Technique training does not improve the ability of most patients to use pressurised metered-dose inhalers (pMDIs)

Abstract

Aims:

According to guidelines, inhaler technique should be tested in all patients, particularly those with poorly controlled asthma. We aimed to assess uncontrolled asthma patients' ability to use a pressurised metered-dose inhaler (pMDI) using the Aerosol Inhalation Monitor (AIM, © Vitalograph).

Methods:

Practices invited patients for a detailed clinical review by trained asthma nurses according to practice-agreed protocols. Reviews took place from 1st April to 30th June 2008, and included checking of inhaler technique. Reasons for invitations included time since last review, asthma control, prescriptions, and adherence to medical advice. A proxy measure of control — the total number of short-acting β₂-agonist (SABA) bronchodilator inhaler canisters prescribed in the previous 12 months — was used. Data on 77 pre-determined clinical parameters (including prescribing and healthcare utilisation data) were collected. Patient-completed postal symptom questionnaires (the RCP 3 questions) were obtained in some patients. All patients using pMDIs had at least two assessments using the AIM, and where appropriate inhaler technique education was provided.

Results:

2123 (24% of those invited) symptomatic asthma patients were reviewed; 1291 (61%) were using pMDIs (mean age 52 years; SD 21), of whom over 80% were in BTS/SIGN Steps 2 and 3. 1092 (85.6%) of those patients using pMDIs failed the first AIM assessment. There was a significant increase in the number of patients able to use their pMDIs correctly following instruction after the second (129 to 260 of 1197 patients, p<0.01) and third (61 to 181 of 528 patients, p< 0.01) tests. However, 78.4% and 65.7% of those tested twice and three times, respectively, failed the AIM assessment despite instruction. Logistic regression analysis failed to show any effect of age and BTS step on these outcomes.

Conclusions:

A majority of symptomatic asthma patients in this study were unable to use pMDIs correctly. It is essential to check all patients' ability to use their prescribed inhalers regularly. Cost alone should not determine prescribing recommendations.