Asthma patients' inability to use a pressurised metered-dose inhaler (pMDI) correctly correlates with poor asthma control as defined by the Global Initiative for Asthma (GINA) strategy: a retrospective analysis

BACKGROUND: In practice it is logical that inhalers are prescribed only after patients have received training and demonstrated their ability to use the device. However, many patients are unable to use their pressurised metered-dose inhaler devices (pMDIs) correctly. We assessed the relationship between asthma control and patients' ability to use their prescribed pMDIs. METHODS: Evaluation of 3,981 (46% male) primary care asthma patient reviews, which included inhaler technique and asthma control, by specialist nurses in primary care in 2009. The paper focuses on people currently prescribed pMDI devices. RESULTS: Accurate data on reliever and preventer inhaler prescriptions were available for 3,686 and 2,887 patients, respectively. In patients prescribed reliever inhalers, 2,375 (64%) and 525 (14%) were on pMDI alone or pMDI plus spacer, respectively. For those prescribed preventers, 1,976 (68%) and 171 (6%) were using a pMDI without and with a spacer, respectively. Asthma was controlled in 50% of patients reviewed. The majority of patients (60% of 3,686) were using reliever pMDIs, 13% with spacers. Incorrect pMDI use was associated with poor asthma control (p<0.0001) and more short burst systemic steroid prescriptions in the last year (p=0.038). Of patients using beclometasone (the most frequently prescribed preventer drug in our sample), significantly more of those using a breath-actuated pMDI device (p<0.0001) and a spacer (p<0.0001) were controlled compared with those on pMDIs alone. CONCLUSIONS: Patients who are able to use pMDIs correctly have better asthma control as defined by the GINA strategy document. Beclometasone via a spacer or breath-actuated device resulted in better asthma control than via a pMDI alone. Patients prescribed pMDIs should be carefully instructed in technique and have their ability to use these devices tested; those unable to use the device should be prescribed a spacer or an alternative device such as one that is breath-actuated.