Introduction The identification of intentional and non-intentional non-adherence in patients with “difficult” asthma and establishing who should respond well to inhaled steroid treatment is essential to prevent the inappropriate escalation of inhaled corticosteroids (ICS) and the initiation of complex biological therapies. One week FeNO suppression testing can identify non-adherence and ascertain which patients who should achieve good asthma control with better adherence to standard treatment. Combining this test with simple remote technology it can be determined whether they are intentionally or non-intentionally non-adherent, and can show technique and timing errors.

Methods The INCA device was developed by Professor Richard Costello in conjunction with Vitalograph and is designed to work with the Accuhaler inhaler. The INCA device time and date stamps the activation of a microphone and records a sound file of the inhaler being used; these sound files can then be transferred to the computer and uploaded onto a server where they are analysed by an algorithm. Within the Belfast City Hospital 40 patients have carried out the one week FeNO suppression testing, 20 of those in combination with INCA technology. This testing is relatively simple and is part of the Medical Research Council funded Refractory Asthma Stratification Programme and is currently being piloted in five specialist Difficult Asthma Centres in the UK.

Results Within the 40 patients there were 23 non-suppressors (ie adherent patients) and 17 suppressors (ie non-adherent patients). With the patients using the INCA technology, the server highlighted technique errors; for example, not activating the drug blister or exhaling into the mouthpiece, as well as erratic timing issues. At subsequent follow up appointments these issues were emphasised and addressed by using patient-friendly print outs showing the usage of the inhaler, with the addition of alarm reminders and behavioural cues to encourage adherence.

Conclusion FeNO Suppression and INCA testing is an effective method of identifying and managing non-adherence with the capability of encouraging improved technique and timing also having the capability to be used as a long term behavioural assistance to adherence to ICS.