The association of environmental, meteorological, and pollen count variables with asthma-related emergency department visits and hospitalizations in the Bronx

Seasonal variations and social disparities in asthma hospitalizations and outcomes

OBJECTIVE

Exposure to asthma exacerbating triggers may be dependent on the season and an individual's social factors and subsequent means to avoid triggers. We assessed for seasonal variations and differential outcomes based on race and income in admissions for asthma in a United States nationwide assessment.

METHODS

This retrospective study assessed adult hospitalizations for asthma 2016-2019 using the National Inpatient Sample. Hospitalizations were categorized by season: winter (December-February), spring (March-May), summer (June-August), fall (September-November). Multivariable linear and logistic regression were used to assess associations between season, race, income quartile (determined by the median income within a patient's ZIP code), and outcomes.

RESULTS

The study included 423,140 admissions with a mean age of 51 years, and 73% of the cohort being female and 56% non-white. Admissions peaked during winter (124, 145) and were lowest in summer (80,525). Intubation rates were increased in summer compared to winter (2.73 vs 1.93%, aOR = 1.19, 95% CI: 1.04-1.37) as were rates of noninvasive positive pressure ventilation (NIPPV) (7.92 vs 7.06%, aOR = 1.08, 95% CI: 1.00-1.17). Compared to white patients, intubation (2.53 vs 1.87%, absolute difference 0.66%, aOR = 1.14, 95% CI: 1.02-1.29) and NIPPV (9.95 vs 5.45%, absolute difference 4.5%, aOR = 1.69, 95% CI: 1.57-1.82) were increased in Black patients. No significant associations between income and clinical outcomes were found.

CONCLUSIONS

Asthma admission peak during winter, while summer admissions and non-white race are associated with higher rates of NIPPV and intubation. Public health initiatives and strategically timed outpatient visits could combat seasonal variation and social disparities in asthma outcomes.

The Sleep Environment, Napping, and Sleep Outcomes among Urban Children With and Without Asthma

OBJECTIVES

Children with asthma living in U.S. urban neighborhoods experience increased risk for asthma morbidity and poor sleep outcomes. In addition to asthma, environmental factors (e.g. noise, uncomfortable temperature, light exposure) related to urban poverty may disturb children's sleep. This study examined the association between environmental factors and sleep outcomes among urban children with and without asthma, and whether napping underlies the environment-sleep link. Additionally, the study tested whether these associations differed by health status (i.e. asthma) or race/ethnicity.

METHOD

Participants included urban children aged 7-9 years with (N = 251) and without (N = 130) asthma from Latino, Black, or non-Latino White (NLW) background. Caregivers reported sleep environmental factors and naps. Sleep duration, efficiency, and nightly awakenings were assessed via actigraphy.

RESULTS

Regardless of health status, frequent exposure to noise and light was associated with poorer sleep outcomes only among Latino children. In the full sample with and without asthma, noise exposure during nighttime sleep was related to more frequent daytime naps, which were linked to shorter nighttime sleep duration.

CONCLUSIONS

Exposure to noise and light may play a particularly influential role in shaping urban children's sleep outcomes. Racial/ethnic differences and the potential mediating role of napping in this environment-sleep association may inform tailored interventions.

Association of asthma exacerbations with paper mulberry (Broussenetia papyrifera) pollen in Islamabad: An observational study

Background

Although the role of airborne plant pollen in causing allergic rhinitis has been established, the association of concentrations of paper mulberry (Broussenetia papyrifera) pollens in the air and incidence of asthma exacerbations has not, despite an observed increase in the number of asthma patients attending physician clinics and hospital Accident and Emergency (A&E) Departments during the paper mulberry pollen season. We aimed to assess the association between paper mulberry pollen concentrations (typically peaking in March each year) and asthma exacerbations in the city of Islamabad.

Methods

We used three approaches to investigate the correlation of paper mulberry pollen concentration with asthma exacerbations: A retrospective analysis of historical records (2000-2019) of asthma exacerbations of patients from the Allergy and Asthma Institute, Pakistan (n = 284), an analysis of daily nebulisations in patients attending the A&E Department of the Pakistan Institute of Medical Sciences (March 2020 to July 2021), a prospective peak expiratory flow rate (PEFR) diary from participants (n = 40) with or without asthma and with or without paper mulberry sensitisation. We examined associations between pollen data and asthma exacerbations using Pearson correlation.

