In this study, patient satisfaction and preference with regard to two different inhaled medications, VFC Ellipta and FFC pMDI, were compared in a ≤ 64-year-old group (group 1) and a ≥ 65-year-old group (group 2) after three preconditions: stable asthma control (Table 2), drug adherence rate ≥ 97%, and appropriate inhalation technique. No significant difference in patient satisfaction was seen between the two inhaled medications in group 1 (p = 0.690), but in group 2, patient satisfaction was found to be significantly higher with the FFC pMDI than with the VFC Ellipta (p = 0.009) (Fig. 2). Two factors affected the significantly higher level of satisfaction with the FFC pMDI in group 2: differences in the devices and BMI. Of the differences in the devices, the FFC pMDI device was associated with significantly greater patient satisfaction than the Ellipta device (OR 5.77, p = 0.024). However, the results of the questionnaire on device operability for VFC Ellipta and FFC pMDI showed no significant differences in any of the individual questions Q1–Q8, and no significant difference in an assessment of Q1–Q8 overall (p = 0.506) (Table 5). Why, then, does the pMDI device have a significantly higher level of satisfaction among elderly people?
First, subjects responded that the FFC pMDI was significantly less bothersome than the VFC Ellipta, as shown in the results for Q1 (Table 3). The responses to Q2 on the specific things that were felt to be bothersome are shown in Table 4. In group 2, specific examples of difficulties with the VFC Ellipta that were reported can be roughly categorized into two types: those related to the formulation physical properties, such as a “powdery feeling” and “discomfort in the mouth and tongue,” and those related to the device, such as the mouthpiece and lever. More than half of the subjects in group 2 had some kind of complaint. In contrast, specific examples of the negative reactions to the FFC pMDI were mainly two cases of difficulty in coordinating breathing and two cases regarding the smell of the drug; the absolute number of complaints itself was smaller than with the VFC Ellipta. The negative reaction as a result of the difficulty in coordinating breathing with this pMDI preparation is something that was already known before the introduction of the drug, deriving from device characteristics of the pMDI preparation , and is not something new in this study. The use of a spacer is an effective way to counter this, although spacers were not used in this study. In previous reports that used conventional pMDI preparations, while there were differences in the degree of negative response depending on age cohort and other factors, 24.4–81.4% of patients were reported to have difficulty in coordinating their breathing [9, 10, 14]. In the present group 2, however, only two subjects reported difficulty in coordinating breathing as a specific reason that this device was bothersome. This was less than 10% of group 2 overall, and much less than in previous reports . One point of difference between the FFC pMDI and conventional pMDI is that the FFC pMDI was developed so that the spray velocity of the drug would be slower, to make breathing coordination easier, and a spacer is usually needed . It is speculated that one of the reasons for the significantly higher satisfaction with the FFC pMDI in group 2 may have stemmed from this feature of the FFC pMDI device.
The level of satisfaction with the pMDI in group 2 was also found to be significantly higher in patients with lower BMI (OR 7.98, p = 0.010). Why was the level of satisfaction with pMDI significantly higher in patients with lower BMI? As shown in Table 1, despite no significant difference in BMI between groups 1 and 2 (p = 0.659), the patients in group 2 had significantly lower grip strength, finger muscle strength, and peak inspiratory flow than those in group 1 (all p < 0.05). These data may be taken as a characteristic of group 2 as a group of elderly patients. Looking at the correlations of these parameters with BMI in group 2, a weak correlation was seen between BMI and grip strength (r = 0.374, p = 0.095), and relatively strong correlations were seen between grip strength and finger muscle strength and between grip strength and peak inspiratory flow (r = 0.515, p = 0.017 and r = 0.501, p = 0.021, respectively). While these data express different things, they may be taken as showing different aspects of decreased muscle strength in elderly people.
With the Ellipta device, the action of opening the cover loads the drug and prepares the blister for inhalation of the medication, a feature of which is a squeaking sound together with fairly strong resistance. This requires a certain amount of finger muscle and grip strength, and while it had little effect in group 1 patients, who had sufficient strength (Table 1), it may have been felt to be a burden by patients in group 2, who had significantly less grip strength. Moreover, since the VFC Ellipta is a DPI preparation, the dry powder needs to be strongly and deeply inhaled at the time of inhalation, which demands a sufficient peak inspiratory flow level in patients. Therefore, the drug cannot be satisfactorily inhaled in some cases when patients do not have the muscle strength needed to inhale strongly, such as in the respiratory muscles and diaphragm. On the other hand, since the FFC pMDI has a relatively stiff cylinder, this study was conducted with all patients using an inhalation assistance device (Full Push) from the beginning. Therefore, among elderly patients with low BMI, the device could be used readily despite significantly decreased grip and finger muscle strength, and this was thought to be reflected in the results showing significantly higher levels of satisfaction compared with the VFC Ellipta. This is consistent with the finding that in group 2, there tended to be a better response for the FFC pMDI to Q4 in Table 3.
