O5. Inhaler technique and adherence

O5.1 Inhaler technique

Incorrect inhaler technique is common and is associated with worse outcomes.  Inhaler devices must be explained and demonstrated for patients to achieve optimal benefit. It is necessary to check regularly that the patient has the correct inhaler technique. Elderly and frail patients, especially those with cognitive deficits, may have difficulty with some devices. Correct inhaler technique is essential for the optimal use of all inhaled medications (Melani 2011) [evidence level I] and is associated with fewer severe exacerbations. An observational study involving 2,935 patients with COPD, reported that in individuals who were treated for at least three months (n=2,760), the occurrence of prior (past three months) severe exacerbation was significantly associated with at least one observed critical error using prescribed inhalers (OR 1.86, 95% CI 1.14-3.04; p=0.0053) (Molimard 2017).  Ease of operating and dose preparation were rated as being the most important inhaler features leading to higher patient satisfaction and fewer critical errors in a randomised, open-label, multicentre, cross-over study of two inhaler devices (van der Palen 2013) [evidence level II]. An Australian cross-sectional study found that the proportion of patients with COPD who made at least one error in inhaler technique ranged from 50% to 83%, depending on the device used (Sriram 2016). Similarly a systematic review and meta-analysis of 72 studies involving asthma and COPD patients, reported that 50-100% of patients performed at least one handling error.  The pooled summary results for pMDI estimated an overall error rate of 86.6% (95% CI 79.4-91.9) and for DPIs it was 60.9% (95% CI 39.3-79.0) (Chrystyn 2017) [evidence level I].

With the proliferation of new inhaler devices, inhaler device poly-pharmacy is becoming an increasing problem amongst COPD patients and has a negative impact on outcomes (Bosnic-Anticevich 2017).  A study of 16,450 COPD patients compared exacerbation frequency and SABA use of patients who were using similar style inhalers e.g. all MDI to those that were prescribed devices that required a different technique.  Those in the similar device cohort experienced fewer exacerbations (adjusted IRR 0.82, 95%CI 0.80 to 0.84; and used less SABA (adjusted OR 0.54, 95% CI 0.51-0.57), compared to the mixed device cohort.  These data support the recommendation to minimise the number of different devices prescribed in COPD patients.

The National Asthma Council has produced a number of “how-to” video clips instructing patients how to use their inhalers, which are available on its website at https://www.nationalasthma.org.au/living-with-asthma/how-to-videos. Lung Foundation Australia has guidance on inhaler technique at http://lungfoundation.com.au/patient-support/copd/inhaler-technique-fact-sheets.  The Lung Foundation Australia resource, Better Living With COPD: A Patient Guide contains an inhalation devices chapter which can be accessed at http://lungfoundation.com.au/wp-content/uploads/2014/02/08.-Using-your-inhalation-devices.pdf.

The cost of inhaler devices varies between products. As there are no differences in patient outcomes for the different devices, the cheapest device the patient can use adequately should be prescribed as first line treatment (NHS Centre for Reviews and Dissemination 2003). The range of devices currently available, the products and dosage, as well as their advantages or disadvantages, are listed in Appendix 2. Brief counselling; monitoring and feedback about inhaler use through electronic medication delivery devices; and multi-component interventions consisting of self-management and care co-ordination delivered by pharmacists and primary care teams have been shown to improve medication adherence (Bryant 2013) [evidence level I].

Pragmatic pharmacist care programmes may improve inhaler technique and refill adherence in patients with COPD (Tommelein 2014) [evidence level II].