Date Published: May 30, 2017
Publisher: Springer Medizin
Author(s): Ann-Kathrin Weschenfelder, Ludger Klimek, Norbert Mülleneisen, Harald Renz, Wolfgang Wehrmann, Thomas Werfel, Eckard Hamelmann, Jürgen Wasem, Janine Biermann.
Allergic respiratory diseases represent a global health problem. The two major treatment strategies are symptom treatment and specific immunotherapy (SIT). SIT is considered the only causal treatment option available with the ability to alter the course of the disease. This study aims to describe the course of disease and medication of respiratory allergy across treatment strategies and disease groups.
The analysis is based on routine data from a German statutory health insurance. The patient cohort is observed from 2007–2012. For each year based on assured outpatient diagnoses patients are assigned to a disease group: rhinitis, asthma or both diseases. Additionally, prescribed medication is considered. Treatment comparisons are based on matched pairs.
The study population comprises 165,446 patients with respiratory allergy. In 2007 the most frequent disease group is rhinitis (70%), followed by asthma (16%) and both diseases (14%). During the observation period a second allergic respiratory diagnosis occurs only in about 12% of rhinitis patients and 28% of asthma patients. In about 50% of patients with both diseases one of the diagnoses is omitted. These patients are more likely to no longer report their asthma diagnosis when receiving immunotherapy compared to symptom treatment. Furthermore immunotherapy reduces the frequency of asthma medication use.
Results of detailed analysis of diagnoses reflect the alternating nature of allergic diseases. Although limited by accuracy of documentation and the lack of clinical information, the comparison of treatment strategies shows some advantages of immunotherapy regarding course of disease and asthma medication use.
Occurring in both developed and developing countries and across all ethnic groups and ages allergic respiratory diseases represent a global health problem . Their global prevalence ranges between 5% and 40% [2, 3]; in Germany the prevalence for asthma is 9% and for allergic rhinitis it is 15% . Respiratory allergy patients experience symptoms and impairments in daily life activities, social life, sleep and ability to work reducing their quality of life [5–7].
This study is based on routine data of a nationwide German statutory health insurance (SHI) company available for the years 2005–2012. The study population is derived from all insured persons in 2007. This cohort is then observed from the baseline year 2007 until 2012, while 2005 and 2006 data are used for population selection.
The most frequently documented courses of disease are similar for patients with isolated rhinitis or isolated asthma at baseline: roughly 30% show continuous diagnosis, another 30% report omission of diagnosis and 13–20% have intermittent diagnosis and diagnosis-free periods. About 12% of rhinitis patients and 28% of asthma patients present a second allergic respiratory disease diagnosis during the observation period. In patients with both diseases there is a broader variety of courses of disease: while 30% have continuous diagnosis, 13%, 12% and 9% report omission of both diagnoses, omission of asthma diagnosis and omission of rhinitis diagnosis, respectively. There are also courses of omission and reoccurrence of the omitted diagnosis. In conclusion there are few courses of disease which cover a large share of patients, while the other, smaller share of patients shows a broad variety of courses of disease, sometimes changing disease group every year. This reflects the volatile nature characteristic of the course of allergic diseases.