Results

We found a strong positive correlation between mean paper mulberry pollen counts and clinical records of asthma exacerbations in patients sensitised to paper mulberry (Pearson correlation coefficient (r) = 0.86; P < 0.001), but not in non-sensitised patients (r = 0.32; P = 0.3). There was a moderate positive correlation between monthly nebulisation counts and pollen counts (r = 0.56; P = 0.03), and a strong negative correlation between percent predicted PEFR and pollen counts in sensitised asthma patients (r = -0.72, P < 0.001). However, these correlations were of low magnitude in the non-sensitised asthma (r = -0.16; P < 0.001) and sensitised non-asthma (r = -0.28; P < 0.001) groups.

Conclusions

Our three approaches to analysis all showed an association between high paper mulberry pollen concentration in Islamabad and asthma exacerbations. Predicting pollen peaks could enable alerts and mobilise strategies to proactively manage these peaks of asthma exacerbations.

Trends in seasonal pollen and asthma-related morbidity among adults and children in a U.S. high-density urban center, 2001-2020

OBJECTIVE

To analyze the long-term trends in pollen counts and asthma-related emergency department visits (AREDV) in adult and pediatric populations in the Bronx.

METHODS

Daily values of adult and pediatric AREDV were retrospectively obtained from three major Bronx hospitals using ICD-10 codes and pollen counts were obtained from the Armonk station from 2001-2020. Wilcoxon Ranked Sum was applied to compare median values, while Spearman correlation was employed to examine the association between these variables, for both decades and each season.

RESULTS

The median value of pediatric AREDV increased by 200% from the 1st to 2nd decade (p < 0.001) and AREDV peak shifted from predominantly the spring season in the 1st decade to the fall and winter seasons in the 2nd decade. Seasonal patterns were consistent over 20 years with summer AREDV lower than all other seasons (9 vs. 17 per day) (p < 0.001). Spring tree pollen peaks were correlated with AREDV peaks (rho = 0.34) (p < 0.001). Tree pollen exceeding 100 grains/m³ corresponded to a median of 19.0 AREDVs while all other tree pollen (0 - 99 grains/m³) corresponded to a median of 15.0 AREDVs (p < 0.001). AREDVs sharply declined in 2020, coinciding with the emergence of COVID-19.

CONCLUSIONS

Pollen and AREDVs peak earlier in the spring and are more strongly interconnected, while asthma rates among children are rapidly rising, particularly in the fall and winter. These findings can advise targeted awareness campaigns for better management of asthma related morbidity.

Asthma triggered by extreme temperatures: From epidemiological evidence to biological plausibility

BACKGROUND

There is rapidly growing evidence indicating that extreme temperature is a crucial trigger and potential activator of asthma; however, the effects of extreme temperature on asthma are inconsistently reported and the its potential mechanisms remain undefined.

OBJECTIVES

This review aims to estimate the impacts of extreme heat, extreme cold, and temperature variations on asthma by systematically summarizing the existing studies from epidemiological evidence to biological plausibility.

METHODS

We conducted a systematic search in PubMed, Embase, and Web of Science from inception to June 30, 2022, and we retrieved articles of epidemiology and biological studies which assessed associations between extreme temperatures and asthma. This protocol was registered with PROSPERO (CRD42021273613).

RESULTS

From 12,435 identified records, 111 eligible studies were included in the qualitative synthesis, and 37 articles were included in the meta-analysis (20 for extreme heat, 16 for extreme cold, and 15 for temperature variations). For epidemiological evidence, we found that the synergistic effects of extreme temperatures, indoor/outdoor environments, and individual vulnerabilities are important triggers for asthma attacks, especially when there is extreme heat or cold. Meta-analysis further confirmed the associations, and the pooled relative risks for asthma attacks in extreme heat and extreme cold were 1.07 (95%CI: 1.03-1.12) and 1.20 (95%CI: 1.12-1.29), respectively. Additionally, this review discussed the potential inflammatory mechanisms behind the associations between extreme temperatures and asthma exacerbation, and highlighted the regulatory role of immunological pathways and transient receptor potential ion channels in asthma triggered by extreme temperatures.

CONCLUSIONS

We concluded that both extreme heat and cold could significantly increase the risk of asthma. Additionally, we proposed a potential mechanistic framework, which is important for understanding the disease pathogenesis that uncovers the complex mechanisms of asthma triggered by extreme temperatures and protects the sensitive individuals from impacts of extreme weather events and climate change.

