Feasibility and acceptability of using bronchial hyperresponsiveness to manage asthma in primary care: a pilot study

Bronchial Provocation Testing for the Identification of Exercise-Induced Bronchoconstriction

Exercise-induced bronchoconstriction (EIB) occurs in patients with asthma, children, and otherwise healthy athletes. Poor diagnostic accuracy of respiratory symptoms during exercise requires objective assessment of EIB. The standardized tests currently available are based on the assumption that the provoking stimulus to EIB is dehydration of the airway surface fluid due to conditioning large volumes of inhaled air. "Indirect" bronchial provocation tests that use stimuli to cause endogenous release of bronchoconstricting mediators from airway inflammatory cells include dry air hyperpnea (eg, exercise and eucapnic voluntary hyperpnea) and osmotic aerosols (eg, inhaled mannitol). The airway response to different indirect tests is generally similar in patients with asthma and healthy athletes with EIB. Furthermore, the airway sensitivity to these tests is modified by the same pharmacotherapy used to treat asthma. In contrast, pharmacological agents such as methacholine, given by inhalation, act directly on smooth muscle to cause contraction. These "direct" tests have been used traditionally to identify airway hyperresponsiveness in clinical asthma but are less useful to diagnose EIB. The mechanistic differences between indirect and direct tests have helped to elucidate the events leading to airway narrowing in patients with asthma and elite athletes, while improving the clinical utility of these tests to diagnose and manage EIB.

The use of a direct bronchial challenge test in primary care to diagnose asthma

Many asthmatics in primary care have mild symptoms and lack airflow obstruction. If variable expiratory airflow limitation cannot be determined by spirometry or peak expiratory flow, despite a history of respiratory symptoms, a positive bronchial challenge test (BCT) can confirm the diagnosis of asthma. However, BCT is traditionally performed in secondary care. In this observational real-life study, we retrospectively analyze 5-year data of a primary care diagnostic center carrying out BCT by histamine provocation. In total, 998 primary care patients aged ≥16 years underwent BCT, without any adverse events reported. To explore diagnostic accuracy, we examine 584 patients with a high pretest probability of asthma. Fifty-seven percent of these patients have a positive BCT result and can be accurately diagnosed with asthma. Our real-life data show BCT is safe and feasible in a suitably equipped primary care diagnostic center. Furthermore, it could potentially reduce diagnostic referrals to secondary care.

The Digital Asthma Patient: The History and Future of Inhaler Based Health Monitoring Devices

The wave of digital health is continuously growing and promises to transform healthcare and optimize the patients' experience. Asthma is in the center of these digital developments, as it is a chronic disease that requires the continuous attention of both health care professionals and patients themselves. The accurate and timely assessment of the state of asthma is the fundamental basis of digital health approaches and is also the most significant factor toward the preventive and efficient management of the disease. Furthermore, the necessity of inhaled medication offers a basic platform upon which modern technologies can be integrated, namely the inhaler device itself. Inhaler-based monitoring devices were introduced in the beginning of the 1980s and have been evolving but mainly for the assessment of medication adherence. As technology progresses and novel sensing components are becoming available, the enhancement of inhalers with a wider range of monitoring capabilities holds the promise to further support and optimize asthma self-management. The current article aims to take a step for the mapping of this territory and start the discussion among healthcare professionals and engineers for the identification and the development of technologies that can offer personalized asthma self-management with clinical significance. In this direction, a technical review of inhaler based monitoring devices is presented, together with an overview of their use in clinical research. The aggregated results are then summarized and discussed for the identification of key drivers that can lead the future of inhalers.

The effect of omega-3 fatty acids on bronchial hyperresponsiveness, sputum eosinophilia, and mast cell mediators in asthma

BACKGROUND

Omega-3 fatty acid supplements have been reported to inhibit exercise-induced bronchoconstriction (EIB). It has not been determined whether omega-3 supplements inhibit airway sensitivity to inhaled mannitol, a test for bronchial hyperresponsiveness (BHR) and model for EIB in people with mild to moderate asthma.

