The Danish National Register for Asthma

Vibeke Backer,1 Jesper Lykkegaard,2 Uffe Bodtger,3,4 Lone Agertoft,5 Lene Korshoej,6 Elvira Vaclavik Braüner7,8 1Department of Respiratory Medicine L, Bispebjerg Frederiskberg University Hospital, Copenhagen, 2Research Unit of General Practice, Institute of Public Health, University of Southern Denmark, Odense, 3Department of Respiratory Medicine, Næstved Hospital, Næstved, 4Institute of Regional Health Research, University of Southern Denmark, 5Hans Christian Andersen Children's Hospital, Odense University Hospital, Odense, 6Competence Centre for Clinical Quality and Information Technology West (KCKS West), Aarhus, 7Research Center for Prevention and Health, Center for Health, Glostrup Hospital, Capital Region of Denmark, Glostrup, 8Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Capital Region of Denmark, Copenhagen, Denmark Aim of the database: Asthma is the most prevalent chronic disease in children, adolescents, and young adults. In Denmark (with a population of 5.6 million citizens), >400,000 persons are prescribed antiasthmatic medication annually. However, undiagnosed cases, dubious diagnoses, and poor asthma management are probably common. The Danish National Database for Asthma (DNDA) was established in 2015. The aim of the DNDA was to collect the data on all patients treated for asthma in Denmark and to monitor asthma occurrence, the quality of diagnosis, and management. Study population: Persons above the age of 6 years, with a specific focus on 6–44 years, are included. The DNDA links three existing nationwide registries of administrative records in the Danish health care system: the National Patient Register, the National Health Insurance Services Register, and the National Prescription Registry. For each year, the inclusion criteria are a second purchase of asthma prescription medicine within a 2-year period (National Prescription Registry) or a diagnosis of asthma (National Patient Register). Patients with chronic obstructive pulmonary disease are excluded, but smokers are not excluded. Descriptive data: A total of 366,471 prevalent patients with asthma have been identified (year 2014 – as a preliminary test search). This number is in agreement with the estimates of ~400,000 inhabitants that are available for patients with possible asthma in Denmark. Data encompass the following quality indicators: annual asthma control visits and pharmacological therapy. Main variables: The variables included are spirometry, as well as tools for diagnosis (including allergy testing), smoking status, height, weight, and acute hospital admissions and unscheduled visits. Conclusion: DNDA is available from January 1, 2016. Keywords: indicator, asthma control, asthma management, prescription data, hospital data