Development and evaluation of a tool to optimise inhaler selection prior to hospital discharge following an exacerbation of COPD.

Introduction: Rates of mortality and re-admission after a hospitalised exacerbation of COPD are high and resistant to change. COPD guidelines do not give practical advice about the optimal selection of inhaled drugs and device in this situation. We hypothesised that a failure to optimise inhaled drug and drug delivery prior to discharge from hospital after an exacerbation would be associated with a modifiable increased risk of re-admission and death. We designed a study to 1) develop a practical inhaler selection tool to use at the point of hospital discharge and 2) implement this tool to understand the potential impact on modifying inhaler prescriptions, clinical outcomes, acceptability to clinicians and patients, and the feasibility of delivering a definitive trial to demonstrate potential benefit. Methods: We iteratively developed an inhaler selection tool for use prior to discharge following a hospitalised exacerbation of COPD using surveys with multiprofessional clinicians and a focus group of people living with COPD. We surveyed clinicians to understand their views on the minimum clinically important difference (MCID) for death and re-admission following a hospitalised exacerbation of COPD. We conducted a mixed-methods implementation feasibility study using the tool at discharge, and collated 30- and 90-day follow-up data including death and re-admissions. Additionally, we observed the tool being used and interviewed clinicians and patients about use of the tool in this setting. Results: We completed the design of an inhaler selection tool through two rounds of consultations with 94 multiprofessional clinicians, and a focus group of four expert patients. Regarding MCIDs, there was majority consensus for the following reductions from baseline being the MCID: 30-day readmissions 5-10%, 90-day readmissions 10-20%, 30-day mortality 5-10% and 90-day mortality 5-10%. 118 patients were assessed for eligibility and 26 had the tool applied. A change in inhaled medication was recommended in nine (35%) out of 26. Re-admission or death at 30 days was seen in 33% of the switch group and 35% of the no-switch group. Re-admission or death at 90 days was seen in 56% of the switch group and 41% of the no-switch group. Satisfaction with inhalers was generally high, and switching was associated with a small increase in the Feeling of Satisfaction with Inhaler questionnaire of 3 out of 50 points. Delivery of a definitive study would be challenging. Conclusion: We completed a mixed-methods study to design and implement a tool to aid optimisation of inhaled pharmacotherapy prior to discharge following a hospitalised exacerbation of COPD. This was not associated with fewer re-admissions, but was well received and one-third of people were eligible for a change in inhalers.

Improving asthma outcomes: Clinicians' perspectives on peripheral airways.

Disease of the peripheral (or small) airways is fundamental in asthma, being closely related to symptoms (or lack of control of them), airway hyperresponsiveness, spirometric abnormalities, risk of loss of control, or exacerbations and inflammation. Current technology now allows routine measurement of peripheral airway function. Having a working concept of peripheral airways disease in asthma is arguably very useful to clinicians and beneficial to patients because it allows a more comprehensive assessment of asthma severity (rather than just symptoms alone, which is the norm), tracking of progress or deterioration, and assessing response to treatment. Oscillometry is a sensitive way to monitor the peripheral airways, whereas multiple breath nitrogen washout parameters are excellent measures of future risk. In the longer term, physiologic measurements will be crucial in research to define causes and find new disease-modifying treatments.

Demystifying Dry Powder Inhaler Resistance with Relevance to Optimal Patient Care.

The selection of an inhaler device is a key component of respiratory disease management. However, there is a lack of clarity surrounding inhaler resistance and how it impacts inhaler selection. The most common inhaler types are dry powder inhalers (DPIs) that have internal resistance and pressurised metered dose inhalers (pMDIs) that use propellants to deliver the drug dose to the airways. Inhaler resistance varies across the DPIs available on the market, depending largely on the design geometry of the device but also partially on formulation parameters. Factors influencing inhaler choice include measures such as flow rate or pressure drop as well as inhaler technique and patient preference, both of which can lead to improved adherence and outcomes. For optimal disease outcomes, device selection should be individualised, inhaler technique optimised and patient preference considered. By addressing the common clinically relevant questions, this paper aims to demystify how DPI resistance should guide the selection of the right device for the right patient.

