Allergic rhinitis (AR) affects 23-30% of the European population and is associated with a major burden on public health. AR and asthma frequently coexist, and may both be caused by allergen exposure. While the efficacy of AIT, i.e. reduce symptoms and medication use in patients with AR and asthma, has been demonstrated in several randomized clinical trials, little is known about the use and effectiveness of AIT in real world clinical practice.
This study is a retrospective database study that uses real-world data from Germany. The study population consists of AR patients with and without asthma treated with AIT and matched controls not treated with AIT. Information about the patients and treatments will be obtained from the 'BKK German Sickness Fund Database' from 2007 until 2017.