Trends in Tympanostomy Tube Insertion Among Children Aged 0–12 Years: A Register-Based Cohort Study in Denmark (2003–2023)

Michael Lüscher,1 Nikolaj B Pedersen,1 Steven AW Andersen,2 Thomas Qvist Barrett,3 Peter Tingsgaard,4 Lene Dahl Siggaard,5 Per Kallestrup,1,6 Anders Prior1,61Research Unit for General Practice, Department of Public Health, Aarhus University, Aarhus, Denmark; 2Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; 3Ear, Nose, and Throat Practice, Randers, Denmark; 4Ear, Nose, and Throat Practice, Slagelse, Denmark; 5Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; 6Department of Public Health, Aarhus University, Aarhus, DenmarkCorrespondence: Michael Lüscher, Research Unit for General Practice, Department of Public Health, Aarhus, Denmark, Email [email protected]: Tympanostomy tube insertion (TTI) is one of the most frequently performed surgical procedures in children. Yet, substantial temporal and geographical variations persist across comparable healthcare systems. We aimed to describe nationwide trends in TTI among Danish children in 2003– 2023, with particular attention to changes associated with the COVID-19 pandemic and regional differences in treatment patterns.Patients and methods: In this nationwide register-based cohort study, we included all Danish children aged 0– 12 years between 2003 and 2023 (n=2,243,285). Data on TTIs were obtained from the Danish National Patient Register and the Danish National Health Service Register. Incidence rates, cumulative proportions, age at first procedure, and regional variation were analyzed using calendar year and birth cohorts.Results: We identified 704,013 TTI procedures performed in 371,818 children; 96.6% were conducted in ear, nose, and throat (ENT) practices. Annual procedure numbers peaked at 40,826 cases in 2010 and declined steadily to 29,846 cases in 2019. A marked reduction occurred during the COVID-19 pandemic in 2020– 2021, followed by a rebound to the pre-pandemic level in 2022 and a further increase to 35,024 procedures in 2023. The proportion of children receiving at least one TTI increased from 3.11% in 2019 to 3.67% in 2023 (proportion ratio (PR) 1.18, 95% confidence interval (CI) 1.16– 1.20). Median age at first TTI was 18.1 months, with persistent regional variation; rates were highest in the North Denmark Region and lowest in the Capital Region of Denmark.Conclusion: TTI rates in Danish children decreased substantially over the past decade, declined further during the COVID-19 pandemic, and subsequently returned to pre-pandemic levels. Persistent regional differences indicate variation in clinical practice that cannot be explained solely by underlying disease epidemiology. The long-term effects of the pandemic on TTI utilization remain uncertain.Keywords: tympanostomy tube insertion, otitis media, pediatrics, epidemiology, registries, cohort studies, COVID-19, healthcare disparities