METHODS

In a double-blind, crossover trial, subjects with asthma who had BHR to inhaled mannitol (n = 23; 14 men; mean age, 28 years; one-half taking regular inhaled corticosteroids) were randomized to omega-3 supplements (4.0 g/d eicosapentaenoic acid and 2.0 g/d docosahexaenoic acid) or matching placebo for 3 weeks separated by a 3-week washout. The primary outcome was the provoking dose of mannitol (mg) to cause a 15% fall in FEV1 (PD15). Secondary outcomes were sputum eosinophil count, spirometry, Asthma Control Questionnaire (ACQ) score, serum triacylglyceride level, and lipid mediator profile in urine and serum.

RESULTS

PD15 (geometric mean, 95% CI) to mannitol following supplementation with omega-3s (78 mg, 51-119 mg) was not different from placebo (88 mg, 56-139 mg, P = .5). There were no changes in sputum eosinophils (mean ± SD) in a subgroup of 11 subjects (omega-3, 8.4% ± 8.2%; placebo, 7.8% ± 11.8%; P = .9). At the end of each treatment period, there were no differences in FEV1 % predicted (omega-3, 85% ± 13%; placebo, 84% ± 11%; P = .9) or ACQ score (omega-3, 1.1% ± 0.5%; placebo, 1.1% ± 0.5%; P = .9) (n = 23). Omega-3s caused significant lowering of blood triglyceride levels and expected shifts in serum fatty acids and eicosanoid metabolites, confirming adherence to the supplements; however, no changes were observed in urinary mast cell mediators.

CONCLUSIONS

Three weeks of omega-3 supplements does not improve BHR to mannitol, decrease sputum eosinophil counts, or inhibit urinary excretion of mast cell mediators in people with mild to moderate asthma, indicating that dietary omega-3 supplementation is not useful in the short-term treatment of asthma.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00526357; URL: www.clinicaltrials.gov.

Using electronic monitoring devices to measure inhaler adherence: a practical guide for clinicians

Use of electronic monitoring devices (EMDs) for inhalers is growing rapidly because of their ability to provide objective and detailed adherence data to support clinical decision making. There is increasing potential for the use of EMDs in clinical settings, especially as cost-effectiveness is realized and device costs reduce. However, it is important for clinicians to know about the attributes of different EMDs so that they can select the right device for their patients and understand the factors that affect the reliability and accuracy of the data EMDs record. This article gives information on where to obtain EMDs, describes device specifications, and highlights useful features for the clinician and the patient, including user feedback data. We discuss the benefits and potential drawbacks of data collected by EMDs and provide device users with a set of tools to optimize the use of EMDs in clinical settings, such as advice on how to carry out brief EMD checks to ensure data quality and device reliability. New EMDs on the market require pretesting before use by patients. We provide information on how to carry out EMD pretesting in the clinic and patients' homes, which can be carried out by health professionals or in collaboration with researchers or manufacturers. Strategies for interpreting and managing common device malfunctions are also discussed.

Combining the Mannitol Test and FeNO in the Assessment of Poorly Controlled Asthma

BACKGROUND

International guidelines recommend up-titration of anti-inflammatory treatment in asthmatic patients with poor symptom control, but patients without eosinophilic airway inflammation are less likely to benefit from this. The mannitol bronchoprovocation test and fractional exhaled nitric oxide (FeNO) are increasingly used in the diagnostic assessment of asthma, but the utility of combining these tests has not been evaluated.

AIM

The aim of this study was to determine the value of combining FeNO and the mannitol test to assess patients with asthma referred for specialist assessment because of poor symptom control.

METHODS

All patients referred consecutively over a 12-month period for the assessment of asthma at the Respiratory Outpatient Clinic at Bispebjerg Hospital in Copenhagen were examined with bronchial provocation to mannitol, FeNO, and induced sputum.

RESULTS

Among asthmatic patients with partly controlled or uncontrolled symptoms according to Global Initiative for Asthma criteria, only 23% had sputum eosinophilia (eosinophils >2.99%). A positive mannitol test did not increase the likelihood of airway eosinophilia significantly (positive test: 32% vs negative test: 18%, P = .12). However, a positive mannitol test combined with a FeNO > 25 ppb indicated a high likelihood of airway eosinophilia (73%), compared with FeNO > 25 ppb and a negative mannitol test (29%) (P < .05). In contrast, in patients with FeNO < 25 ppb, a positive mannitol test was not associated with airway eosinophilia (sputum eosinophils > 2.99%: positive mannitol test: 0%, negative test: 11%, ns).