A Review of the Respiratory Health Burden Attributable to Short-Term Exposure to Pollen

Respiratory diseases such as asthma, allergic rhinitis (AR) and chronic obstructive pulmonary disease (COPD) affect millions worldwide and pose a significant global public health burden. Over the years, changes in land use and climate have increased pollen quantity, allergenicity and duration of the pollen season, thus increasing its impact on respiratory disease. Many studies have investigated the associations between short-term ambient pollen (i.e., within days or weeks of exposure) and respiratory outcomes. Here, we reviewed the current evidence on the association between short-term outdoor pollen exposure and thunderstorm asthma (TA), asthma and COPD hospital presentations, general practice (GP) consultations, self-reported respiratory symptoms, lung function changes and their potential effect modifiers. The literature suggests strong evidence of an association between ambient pollen concentrations and almost all respiratory outcomes mentioned above, especially in people with pre-existing respiratory diseases. However, the evidence on sub-clinical lung function changes, COPD, and effect modifiers other than asthma, hay fever and pollen sensitisation are still scarce and requires further exploration. Better understanding of the implications of pollen on respiratory health can aid healthcare professionals to implement appropriate management strategies.

Environmental and clinical data utility in pediatric asthma exacerbation risk prediction models

BACKGROUND

Asthma exacerbations are triggered by a variety of clinical and environmental factors, but their relative impacts on exacerbation risk are unclear. There is a critical need to develop methods to identify children at high-risk for future exacerbation to allow targeted prevention measures. We sought to evaluate the utility of models using spatiotemporally resolved climatic data and individual electronic health records (EHR) in predicting pediatric asthma exacerbations.

METHODS

We extracted retrospective EHR data for 5982 children with asthma who had an encounter within the Duke University Health System between January 1, 2014 and December 31, 2019. EHR data were linked to spatially resolved environmental data, and temporally resolved climate, pollution, allergen, and influenza case data. We used xgBoost to build predictive models of asthma exacerbation over 30-180 day time horizons, and evaluated the contributions of different data types to model performance.

RESULTS

Models using readily available EHR data performed moderately well, as measured by the area under the receiver operating characteristic curve (AUC 0.730-0.742) over all three time horizons. Inclusion of spatial and temporal data did not significantly improve model performance. Generating a decision rule with a sensitivity of 70% produced a positive predictive value of 13.8% for 180 day outcomes but only 2.9% for 30 day outcomes.

CONCLUSIONS

EHR data-based models perform moderately wellover a 30-180 day time horizon to identify children who would benefit from asthma exacerbation prevention measures. Due to the low rate of exacerbations, longer-term models are likely to be most clinically useful.

TRIAL REGISTRATION

Not applicable.

Reduced pediatric urgent asthma utilization and exacerbations during the COVID-19 pandemic

The COVID-19 pandemic has had a profound impact on healthcare access and utilization, which could have important implications for children with chronic diseases, including asthma. We sought to evaluate changes in healthcare utilization and outcomes in children with asthma during the COVID-19 pandemic. We used electronic health records data to evaluate healthcare use and asthma outcomes in 3959 children and adolescents, 5-17 years of age, with a prior diagnosis of asthma who had a history of well-child visits and encounters within the healthcare system. We assessed all-cause healthcare encounters and asthma exacerbations in the 12-months preceding the start of the COVID-19 pandemic (March 1, 2019-February 29, 2020) and the first 12 months of the pandemic (March 1, 2020-February 28, 2021). All-cause healthcare encounters decreased significantly during the pandemic compared to the preceding year, including well-child visits (48.1% during the pandemic vs. 66.6% in the prior year; p < .01), emergency department visits (9.7% vs. 21.0%; p < .01), and inpatient admissions (1.6% vs. 2.5%; p < .01), though there was over a 100-fold increase in telehealth encounters. Asthma exacerbations that required treatment with systemic steroids also decreased (127 vs. 504 exacerbations; p < .01). Race/ethnicity was not associated with changes in healthcare utilization or asthma outcomes. The COVID-19 pandemic corresponded to dramatic shifts in healthcare utilization, including increased telehealth use and improved outcomes among children with asthma. Social distancing measures may have also reduced asthma trigger exposure.

The ongoing impact of COVID-19 on asthma and pediatric emergency health-seeking behavior in the Bronx, an epicenter

Background

The Bronx has the highest prevalence of asthma in the United States (US), and was also an early COVID-19 epicenter, making it a unique study location. Worldwide reports describe significant declines in pediatric emergency department (PED) visits during COVID-19. The ongoing impact of COVID-19 on all PED presentations, including asthma, at an early epicenter has not been studied beyond the pandemic peak and into the early phases of state re-opening.

