Discussion
This study shows that more participants achieved device mastery using the empty Spiromax inhaler compared with empty Easyhaler or Turbuhaler inhalers. In step 1, 37.5% of participants were able to use Spiromax correctly (intuitive use), whereas only 9.2% of participants used Turbuhaler correctly and none of the participants were able to use Easyhaler without handling errors. Information provided in the PIL was beneficial in instructing participants how to use the inhaler device properly. Fewer errors were reported for all three devices in step 2; respectively, 93.3%, 58.3% and 76.7% of participants were able to use Spiromax, Easyhaler and Turbuhaler correctly. The superiority in device mastery with Spiromax over Easyhaler and Turbuhaler was maintained in step 2 (p<0.001). Inhaler technique mastery was better using Turbuhaler compared with Easyhaler in steps 1 and 2. In step 3, when participants were trained on how to use each of the inhaler devices by an HCP, almost all participants (>95%) were able to use the inhaler devices correctly. No significant differences between the three devices were reported in step 3. Two independent studies are currently investigating device mastery for Spiromax compared with Turbuhaler among HCPs (in Australia) and patients with asthma (in the UK). Outcomes from the study presented here are similar to results reported in the device mastery study among Australian HCPs. More HCP participants achieved device mastery with Spiromax prior to training or after reading the PIL compared with Turbuhaler.17
The improvement of device mastery in response to training highlights the importance of face-to-face training of participants at clinical visits. Inhaler technique is now an integral part of the Global Initiative for Asthma (GINA) management strategy.18 GINA guidelines recommend training patients in the use of inhalers as a fundamental and essential component of good clinical practice.18 Although training patients in inhaler use is of particular importance, and it is not recommended that patients are left to educate themselves, at least 25% of asthma patients have never received training.5 In some situations, it might not be possible or practical to provide training to a particular patient, which highlights the importance of an intuitive inhaler device. An innovative inhaler that is easy to use ‘out-of-box’ could potentially minimise the risk of poor asthma control by ensuring that patients are able to use the inhaler correctly even if they have not been verbally educated by an HCP in inhaler use or have not read the PIL, which is also of importance in instances where a switch/automatic substitution of inhaler devices postprescription takes place. Although an intuitive device might minimise the risk of error in the event of a switch, it should be noted that a switch without instruction and training is not recommended and is considered to be against good clinical practice. In this study, Spiromax was associated with fewer errors compared with Easyhaler and Turbuhaler when participants used the devices intuitively (step 1) or after reading instructions available in the PIL (step 2). Spiromax was also associated with the lowest number of errors during the ‘preparation’ of the device in step 1 and step 2. Such innovation in inhaler design could contribute to improving patient inhaler technique and achieving disease control leading to better allocation of healthcare resources.19
Optimal inhaler technique differs between devices.20 Manoeuvres while preparing the device and after inhalation are device-specific. This study further investigated the proportion of errors committed for each of the device-specific manoeuvres for Spiromax, Easyhaler and Turbuhaler.
The most common error reported for Spiromax was linked to the orientation of the device. Participants held the device upside down, both when preparing the device and during inhalation, which accounted for 51.3% of errors committed with Spiromax in step 1. Also, two of the participants held the device in a horizontal position. Per the inclusion criteria, participants were healthy individuals, inhaler-naïve and inhaler training-naïve. As such, this error could be related to participants not being familiar with the shapes of inhalers, whereas patients would probably be less likely to hold an inhaler in the horizontal position. Of note, during the device mastery observations, participants commented on the lack of text on the Spiromax device, which potentially could have contributed to holding the device in a wrong position. In contrast, the empty versions of the Easyhaler and Turbuhaler devices included text (figure 2). Given that the marketed Spiromax device will have a label with text on, it is likely this error would be less frequently seen in clinical practice. Although Spiromax needs to be held in the upright position during the preparation manoeuvre (while opening the cap of the inhaler device for dose preparation), the finding from a recent study that assessed the dose consistency delivered with Spiromax when the device is held at different orientations revealed that dose consistency is maintained when the inhaler is held at a + or −90° orientation.16 As such, the orientation error reported in this study with Spiromax might not be considered a critical error/error that could affect drug dose delivery to the lungs. Patients holding Spiromax in a different orientation than the recommended upright position during the inhalation manoeuvre might still be receiving the appropriate drug dose.
