Abstract
Background
Activating pressurized metered dose inhalers (pMDIs) is often challenging for children. The Easy Squeezy (ES) is a novel sleeve attachment device that reduces activation force by 3 times. Although users have favored using the ES over using a pMDI alone, the clinical impact of the ES remains unknown. The aim of this study was to compare lung function and quality of life between ES users and users of a pMDI alone.
Objectives
Our aim was to measure and compare lung function of asthmatic children after they used the ES and pMDI alone.
Methods
In this crossover study we recruited 65 asthmatic children between the ages of 5 and 12 years. The participants were randomized into 2 groups. One of the groups used the ES for 6 weeks whereas the other group used a pMDI. After 6 weeks the participants crossed over to the other group. Lung function test parameters were measured after randomization and after each 6 weeks of device use. Quality of life (measured by the Patient Asthma Quality of Life Questionnaire [PAQLQ]) and Childhood Asthma Control Test were measured after each period of device use.
Results
There was no significant difference in the baseline lung function between the groups. The ES group had a significantly lower percentage difference between prebronchodilator and postbronchodilator FEV1 values. Although no significant differences were observed in PAQLQ scores between the groups, more patients in the ES group had improvement of their PAQLQ score than did patients in the group using a pMDI alone. Total Childhood Asthma Control Test scores were significantly higher for the ES group.
Conclusions
The ES device may allow users’ asthma to be better controlled than by using a pMDI alone.
Key words: Pressured metered dose inhaler, children, Easy Squeezy, quality of life, lung function, asthma
In 2019, asthma affected 262 million people, caused 455,000 deaths, and was responsible for 21.6 million disability-adjusted life years.1,2 Higher loss in years owing to disability caused by asthma has been observed in children aged 1 year to 14 years and in low- and middle-income countries.1
Several management options are available to control asthma. Pressurized metered dose inhalers (pMDI) are the most commonly used treatment devices for asthma in children and adults.3 The high activation forces required to activate pMDIs make it difficult for children to use them independently.4 Most children need cooperation from parents or caregivers to activate metered dose inhalers.4 This means that many children are unable to use their pMDI away from their parents, for instance, in their school or while performing independent extracurricular activities.
Recently, a sleeve attachment device, the Easy Squeezy (ES) (see Fig E1 in the Online Repository at www.jaci-global.org), was developed to reduce the force of pMDI activation.5 This device is acceptable to pediatric pMDI users and their caregivers, who report that the device made it easier for children to activate the pMDI, that the children were more likely to take the pMDI with them to school, and that the built-in dose counter made it easier to keep count of the doses.6 There are no studies evaluating the clinical efficacy of any lever aid device7 such as the ES. This study aimed to assess whether use of a pMDI with the ES device affected the clinical efficacy of regular controller therapy (asthma control, lung function and quality of life) in children with moderate-to-severe asthma who were receiving inhaled corticosteroids.
Methods
A total of 65 participants with asthma who were aged 5 to 12 years and using either inhaled corticosteroids or inhaled corticosteroid–long-acting β2 agonist combination therapy via a metered dose inhaler at a stable dose for more than 3 months before enrollment were included in this 12-week crossover study. Participants were excluded if they had coronavirus 2019 disease COVID-19–related symptoms, were experiencing or had recently (<14 days) recovered from COVID-19, had household contact with someone who was experiencing COVID-19 or had recently recovered from COVID-19, had any physical or mental disease or injury that might reduce ability to activate a pMDI, or were unable to follow basic instructions in English. Participants were randomly assigned to the order in which they would commence the study, either continuing with use of a pMDI alone or commencing with use of a pMDI together with the ES. This study was performed with ethical approval from the University of Cape Town, South Africa (human research ethics committee reference no. 592/2021) in accordance with the Declaration of Helsinki and South African Good Clinical Practice guidelines. To calculate the sample size required to ensure no significant adverse effect of using the device, we expected that the difference in FEV1 value–to–forced vital capacity (FVC) ratio between participants using a pMDI alone and those using a pMDI along with the ES would be less than 10%. By assuming an SD of 15, an equivalence limit of 10, a P value of .05, and a power of 95%, we determined that 59 participants in total would be required.