Selection of the right inhaler is important to ensure that patients with respiratory diseases get the most benefit from their treatment. Dry powder inhalers and pressurised metered dose inhalers are the most common inhaler types. Pressurised metered dose inhalers use propellants to deliver the drug to the lungs. In contrast, dry powder inhalers deliver the drug to the lungs by having internal resistance. This restricts the flow of air through the inhaler. As the patient inhales through the inhaler, the resistance against the air flow generates the power to separate the drug molecules and carry them to the lungs. While there are many factors to be considered for inhaler selection, there is often confusion around how resistance should guide selection of inhaler. With low-resistance devices, patients must inhale faster to generate the power to separate the drug molecules, which may be difficult in patients with poor lung function. With high-resistance devices, patients do not need to inhale as fast to separate the drug, and most patients can effectively use the inhaler. This article addresses the common clinically relevant questions to clarify how the internal resistance of the inhaler should be used to help guide the selection of the right device for the right patient.

Does mixing inhaler devices lead to unchecked inhaler technique errors in patients with COPD? Findings from the cross-sectional observational MISMATCH study.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) may be prescribed multiple inhalers that require different techniques for optimal performance. Mixing devices has been associated with poorer COPD outcomes suggesting that it leads to inappropriate inhaler technique. However, empirical evidence is lacking. AIMS: Compare the nature and frequency of dry powder inhaler (DPI) technique errors in patients with COPD using (1) a single DPI or (2) mixed-devices (a DPI and pressurised metered dose inhaler (pMDI)). METHODS: Data from the PIFotal study-a cross-sectional study on Peak Inspiratory Flow in patients with COPD using a DPI as maintenance therapy, capturing data from 1434 patients on demographic characteristics, COPD health status and inhaler technique-were used to select 291 patients using mixed-devices. Frequency matching based on country of residence and DPI device type was used to select 291 patients using a DPI-only for comparison. Predetermined checklists were used for the evaluation of DPI video recordings and complemented with additional errors that were observed in ≥10%. Error proportions were calculated for the (1) individual and total number of errors, (2) number of critical errors and (3) number of pMDI-related errors. RESULTS: The study sample contained 582 patients (mean (SD) age 69.6 (9.4) years, 47.1% female). DPI technique errors were common, but not significantly different between the groups. The majority of patients made at least one critical error (DPI-only: 90.7% vs mixed-devices: 92.8%). Proportions of total, 'pMDI-related' and critical errors did not significantly differ between the groups. CONCLUSION: The nature and frequency of inhaler technique errors did not substantially differ between patients prescribed with a single DPI and mixed-devices. Currently, 'pMDI-related errors' in DPI use are not accounted for in existing checklists. TRIAL REGISTRATION NUMBER: ENCEPP/EUPAS48776.

Modeled small airways lung deposition of two fixed-dose triple therapy combinations assessed with in silico functional respiratory imaging.

BACKGROUND: Small airways disease plays a key role in the pathogenesis of chronic obstructive pulmonary disease (COPD) and is a major cause of obstruction; therefore, it is a critical pharmacotherapy target. This study evaluated lung deposition of two inhaled corticosteroid (ICS)/long-acting ß2-agonist/long-acting muscarinic antagonist single-inhaler triple therapies using in silico functional respiratory imaging (FRI). Deposition was assessed using real-world inhalation profiles simulating everyday use where optimal inhalation may be compromised. METHODS: Three-dimensional airway models were produced from 20 patients with moderate-to-very severe COPD. Total, central, and regional small airways deposition as a percentage of delivered dose of budesonide/glycopyrronium/formoterol fumarate dihydrate (BGF) 160/7.2/5 µg per actuation and fluticasone furoate/umeclidinium/vilanterol (FF/UM/VI) 100/62.5/25 µg were evaluated using in silico FRI based on in vitro aerodynamic particle size distributions of each device. Simulations were performed using multiple inhalation profiles of varying durations and flow rates representing patterns suited for a pressurized metered-dose inhaler or dry-powder inhaler (four for BGF, two for FF/UM/VI, with one common profile). For the common profile, deposition for BGF versus FF/UM/VI was compared post-hoc using paired t-tests. RESULTS: Across inhalation profiles, mean total lung deposition was consistently higher with BGF (47.0-54.1%) versus FF/UM/VI (20.8-22.7%) and for each treatment component, with greater deposition for BGF also seen in the central large airways. Mean regional small airways deposition was also greater across inhalation profiles with BGF (16.9-23.6%) versus FF/UM/VI (6.8-8.7%) and for each treatment component. For the common profile, total, central, and regional small airways deposition were significantly greater for BGF versus FF/UM/VI (nominal p < 0.001), overall and for treatment components; notably, regional small airways deposition of the ICS components was approximately five-fold greater with budesonide versus fluticasone furoate (16.1% vs. 3.3%). CONCLUSIONS: BGF was associated with greater total, central, and small airways deposition for all components versus FF/UM/VI. Importantly, using an identical inhalation profile, there was an approximately five-fold difference in small airways deposition for the ICS components, with only a small percentage of the ICS from FF/UM/VI reaching the small airways. Further research is needed to understand if the enhanced delivery of BGF translates to clinical benefits.

