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Stable admission rate for acute asthma in Danish children since 1977

  • RESPIRATORY EPIDEMIOLOGY
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Abstract

Childhood asthma is consistently reported to have increased in recent decades in most westernized countries, but it is unknown if this increase is similar across severities. We aimed to study the time-trend of acute hospital admission and readmission for asthma of school-aged children in the recent 35 years in Denmark. We analyzed time-trends in the national incidence rate of hospitalization for acute severe asthma in children aged 5–15 in Denmark during the 35-year period 1977–2012 in the Danish national registry. Only in-patient admissions with a principal diagnosis of asthma (ICD-8: 493** or ICD-10: J45** or J46**) were included. Among children with asthma hospitalizations, we investigated the risk of readmission beyond 1 month of first admission. Admissions were summarized as rates per thousand person years at risk. The overall time-trend is stable with a rate of one admission per year per thousand children at risk and a per-year incidence rate ratio 0.999 [95 % CI 0.997–1.001]. The rate of any readmission decreased from approximately 20 per thousand children in the eighties to less than 10 in the early nineties before stabilizing at around 10 per thousand children from mid-nineties and onwards. During 35 years of nation-wide follow-up, we find a highly stable incidence rate of first hospital admission for acute severe asthma in children. Moreover, rates of readmission halved during the seventies and stabilized in the last twenty years. In conclusion, our data suggest that the reported increase in childhood asthma is mainly due to less severe cases.

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Abbreviations

ICD:

International classification of diseases

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Authors contributions

The guarantor of the study is HB, from conception and design to conduct of the study and acquisition of data, data analysis, and interpretation of data. AS was responsible for data acquisition and analysis, interpretation and writing the manuscript. CBP contributed substantially to the analyses and interpretation of the data, and provided important intellectual input. All authors have agreed that the accuracy and integrity of any part of the work has been appropriately investigated and resolved and all have approved the final version of the manuscript. The corresponding author had full access to the data and had final responsibility for the decision to submit for publication. No honorarium, grant, or other form of payment was given to anyone to produce the manuscript.

Funding

COPSAC is funded by private and public research funds all listed on www.copsac.com. The Lundbeck Foundation; The Ministry of Health; Danish Council for Strategic Research; The Danish Council for Independent Research and The Capital Region Research Foundation have provided core support for COPSAC. No pharmaceutical company was involved in the study. The funding agencies did not have any role in design and conduct of the study; collection, management, and interpretation of the data; or preparation, review, or approval of the manuscript.

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Correspondence to Hans Bisgaard.

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Sevelsted, A., Pipper, C.B. & Bisgaard, H. Stable admission rate for acute asthma in Danish children since 1977. Eur J Epidemiol 31, 325–329 (2016). https://doi.org/10.1007/s10654-015-0078-6

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  • DOI: https://doi.org/10.1007/s10654-015-0078-6

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