Factors associated with relapse in adult patients discharged from the emergency department following acute asthma: a systematic review

Machine Learning Approaches to Predict Asthma Exacerbations: A Narrative Review

The implementation of artificial intelligence (AI) and machine learning (ML) techniques in healthcare has garnered significant attention in recent years, especially as a result of their potential to revolutionize personalized medicine. Despite advances in the treatment and management of asthma, a significant proportion of patients continue to suffer acute exacerbations, irrespective of disease severity and therapeutic regimen. The situation is further complicated by the constellation of factors that influence disease activity in a patient with asthma, such as medical history, biomarker phenotype, pulmonary function, level of healthcare access, treatment compliance, comorbidities, personal habits, and environmental conditions. A growing body of work has demonstrated the potential for AI and ML to accurately predict asthma exacerbations while also capturing the entirety of the patient experience. However, application in the clinical setting remains mostly unexplored, and important questions on the strengths and limitations of this technology remain. This review presents an overview of the rapidly evolving landscape of AI and ML integration into asthma management by providing a snapshot of the existing scientific evidence and proposing potential avenues for future applications.

Asthma-related emergency admissions and associated healthcare resource use in Alberta, Canada

BACKGROUND

There is a lack of real-world research assessing asthma management following asthma-related emergency department (ED) discharges. The objective of this study was to characterise follow-up care, healthcare resource use (HCRU) and medical costs following ED admissions in Alberta, Canada.

METHODS

A retrospective cohort study was conducted on adults with asthma using longitudinal population-based administrative data from Alberta Health Services. Adult patients with asthma and ≥1 ED admission from 1 April 2015 to 31 March 2020 were included. ED admissions, outpatient visits, hospitalisations and asthma-specific medication use were measured in the 30 days before and up to 90 days after each asthma-related ED admission. Mean medical costs attributable to each type of HCRU were summarised. All outcomes were stratified by patient baseline disease severity.

RESULTS

Among 128 063 patients incurring a total of 20 142 asthma-related ED visits, a substantial rate of ED readmission was observed, with 10% resulting in readmissions within 7 days and 35% within 90 days. Rates increased with baseline asthma severity. Despite recommendations for patients to be followed up with an outpatient visit within 2-7 days of ED discharge, only 6% were followed up within 7 days. The mean total medical cost per patient was $C8143 in the 30 days prior to and $C5407 in the 30 days after an ED admission.

CONCLUSIONS

Despite recommendations regarding follow-up care for patients after asthma-related ED admissions, there are still low rates of outpatient follow-up visits and high ED readmission rates. New or improved multidimensional approaches must be integrated into follow-up care to optimise asthma control and prevent readmissions.

Recovery of Breakthrough Asthma Attacks Treated With Oral Steroids While on Monoclonal Antibody Therapy: Protocol for a Prospective Observational Study (BOOST)

BACKGROUND

Asthma attacks are a common and important problem. Someone experiences an asthma attack in the United Kingdom every 10 seconds. Asthma attacks cause coughing, wheezing, breathlessness, and chest tightness and are highly stressful for patients. They result in reduced quality of life, with days lost from work or school. Asthma attacks are treated with oral corticosteroids (OCSs), but these have many short- and long-term side effects. Asthma monoclonal antibodies (mAbs) have revolutionized the treatment of severe asthma by reducing asthma attacks and OCS burden by over 50%, but some people still experience attacks while on mAbs. The MEX study showed that residual asthma attacks are broadly eosinophilic (high fractional exhaled nitric oxide [FeNO]) or noneosinophilic (low FeNO), but it did not measure response to OCS treatment. There is an evidence gap in understanding the clinical and inflammatory responses that occur when using OCSs to treat residual asthma attacks in patients taking asthma mAbs.

OBJECTIVE

The primary objective is to compare the clinical recovery between high-FeNO and low-FeNO attacks after acute treatment with oral prednisolone among people established on long-term asthma mAb treatment. The exploratory objective is to compare the inflammatory response to acute treatment with oral prednisolone between high-FeNO and low-FeNO attacks.

