Faculty Bibliography

BACKGROUND:The efficacy of drug delivery from inhalers is very much dependent on the user's peak inspiratory flow rate (PIFR). Current methods to measure PIFR in inhalers are based on subjective checklists. There is a lack of methods currently available to objectively remotely monitor PIFR in pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). In this study, for the first time, non-contact acoustic methods were employed to estimate PIFR through three commonly used inhalers (Diskus™ DPI, Turbuhaler™ DPI, and Evohaler™ pMDI) with the aim of applying these methods to remotely monitor inhaler inhalation technique in future clinical applications. METHODS:Each inhaler was placed inside an airtight container connected to a spirometer to measure PIFR. A high quality microphone was placed 5 cm from the mouthpiece of the inhalers to record inhalation sounds. Over 2000 inhaler inhalation sounds were recorded from 11 healthy participants. A range of temporal and spectral acoustic features from the inhalation sounds were correlated with PIFR. The variation of acoustic features and the repeatability of the inhalation acoustic spectral profile were investigated to further characterize inhaler inhalation sounds and to determine the reliability of acoustics to estimate PIFR. RESULTS: = 0.75 (Evohaler™)]. Acoustic features generated low variation and the spectral profile of inhalation sounds was repeatable regardless of flow rate, suggesting that acoustic methods are a reliable method of estimating PIFR. CONCLUSIONS:The methods presented in this study may be employed in a wearable monitoring device in future applications to measure inhaler PIFR. Objective monitoring of PIFR in inhalers may help patients improve their inhaler inhalation technique and therefore may be of significant clinical benefit to both patients and clinicians.

Asthma is a chronic respiratory disease affecting millions of people worldwide, and is consequently a major issue for global health. Exacerbations are acute events involving the worsening of asthma's primary respiratory symptoms and are a major cause of morbidity in asthma patients, largely due to the unpredictability of their onset. This study aimed to investigate the relationship between changes in acoustic features of inhaler inhalations and changes in forced expiratory volume in one second (FEV1) that occur during a simulated exacerbation, a bronchial challenge test (BCT). This is a clinical test that simulates an asthma exacerbation through the administration of a bronchoconstrictor agent. Eight patients indicated for a BCT were recruited for this study. Non-contact and tracheal microphones were employed to record Diskusâ„¢ inhaler inhalations throughout the course of a BCT. A spirometer was employed to measure inhaler peak inspiratory flow rate (PIFR). In patients responsive to the BCT (n=4), significant correlations between changes in FEV1 and acoustic features on both microphones existed, with fractal increment of Katz fractal dimension yielding the strongest correlation (R=0.58), and between FEV1 and PIFR (R=0.62). These findings suggest that inhaler inhalation acoustic features may assist in the early detection of exacerbations. Future research will determine whether this is the case in a larger cohort of patients with non-simulated exacerbations.

BACKGROUND:Cross-sectional observational studies suggest that between 50% and 60% of patients misuse a dry powder inhaler, whereas studies with electronic monitors indicate that patients sometimes overuse/underuse their inhalers. It is not known what impact errors and erratic use have on inhaler adherence. OBJECTIVES:The purpose of this study was to longitudinally quantify when and how patients adhered to a twice-daily preventer treatment by using a novel acoustic recording device attached to an inhaler (INhaler Compliance Assessment). METHODS:Patients with a history of asthma or chronic obstructive pulmonary disease (n = 123) from primary care and community pharmacies were given an INhaler Compliance Assessment-adapted inhaler for 1 month. Analysis of the audio files provided quantitative information on time and technique of inhaler use. RESULTS:Data were available for 103 patients. Twenty-one patients (20%) used their inhaler in the correct manner at the correct interval. There were 5045 audio files with attempted inhalations, of which 1204 had technique errors (24%). Errors included inadequate flow (27%), drug priming without inhalation (19%), exhalation into the inhaler (18%), and multiple inhalations (25%). On average, participants made errors 20% of the time. Of 60 doses expected to be taken in a month per person, on average 49 doses (82%) were attempted and when errors were accounted for, the average number of actual doses taken was 34 doses (57%; P < .01) comparing attempted to actual doses. DISCUSSION:These data highlight that ineffective and irregular inhaler use is common and when combined in a single calculation indicate that only 20% of participants used their inhaler correctly and on time.