CONCLUSION

Combining the mannitol test and FeNO may aid in the differentiation between eosinophilic and noneosinophilic asthma in patients referred for specialist management because of poorly controlled asthma symptoms.

Recommendations for the allergy management in the primary care

The majority of patients seeking medical advice for allergic diseases are first seen in a primary care setting. Correct diagnosis with identification of all offending allergens is an absolute prerequisite for appropriate management of allergic disease by the general practitioner. Allergy diagnostic tests recommended for use in primary care are critically reviewed in accordance with the significant workload in a primary care setting. Simplified pathways for recognition and diagnosis of allergic diseases are proposed, that should be further adapted to local (national) conditions.

Practical approach to exercise-induced bronchoconstriction in athletes

Exercise-induced bronchoconstriction (EIB) is highly prevalent in athletes of all abilities and can impact on their health and performance. The majority of athletes with exertional dyspnoea will be initially assessed and managed in primary care. This report provides a practical and pragmatic approach to the assessment and management of a young athlete presenting with suspected EIB in this setting.

Adherence monitoring and e-health: how clinicians and researchers can use technology to promote inhaler adherence for asthma

In the past decade, rapid technological developments have advanced electronic monitoring devices (EMD) for asthma inhalers beyond simple recording of actuations to providing adherence promotion features and detailed information about patterns of medication use. This article describes currently available EMDs, discusses their utility and limitations in assessing adherence, and describes the potential for EMD-based adherence promotion interventions in clinical settings. To date, the main use of EMDs has been in clinical research. In selected populations, simple EMD-based adherence interventions, delivered either through clinician-to-patient feedback about medication use or by direct-to-patient reminders for missed doses, can significantly improve adherence. Further work is now needed to determine the impact of EMDs on clinical outcomes and their cost-effectiveness and feasibility for different clinical settings, including in disadvantaged populations. If this evidence can be provided, then the use of EMDs could expand into the management of asthma in populations with high health care costs, eg, severe asthma. In the future, medication monitoring could help distinguish poor treatment response from poor adherence, guide prescribing decisions, and prompt providers to discuss barriers to adherence; electronic health records may provide the gateway for integrating medication-use monitoring into digital chronic care management.

Medication adherence in asthma patients

PURPOSE OF REVIEW

Although current asthma guidelines stress the importance of assessing and enhancing adherence to asthma treatment, medication adherence rates in asthma patients are consistently low in practice. In this review, we summarize current literature on method of measurement, prevalence, outcome and intervention of medication adherence in asthma patients.

RECENT FINDINGS

Nonadherence to prescribed treatment continues to be a frequent problem in patients with asthma even in recent years. Objective measurement of adherence should be implemented whenever possible. Review of pharmacy refill data or electronic monitoring of inhaler actuation may be a preferred method to assess adherence. Educational programmes should be specifically designed to address the unmet need and specific reasons for nonadherence for the target population. Large, well designed clinical trials to assess the efficacy of remote electronic monitoring and reminder systems to improve adherence are needed.

SUMMARY

There is an urgent clinical need for systematic, proven methods to assess and address medication nonadherence in asthma patients.

Airway hyperresponsiveness in asthma: mechanisms, clinical significance, and treatment

