Asthma: diagnosis, monitoring and chronic asthma management (BTS, NICE, SIGN)

Using fractional exhaled nitric oxide (FeNO) testing in adults for regular monitoring reduces the number of asthma exacerbations by around 19%.

Using FeNO testing in adults may also lead to reductions in:

In children, regular FeNO monitoring showed significant improvements in lung function.

In both adults and children, peak expiratory flow (PEF) monitoring was associated with an increase in asthma exacerbations. So it should not be used to assess asthma control unless there are person-specific reasons for doing so.

We are aware that there is variation in the availability of FeNO testing in primary care so providing access to this may need investment.

In primary care settings, incorporating FeNO testing into routine asthma reviews can be difficult because testing takes longer and more space is needed for equipment.

The quality of annual reviews varies. High-quality annual asthma reviews should include objective measures of control (FeNO testing where available), alongside symptom assessment and inhaler technique checks.

Healthcare professionals may need further support and training to understand the role of FeNO testing in asthma diagnosis and monitoring.