Identifying critical inhalation technique errors in Dry Powder Inhaler use in patients with COPD based on the association with health status and exacerbations: findings from the multi-country cross-sectional observational PIFotal study.

BACKGROUND: Correct inhaler use depends on a complex interplay of factors, including device preparation and generating sufficient inspiratory flow. It is currently unknown which inhalation technique errors can be considered critical in Chronic Obstructive Pulmonary Disease (COPD) patients on Dry Powder Inhaler (DPI) maintenance therapy. OBJECTIVE: To investigate the association between inhalation technique errors and health status or exacerbations in patients with COPD. Additionally, the association between the number of errors and COPD outcomes was determined. METHODS: The PIFotal study is a cross-sectional multi-country observational study in a primary care setting, including 1434 COPD patients aged ≥ 40 years (50.1% female; mean age 69.2 yrs) using a DPI for their maintenance therapy. Inhalation technique was video recorded and scored by two independent researchers using inhaler-specific checklists. Health status was assessed with two questionnaires; the Clinical COPD Questionnaire (CCQ) and the COPD Assessment Test (CAT). The number of moderate and severe exacerbations in the past 12 months was recorded. Critical errors were identified based on their association with health status or exacerbations through multi-level prediction models adjusted for identified confounding. RESULTS: Errors in inhalation technique steps 'Breathe in', 'Hold breath', and 'Breathe out calmly after inhalation' were significantly associated with poorer CCQ and CAT outcomes and thus deemed critical. None of the errors were significantly associated with moderate exacerbations. Patients with errors 'Preparation', 'Hold inhaler in correct position during inhalation', and 'Breathe in' had significantly more severe exacerbations, and therefore these errors were also deemed critical. 81.3% of patients with COPD made at least one critical error. Specific combinations of errors were associated with worse outcomes. The more inhalation technique errors identified, the poorer the health status and the higher the exacerbation rate. CONCLUSION: In this study, we identified multiple critical inhalation technique errors in COPD patients using DPIs each associated with poorer outcomes. Explorative analysis revealed that specific combinations of errors may be of clinical relevance, especially those related to the inhalation manoeuvre. COPD outcomes worsened with increasing error count. These results warrant further prospective longitudinal studies to establish the effect of correcting these errors on COPD control. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT04532853 (31/08/2020).

ERS International Congress 2022: highlights from the Airway Diseases Assembly.

The European Respiratory Society (ERS) celebrated the return of an in-person meeting in Barcelona, Spain, after 2 years of virtual congresses. The ERS Congress 2022 programme was replete with symposia, skills workshops and abstract presentations from all 14 assemblies, encompassing over 3000 abstracts presented in the form of thematic poster discussion and oral presentations. In this article, highlights from the ERS Congress 2022 (including from thematic poster sessions, oral presentations and symposia from keynote speakers), presented by Assembly 5 (Airway diseases, asthma, COPD and chronic cough), are reviewed by Early Career Members and experts in the field, with the aim of presenting key recent findings in the field.

Small airways disease in patients with alpha-1 antitrypsin deficiency.

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder, characterized by panacinar emphysema mainly in the lower lobes, and predisposes to chronic obstructive pulmonary disease (COPD) at a younger age, especially in patients with concomitant cigarette smoking. Alpha-1 antitrypsin (a1-AT) is a serine protease inhibitor that mainly blocks neutrophil elastase and maintains protease/antiprotease balance in the lung and AATD is caused by mutations in the SERPINA1 gene that encodes a1-AT protein. PiZZ is the most common genotype associated with severe AATD, leading to reduced circulating levels of a1-AT. Besides its antiprotease function, a1-AT has anti-inflammatory and antioxidative effects and AATD results in defective innate immunity. Protease/antiprotease imbalance affects not only the lung parenchyma but also the small airways and recent studies have shown that AATD is associated with small airway dysfunction. Alterations in small airways structure with peripheral ventilation inhomogeneities may precede emphysema formation, providing a unique opportunity to detect early disease. The aim of the present review is to summarize the current evidence for the contribution of small airways disease in AATD-associated lung disease.

