Inhaler technique has been proven to be inadequate in children’s asthma (10, 21) and is associated with poor asthma outcomes, including death (22). Optimal pharmacotherapy is predicated on children performing a complicated series of steps correctly and in a proper sequence to ensure optimal therapeutic effect (10). Therefore, proper use of an inhaler (either pMDI or DPI) is not a straightforward task and requires substantial time and effort in order to master the technique. Unfortunately, at the point at which inhalers are commonly prescribed in children (primary care and in the emergency department), this time and expert teaching is not afforded.
Interpretation of results
Dates and origin of studies
Geographically there has been a wide range of countries producing research in this particular field which is reassuring and aligns with asthma being a common paediatric disease worldwide with increasing prevalence in low and middle income countries (23) (24). The bulk of this work emanates from the USA which contributed to nearly half of identified studies. The UK only yielded 3 (out of 28) studies that fit the inclusion criteria. This is particularly disappointing when considering the findings from the National Review of Asthma Deaths (NRAD) report (25) and we feel that the UK could and should be making a bigger impact into teaching inhaler technique to children with asthma.
More reassuringly, there has been a spike in research in this field in recent years with 12 (out of 28) studies included having been published in the last five years. This likely reflects recent changes in attitude within the academic community for the need to improve this specific aspect of children’s asthma care. Interestingly, there were no studies prior to 1995 which met our inclusion criteria despite the fact that the metered dose inhaler was first introduced in 1956 (19). This suggests that there was an assumption following the introduction of inhalers that they were easy to use and, once prescribed, drug delivery to the lungs would presumably be effective.
Type of inhaler used
There are two main types of inhaler, pMDIs and DPIs. The decision upon which of these is prescribed is a clinical one and at the discretion of the clinician. The method by which these inhalers are to be used is described in an instructional leaflet provided with each inhaler. The purpose of this scoping review was not to search for studies which could improve on these instructions (as they are inherent to each inhaler type) but rather to search for studies which helped patients improve their ability to follow these set of instructions. The results of our search yielded papers which were either non-device specific or specifically of pMDIs, with only 3 (of 28) specifically studying DPIs. The high number of papers using pMDIs reflects their popularity as the ‘core inhaler device’ globally (26).
One of the main aims of our study was to describe what methods had been previously used to teach and improve children’s inhaler technique, regardless of what type of inhaler they were prescribed. The teaching techniques described in each of our included papers would be transferable across all inhaler types and so are all suitable for inclusion and analysis of their potential worth.
It is important to mention that none of the studies specifically included use of a spacer device (despite this being included as a search term). It is best practice for children to be prescribed a spacer device alongside their pMDI, as this is proven to improve drug deposition to the lungs (9). However, the studies included in this scoping review provide methods of teaching inhaler technique which are generic and could be feasibly used for all inhaler types including the use of spacers.
Who provided the training and where?
Our findings show that there is a broad range of health care professionals involved in the provision of inhaler training. Interestingly, it was the doctors who were least involved in actually providing the inhaler training despite the fact that in most circumstances they will be the team-member making the decision as to whether the child should be prescribed the medication. There was also a wide range of locations of where inhaler training was taking place with only half in the traditional hospital setting and a few being provided remotely.
These findings broaden the scope by which, as a community, we can improve our ability to teach children how to use their inhalers, as it has been shown to be feasible in such a diverse number of ways. ‘Not every patient is the same’ is equally true regarding their suitability for an educational intervention as it is to their specific disease process and how they respond to certain treatments.
Ages of participants
Patients perform more errors in inhaler technique at the extremes of age (27).
For paediatric patients, previous studies have shown that inhaler technique tends to improve beyond pre-school age only to dip again coming into adolescence and teenage years (28). This scoping review identified three papers which exclusively studied pre-school children. Agertoft et al (29) showed that improvements in technique can be made in younger children but is more difficult the younger they are. Schultz et al (30) showed that improvements in technique can be made in younger children but that their intervention was more beneficial up until the age of 4 years, after which point it was still of benefit but not more than conventional training. The paper from Shaw et al (31) was a study on 2-7 year-olds which showed improvements can be made in younger children and that increasing age correlates with improved technique.
There were 7 studies which included (but not exclusively) preschool children. Not all of these studies attempted to stratify or compare between different ages (32-35). Khan et al (36) stated that “increasing age correlated directly with improved technique.” Shields et al (37) stratified into 2-5,5-12,>12 year olds, however this was a feasibility pilot study and so comparison between age groups was not made.
When designing educational interventions to improve inhaler technique in the future, it would be important to consider that there are distinct challenges within the different age groups of children.
Method used to measure inhaler technique
There were different means by which investigators chose to measure the effect that their educational intervention had on inhaler technique. The most commonly used was by using a standardised checklist of approved ‘steps’ which were used to score pre and post intervention. Rather than specifically counting each individual step, some researchers stratified technique based on whether the patient performed what was considered the ‘critical steps’ or categorised their ability into an overall ‘level’ of competence.
Using a defined set of steps by which to use as an ordinal measure would seem to be initially the most appealing as it takes away the bias of subjectivity. However, this may need to be balanced by the fact that many of the prescribed steps may have limited effect on drug deposition and teaching should be designed to have its biggest impact on the most clinically important aspects of inhaler use. In that sense, the studies which used PIF as a surrogate marker of good technique are also appealing (29, 38).
