitis, machine learning, healthcare register, prediction

Abstract

Atopic dermatitis is a chronic skin disease, causing itching and recurrent eczematous lesions. In Danish national register data, adults with atopic dermatitis can only be identified if they have a hospital-diagnosed atopic dermatitis. The purpose of this study was to develop a machine learning model to identify all patients with atopic dermatitis by proxy, using data for contacts with primary care, prescription medication, and hospital contacts not related to skin diseases. Individuals redeeming a prescription for dermatological preparations were extracted as potential patients with atopic dermatitis. Individuals with a registered hospital diagnosis of atopic dermatitis were classified as “Known AD”, “Other skin disease” (registrations of other dermatological diagnosis codes indicating other skin disease), or “Uncertain AD status”’ (no hospital diagnosis registered). Patients categorized as “Known AD” and “Other skin disease” were used to develop the model. All uses of healthcare services 2 years prior to hospital diagnosis were used as potential predictors. The data were split into training and validation sets (70/30). From 1996 to 2022, 385,135 individuals had uncertain atopic dermatitis status. The most important predictors were corticosteroid prescriptions for dermatological use, consultations with dermatologist, and age. Of the 385,135 individuals, the model predicted that 230,522 individuals likely have atopic dermatitis.

Downloads

Download data is not yet available.

Author Biographies

Mie Sylow Liljendahl, Department of Dermatology and Allergy, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark

Department of Dermatology and Allergy

Kristina Ibler, Department of Dermatology, Bispebjerg Hospital, Copenhagen University Hospital, Denmark

Department of Dermatology

Christian Vestergaard, Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark

Department of Dermatology

Lone Skov, Department of Dermatology and Allergy, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark

Department of Dermatology and Allergy

Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark

Pavika Jain, Market Access, Sanofi Denmark A/S

Market Access

Ann Hærskjold, Department of Dermatology, Bispebjerg Hospital, Copenhagen University Hospital, Denmark

Department of Dermatology

Mathias Torpet, Medical Affairs, Sanofi Denmark A/S

Medical Affairs

References

Silverberg JI, Gelfand JM, Margolis DJ, Boguniewicz M, Fonacier L, Grayson MH, et al. Pain is a common and burdensome symptom of atopic dermatitis in United States adults. J Allergy Clin Immunol Pract 2019; 7: 2699–2706.

https://doi.org/10.1016/j.jaip.2019.05.055 DOI: https://doi.org/10.1016/j.jaip.2019.05.055

Yu SH, Attarian H, Zee P, Silverberg JI. Burden of sleep and fatigue in US adults with atopic dermatitis. Dermatitis 2016; 27: 50–58.

https://doi.org/10.1097/DER.0000000000000161 DOI: https://doi.org/10.1097/DER.0000000000000161

Blome C, Radtke MA, Eissing L, Augustin M. Quality of life in patients with atopic dermatitis: disease burden, measurement, and treatment benefit. Am J Clin Dermatol 2016; 17: 163–169.

https://doi.org/10.1007/s40257-015-0171-3 DOI: https://doi.org/10.1007/s40257-015-0171-3

Ali F, Vyas J, Finlay A. Counting the burden: atopic dermatitis and health-related quality of life. Acta Derm Venereol 2020; 100: 5766.

https://doi.org/10.2340/00015555-3511 DOI: https://doi.org/10.2340/00015555-3511

Malik K, Heitmiller KD, Czarnowicki T. An update on the pathophysiology of atopic dermatitis. Dermatol Clin 2017; 35: 317–326.

https://doi.org/10.1016/j.det.2017.02.006 DOI: https://doi.org/10.1016/j.det.2017.02.006

Bieber T, Paller AS, Kabashima K, Feely M, Rueda MJ, Ross Terres JA, et al. Atopic dermatitis: pathomechanisms and lessons learned from novel systemic therapeutic options. J Eur Acad Dermatol Venereol 2022; 36:1432–1449.