BACKGROUND:Mortality rates within the Irish farming community are increasing, whilst that of the general population falls. The aim of this cross-sectional study was to determine the prevalence of respiratory disease amongst Irish farmers. METHODS:All study participants were farming volunteers attending an agricultural exhibition. Data collected by questionnaire included baseline demographics, respiratory history, presence of respiratory symptoms and occupational exposures. Spirometry was performed on all participants. RESULTS:Data from 372 farmers was analysed. The majority were male (76%) with median age of 55 years. 61% were never smokers. 13% were previously diagnosed with airway disease (Chronic Obstructive Pulmonary Disease(COPD)/Asthma/Inhaler use) with 14% reporting hayfever/allergies. Almost two-thirds reported one or more chronic respiratory symptom. Forty-four (12%) had obstructive spirometry using fixed FEV1/FVC < 0.70 criterion and 29 (7.8%) using FEV1/FVC < 5% lower limit of normal. The majority, two-thirds, were never smokers. Amongst never smokers with obstruction (13%), there was a significantly higher proportion with a prior diagnosis of airway disease and hayfever/allergies. There was no significant association between specific occupational exposures and obstruction. CONCLUSION:The majority of Irish farmers are never smokers. They have a high prevalence of respiratory symptoms. 13% of never smokers have airflow obstruction (FEV1/FVC < 0.70). The presence of airflow obstruction is significantly associated with self-reported allergy history and prior airway disease. Further studies are needed to identify the workplace factors accounting for these findings.

BACKGROUND:Poor adherence to inhaled medication may lead to inadequate symptom control in patients with respiratory disease. In practice it can be difficult to identify poor adherence. We designed an acoustic recording device, the INCA® (INhaler Compliance Assessment) device, which, when attached to an inhaler, identifies and records the time and technique of inhaler use, thereby providing objective longitudinal data on an individual's adherence to inhaled medication. This study will test the hypothesis that providing objective, personalised, visual feedback on adherence to patients in combination with a tailored educational intervention in a community pharmacy setting, improves adherence more effectively than education alone. METHODS/DESIGN/METHODS:The study is a prospective, cluster randomised, parallel-group, multi-site study conducted over 6 months. The study is designed to compare current best practice in care (i.e. routine inhaler technique training) with the use of the INCA® device for respiratory patients in a community pharmacy setting. Pharmacies are the unit of randomisation and on enrolment to the study they will be allocated by the lead researcher to one of the three study groups (intervention, comparator or control groups) using a computer-generated list of random numbers. Given the nature of the intervention neither pharmacists nor participants can be blinded. The intervention group will receive feedback from the acoustic recording device on inhaler technique and adherence three times over a 6-month period along with inhaler technique training at each of these times. The comparator group will also receive training in inhaler use three times over the 6-month study period but no feedback on their habitual performance. The control group will receive usual care (i.e. the safe supply of medicines and advice on their use). The primary outcome is the rate of participant adherence to their inhaled medication, defined as the proportion of correctly taken doses of medication at the correct time relative to the prescribed interval. Secondary outcomes include exacerbation rates and quality of life measures. Differences in the timing and technique of inhaler use as altered by the interventions will also be assessed. Data will be analysed on an intention-to-treat and a per-protocol basis. Sample size has been calculated with reference to comparisons to be made between the intervention and comparator clusters and indicates 75 participants per cluster. With an estimated 10 % loss to follow-up we will be able to show a 20 % difference between the population means of the intervention and comparator groups with a power of 0.8. The Type I error probability associated with the test of the null hypothesis is 0.05. DISCUSSION/CONCLUSIONS:This clinical trial will establish whether providing personalised feedback to individuals on their inhaler use improves adherence. It may also be possible to enhance the role of pharmacists in clinical care by identifying patients in whom alteration of either therapy or inhaler device is appropriate. REGISTRATION/BACKGROUND:ClinicalTrials.gov NCT02203266 .

This Letter investigated the efficacy of a decision-support system, designed for respiratory medicine, at predicting asthma exacerbations in a multi-site longitudinal randomised control trial. Adherence to inhaler medication was acquired over 3 months from patients with asthma employing a dose counter and a remote monitoring adherence device which recorded participant's inhaler use: n = 184 (23,656 audio files), 61% women, age (mean ± sd) 49.3 ± 16.4. Data on occurrence of exacerbations was collected at three clinical visits, 1 month apart. The relative risk of an asthma exacerbation for those with good and poor adherence was examined employing a univariate and multivariate modified Poisson regression approach; adjusting for age, gender and body mass index. For all months dose counter adherence was significantly (p < 0.01) higher than remote monitoring adherence. Overall, those with poor adherence had a 1.38 ± 0.34 and 1.42 ± 0.39 (remotely monitored) and 1.25 ± 0.32 and 1.18 ± 0.31 (dose counter) higher relative risk of an exacerbation in model 1 and model 2, respectively. However, this was not found to be statistically significantly different. Remotely monitored adherence holds important clinical information and future research should focus on refining adherence and exacerbation measures. Decision-support systems based on remote monitoring may enhance patient-physician communication, possibly reducing preventable adverse events.

