https://orcid.org/0000-0002-4478-1297
![Sample our Health and Social Care journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5938/TOC-Subject-Sample-2021-Health-Social-Care.jpg"})
Abstract
Background
Acquired hemolytic disorders—autoimmune hemolytic anemia (AIHA), cold agglutinin disease (CAD), paroxysmal nocturnal hemoglobinuria (PNH), drug-induced hemolysis (DIHA), and acquired hemolysis not otherwise specified (AHNOS)—are considered rare. Despite their potentially major health implications, data regarding their incidence and prevalence are scarce.
Methods
To fill this gap we collected data regarding all patients with acquired hemolytic disorder diagnoses in 1977–2016 from the Danish National Patient Register. These data were linked with vital and migration status information from the Danish Civil Registration System. From these data combined with annual demographic data for the background population, we calculated age- and sex-specific incidence rates and prevalence proportions of acquired hemolytic disorders for specified time periods.
Results
Our analysis included 5868 patients with acquired hemolytic disorders (2715 with AIHA, 112 CAD, 397 DIHA, 116 PNH, and 2154 AHNOS). The incidence rates per 100 000 person-years in 1980–1993 and 2008–2016 were 0.81 and 1.77 for AIHA, 0.31 and 0.12 for DIHA, and 0.04 and 0.08 for PNH, respectively. The 2008–2016 CAD incidence rate was 0.18/100 000 person-years, CAD diagnosis code was not defined before 1994. All incidence rates increased with age. The prevalence proportion per 100 000 persons in 1980 and 2015 was 2.52 and 17.01 for AIHA, 0.80 and 1.50 for DIHA, and 0.18 and 1.04 for PNH. CAD prevalence in 2015 was 1.04/100 000 persons.
Conclusion
Acquired hemolytic anemia incidence rates and prevalence proportions with the exception of DIHA are markedly increasing.
Acknowledgments
The authors would like to thank Cathrine Fox Maule at Statistics Denmark for help with defining and hosting data; as well as Kristoffer Andresen, MD, PhD, and Cecilie Bøge Paulsen, BSc, for their constructive comments and thoughts regarding manuscript improvement.
Author Contributions
All authors participated in defining the Danish Hemolysis Cohort. DLH and HF conceived the study. All authors participated in designing the study. DLH performed the analyses, aided by SM. The first draft of the paper was written by DLH, and all authors participated in writing subsequent drafts. All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.
Disclosure
DLH declares that as part of the funding for the PhD fellowship, this study received funding from the University of Southern Denmark, The Region of Southern Denmark, and study grants from Alexion Pharma Nordic AB, Novartis Healthcare and The A. P. Møller and Chastine Mc-Kinney Møller Foundation. The remaining authors declare no competing financial interests. Beyond this, none of the authors have any other conflicts of interest with the study.