Risk Of Hospitalization For Asthma Research Articles

Spatial distribution of hospital admissions for asthma in the central area of Asturias, Northern Spain

BackgroundAsturias is one of the communities with the highest rates of hospital admission for asthma in Spain. The environmental pollution or people lifestyle are some of the factors that contribute to the appearance or aggravation of this illness. The aim of this study was to show the spatial distribution of asthma admissions risks in the central municipalities of Asturias and to analyze the observed spatial patterns.MethodsUrgent hospital admissions for asthma and status asthmaticus occurred between 2016 to 2018 on the public hospitals of the central area of Asturias were used. Population data were assigned in 5 age groups. Standardised admission ratio (SAR), smoothed relative risk (SRR) and posterior risk probability (PP) were calculated for each census tract (CT). A spatial trend analysis was run, a spatial autocorrelation index (Morans I) was calculated and a cluster and outlier analysis (Anselin Local Morans I) was finally performed in order to analyze spatial clusters.ResultsThe total number of hospital urgent asthma admissions during the study period was 2324, 1475 (63.46%) men and 849 (36.56%) women. The municipalities with the highest values of SRR and PP were located on the northwest area: Avilés, Gozón, Carreño, Corvera de Asturias, Castrillón and Illas. A high risk cluster was found for the municipalities of Avilés, Gozón y Corvera de Asturias.ConclusionsThe spatial analysis showed high risk of hospitalization for asthma on the municipalities of the northwest area of the study, which highlight the existence of spatial inequalities on the distribution of urgent hospital admissions.

Association between cold weather, influenza infection, and asthma exacerbation in adults in Hong Kong.

Despite a conspicuous exacerbation of asthma among patients hospitalized due to influenza infection, no study has attempted previously to elucidate the relationship between environmental factors, influenza activity, and asthma simultaneously in adults. In this study, we examined this relationship using population-based hospitalization records over 22 years. Daily numbers of hospitalizations due to asthma in adults of 41 public hospitals in Hong Kong during 1998-2019 were obtained. The data were matched with meteorological records and air pollutant concentrations. We used type-specific and all-type influenza-like illness plus (ILI+) rates as proxies for seasonal influenza activity. Quasi-Poisson generalized additive models together with distributed-lag non-linear models were used to examine the association. A total of 212,075 hospitalization episodes due to asthma were reported over 22 years. The cumulative adjusted relative risk (ARR) of asthma hospitalizations reached 1.15 (95 % confidence interval [CI], 1.12-1.18) when the ILI+ total rate increased from zero to 20.01 per 1000 consultations. Compared with the median temperature, a significantly increased risk of asthma hospitalization (cumulative ARR = 1.10, 95 % CI, 1.05-1.15) was observed at the 5th percentile of temperature (i.e., 14.6 °C). Of the air pollutants, oxidant gas was significantly associated with asthma, but only at its extreme level of concentrations. In conclusion, cold conditions and influenza activities are risk factors to asthma exacerbation in adult population. Influenza-related asthma exacerbation that appeared to be more common in the warm and hot season, is likely to be attributable to influenza A/H3N2. The heavy influence of both determinants on asthma activity implies that climate change may complicate the asthma burden.

Associations between ambient temperature and adult asthma hospitalizations in Beijing, China: a time-stratified case-crossover study

