suspended due to lack of data.

This study will compare the absolute and relative effectiveness of managing real-life asthma with and without the use of NIOX MINO® and NIOX Flex® to measure exhaled nitric oxide (eNO) as a marker of underlying airway inflammation to guide appropriate management. As exhaled nitric oxide responds rapidly to environmental changes and can act as a marker of underlying inflammation it is proposed that incorporating eNO monitoring into routine asthma management treatment allows strategies to be more accurately tailored to the patients needs, increasing the probability of good asthma control.

Inclusion Criteria:

1. Aged: 6-80 years
2. Evidence of active asthma (diagnostic code and/or ≥6 prescriptions for asthma therapy at any time in their records)
3. Evidence of current asthma treatment (≥2 asthma prescriptions during baseline year and outcome year)
4. Have at least one year of up-to-standard (UTS) baseline data and at least one year of UTS outcome data (following the IPD)

Exclusion Criteria:

1. Had a COPD read code at any time; and/or
2. Had any chronic respiratory disease, except asthma, at any time; and/or
3. Patients on maintenance oral steroids during baseline year
4. Smoker or ex-smoker aged over 60

Asthma patients who either:

• Use eNO monitoring in their asthma management
• Do not use eNO monitoring