The process by which patients use the device and inhale the medication was broadly divided into two components: the process of setting the drug in the device to prepare for inhalation (a device operability aspect) and the process of actual inhalation by the patients (a drug inhalation aspect). Modifications and improvement in the former can be expected with patient education by repeatedly going through the appropriate operation method and proper procedures. In this study, the subjects were fully instructed on inhalation before they started to use each device, and no significant differences were seen in any of Q1–Q8 concerning the evaluation of device operability at week 4, nor were any significant differences seen in the evaluation of the overall impression of the device in Q1–Q8 (p = 0.506).
For the latter, however, much was attributable to the patients’ own physical ability, and though improvement could be expected from training in younger people, in many cases there was a cut-off age beyond which improvement could not be anticipated in elderly people [17, 18]. For peak inspiratory flow and grip and finger muscle strength, there are limitations to what elderly patients can do themselves. The BMI of the study subjects was around 23 kg/m2, which is the Japanese average. No patient was obese, and so it may be supposed that body weight reflected muscle mass, and that when BMI was low, muscle mass was also low. This is consistent with low grip strength and finger muscle strength. The reason for the significantly higher satisfaction with the FFC pMDI than the VFC Ellipta in the elderly patient group was thus not only the type of device used; the fact that BMI had a significant effect is useful information when selecting the device for elderly people. Another major advantage to using the pMDI is that the adverse circumstances affecting inhaler coordination of individual patients can be dealt with by using options such as spacers or valved holding chambers as auxiliary devices . Especially in elderly people with decreased muscle strength and physical ability, it is possible that a feeling of achievement can be obtained from effective inhalation with the use of auxiliary devices, leading to higher levels of satisfaction and preference.
A point to be noted is that, despite full guidance and confirmation of the appropriate inhalation technique before the study, mistakes in operation of both devices appeared after 4 weeks in group 2 (Fig. 3). With the VFC Ellipta, errors included that the cover was not fully opened, a finger blocked the air hole, and the patient did not inhale strongly and deeply during inhalation, whereas with the FFC pMDI, a case occurred in which the patient could not coordinate breathing when the drug was sprayed. In a report comparing conventional pMDI and DPI preparations Diskus, HandiHaler, and Turbuhaler, operation errors were significantly higher with these DPI preparations than with the pMDI in an elderly patient group, despite inhalation instruction . In a different study, operation errors were also significantly higher with prefilled dry power inhaler DPI preparations . In a reported investigation of patients with asthma and those with chronic obstructive pulmonary disease, 59% of patients made operation errors at least once after receiving inhalation instructions. Mistakes were seen in the inhalation operation during breathing coordination with the conventional pMDI and in operation of the device with DPI. All were related to low air intake speed .
Many patients in group 2 gave fair (4 points) or good (5 points) responses to questions Q1–Q8 (Table 5), and there were no significant differences between the Ellipta and pMDI. In group 2, the operation errors that occurred after 4 weeks cannot be expressed with the response to questions on this questionnaire because most patients reported “fair” or “good” about device operability, and it is possible that, though the patients themselves thought that they were using the devices properly, operation errors occurred unconsciously. This suggests that inhalation guidance needs to be repeated.
The types of patient adherence, both for the drug and for the inhalation device, need to be simultaneously stored in accordance with the instructions for use and operated correctly for the effective continuation of inhalation therapy. This requires that physicians, pharmacists, and other healthcare professionals provide not only instruction for taking the medication, but also repeated instruction in the inhalation technique. This helps ensure that the inhalation device is always used with an appropriate operational technique and procedure so that effective inhalation therapy can continue. One study showed that the feeling that the drug could be effectively inhaled produces a sense of achievement in patients with regard to the therapy, leading to satisfaction and preference toward the treatment . Such patient satisfaction and preference are important feedback as a key to maintaining good adherence, leading to the continuation of effective inhalation therapy. The results obtained in this study showed significantly higher patient satisfaction with the FFC pMDI in older patients, but there were differences in satisfaction and preferences among patients, which may change with time based on various factors, such as age. In clinical settings, there are frequent switches from the VFC Ellipta to the FFC pMDI or vice versa. The results obtained in this study may provide useful hints at such times.