METHODS

BOOST (Breakthrough Asthma Attacks Treated With Oral Steroids) is a single-center, prospective observational study of 60 adults established on long-term asthma mAb treatment who receive acute treatment with oral prednisolone (usual care) for an asthma attack. The primary outcome will be the proportion of treatment failure (the need to start oral prednisolone or antibiotics or an unscheduled health care visit for asthma, following an attack) at day 28. The secondary outcomes will be the change in forced expiratory volume in 1 second and the change in visual analogue scale symptom score between the stable state, attack, day 7, and day 28 visits. The exploratory outcomes include the changes in sputum, nasal, and blood inflammometry between the stable state, attack, day 7, and day 28 visits.

RESULTS

The last asthma attack visit is anticipated to occur in December 2023. Data analysis and publication will take place in 2024.

CONCLUSIONS

We will test the hypothesis that there is a difference in the rate of recovery of clinical and inflammatory measures between high-FeNO and low-FeNO asthma attacks that occur in patients on mAb therapy. The study data will help power a future randomized placebo-controlled trial of prednisolone treatment for nonsevere attacks in patients treated with asthma mAbs and will provide important information on whether corticosteroid treatment should be FeNO-directed.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/46741.

Predictors of outpatient follow-up care after adult emergency department asthma visits and association with 30-day outcomes

Objective: Guidelines recommend outpatient follow-up after emergency department visits for asthma, but factors related to rates of follow-up among the adult population are understudied. We sought to describe patient and community-level predictors of outpatient follow-up after an index ED visit for asthma and evaluate the association between outpatient follow-up visits and subsequent ED revisits.Methods: We conducted a retrospective observational cohort study of adult patients with emergency departments visits for asthma. The primary predictor was time to outpatient follow-up visit within 30 days of the index ED visit. The primary outcome was all-cause ED revisit within 30 days of the index ED visit. Cox proportional hazards regression was utilized to test the association between time to outpatient follow-up and hazard of ED revisit within 30 days.Results: Time to outpatient follow-up visit within 30 days was not significantly associated with hazard of 30-day ED revisit for asthma (HR 1.05; 95% CI 0.69-1.61). However, male patients (HR 1.45; 95% C 1.11-1.89) and smokers (HR 1.67; 95% CI 1.22-2.29) were significantly more likely to have an ED revisit.Conclusion: Younger, Black patients with Medicaid were less likely to receive follow-up care relative to older patients insured by Medicare. While follow-up visits were not associated with 30-day revisit rates, differences by age, race, and insurance status suggest disproportionate barriers to accessing care. Future research may target these subgroups to improve transitions of care after an ED visit for asthma.

Characteristics of Asthma Exacerbations in Emergency Care in Switzerland-Demographics, Treatment, and Burden of Disease in Patients with Asthma Exacerbations Presenting to an Emergency Department in Switzerland (CARE-S)

Emergency care for asthma is provided by general practitioners, pulmonologists, and emergency departments (EDs). Although it is known that patients presenting to EDs with acute asthma exacerbations are a vulnerable population and that this mode of presentation is a risk marker for more severe complications, research on this population is scarce. We conducted a retrospective study on patients with asthma exacerbations who presented to the ED of the University Hospital Basel, Switzerland, during 2017-2020. Of the last 200 presentations, 100 were selected and analyzed to assess demographic information, the use of previous and ED-prescribed asthma medication, and clinical outcomes after a mean period of time of 18 months. Of these 100 asthma patients, 96 were self-presenters, and 43 had the second highest degree of acuity (emergency severity index 2). Global Initiative for Asthma (GINA) step 1 and step 3 were the most common among patients with known GINA levels, accounting for 22 and 18 patients, respectively. A total of 4 patients were undergoing treatment with oral corticosteroids at presentation, and 34 were at discharge. At presentation, 38 patients used the combination therapy of inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA), and 6 patients underwent ICS monotherapy. At discharge, 68 patients were prescribed with ICS/LABA. At entry to the ED, about one-third of patients did not use any asthma medication. In total, 10 patients were hospitalized. None of them needed invasive or non-invasive ventilation. A follow-up for the study was precluded by the majority of patients. This group of asthma patients seemed particularly vulnerable as their asthma medication at presentation was often not according to guidelines or even lacking, and almost all the patients had self-presented to the ED without any reference from a physician. The majority of patients did not give consent to the collection of any follow-up information. These medical shortcomings reflect an urgent medical need to improve care for patients at high risk of asthma exacerbations.