Domiciliary Fractional Exhaled Nitric Oxide and Spirometry in Monitoring Asthma Control and Exacerbations.

BACKGROUND: Domiciliary measurements of airflow obstruction and inflammation may assist healthcare teams and patients in determining asthma control and facilitate self-management. OBJECTIVE: To evaluate parameters derived from domiciliary spirometry and fractional exhaled nitric oxide (Feno) in monitoring asthma exacerbations and control. METHODS: Patients with asthma were provided with hand-held spirometry and Feno devices in addition to their usual asthma care. Patients were instructed to perform twice-daily measurements for 1 month. Daily symptoms and medication change were reported through a mobile health system. The Asthma Control Questionnaire was completed at the end of the monitoring period. RESULTS: One hundred patients had spirometry, of which 60 were given additional Feno devices. Compliance rates for twice-daily measurements were poor (median [interquartile range], 43% [25%-62%] for spirometry; 30% [3%-48%] for Feno); at least 15% of patients took little or no spirometry measurements and 40% rarely measured Feno. The coefficient of variation (CV) values in FEV1 and Feno were higher, and the mean % personal best FEV1 lower in those who had major exacerbations compared with those without (P < .05). Feno CV and FEV1 CV were associated with asthma exacerbation during the monitoring period (area under the receiver-operating characteristic curve, 0.79 and 0.74, respectively). Higher Feno CV also predicted poorer asthma control (area under the receiver-operating characteristic curve, 0.71) at the end of the monitoring period. CONCLUSIONS: Compliance with domiciliary spirometry and Feno varied widely among patients even in the setting of a research study. However, despite significant missing data, Feno and FEV1 were associated with asthma exacerbations and control, making these measurements potentially clinically valuable if used.

Fixed-dose combination fluticasone/formoterol for asthma treatment in a real-world setting: meta-analysis of exacerbation rates and asthma control.

BACKGROUND: Treatment guidelines for asthma management are derived almost exclusively from the results of controlled clinical trials undertaken in carefully selected patient populations; meaning that their outcomes may not reflect the true performance of treatments when used in general daily medical practice. The aim of this meta-analysis was to combine the results of observational studies investigating the fluticasone propionate/formoterol (FP/FORM) fixed-dose combination in real-world asthma patients. METHODS: A systemic literature review was completed in March 2019 using the PubMed database. We identified 394 studies. Five studies, which included a total of 4756 patients treated with FP/FORM, were judged eligible and included in the meta-analysis. RESULTS: The estimated severe asthma exacerbation rate was 11.47% (95% CI, 5.8 to 18.72%), calculated from the random effect model. A sensitivity analysis excluding 2 studies (one was an outlier, and the exacerbation rate for the studied treatment alone could not be determined in the other) showed a 7.04% rate of severe asthma exacerbations. The estimated relative risk of the incidence of severe asthma exacerbations was 0.323 (95% CI, 0.159 to 0.658). The estimated asthma control rate was 60.6% (95% CI, 55.7% to 65.6%). The odds of achieving asthma control significantly increased by FP/FORM compared with pre-study conditions (estimated odds ratio: 2.214 [95% CI, 1.292 to 3.795]; p < 0.001). CONCLUSIONS: The findings of this meta-analysis confirm the effectiveness of FP/FORM for the treatment of asthma patients in a real-world setting beyond the limitations of RCTs.

A narrative review on the Synchrobreathe™: A novel breath-actuated pressurised metered-dose inhaler for the treatment of obstructive airway diseases.