The most common error reported with Easyhaler was also during the preparation of the device. Participants did not shake the device prior to inhalation in step 1 (95.8%) and step 2 (13.3%). A surprisingly large proportion of participants (41.7%) were observed making handling errors even after reading the PIL with Easyhaler (compared with <10% of participants when using Spiromax or Turbuhaler). The high number of errors in step 2 with Easyhaler might be linked to some ambiguities in the Swedish language of the PIL. For example, one of the Swedish PIL instructions is: “skaka upp och ned”, which translates to: “shake the device up and down”, and the following instruction is: “se till att du skakar den upp och ner”, which, coming straight after the first instruction, could translate as: “make sure you shake the device holding it upside down”. This is different to the English version of the PIL in which the instructions are: “shake the Easyhaler vigorously up and down three to five times, to allow proper powder flow and a correct dose. After shaking, hold the Easyhaler in the upright position”.16
The most common handling errors with the Turbuhaler were also during the preparation of the device. Incorrect priming of the device, especially the lack of twisting forward and back, which would result in dose loading errors if an active device were being used (little or low medication would reach the lungs),21 was reported for 55.8% of the participants in step 1. Interestingly, in step 1, Easyhaler performed better than Turbuhaler and Spiromax during the ‘inhalation’ manoeuvres. This could be attributed to some participants (12 with Spiromax, 1 with Easyhaler and 6 with Turbuhaler) requesting instructions before inhaling through the device; inhalation manoeuvres were recoded as ‘errors’ in those instances. Of note, in general, errors during the ‘inhalation’ manoeuvre are not considered device specific. All DPIs require that patients inhale as deeply and as fast as possible from the start.
It is recognised that the selection of the most appropriate inhaler requires consideration of the patient’s ability to use the device correctly, preference and satisfaction with the device.13 ,22 When participants were asked to rate Spiromax, Easyhaler and Turbuhaler for device preference (using the DPQ), the majority of participants (73.1%) indicated that they found Spiromax the easiest device to use and 74.1% indicated that if they were prescribed an inhaler they would prefer Spiromax over Easyhaler or Turbuhaler. Similar findings were reported in a recent study that assessed device preference comparing Spiromax with Turbuhaler in patients with asthma. In this study, device preference was measured using the Patient Satisfaction and Preference. Preference for budesonide-formoterol (BF) Spiromax, which is easy to use, intuitive and preferred by patients using asthma inhalers—versus BF Turbuhaler—could ultimately improve adherence.19 Good medication adherence is an essential requirement for optimal clinical outcome and would also help to reduce treatment costs.19 Compared with Easyhaler and Turbuhaler, Spiromax was the ‘preferred’ inhaler by the participants of this study. Choosing the most appropriate inhaler for the patient has been shown to enhance adherence to therapy and, consequently, improve clinical outcomes.22–24 These results suggest that Spiromax use could have positive clinical implications on asthma management.
Among the strengths of this study is the crossover study design, which reduces bias that could potentially result from variations between study groups. The inclusion of participants who were inhaler naïve is another strength of this study. Randomised controlled trials have previously reported no differences in efficacy between inhaler devices.25 In most of these trials, patients enrolled had received training and demonstrate good inhaler technique. In the real world, most patients do not use their inhalers correctly and some have not received any training. As such, this study allows the evaluation of device handling and mastery without the influence of prior experience or knowledge of inhalers confounding the results.
One of the limitations of this study is that almost all participants were educated to university level (99%). Literacy and education play an important part in inhaler technique. A greater number of inhalation errors are committed by patients who are illiterate and educated to primary level compared with patients educated to a higher level and university graduates.26 It would be interesting to assess whether the superiority of Spiromax over Easyhaler and Turbuhaler is maintained if a similar study is conducted in naïve participants with low education and literacy levels. Ultimately, it would be most informative if a similar study is conducted in a ‘real world’ context, in a heterogeneous group of patients with asthma.
In conclusion, outcomes from this study indicate that more participants achieved device mastery with Spiromax compared with Easyhaler or Turbuhaler. Spiromax was associated with a lower number of errors after intuitive use (step 1) and after reading the PIL (step 2). More participants felt that Spiromax was easier to use than Easyhaler or Turbuhaler and reported that they would prefer Spiromax if they were prescribed an inhaler. The higher levels of device mastery achieved with Spiromax, combined with the ease of use of the device, could potentially improve adherence, leading to improved asthma control and potentially reducing treatment costs. In general, it is clear that face-to-face instruction is essential when prescribing inhalation therapy; however, an optimally designed device can play a role in maximising patient compliance and device mastery.