Dual activation of estrogen receptor alpha and glucocorticoid receptor upregulate CRTh2-mediated type 2 inflammation; mechanism driving asthma severity in women?

BACKGROUND

Type 2-high asthma is characterized by elevated levels of circulating Th2 cells and eosinophils, cells that express chemoattractant-homologous receptor expressed on Th2 cells (CRTh2). Severe asthma is more common in women than men; however, the underlying mechanism(s) remain elusive. Here we examined whether the relationship between severe asthma and type 2 inflammation differs by sex and if estrogen influences Th2 cell response to glucocorticoid (GC).

METHODS

Type 2 inflammation and the proportion of blood Th2 cells (CD4⁺ CRTh2⁺ ) were assessed in whole blood from subjects with asthma (n = 66). The effects of GC and estrogen receptor alpha (ERα) agonist on in vitro differentiated Th2 cells were examined. Expression of CRTh2, type 2 cytokines and degree of apoptosis (Annexin V⁺ , 7-AAD) were determined by flow cytometry, qRT-PCR, western blot and ELISA.

RESULTS

In severe asthma, the proportion of circulating Th2 cells and hospitalizations were higher in women than men. Women with severe asthma also had more Th2 cells and serum IL-13 than women with mild/moderate asthma. Th2 cells, eosinophils and CRTh2 mRNA correlated with clinical characteristics associated with asthma control in women but not men. In vitro, GC and ERα agonist treated Th2 cells exhibited less apoptosis, more CRTh2 as well as IL-5 and IL-13 following CRTh2 activation than Th2 cells treated with GC alone.

CONCLUSION

Women with severe asthma had higher levels of circulating Th2 cells than men, which may be due to estrogen modifying the effects of GC, enhancing Th2 cell survival and type 2 cytokine production.

Primary Care Management of Asthma Exacerbations or Attacks: Impact of the COVID-19 Pandemic

The COVID-19 pandemic has brought a renewed focus on appropriate management of chronic respiratory conditions with a heightened awareness of respiratory symptoms and the requirement for differential diagnosis between an asthma attack and COVID-19 infection. Despite early concerns in the pandemic, most studies suggest that well-managed asthma is not a risk factor for more severe COVID-related outcomes, and that asthma may even have a protective effect. Advice on the treatment of asthma and asthma attacks has remained unchanged. This article describes some challenges faced in primary care asthma management in adults and in teenagers, particularly their relevance during a pandemic, and provides practical advice on asthma attack recognition, classification, treatment and continuity of care. Acute attacks, characterised by increased symptoms and reduced lung function, are often referred to as exacerbations of asthma by doctors and nurses but are usually described by patients as asthma attacks. They carry a significant and underestimated morbidity and mortality burden. Many patients experiencing an asthma attack are assessed in primary care for treatment and continuing management. This may require remote assessment by telephone and home monitoring devices, where available, during a pandemic. Differentiation between an asthma attack and a COVID-19 infection requires a structured clinical assessment, taking account of previous medical and family history. Early separation into mild, moderate, severe or life-threatening attacks is helpful for continuing good management. Most attacks can be managed in primary care but when severe or unresponsive to initial treatment, the patient should be appropriately managed until transfer to an acute care facility can be arranged. Good quality care is important to prevent further attacks and must include a follow-up appointment in primary care, proactive regular dosing with daily controller therapy and an understanding of a patient's beliefs and perceptions about asthma to maximise future self-management.

Association of Affordable Care Act Implementation With Ambulance Utilization for Asthma Emergencies in New York City, 2008-2018

IMPORTANCE

Emergency medical services (EMS) are an essential component of the health care system, but the effect of insurance expansion on EMS call volume remains unclear.

OBJECTIVE

This study investigated the association between health insurance expansion and EMS dispatches for asthma, an ambulatory care-sensitive condition. We hypothesized that insurance expansion under the Patient Protection and Affordable Care Act (ACA) would be associated with decreased EMS dispatches for asthma emergencies.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined 14 865 267 ambulance calls dispatched within New York City from 2008 to 2018, including 217 303 calls for asthma-related emergencies, and used interrupted time series analysis to study the change in the annual incidence of EMS dispatches for asthma emergencies after implementation of the ACA. Multivariable linear regression examined the association between the uninsured rate and the incidence of asthma-related dispatches, controlling for population demographic characteristics and air quality index.