Clearly the best way to prove the efficacy of a new technique (including a teaching technique) is by comparing its effect against a control. By that measure, it is reassuring that half of the studies included for analysis were of randomised controlled trials (RCT). Many of the other studies included were observational studies which helps provide the basis and rational for future work. Whilst there is a lot to be gained from other methodologies, future studies attempting to provide definitive evidence of the best means to teach children to use their inhaler correctly should ideally follow RCT methodology.
Feasibility of educational interventions studied
It is beyond the scope or purpose of this scoping review to compare the efficacy of each of the included studies. However, all of the studied interventions proved feasible and showed some degree of benefit in inhaler technique. As already discussed, not all of the interventions were designed to take place in the traditional hospital clinic but rather be implemented at a variety of possibly more convenient locations such as at home or in the patient’s local community.
Sustained effect of intervention on inhaler technique.
One of the most important aspects to teaching inhaler technique to children is not just the ability to perform correctly the technique on the day of the consultation but to sustain this ability for a prolonged period of time until mastery is achieved. Three of the studies included in this coping review reported the sustained effect which their intervention had on inhaler technique (31, 36, 39). Khan et al (36) studied the effect of a DVD recording of the patient performing with good technique versus physiotherapist delivered teaching in a clinic, showed an improvement in technique sustained at 3 months (despite no difference initially). Shaw et al (31) showed that video demonstration along with physical demonstration immediately improved technique on the first visit (compared with just physical demonstration). This difference in improvement was not sustained on subsequent follow up at 9 months. However, overall technique did improve on follow-up and so it was likely that it was the physical demonstration rather than the repeated video that sustained technique. In the paper by Sirimontakan et al (39), technique improvement was sustained at 3 months with the introduction of a cartoon video demonstration.
Primary concept: Brief-Intervention V Teach-Back
In her paper published in 2012, Valerie Press (40) describes ‘Brief-Intervention’ as a means of teaching a patient how to use their inhaler by providing verbal and written instruction. This is considered the most basic, least time consuming and most common means by which patients are educated to use their inhaler. This was compared with a more complex and timely strategy named ‘Teach-To-Goal’ (TTG) which “employs instruction followed by patient ‘Teach-Back,’ then repeated iterative cycles of learning and assessment until a skill is mastered.” They showed a significant improvement in inhaler technique by using this TTG strategy, however, this study did not include children. While the Press group described quite a specific method by which to provide TTG training, the essence of the method is in the ‘Teach-Back’ aspect of it. That is, a patient has not proved that they have adequate technique until they have physically demonstrated this back to their instructor.
On analysing the included studies for this scoping review we noted that many of the studies employed a strategy that had elements of ‘Teach-Back’ without explicitly being named ‘Teach-To-Goal’ and so we considered this a primary concept by which inhaler technique could be taught to children. As with the Press paper, the other half of included studies had methods, which were very basic and essentially aligned with her definition of ‘Brief-Intervention’. Root et al (41) and Volerman et al (42) are the only two that mention TTG specifically but neither are in preschool children.
Psychological basis of teach back
There appear to be three key processes at the core of Teach-Back; information retrieval, feedback and ’spaced learning’. In cognitive psychology it is recognised that re-testing and retrieval, as demonstrated by Teach-Back are important to consolidate learning (43). Study and testing form separate memories and this aids retrieval and long- term retention. Disappointingly this was reported nearly 20 years ago and yet poor inhaler technique still persists (44). The provision of feedback helps to expedite and close the learning cycle and it is recognised that feedback-driven metacognition improves ultimate task performance (45). The effectiveness of spaced repetition in creating long-term memories has been experimentally demonstrated in many species showing the value of spaced practice (many short sessions) over massed practice (a single long session) in long-term memory (46, 47). Repeated stimuli separated by timed spaces without stimuli can initiate long-term memory encoding (48).
While we split the primary concepts into two mutually exclusive categories, there was overlap within the secondary concepts (i.e. a number of studies used more than one secondary concept). The most common secondary concept, unsurprisingly, was the use of physical demonstration to teach inhaler technique to children. However, this was often supplemented or enhanced by other secondary concepts such as the use of inhaler devices, videos, written instructions or by performing the demonstration remotely (via video-call).
On further analysis of the different means of using videos, some of the studies used a standard video (i.e. the same instructional video shown to all participants) while others developed ‘bespoke’ videos tailored to the patients specific learning needs.
There were a number of studies which used a device. These were mostly in the form of a simple placebo or a peak flow attachment which was used to train the user to the achieve adequate flow required to use DPIs (and were therefore device- specific). There was an ‘incentive’ device named the Funhaler (30) that facilitated an improvement in inhaler technique for very young children with the benefit plateauing by 4 years old.
It was interesting that the use of remotely directly observed therapy (using video calls) had actually been studied 20 years ago (49, 50) but has been enhanced with improving technology over the years as seen in the Shields paper from 2017 (37).
‘Precision medicine’ has become a buzzword within medicine. The European Respiratory Journal have provided their definition within the context of asthma focusing on the stratification of patients (51). The application of precision medicine within asthma mostly focuses on the heterogeneity of the patients and their response to specific treatments (corticosteroids and biologics etc). The same approach should therefore be used when determining how best to teach these patients how to use their inhaler device.
For example, TTG (41, 42) is a type of precision medicine as the teacher's feedback is tailored to that specific patient's needs. The paper by Carpenter et al (52) regarding use of video cartoons is a perfect example where the cartoon made is bespoke to that specific child.
We acknowledge that this study has been limited to those publications in the English language; however, the broad nature of the research question still allows us to capture a significant proportion of the available literature.