BackgroundStudies on the associations between ambient temperature and asthma hospitalizations are limited, and the results are controversial. We aimed to assess the short-term effects of ambient temperature on the risk of asthma hospitalizations and quantify the hospitalization burdens of asthma attributable to non-optimal temperature in adults in Beijing, China.MethodsWe collected daily asthma hospitalizations, meteorological factors and air quality data in Beijing from 2012 to 2015. We applied a time-stratified case-crossover design and fitted a distributed lag non-linear model with a conditional quasi-Poisson regression to explore the association between ambient temperature and adult asthma hospitalizations. The effect modifications of these associations by gender and age were assessed by stratified analyses. We also computed the attributable fractions and numbers with 95% empirical confidence intervals (eCI) of asthma hospitalizations due to extreme and moderate temperatures.ResultsFrom 2012 to 2015, we identified a total of 18,500 hospitalizations for asthma among adult residents in Beijing, China. Compared with the optimal temperature (22 °C), the cumulative relative risk (CRR) over lag 0–30 days was 2.32 with a 95% confidence interval (CI) of 1.57–3.42 for extreme cold corresponding to the 2.5th percentile (− 6.5 °C) of temperature distribution and 2.04 (95% CI 1.52–2.74) for extreme heat corresponding to the 97.5th percentile (29 °C) of temperature distribution. 29.1% (95% eCI 17.5–38.0%) of adult asthma hospitalizations was attributable to non-optimum temperatures. Moderate cold temperatures yielded most of the burdens, with an attributable fraction of 20.3% (95% eCI 9.1–28.7%). The temperature-related risks of asthma hospitalizations were more prominent in females and younger people (19–64 years old).ConclusionsThere was a U-shaped association between ambient temperature and the risk of adult asthma hospitalizations in Beijing, China. Females and younger patients were more vulnerable to the effects of non-optimum temperatures. Most of the burden was attributable to moderate cold. Our findings may uncover the potential impact of climate changes on asthma exacerbations.

Air Pollutants and Asthma Hospitalization in the Medicaid Population.

Rationale: Risk of asthma hospitalization and its disparities associated with air pollutant exposures are less clear within socioeconomically disadvantaged populations, particularly at low degrees of exposure. Objectives: To assess effects of short-term exposures to fine particulate matter (particulate matter with an aerodynamic diameter of ⩽2.5 μm [PM2.5]), warm-season ozone (O3), and nitrogen dioxide (NO2) on risk of asthma hospitalization among national Medicaid beneficiaries, the most disadvantaged population in the United States, and to test whether any subpopulations were at higher risk. Methods: We constructed a time-stratified case-crossover dataset among 1,627,002 hospitalizations during 2000-2012 and estimated risk of asthma hospitalization associated with short-term PM2.5, O3, and NO2 exposures. We then restricted the analysis to hospitalizations with degrees of exposure below increasingly stringent thresholds. Furthermore, we tested effect modifications by individual- and community-level characteristics. Measurements and Main Results: Each 1-μg/m3 increase in PM2.5, 1-ppb increase in O3, and 1-ppb increase in NO2 was associated with 0.31% (95% confidence interval [CI], 0.24-0.37%), 0.10% (95% CI, 0.05 - 0.15%), and 0.28% (95% CI, 0.24 - 0.32%) increase in risk of asthma hospitalization, respectively. Low-level PM2.5 and NO2 exposures were associated with higher risk. Furthermore, beneficiaries with only one asthma hospitalization during the study period or in communities with lower population density, higher average body mass index, longer distance to the nearest hospital, or greater neighborhood deprivation experienced higher risk. Conclusions: Short-term air pollutant exposures increased risk of asthma hospitalization among Medicaid beneficiaries, even at concentrations well below national standards. The subgroup differences suggested individual and contextual factors contributed to asthma disparities under effects of air pollutant exposures.

Evaluation of a pediatric asthma high-risk scoring algorithm.

Identification of patients with asthma at increased risk for hospitalization and emergency department (ED) visits presents opportunity for intervention. Retrospective analysis of computerized health plan claims data. Texas Children's Health Plan, a large Medicaid managed care program, developed an asthma risk scoring algorithm using the clinically relevant parameters of hospitalization for asthma, ED visits for asthma, short-acting β agonist medication dispensing, inhaled corticosteroid medication dispensing, number of prescribing providers, loss to follow-up, and oral corticosteroid dispensing. The risk score performance was evaluated using 2016-2018 risk scores to predict 2017-2019 asthma hospitalizations and ED visits. We identified 107,811 unique members aged 1 to less than 18 years with an asthma diagnosis. For those aged 3 to less than 18 years, the area under the receiver operating characteristic curve (AUC) for risk score predicting hospitalization ranged from 0.72 to 0.79. For those aged 1 to less than 3 years, the AUC ranged from 0.65 to 0.69. Those with a risk score of 1 or greater accounted for 20% to 23% of pediatric members 3 to less than 18 years with asthma but 53% to 56% of asthma hospitalizations in the follow-up year. Sixteen to eighteen percent of those aged 3 to less than 18 years with a risk score of 9 or greater were hospitalized in the follow-up year. Texas Children's Health Plan asthma risk score stratifies risk of asthma hospitalization and ED visits for Medicaid-insured children. The risk score performs better for children aged 3 to less than 18 years than for those aged 1 to less than 3 years.

