Clinicians are aware that inhalers are often improperly used incorrectly by patients. However, it often difficult to assess, because at present there is no tool that directly quantify adherence. We designed a device, the INCA device that makes an acoustic recording each time an inhaler is used. Opening the device starts the recording, this electronic sound file is “time-stamped” which means that the timing of drug administration is recorded, while analysis of the acoustics identifies the technique of inhaler use. When the INCA device is retrieved and acoustic analysis performed, the steps involved in using the inhaler are determined. Hence, both inhaler technique and the time when the inhaler was used can be identified. Together this means gives an objective quantitative assessment of inhaler adherence.
In this study we attached the INCA device to a diskus dry powder inhaler and studied inhaler use by people in Hospital who were prescribed a diskus inhaler.
Initial results from three general Hospitals (n = 50) indicated that there were errors in both overuse 15% of doses, missed doses in 30% of patients and poor inhaler technique was seen in 45% of patients, in no case was it suggested that the device be changed. Overall, <40% of inhaler doses were administered on time and in the correct manner. Investigation indicated that inhaler administration was not supervised which together meant that errors in inhaler use were not rectified. Subsequently we undertook an institution wide comprehensive practice change involving prescription review, changes to storage and administration policy, supervised inhaler administration to correct inhaler misuse and a follow-up when inhaler misuse persisted despite ward level instruction. Six months after the introduction of practice change a series of follow on audits were performed. One audit indicated that the storage and administration practice was adopted on the wards. The second indicated in 100 consecutive admissions that observed inhaler technique was adequate in 33% of patients on admission, improved in 33% and was unchanged by discharge in 33%. Thirdly, studies with the INCA device, (n = 40) indicated that overdosing was documented in only 2% of recordings, missed doses were reduced to 20% and 10% of patients were changed from one device to a more suitable one. Hence, data from the INCA device prompted a change in practice Improvements in inhaler use on the wards were achieved by a simple quality improvement intervention.