Objectives

To compare PED health-seeking behaviors and clinical characteristics during the 2020 pandemic and subsequent initial New York State (NYS) phased re-opening to the same period in 2019.

Methods

Retrospective chart review of children <21 years utilizing the PED at a high-volume quaternary children's hospital in The Bronx, NY from March 15th 2020 – July 6th 2020 (pandemic cohort) and the same interval in 2019 (comparison cohort). Visits were assigned to pre-determined diagnostic categories. Demographic and clinical data were compared.

Results

19,981 visits were included. Visits declined by 66% during 2020. Proportions of asthma visits (2% vs. 7%, p < 0.0001) and minor medical problems (61% vs. 67%, p < 0.0001) had significant declines in the pandemic cohort, while major medical problems (13% vs. 8%, p < 0.0001), appendicitis (1% vs. 0.4%, p < 0.0001) and other surgical complaints (1% vs. 0.5%, p < 0.0001) had proportional increases in the pandemic cohort. No significant proportional changes were noted among psychosocial and trauma groups between the two cohorts.

Conclusion

The pandemic cohort experienced a substantial decrease in PED volume, but an increase in acuity and admission rates, which was sustained through the NYS phase-II re-opening. Despite being located in an asthma hub, the incidence of asthma-related PED visits declined appreciably in the pandemic cohort. Future studies examining the effects of indoor allergens in isolation on pediatric asthma are warranted.

Eosinophilia in Asthma Patients Is Protective Against Severe COVID-19 Illness

Background

There is a paucity of information on coronavirus disease 2019 (COVID-19) outcomes in asthmatics.

Objective

To identify risk factors associated with admission and subsequent mortality among COVID-19–infected asthmatics.

Methods

Adults at our institution with a positive polymerase chain reaction for COVID-19 between March 14 and April 27, 2020, were retrospectively identified. Comorbidities, laboratory results, and mortality rates during hospitalization were recorded.

Results

In total, 737 of 951 (77.5%) asthma patients with COVID-19 were seen in the emergency department (ED), and 78.8% of these ED patients (581 of 737) were admitted. Individuals with previously measured mean absolute eosinophil counts (AEC) ≥150 cells/μL were less likely to be admitted (odds ratio [OR] = 0.46, 95% confidence interval [CI]: 0.21-0.98, P = .04), whereas concomitant heart failure (CHF), chronic kidney disease (CKD), and chronic obstructive pulmonary disease (COPD) were risk factors for admission. Hospitalized patients with asthma with peak hospital-measured AEC ≥150 cells/μL (n = 104) were less likely to die compared with those whose AEC remained <150 cells/μL (n = 213) (mortality rate 9.6% vs 25.8%; OR = 0.006, 95% CI: 0.0001-0.64, P = .03). This group had also higher preadmission mean AEC (237 ± 181 vs 163 ± 147 cells/μL, P = .001, OR = 2012, 95% CI: 27.3-14,816). The mortality rate in patients with asthma alone (no associated CHF, CKD, COPD, diabetes, or hypertension) was similar to that of patients without asthma or any of these comorbidities.

Conclusions

In asthmatics, pre-existing eosinophilia (AEC ≥150 cells/μL) was protective from COVID-19–associated admission, and development of eosinophilia (AEC ≥150 cells/μL) during hospitalization was associated with decreased mortality. Preadmission AEC influenced the AEC trend during hospitalization. Having a Th2-asthma phenotype might be an important predictor for reduced COVID-19 morbidity and mortality that should be further explored in prospective and mechanistic studies.

Extrafine triple therapy and asthma exacerbation seasonality: TRIMARAN and TRIGGER post hoc analyses

BACKGROUND

Previous studies have shown seasonal variation in asthma exacerbations, peaking over the winter months. A single-inhaler triple therapy containing extrafine formulations of the inhaled corticosteroid (ICS) beclomethasone dipropionate (BDP), long-acting β₂-agonist formoterol fumarate (FF), and long-acting muscarinic antagonist glycopyrronium (G) is in development for asthma.

OBJECTIVE

We sought to evaluate whether calendar season impacted the relative effect of BDP/FF/G versus BDP/FF on moderate and severe asthma exacerbations.