On the day of inclusion, prebronchodilator and postbronchodilator lung function tests were performed to obtain the prebronchodilator FEV1 value, the prebronchodilator FEV1/FVC ratio, and the percentage difference between prebronchodilator and postbronchodilator FEV1 values. The participants who were randomized to group 1 continued to use the pMDI inhaler for the next 6 weeks, whereas the participants in group 2 used the ES to activate their pMDI for the next 6 weeks. After randomization, the investigator trained the participants in use of both a pMDI alone and a pMDI with the ES, witnessed the children's use of the devices independently, and recorded the method with which the device was actuated (1 finger or the whole hand). After 6 weeks (T1), the lung function tests were repeated, quality of life was assessed by using the Pediatric Asthma Quality of Life Questionnaire (PAQLQ),8,9 and asthma control was assessed by using the Childhood Asthma Control Test (C-ACT).10,11 Participants then crossed over to use the other device, and after another 6 weeks (T2), the same investigations were repeated (Fig 1). Apart from changes in treatment required for a severe exacerbation, no changes in asthma treatment were permitted between randomization and conclusion of the study.
Fig 1.
Schematic flowchart of participant recruitment, randomization, and crossover.
Analysis
Distribution of the data was checked by using the Shapiro-Wilk test. The data did not follow a normal distribution. Baseline lung function data were compared between group 1 and group 2 at randomization. PAQLQ score, C-ACT score, and lung function data were compared at the end of the study, when the participant had used each of the devices for 6 weeks. Use of the ES with a pMDI and use of a pMDI alone were compared with each other, regardless of time point (use of the ES with a pMDI at T1 + use of the ES with a pMDI at T2 vs use of a pMDI at T1 + a pMDI T2 [Fig 1]). In addition, the difference in lung function test parameters from the previous measurement was calculated, grouped according to whether the measurements were made after use of the pMDI ([group 1 T2 – T1] + [group 2T1 – T0]) or ES alone (group 1, T1 – T0 + group 2, T2 – T1), and compared between the groups (Fig 1). Mann-Whitney U tests were performed to find significant differences, with a P value less than .05 serving as the criterion for statistical significance. The proportion of subjects with the minimal important difference in total PAQLQ score8,9 was calculated and reported in terms of percentages.
Results
Ultimately, 55 participants completed the study (after 10 participants were randomized but did not attend their first follow-up visit). Of the participants lost to follow-up, 7 were assigned to group 1 (commenced with use of a pMDI alone) and 3 were assigned to group 2 (commenced with use of the ES device with a pMDI). The average age of our cohort was 7.2 ± 1.5 years. Their height, weight, and body mass index were 25.7 ± 9.3 kg, 1.2 ± 0.1 m, and 16.6 ± 2.9 kg/m2, respectively The majority of our participants (64%) were males and went to school (93%). All of the participants had had asthma for an average of 4.5 ± 2.0 years, had experience using a pMDI for 4.4 ± 2.0 years, and had been using their pMDI through a spacer.
Of those participants who completed the study, 24 were in group 1 and 31 were in group 2. The baseline characteristics of the 2 groups of those who completed the study (Fig 2) had no statistically significant differences in prebronchodilator FEV1 value (82.9 ± 16.4 vs 87.2 ± 15.8), percentage difference between prebronchodilator and postbronchodilator FEV1 value (13.6 ± 11.5 vs 11.0 ± 15.4), or prebronchodilator FEV1/FVC ratio (82.3 ± 7.6 vs 85.0 ± 9.4).
Fig 2.
Outcomes of the lung function tests for recruited participants on the day of randomization. Diff, Difference; Pre, prebronchodilator.
The outcomes of the lung function test, for the whole cohort, are reported in Table I. There were no significant differences between FEV1 value and FEV1/FVC ratio when participants used the ES together with a pMDI and when they used a pMDI alone. The difference in FEV1 values between the 2 groups was just 2.5%, indicating clinical equivalence. However, the bronchodilator reversibility (postbronchodilator – prebronchodilator FEV1 value) was significantly lower (P < .05) in the ES group than in the pMDI group (Fig 3). The differences in lung function parameters from previous measurement (Fig 4) with the ES together with a pMDI (FEV1 value, 9.1 ± 15.7; difference in FEV1 value, –6.5 ± 15.7; FEV1/FVC ratio 2.5 ± 7.5) were found to be significantly better than with the pMDI alone (FEV1 value, –3.5 ± 14.6; difference between FEV1 values, 3.4±13.8; FEV1/FVC ratio, –2.6 ± 7.4).