INTRODUCTION/BACKGROUND:In clinical practice, it is difficult to distinguish between patients with refractory asthma from those with poorly controlled asthma, where symptoms persist due to poor adherence, inadequate inhaler technique or comorbid diseases. We designed an audio recording device which, when attached to an inhaler, objectively identifies the time and technique of inhaler use, thereby assessing both aspects of adherence. This study will test the hypothesis that feedback on these two aspects of adherence when passed on to patients improves adherence and helps clinicians distinguish refractory from difficult-to-control asthma. METHODS:This is a single, blind, prospective, randomised, clinical trial performed at 5 research centres. Patients with partially controlled or uncontrolled severe asthma who have also had at least one severe asthma exacerbation in the prior year are eligible to participate. The effect of two types of nurse-delivered education interventions to promote adherence and inhaler technique will be assessed. The active group will receive feedback on their inhaler technique and adherence from the new device over a 3-month period. The control group will also receive training in inhaler technique and strategies to promote adherence, but no feedback from the device. The primary outcome is the difference in actual adherence, a measure that incorporates time and technique of inhaler use between groups at the end of the third month. Secondary outcomes include the number of patients who remain refractory despite good adherence, and differences in the components of adherence after the intervention. Data will be analysed on an intention-to-treat and a per-protocol basis. The sample size is 220 subjects (110 in each group), and loss to follow-up is estimated at 10% which will allow results to show a 10% difference (0.8 power) in adherence between group means with a type I error probability of 0.05. TRIAL REGISTRATION NUMBER/BACKGROUND:NCT01529697; Pre-results.

Inhalers are hand-held devices used to treat chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). Medication is delivered from an inhaler to the user through an inhalation maneuver. It is unclear whether gender and anthropometric features such as age, height, weight and body mass index (BMI) influence the acoustic properties of inspiratory inhaler sounds and peak inspiratory flow rate (PIFR) in inhalers. In this study, healthy male (n=9) and female (n=7) participants were asked to inhale at an inspiratory flow rate (IFR) of 60 L/min in four commonly used inhalers (Turbuhaler(â„¢), Diskus(â„¢), Ellipta(â„¢) and Evohaler(â„¢)). Ambient inspiratory sounds were recorded from the mouthpiece of each inhaler and over the trachea of each participant. Each participant's PIFR was also recorded for each of the four inhalers. Results showed that gender and anthropometric features have the potential to influence the spectral properties of ambient and tracheal inspiratory inhaler sounds. It was also observed that males achieved statistically significantly higher PIFRs in each inhaler in comparison to females (p<;0.05). Acoustic features were found to be significantly different across inhalers suggesting that acoustic features are modulated by the inhaler design and its internal resistance to airflow.

PURPOSE/OBJECTIVE:Some patients are unable to generate the peak inspiratory flow rate (PIFR) necessary to de-agglomerate drug particles from dry powder inhalers (DPIs). In this study we tested the hypothesis that the acoustic parameters of an inhalation are related to the PIFR and hence reflect drug delivery. METHODS:A sensitivity analysis of the relationship of the acoustics of inhalation to simultaneously recorded airflow, in a cohort of volunteers (n = 92) was performed. The Next Generation Impactor (NGI) was used to assess in vitro drug delivery from salmeterol/fluticasone and salbutamol Diskus™ DPIs. Fine particle fraction, FPF, (<5 μm) was measured at 30-90 l/min for 2-6 s and correlated with acoustically determined flow rate (IFRc). In pharmacokinetic studies using a salbutamol (200 μg) Diskus™, volunteers inhaled either at maximal or minimal effort on separate days. RESULTS:PIFRc was correlated with spirometrically determined values (R (2) = 0.88). In in vitro studies, FPF increased as both flow rate and inhalation duration increased for the salmeterol/fluticasone Diskus™ (Adjusted R (2) = 0.95) and was proportional to flow rate only for the salbutamol Diskus™ (Adjusted R (2) = 0.71). In pharmacokinetic studies, blood salbutamol levels measured at 20 min were significantly lower when PIFRc was less than 60 l/min, p < 0.0001. CONCLUSION/CONCLUSIONS:Acoustically-determined PIFR is a suitable method for estimating drug delivery and for monitoring inhalation technique over time.