https://doi.org/10.1111/jdv.18225 DOI: https://doi.org/10.1111/jdv.18225

Bylund S, Kobyletzki L, Svalstedt M, Svensson Å. Prevalence and incidence of atopic dermatitis: a systematic review. Acta Derm Venereol 2020; 100: 320–329.

https://doi.org/10.2340/00015555-3510 DOI: https://doi.org/10.2340/00015555-3510

Barrett M, Luu M. Differential diagnosis of atopic dermatitis. Immunol Allergy Clin North Am 2017; 37: 11–34.

https://doi.org/10.1016/j.iac.2016.08.009 DOI: https://doi.org/10.1016/j.iac.2016.08.009

Lynge E, Sandegaard JL, Rebolj M. The Danish National Patient Register. Scand J Public Health 2011; 39: 30–33.

https://doi.org/10.1177/1403494811401482 DOI: https://doi.org/10.1177/1403494811401482

Henriksen L, Simonsen J, Haerskjold A, Linder M, Kieler H, Thomsen SF, et al. Incidence rates of atopic dermatitis, asthma, and allergic rhinoconjunctivitis in Danish and Swedish children. J Allergy Clin Immunol 2015; 136: 360–366.

https://doi.org/10.1016/j.jaci.2015.02.003 DOI: https://doi.org/10.1016/j.jaci.2015.02.003

Stensballe LG, Klansø L, Jensen A, Haerskjold A, Thomsen SF, Simonsen J. The validity of register data to identify children with atopic dermatitis, asthma or allergic rhinoconjunctivitis. Pediatr Allergy Immunol 2017; 28: 535–542.

https://doi.org/10.1111/pai.12743 DOI: https://doi.org/10.1111/pai.12743

Ortsäter G, De Geer A, Geale K, Rieem Dun A, Lindberg I, Thyssen JP, et al. Validation of patient identification algorithms for atopic dermatitis using healthcare databases. Dermatol Ther (Heidelb) 2022; 12: 545–559.

https://doi.org/10.1007/s13555-021-00670-1 DOI: https://doi.org/10.1007/s13555-021-00670-1

Wallach Kildemoes H, Toft Sørensen H, Hallas J. The Danish National Prescription Registry. Scand J Public Health 2011; 39: 38–41.

https://doi.org/10.1177/1403494810394717 DOI: https://doi.org/10.1177/1403494810394717

Sahl Andersen J, De Fine Olivarius N, Krasnik A. The Danish National Health Service Register. Scand J Public Health 2011; 39: 34–37.

https://doi.org/10.1177/1403494810394718 DOI: https://doi.org/10.1177/1403494810394718

Breiman L. Random forests. Machine Learning 2001; 45: 5–32.

https://doi.org/10.1023/A:1010933404324 DOI: https://doi.org/10.1023/A:1010933404324

Alba AC, Agoritsas T, Walsh M, Hanna S, Iorio A, Devereaux PJ, et al. Discrimination and calibration of clinical prediction models: users’ guides to the medical literature. JAMA 2017; 318: 1377–1384.

https://doi.org/10.1001/jama.2017.12126 DOI: https://doi.org/10.1001/jama.2017.12126

Wennberg JE. Unwarranted variations in healthcare delivery: implications for academic medical centres. BMJ 2002; 325: 961–964.

https://doi.org/10.1136/bmj.325.7370.961 DOI: https://doi.org/10.1136/bmj.325.7370.961

Additional Files

Published

2025-05-13

How to Cite

Liljendahl, M. S., Ibler, K., Vestergaard, C., Skov, L., Jain, P., Rudolfsen, J. H., … Torpet, M. (2025). Identifying Mild-to-Moderate Atopic Dermatitis Using a Generic Machine Learning Approach: A Danish National Health Register Study. Acta Dermato-Venereologica, 105, adv42250. https://doi.org/10.2340/actadv.v105.42250