Airway hyperresponsiveness (AHR) and airway inflammation are key pathophysiological features of asthma. Bronchial provocation tests (BPTs) are objective tests for AHR that are clinically useful to aid in the diagnosis of asthma in both adults and children. BPTs can be either “direct” or “indirect,” referring to the mechanism by which a stimulus mediates bronchoconstriction. Direct BPTs refer to the administration of pharmacological agonist (e.g., methacholine or histamine) that act on specific receptors on the airway smooth muscle. Airway inflammation and/or airway remodeling may be key determinants of the response to direct stimuli. Indirect BPTs are those in which the stimulus causes the release of mediators of bronchoconstriction from inflammatory cells (e.g., exercise, allergen, mannitol). Airway sensitivity to indirect stimuli is dependent upon the presence of inflammation (e.g., mast cells, eosinophils), which responds to treatment with inhaled corticosteroids (ICS). Thus, there is a stronger relationship between indices of steroid-sensitive inflammation (e.g., sputum eosinophils, fraction of exhaled nitric oxide) and airway sensitivity to indirect compared to direct stimuli. Regular treatment with ICS does not result in the complete inhibition of responsiveness to direct stimuli. AHR to indirect stimuli identifies individuals that are highly likely to have a clinical improvement with ICS therapy in association with an inhibition of airway sensitivity following weeks to months of treatment with ICS. To comprehend the clinical utility of direct or indirect stimuli in either diagnosis of asthma or monitoring of therapeutic intervention requires an understanding of the underlying pathophysiology of AHR and mechanisms of action of both stimuli.

Use of metered-dose inhaler electronic monitoring in a real-world asthma randomized controlled trial

BACKGROUND

Electronic monitoring of inhaled asthma medications is one method to measure medication adherence and patterns of use. Information on the performance of monitors in a randomized controlled trial allows researchers and clinicians to understand their utility and limitations. The Smartinhaler Tracker is an electronic monitor for metered-dose inhalers (MDIs) that records the date, time, and number of actuations.

OBJECTIVE

To determine the performance of the Smartinhaler monitors used in a 24-week randomized controlled trial of 303 patients with asthma in a real-world setting.

METHODS

Prestudy use checks involved 2 actuations of the MDI, with a further 2 performed 2 hours later. Within-study monitor checks, performed before dispensing at clinic visits 2 to 4, included a computerized check of monitor clock function, actuation accuracy, and battery life. Within-study data checks involved computerized checks of monitor clock function before data upload.

RESULTS

Two thousand six hundred seventy-eight of 2728 monitors (98.2%) passed prestudy use checks. Seventy-six of 2642 monitors (2.9%) dispensed to participants failed within-study monitor checks. Fifty-one of 2642 monitors (1.9%) malfunctioned before data upload, mostly as a result of fluid immersion. Ninety-three of 2642 monitors (3.5%) were lost or thrown away by participants. Complete data was available from 2498 of 2642 dispensed monitors (94.5%) and 2498 of 2549 returned monitors (98.0%).

CONCLUSIONS

The Smartinhaler Tracker is a reliable monitor for measuring MDI use in a real-world setting. Use of extensive monitor and data-checking protocols reduces data loss. In a research or clinical setting, the use of a validated and reliable electronic monitor represents the reference standard for assessing patterns of medication use.

The reliability and patient acceptability of the SmartTrack device: a new electronic monitor and reminder device for metered dose inhalers

OBJECTIVE

The SmartTrack (ST) is a new adherence monitoring device for pressurized metered-dose inhalers (pMDI), with remote upload and ringtone reminder capabilities. Our aim was to assess its reliability and patient acceptability.

METHODS

Baseline Quality Control (QC): Actuation log accuracy and device functionality tests were undertaken. Simulated Patient Use: Salmeterol/fluticasone inhalers with STs were actuated two times twice daily for 48 h. Accuracy of reminders, data logging, and uploads was tested. Patient Field Testing: Devices were quality tested before dispensing. Asthma patients each field-tested one ST for 7 days and recorded actuations in a diary. Uploaded data were compared to pMDI dose counter and patient diaries. Patient-reported ease of use for the ST was recorded.

RESULTS

Baseline QC: 9/10 devices had 100% accuracy; one had an electrical circuit failure. Simulated Patient Use: Accuracy was 99% (2/342 actuations duplicated). Patient Field Testing: One device failed pre-dispensing testing (electrical circuit failure). Eight devices were field-tested by asthma patients (mean age 45, 5 females). Mean actuation log accuracy was 97%. Reminders were 100% accurate. All devices successfully uploaded data. Average patient-rated difficulty of use was 6/100 (1 = extremely easy, 100 = extremely difficult).

CONCLUSIONS

The ST has acceptable reliability and utility comparable to other electronic monitoring devices. Its remote data upload capability, reminder functions for missed doses, and graphical display of medication use for patient- and physician-feedback are useful additional features.