Pressurised metered-dose inhalers (pMDIs) and dry powder inhalers (DPIs), are widely used to deliver drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Incorrect use of inhalers is one of the main obstacles to achieving better clinical control. Indeed, with pMDIs, patients fail to synchronise actuation with inhalation due to a lack of coordination and with DPIs insufficient inspiratory effort compromises drug deposition in lungs. More than 50% of patients desire to switch their pMDIs and DPIs for a better device. This led to the development of pressurised breath-actuated inhalers (BAIs) with the aim of combining the beneficial features of pMDIs and DPIs and mitigating their problems. BAIs, e.g., Synchrobreathe™, are designed such that they are activated by a low inhalation effort and mechanically actuate the dose in synchrony to inspiration, thereby resolving the need to coordinate actuation with inspiration. BAIs have advantages, including ease of use, high lung deposition of medication, and greater patient preference. We discussed the design features, operating procedure, and clinical evidence of the Synchrobreathe™ device (Cipla Ltd, India), a BAI available with a wide range of drug combinations. Studies have shown that a higher number of patients (68.19%) used the Synchrobreathe™ without any error than the pMDI (56.21%), and that the vast majority of them (92%) found it easy to understand and use. The Synchrobreathe™ is an innovative, easy-to-use inhaler that may overcome many limitations associated with pMDIs and DPIs, thus potentially improving management of obstructive airway diseases and patients' quality of life.

Clinical recommendations for dry powder inhaler use in the management of COPD in primary care.

Over 1400 patients using dry powder inhalers (DPIs) to deliver COPD maintenance therapies were recruited across Europe and Australia. Their peak inspiratory flow (PIF) was measured, inhaler technique was observed, and adherence to treatment assessed. From relating the findings with patient health status, and thereby identifying critical errors, key clinical recommendations for primary care clinicians were determined, namely - measure PIF before prescribing a DPI to ensure inhalation manoeuvre ability is well-matched with the device. Some patients could benefit from inhalation training whereas others should have their DPI changed for one better suited to their inspiratory ability or alternatively be prescribed an active device (such as a soft mist inhaler or pressurized metered dose inhaler). Observing the inhalation technique was valuable however this misses suboptimal PIF (approaching one fourth of patients with a satisfactory observed manoeuvre had a suboptimal PIF for their DPI). Assess adherence as deliberate non-adherence can point to a mismatch between a patient and their inhaler (deliberate non-adherence was significantly associated with PIFs below the minimum for the DPI). In-person observation of inhalation technique was found to be inferior to video rating based on device-specific checklists. Where video assessments are not possible, observation training for healthcare professionals would therefore be valuable particularly to improve the ability to identify the critical errors associated with health status namely 'teeth and lips sealed around mouthpiece', 'breathe in' and 'breathing out calmly after inhalation'. However, it is recommended that observation alone should not replace PIF measurement in the DPI selection process.Trial registration: https://clinicaltrials.gov/ct2/show/NCT04532853 .

Suboptimal Peak Inspiratory Flow and Critical Inhalation Errors are Associated with Higher COPD-Related Healthcare Costs.

Purpose: To assess the relationship between suboptimal Peak Inspiratory Flow (sPIF), inhalation technique errors, and non-adherence, with Healthcare Resource Utilisation (HCRU) in Chronic Obstructive Pulmonary Disease (COPD) patients receiving maintenance therapy via a Dry Powder Inhaler (DPI). Patients and methods: The cross-sectional, multi-country PIFotal study included 1434 COPD patients (≥40 years) using a DPI for maintenance therapy. PIF was measured with the In-Check DIAL G16, and sPIF was defined as a typical PIF lower than required for the device. Inhalation technique was assessed by standardised evaluation of video recordings and grouped into 10 steps. Patients completed the "Test of Adherence to Inhalers" questionnaire. HCRU was operationalised as COPD-related costs for primary healthcare, secondary healthcare, medication, and total COPD-related costs in a 1-year period. Results: Participants with sPIF had higher medication costs compared with those with optimal PIF (cost ratio [CR]: 1.07, 95% CI [1.01, 1.14]). Multiple inhalation technique errors were associated with increased HCRU. Specifically, "insufficient inspiratory effort" with higher secondary healthcare costs (CR: 2.20, 95% CI [1.37, 3.54]) and higher total COPD-related costs (CR: 1.16, 95% CI 1.03-1.31). "no breath-hold following the inhalation manoeuvre (<6 s)" with higher medication costs (CR: 1.08, 95% CI [1.02, 1.15]) and total COPD-related costs (CR 1.17, 95% CI [1.07, 1.28]), and "not breathing out calmly after inhalation" with higher medication costs (CR: 1.19, 95% CI [1.04, 1.37]). Non-adherence was not significantly associated with HCRU. Conclusion: sPIF and inhalation technique errors were associated with higher COPD-related healthcare utilisation and costs in COPD patients on DPI maintenance therapy.

Clinimetric analysis of outcome measures for airway clearance in people with cystic fibrosis: a systematic review.

