Asthma With Nasal Polyposis

This study will compare the characteristics of asthmatic patients with CRSwNP with those without CRSwNP.

Inclusion criteria

• 1. Aged 18 years and over 2. With a proven diagnosis of asthma as defined by one of the above criteria of current guidelines:

• Forced expiratory volume in one second (FEV1) increase by at least 12% (and ≥200 ml) after administration of a bronchodilator
• Current asthma symptoms and a methacholine provocative concentration inducing a 20% fall in FEV1 (PC20) <16 mg/ml
• A respirologist's current diagnosis of asthma found in the patient's medical report 3. Non-smokers or smokers/ex-smokers defined as someone with a smoking history <10 pack-years 4. Stable asthma and asthma medication for at least 4 weeks before data analysis 5. Written informed consent obtained for inclusion in the database

Patients with CRSwNP

• With a proven diagnosis of CRSwNP, based on endoscopy and defined as the presence of endoscopically visible bilateral polyps growing from the middle meatus with or without involvement of the nasal cavities

Exclusion criteria

• Any respiratory disease apart from asthma and CRSwNP
• Current or ex-smokers should not have a smoking history ≥10 pack-years before data analysis. Patients who administer nicotine in other forms (patches, chew tobacco, e-cigarette, etc.) will be excluded
• Unstable asthma medication <4 weeks before index date
• Asthma exacerbation (see definition below) <4 weeks before index date
• Respiratory tract infection <4 weeks before index date