EXPOSURES

Implementation of ACA on January 1, 2014.

MAIN OUTCOMES AND MEASURES

Incidence of EMS dispatches for asthma emergencies per 100 000 population per year (ie, asthma EMS dispatch rate) as classified by the 911 call-taker.

RESULTS

In this study of 217 303 EMS dispatches for asthma-related emergencies, there was a decrease in the asthma EMS dispatch rate after implementation of the ACA, from a mean (SD) of 261 (24) dispatches per 100 000 population per year preintervention to 211 (47) postintervention (P = .047). This decrease in asthma EMS dispatch rate after ACA implementation was significant on interrupted time series analysis. Prior to 2014, the annual asthma EMS dispatch rate was increasing by 11.8 calls per 100 000 population per year (95% CI, 6.1 to 17.4). After ACA implementation, the asthma EMS dispatch rate decreased annually by 28.5 calls per 100 000 population per year (95% CI, -37.6 to -19.3), a significant change in slope from the preintervention period (P < .001). Multivariable linear regression, controlling for percentage of individuals younger than age 18 years, degree of racial/ethnic diversity, median household income, and air quality index, found that a 1% decrease in the citywide uninsured rate was associated with a decrease of 98.9 asthma dispatches per 100 000 population per year (95% CI, 5.72-192.10; P = .04).

CONCLUSIONS AND RELEVANCE

Insurance expansion within New York City under the ACA was associated with a significant reduction in the asthma EMS dispatch rate. Insurance expansion may be a viable method to reduce EMS utilization for ambulatory care-sensitive conditions such as asthma.

Elevated Circulating Th2 Cells in Women With Asthma and Psychological Morbidity: A New Asthma Endotype?

PURPOSE

Psychological stress shifts the immune system toward the production of T-helper (Th)-2-mediated cytokines and eosinophilia, increases the risks for both asthma and depression, and can precipitate asthma exacerbations. Th2-mediated inflammation is a characteristic of allergic asthma. We have shown that the levels of CD4⁺ Th2 cells in the peripheral blood of patients with asthma are associated with severity and/or control of the disease. To improve our understanding of the interactions between stress and asthma symptoms, we evaluated the effects of psychological comorbidity on Th2-mediated inflammation in patients with asthma.

METHODS

Sixty-six asthmatic patients were recruited from the University of Alberta Asthma Clinic after they gave informed consent. Stress-related effects on asthma and psychological morbidity were assessed using the Asthma Control Questionnaire, completed by the patients at recruitment. Venous blood was collected at recruitment and Th2-mediated immunity evaluated by flow cytometry, quantitative real-time reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay.

FINDINGS

Patients with stress-triggered asthma (n = 12) had higher percentage of CD4⁺ T cells (P = 0.006) and Th2 cells (CD4⁺CRTh2⁺ T cells; P = 0.002) in peripheral blood compared to patients with asthma who did not experience stress-related worsening of disease (n = 54). The same was true when we analyzed patients with any form of psychological comorbidity (n = 19) compared to those without psychological comorbidities (n = 47). These differences were evident among women, but not among men. Women with psychological comorbidity also required higher doses of inhaled and oral corticosteroids compared to those without psychological comorbidity.

IMPLICATIONS

Asthma involving psychological morbidity associates with an elevated level of circulating Th2 cells and increased corticosteroid usage, and may be more prevalent in women. Larger-scale prospective studies are required for assessing whether these women constitute a new endotype of Th2-high asthma responsive to treatments aimed to improve psychological comorbidities.

Assessing effects of personal behaviors and environmental exposure on asthma episodes: a diary-based approach

Background

Quantifying the effects of personal health behaviors and environmental exposure on asthma flare-ups is a challenge. Most studies have focused on monitoring the symptoms and drug usage for relieving symptoms. In this study, we emphasize the need to understand how personal and environmental conditions are related to the occurrence of asthma symptoms.