BACKGROUND: Airway clearance techniques (ACTs) are integral to cystic fibrosis (CF) management. However, there is no consensus as to which outcome measures (OMs) are best for assessing ACT efficacy. OBJECTIVES: To summarise OMs that have been assessed for their clinimetric properties (including validity, feasibility, reliability, and reproducibility) within the context of ACT research in CF. DESIGN AND METHODS: A systematic review was conducted according to Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) standards. Any parallel or cross-over randomised controlled trial (RCT) investigating outcome measures for ACT in the CF population were eligible for inclusion. The search was performed in five medical databases, clinicaltrials.gov, and abstracts from international CF conferences. The authors planned to independently assess study quality and risk of bias using the COnsensus-based Standards for the selection of health status Measurement InstrumeNts (COSMIN) risk of bias checklist with external validity assessment based upon study details (participants and study intervention). Two review authors (GS and MJ) independently screened search results against inclusion criteria, and further data extraction were planned but not required. RESULTS: No completed RCTs from the 187 studies identified met inclusion criteria for the primary or post hoc secondary objective. Two ongoing trials were identified. DISCUSSION AND CONCLUSION: This empty systematic review highlights that high-quality RCTs are urgently needed to investigate and validate the clinimetric properties of OMs used to assess ACT efficacy. With the changing demographics of CF combined with the introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies, an accurate assessment of the current benefit of ACT or the effect of ACT withdrawal is a high priority for clinical practice and future research; OMs which have been validated for this purpose are essential. REGISTRATION: This systematic review was registered on the PROSPERO database (CRD42020206033).

The Role of Viral Infections on Severe Asthma Exacerbations: Present and Future

No disponible

Reference equations for oscillometry and their differences among populations: a systematic scoping review.

Respiratory oscillometry is gaining global attention over traditional pulmonary function tests for its sensitivity in detecting small airway obstructions. However, its use in clinical settings as a diagnostic tool is limited because oscillometry lacks globally accepted reference values. In this scoping review, we systematically assessed the differences between selected oscillometric reference equations with the hypothesis that significant heterogeneity existed between them. We searched bibliographic databases, registries and references for studies that developed equations for healthy adult populations according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A widely used Caucasian model was used as the standard reference and compared against other models using Bland-Altman and Lin's concordance correlational analyses. We screened 1202 titles and abstracts, and after a full-text review of 67 studies, we included 10 in our analyses. Of these, three models had a low-to-moderate agreement with the reference model, particularly those developed from non-Caucasian populations. Although the other six models had a moderate-to-high agreement with the standard model, there were still significant sex-specific variations. This is the first systematic analysis of the heterogeneity between oscillometric reference models and warrants the validation of appropriate equations in clinical applications of oscillometry to avoid diagnostic errors.

Real-World Impact of Nonclinical Inhaler Regimen Switches on Asthma or COPD: A Systematic Review.

BACKGROUND: Switching inhaler regimens can be driven by poor disease control but also by nonclinical factors, such as cost and environmental impact. The consequences of switching for nonclinical reasons are largely unclear. OBJECTIVE: To systematically review the real-world consequences of switching inhaler regimens for nonclinical reasons in asthma and/or chronic obstructive pulmonary disease patients. METHODS: Embase, MEDLINE, EBM Reviews, and EconLit were searched to November 21, 2020. Conference searches and reference checking were also performed. Real-world studies of asthma and/or chronic obstructive pulmonary disease patients undergoing a switch in inhaler regimen for any reason apart from clinical need were included. Two reviewers screened and extracted data. Key outcomes included symptom control, exacerbations, and patient-doctor relationships. RESULTS: A total of 8,958 records were screened and 21 studies included. Higher-quality (matched comparative) studies were prioritized. Five matched studies (6 datasets) reported on symptom control: 5 datasets (n = 7,530) with unclear patient consent reported improved disease control following switching, and 1 dataset (n = 1,648) with non-consented patients reported significantly worsened disease control. Three matched studies (5 datasets, n = 10,084) reported on exacerbation rate ratios; results were heterogeneous depending on the definition used. Two studies (n = 137) reported that switching inhaler regimens could have a negative impact on the doctor-patient relationship, especially when the switches were non-consented. Study quality was generally low. CONCLUSIONS: Switching inhaler regimens is a complex issue that can have variable clinical consequences and can harm the patient-doctor relationship. Limited high-quality evidence was identified, and study designs were heterogeneous. A robust framework is needed to guide the personalized switching of inhalers.