Table I.
Lung function test outcomes of all participants
| Indicator, median (IQR) | Baseline value | pMDI alone | ES with pMDI |
|---|---|---|---|
| Prebronchodilator FEV1 value | 85.0 (17.0) | 89.0 (18.0) | 96.0 (17.0) |
| FEV1 value difference (reversibility) | 9.0 (14.0) | 10.0 (14.0) | 4.0 (9.0)∗ |
| FEV1/FVC ratio | 84.4 (9.4) | 84.2 (11.1) | 85.4 (8.3) |
Statistically significant (P < .05) difference between values with a pMDI alone and the Easy Squeezy used with a pMDI.
Fig 3.
Lung function test results after 6 weeks of using the pMDI alone and ES device with a pMDI. Asterisk suggests statistical significance. Diff, Difference; Pre, prebronchodilator.
Fig 4.
Differences in lung function test parameters due to use of a pMDI and the ES together with a pMDI, as measured from their previous time point. Asterisk indicates statistical significance. Diff, Difference; Pre, prebronchodilator.
Our cohort members could not activate the pMDI by using their index finger and thumb. Most of the cohort members (40%) could activate the pMDI only when using their thumb and 2 fingers, and 25% of them could not activate the pMDI at all. In contrast, 98% of the cohort could activate the pMDI by squeezing the bunny ears of the ES with 1 hand (see Fig E2 in the Online Repository at www.jaci-global.org).
Median (interquartile range) PAQLQ scores (see Table E1 in the Online Repository at www.jaci-global.org) were not statistically significant between the ES group and the pMDI group (see Fig E3 in the Online Repository at www.jaci-global.org). PAQLQ scores increased by more than the minimal important difference in 15% of the ES group compared to 0% of the participants using pMDI alone.
The median C-ACT scores (Table II) were significantly higher after use of the ES with a pMDI than when a pMDI was used alone (Fig 5). In our cohort, 21 participants had a C-ACT score less than 20; of these 21 participants, 15 were in pMDI group and only 6 were in the ES group. In 31% of our cohort (17 of 55), the total C-ACT score was of at least 3 points higher (the minimally clinically significant value) with use of the ES with a pMDI than when a pMDI was used alone (see Fig E4 in the Online Repository at www.jaci-global.org), with this difference reversed in the case of only 1 participant. No participants experienced loss of control severe enough to warrant emergency treatment or a change in controller medication.
Table II.
C-ACT scores for our cohort
| C-ACT questions | Score for a pMDI used alone, median (SD) | Score for n ES used with a pMDI, median (SD) |
|---|---|---|
| Q1. How does your asthma make you feel today? | 3.0 (1.0) | 3.0 (1.0)∗ |
| Q2. How much does your asthma bother you when you run, exercise, or play sports? | 2.0 (1.0) | 2.0 (1.0)∗ |
| Q3. Do you cough because of your asthma? | 2.0 (0) | 2.0 (1.0) |
| Q4. Do you wake up during the night because of your asthma? | 3.0 (1.0) | 3.0 (1.0) |
| Q5. During the past 4 weeks, how many days did your child have any daytime asthma symptoms? | 4.0 (2.0) | 4.0 (1.0)∗ |
| Q6. During the past 4 weeks, how many days did your child wheeze during the day because of asthma? | 4.0 (2.0) | 5.0 (1.0) |
| Q7. During the past 4 weeks, how many days did your child wake up during the night because of asthma? | 4.0 (1.0) | 5.0 (1.0) |
| Total score | 22.0 (6.0) | 24.0 (5.0)∗ |
Statistically significant (P < .05).
Fig 5.
Total C-ACT score for our cohort members after they had used a pMDI alone and ES with a pMDI. Asterisk indicates statistical significance.