METHODS

TRIMARAN and TRIGGER were double-blind 52-week studies comparing BDP/FF/G with BDP/FF (TRIMARAN medium-dose ICS; TRIGGER high-dose) in adults with uncontrolled asthma (Asthma Control Questionnaire-7 score ≥1.5), prebronchodilator FEV₁ less than 80% predicted, history of 1 or more asthma exacerbation, who had been receiving ICS/long-acting β₂-agonist for at least 4 weeks before entry. Moderate and severe asthma exacerbations were captured throughout each study. In these post hoc analyses, the annual moderate and severe exacerbation rate was calculated for each month, with rate ratios determined from events grouped by season.

RESULTS

In patients who received BDP/FF alone, there was a marked seasonal effect on the occurrence of asthma exacerbations, with the rate highest in the winter months. However, the addition of the long-acting muscarinic antagonist component to BDP/FF reduced this seasonal variation, especially during the winter, such that the relative effect of BDP/FF/G versus BDP/FF was greatest in the winter (significant 20.3% reduction [P = .0008]). Reductions in the other seasons ranged between 8.6% and 12.0%.

CONCLUSIONS

These post hoc analyses indicate that inhaled triple therapy with extrafine BDP/FF/G reduces seasonal peaks in moderate and severe exacerbations, and confirm the overall utility of adding long-acting muscarinic antagonist to ICS/long-acting β₂-agonist in the management of asthma.

Synergistic health effects of air pollution, temperature, and pollen exposure: a systematic review of epidemiological evidence

BACKGROUND

Exposure to heat, air pollution, and pollen are associated with health outcomes, including cardiovascular and respiratory disease. Studies assessing the health impacts of climate change have considered increased exposure to these risk factors separately, though they may be increasing simultaneously for some populations and may act synergistically on health. Our objective is to systematically review epidemiological evidence for interactive effects of multiple exposures to heat, air pollution, and pollen on human health.

METHODS

We systematically searched electronic literature databases (last search, April 29, 2019) for studies reporting quantitative measurements of associations between at least two of the exposures and mortality from any cause and cardiovascular and respiratory morbidity and mortality specifically. Following the Navigation Guide systematic review methodology, we evaluated the risk of bias of individual studies and the overall quality and strength of evidence.

RESULTS

We found 56 studies that met the inclusion criteria. Of these, six measured air pollution, heat, and pollen; 39 measured air pollution and heat; 10 measured air pollution and pollen; and one measured heat and pollen. Nearly all studies were at risk of bias from exposure assessment error. However, consistent exposure-response across studies led us to conclude that there is overall moderate quality and sufficient evidence for synergistic effects of heat and air pollution. We concluded that there is overall low quality and limited evidence for synergistic effects from simultaneous exposure to (1) air pollution, pollen, and heat; and (2) air pollution and pollen. With only one study, we were unable to assess the evidence for synergistic effects of heat and pollen.

CONCLUSIONS

If synergistic effects between heat and air pollution are confirmed with additional research, the health impacts from climate change-driven increases in air pollution and heat exposure may be larger than previously estimated in studies that consider these risk factors individually.

Onset of asthma-like symptoms in children with lower respiratory tract infections

Background

Asthma‐like symptoms (ALS) often occur among children with lower respiratory tract infections (LRTIs). We aimed to determine the potential risk factors for ALS onset in LRTIs children.

Methods

A total of 102 LRTIs with ALS and 474 without ALS were enrolled. The relative risk (RR) was used to test the influence of the clinical factors on the ALS risk. We compared the differences of birth data, wheezing history, disease severity, inflammatory markers, infectious pathogens, allergic markers, cardiac, liver, and kidney injury markers between LRTIs with and without ALS onset. Receiver operating curve (ROC) analysis was applied to determine the predictive value of various markers in the ALS risk in LRTIs. Multivariate logistic regression analysis was performed to evaluate the association between various clinical and laboratory parameters and ALS onset in LRTIs.

Results

The RRs of boys/girls ratio and wheezing history for ALS compared with non‐ALS was 1.263 and 2.850, respectively (P = .026, <10⁻⁴). There were significant differences of age, WBC, PLT, EOS, and CK between LRTIs with and without ALS onset (P = .004, .041, .006, .049, and .035). ROC analysis showed that significant associations between the parameters of age, WBC, and PLT and ALS risk among LRTIs were observed. Multivariate logistic regression analysis showed that the clinical and laboratory parameters were not independently associated with the risk of ALS onset among LRTIs.

Conclusions

Lower age, male, inflammation, and allergic state were risk factors for ALS onset in LRTIs. Comprehensive monitoring and evaluation of these factors may be helpful for ALS prevention.