Acute exposures to air pollutants and asthma hospitalization in the Medicaid population

BACKGROUND AND AIM: Few studies have investigated roles of air pollutants on asthma among disadvantaged population. It is also unclear whether some sub-populations or communities experience disproportionate risk from air pollutants. METHODS: We estimated risk of asthma hospitalization associated with moving average exposures to particulate matter (PM2.5), ozone (O3), and nitrogen dioxide (NO2) over lag 0 to 6 days among all individuals enrolled in Medicaid, the largest health coverage to Americans with low income or disabilities, 2000–2012, using a time-stratified case-crossover design. To assess the risk at low levels, we restricted the analysis to hospitalizations with exposure below increasingly stringent thresholds, including those well below the national standards. Further, we performed subgroup analyses by individual- and community-level characteristics. RESULTS:We found positive associations between acute PM2.5, O3, and NO2 exposures and risk of asthma hospitalization: 1-µg/m3 increase in PM2.5, 1-part per billion (ppb) increase in O3, and 1-ppb increase in NO2 was associated with 0.31% (95% confidence interval [CI], 0.27%–0.36%), 0.11% (95% CI, 0.07%−0.15%), and 0.28% (95% CI, 0.25%−0.32%) increase in risk of asthma hospitalization, respectively. At low exposure levels, we found greater risk associated with PM2.5 and NO2. Further, we found consistently higher risk for the three exposures among beneficiaries with only one hospitalization during study period and communities with lower population density, higher average BMI, and longer distance to the nearest hospital. CONCLUSIONS:Our study adds to the existing body of research on acute effects of air pollutants on asthma, bridges the gaps in environmental health disparities, and is useful in informing policy. We found increased risk of asthma hospitalization associated with acute exposures to PM2.5, O3, and NO2 among Medicaid beneficiaries, even at levels well below the national standards. Subgroup analyses suggest that beneficiaries with mild to moderate symptoms and those living in disadvantaged communities experienced disproportionately higher risk from the pollutants. KEYWORDS: Mixtures, Short-term exposure, Asthma, Environmental disparities, Socio-economic factors

Measuring the Association Between Thunderstorms in the Presence of High Pollen and Risk of Severe Asthma

BACKGROUND AND AIM: Studies have shown an acute association between the occurrence of thunderstorm conditions in the presence of high pollen and severe asthma, but minimal work has studied these events over a multi-year time series, using detailed measurements of storms and pollen. METHODS: We estimate the change in risk between thunderstorm asthma events and asthma-related emergency room visits in the Minneapolis-St. Paul metropolitan area for the years 2007-2018. We defined thunderstorm asthma events as daily occurrence of 2 or more lightning strikes during periods of high pollen, interpolated using weather and pollen monitor data and modeled lightning counts. Daily counts of asthma-related emergency department visits were acquired from the Minnesota Hospital Association. We use a 2-stage approach combining zip code level quasi-Poisson time-series regressions in a meta-analysis to estimate an overall relative risk of hospitalizations during thunderstorm asthma events. RESULTS:We observed a 4.4% (RR = 1.044; 95% CI (1.013,1.076), increase in asthma emergency department visits on the day of thunderstorm asthma event and a 3.2% (RR 1.032; 95% CI (1.003,1.062) increase on the day after the storm event. Our findings were robust to adjustment for temperature, humidity, wind, precipitation, ozone, PM2.5, day of week, and natural splines for seasonal variation in asthma cases. Occurrence of lightning alone or pollen alone shows no association with risk of severe asthma. CONCLUSIONS:Our results support an association between co-occurrence of lightning and pollen and risk of asthma hospitalization. This model, while previously described with specific epidemic events, has not been well studied in a time series model to evaluate long-term risk, using measurement of both lightning and pollen, and never using unique small area exposure assignment and outcome counts. Our findings indicate that thunderstorm asthma may be an unidentified environmental risk factor for severe asthma. KEYWORDS: asthma, pollen, thunderstorms, climate

