DEFINE

Around 5.4 million people in the UK receive treatment for asthma. However, although more and more asthma medications are being prescribed each year, numbers of serious asthma attacks are not going down.

To help prevent serious asthma attacks, we need to make sure the right treatments are given to the right people in the right amounts.

The DEFINE study is therefore exploring whether measuring fractional exhaled nitric oxide (FeNO) in GP surgeries can improve management of patients with asthma by helping health care professionals provide a more personalised approach.

FeNO stands for fractional exhaled nitric oxide. It is measured using a simple breath test. 

Nitric oxide is a gas which everyone breathes out. People with inflamed airways breathe out more nitric oxide than people whose airways are not inflamed. These patients are more likely to have an asthma attack if their inflammation remains untreated

FeNO is already measured in patients with severe asthma who are seen in hospital clinics. However, very few GP surgeries routinely use FeNO to help them monitor treatment.

The DEFINE study team have therefore designed an online intervention to support health care professionals and patients with using FeNO during asthma reviews in GP surgeries. As well as providing GP surgeries with FeNO measurement equipment, this intervention also offers the following tools:

• An online training tool to support healthcare professionals in how to measure and interpret FeNO.
• A digital FeNO-guided management algorithm to personalise asthma care.
• Information materials for patients on FeNO and its role in asthma management.

The trials intends to discover over the course of one year whether this intervention helps reduce a patient's risk of having an asthma attack. We have recruited just under 2,600 people with asthma into our study from GP surgeries in Thames Valley, Wessex and East Midlands.

Patients have been randomly sorted into one of two groups. The first group have had their FeNO tested when their asthma is routinely reviewed at their GP surgery; the second group have received usual care at their routine review without FeNO testing.

The video below demonstrates how a FeNO measurement is carried out.