Discussion
Patients find it difficult to adhere to inhaled medications.12 Adherence rates to asthma medication range from 22% to 78%.13 Poor adherence has also been reported in children,14 with their adherence rates ranging from 28% to 67%.15
Poor adherence to inhaled asthma medication reduces patients’ quality of life and lung function.16 Reduced adherence can be intentional or nonintentional.17 Nonintentional lack of adherence may be caused by social barriers, including inability to access medication or inability to use the medication that has been acquired. Physical inability to operate a pMDI can also become a barrier for children18 and the elderly population.19 The activation force required to operate a pMDI could be a limiting factor in these 2 population groups.4,19 In various studies, the proportion of participants who could not use pMDIs varies from 12% to 89%, with an average incidence of misuse of 38%.20
Inability to use inhalers causes lack of control.20,21 The role of difficulty in use of a pMDI as a cause of nonadherence has not been well studied,22, 23, 24 but it has been reported as being among the secondary reasons for nonadherence.25 Lack of adherence in children has been reported as a cause of poor control and death.26 Children using an inhaler on their own, without help from an adult, is correlated with better technique.27 This may imply that fostering patient autonomy is an important aspect of asthma care.
In this study we compared the clinical performance of a novel sleeve attachment device, the ES, with the pMDI over a 6-week period. When compared with use of a pMDI alone, use of the ES together with a pMDI enabled pediatric patients to activate their pMDIs with ease. Use of the ES decreased reversibility, indicating improvements in bronchial hyperreactivity. Use of the ES was associated with improvements in prebronchodilator FEV1 value and FEV1/FVC ratio compared with the prior lung function measurement. This may have contributed toward the improved asthma control in participants after they used the ES. Although total PAQLQ scores between the ES and pMDI groups were not significantly different, more patients in the ES group than in the group using a pMDI alone had improvement in their PAQLQ score exceeding the minimally important difference.
Our study had a few limitations. First, our cohort was younger than the cohorts in most of the studies in the literature. This meant that we could neither compare our results with those in the literature efficiently nor extrapolate our findings to all ages. Studies have shown that advancing age also causes inability to use pMDIs, with the factor best correlated with advanced age being late actuation or inability to activate the device,28 indicating that muscle strength or hand mobility may also play a role in use of a pMDI by elderly patients.19 Second, all of our participants were familiar with pMDI use. If anything, this would mean that they are able to use the device better than patients unfamiliar with a pMDI, as studies have shown that a new device is associated with less ability to use it.29 We observed that the participants found using a ES with a pMDI to be easier than using a pMDI alone. This might mean that our cohort’s previous knowledge of pMDI use did not impair their ability to use the ES. Third, our participants had relatively better PAQLQ scores than those reported in the literature,30 probably because PAQLQ score has been measured predominantly in patients with poor asthma control rather than in a group such as ours, which had stable, well-controlled asthma. This, along with a sample size powered to ascertain differences in lung function testing, may have influenced our ability to show differences in changes in quality of life between groups. We addressed this concern by additionally looking at the proportion of patients with an increased PAQLQ score of more than the minimally important difference of 0.5 in the 2 groups. A larger sample size of approximately 2000 participants would be required to demonstrate differences in quality of life by using median PAQLQ scores. Lastly, we were unable to blind our participants, as they had to actively use the inhaler device.
One of the strengths of our study was that our participants were used as their own control. This reduced interparticipant bias. We had the same clinician throughout the study and single (blinded) impartial lung function measurement. This meant that there was no clinician variability and that the medications prescribed were the same for both arms of the study. We analyzed our data at every time point of data collection, as well as the difference from the previous time point. The baseline lung function test results were the same in group 1 and group 2. This provided us with multiple measures of the actual effect that each device had on the lung function of each of the participants.
Conclusion
The ability to use an inhaler and ability to use it with the best possible technique are important components of asthma management. These data suggest that young children, and possibly other individuals with limited hand strength or mobility, could benefit from using an assistive device such as the ES, which can also facilitate improved lung function test results and asthma control. The ES aids in achieving better asthma control and improved lung functioning.
Disclosure statement
Disclosure of potential conflict of interest: R. Dey consults for Impulse Biomedical Pty Ltd. M. Levin consults for Impulse Biomedical Pty Ltd. K. B. Mapondela declares no relevant conflict of interest.
Clinical implications.
Using a pMDI with the novel sleeve attachment device Easy Squeezy aids in significant improvement in asthma control and lung function, compared to the use of pMDI alone, in children between the age of 5 to 12 years.
Supplementary data
References
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