Methods

We designed an online health diary platform to collect personal health behaviors from children, their parents and other adults with any allergic diseases including asthma, allergic rhinitis, atopic dermatitis and allergic conjunctivitis. The participants used mobile devices or computers to record their daily health-related activities such as sleep, exercise, diet, perception of air quality and temperature, and asthma symptoms. The participants also recorded secondhand smoke exposure and the time of activities, which were combined with ambient air quality measurements for calculating personal air pollution exposure. A generalized linear mixed model was used to estimate the effects of the factors.

Results

During the study period (January 2017–June 2017, and October 2017–September 2018), 132 participants provided 25,016 diary entries, and 84 participants had experienced asthma symptoms in 1458 diary entries. The results showed some different risk factors for the minors and adults. For minors, high-intensity exercise, contact with persons with influenza-like illness (ILI) and the perception of hot temperature and bad indoor air quality were associated with the occurrence of asthma episodes. The identified risk factors for the adult participants included having dehumidifiers at home, exposure to secondhand smoke, having bad sleep quality, contact with persons with ILI, not eating fruit and seafood, perceiving cold temperature, bad quality of indoor and outdoor air, and exposure to high concentration of ozone.

Conclusions

The revealed personal risk factors and perceptions of air quality and temperature may provide guidance on behavioral change for people susceptible to asthma to help control acute onset and severe exacerbation of asthma flare-ups.

Factors associated with hospital admission in adult patients with asthma exacerbations: A systematic review

OBJECTIVES

A variable proportion of patients presenting to the emergency department (ED) with acute asthma require admission to hospital. Previous studies have identified select factors associated with admission following ED presentation; however, no review has synthesized the evidence in this regard. This systematic review summarizes the evidence regarding factors associated with hospital admission following ED presentation.

METHODS

Searches were conducted in seven electronic databases and common sources of grey literature. Studies reporting disposition for adults after ED presentation were included. Admission proportions and factors associated with hospitalization that remained statistically significant in multivariable analyses (p < 0.05) were reported.

RESULTS

Out of an initial 5865 identified articles, 15 articles met full inclusion criteria and 11 were included in the analyses. Female sex (n = 2) and older age (n = 2) were individual factors associated with admission. Patient vital signs and severity followed by patient attributes were the two most frequent domains associated with admission. Admission proportions were analyzed in 10 studies at an median of ∼20% with no clear change between 1996 and 2012.

CONCLUSIONS

Factors such as patient demographics (e.g., female sex, older age), patient vital signs/severity, and history are associated with admission following ED presentation for acute asthma. These can be employed by ED clinicians to effectively discern patients at high risk for admission and lead to more evidence-based decision-making.

Sex differences in outcomes after discharge from Alberta emergency departments for asthma: A large population-based study

OBJECTIVE

Asthma exacerbations frequently result in emergency department (ED) visits. While sex differences have been identified in some asthma studies, there is a paucity of literature on sex differences in the ED setting, especially population-based ones. This study examines sex differences in important outcomes of patients discharged from EDs for acute asthma in Alberta, Canada.

METHODS

Alberta residents aged from 2 to 55 years discharged from EDs with a primary diagnosis of asthma during 1999-2011 were identified from administrative databases from a single-payer health care system for the entire geographic region of Alberta. Multivariable Cox regression models analyzed time to first follow-up physician or specialist visit, and logistic regression models analyzed the binary outcome of ED return within 30 days for asthma.

RESULTS

There were 115,853 discharged patients analyzed (40.4% and 59.1% female in pediatric and adult groups, respectively). Approximately 26% of patients revisited the ED during 1999-2011 and 5.1% did so within 30 days. Women had higher odds of a 30-day ED return after ED discharge than men (unadjusted odds ratio [uOR] = 1.26; 95% confidence interval [CI] 1.17-1.36). Time to first non-ED physician follow-up was shorter for girls (unadjusted hazard ratio [uHR] = 1.05; 95%CI 1.03-1.07) and women (uHR = 1.62; 95%CI 1.59-1.64) than for boys and men, respectively. Significant interactions between sex and age, socio-economic status, area of residence, and comorbidities were identified and changed the effect of sex on outcomes.

CONCLUSIONS

In conclusion, women return to EDs within 30 days of discharge for acute asthma more often than men. Time to first non-ED physician follow-up for children and adults differed by sex. Multiple factors likely contribute to these differences; however, identifying these differences is critical to understand the influence of sex on health behaviors and outcomes.