Changes in Timing of Spring Onset and Increased Risk of Asthma Hospitalization in Maryland: Harbinger of Climate Change

Introduction: The proposed association between climate change and increased burden of allergic diseases are based on three different thematic observational studies that have linked i) increased CO2 concentration with higher pollen production, ii) warmer air/surface temperatures with early spring onset and longer pollen season, and iii) higher pollen exposure with increased risk of asthma hospitalizations. Yet empirical evidence collectively linking climate change with pollen season and asthma exacerbation is still lacking.Methods: We used general additive (GAM, quasi Poisson), and mixed effect (negative binomial) models to investigate the association between changes in timing of spring onset (SOS)- detected using satellite observation - and risk of asthma hospitalization in Maryland during 2001-2012. To characterize the underlying mechanism, we further investigated the relationship between changes in SOS and springtime tree pollen dynamic (timing of pollen season onset, timing and intensity of peak pollen concentration, and pollen season length).Results: In the unadjusted model, very early (Incident Rate Ratio (IRR): 1.17, 95% Confidence Interval (CI): 1.07-1.28) and late (IRR: 1.07, 95% CI: 1.00-1.15) onset of spring were associated with increased risk of asthma hospitalization. When the analysis was adjusted for extreme heat event and PM2.5 concentration, the risk remained significant for very early SOS (IRR: 1.10, 95% CI: 1.02-1.20), but not for late SOS (RR: 1.03, 95% CI: 0.97-1.11). We further observed that very early SOS is significantly associated with the length for Birch and Oak pollen season (p<0.05).Conclusion: Our results show that ongoing changes in timing of spring onset that are tied to climate variability and change increases risk of asthma hospitalization. Our result serve as a wake-up call to public health and medical communities regarding the need to anticipate and adapt to the ongoing changes in the timing and severity of the spring allergy season.

Analysis of hospitalization trends for ambulatory care sensitive conditions in Piauí/Brazil, 2009-18

Abstract Introduction Hospitalizations for ambulatory care sensitive conditions (ACSC) are hospitalizations that can be potentially preventable through care at the first level of contact for health care. In fact, the actions offered in a timely and effective manner can reduce the risk of unnecessary hospitalizations by preventing diseases, controlling acute episodes and managing chronic diseases. Aim Analyze the trends in hospitalizations for ACSC in Piauí, Brazil, from 2009 to 2018. Methods Ecological time-series study based on data from the Hospital Information System (SIH) of the public health system (SUS), which comprised all hospitalizations of residents of Piauí, Brazil, in the period from 2009 to 2018. The explanatory variables were the hospitalizations for ACSC groups. For temporal trend analysis, the Prais-Winsten linear regression model was used in the Stata version 14 program. Results 567,577 were recorded as ACSC, representing 35.3% of the total hospitalizations (1,608,263). Most hospitalizations for ACSC were caused by infectious gastroenteritis (33.5%). The risk of hospitalization for ACSC decreased 36.8%, showing a significant reduction in the trend of the hospitalization rate (Annual Percent Change - APC: -4.6%; 95%CI: -6.4; -2.8). There was a greater decrease in the risk of hospitalization for asthma (70.3%), hypertension (66.4%) and infectious gastroenteritis (61.8%). However, a significant increase was identified for skin infection (6.1 times) and diseases related to prenatal care and childbirth (3.2 times). Conclusions The reduction in hospitalizations due to ACSC is a result of the strengthening of Primary Health Care as the Brazilian health system organizer and the implementation of the Mais Médicos Program, which enabled the presence of doctors in family health teams, especially in places that had not previously been attended. It is also necessary to develop new studies to expand the discussions and debates on these findings. Key messages Hospitalizations reflect the living conditions of individuals, with social changes being perceived by changes in hospitalization patterns over time. The strengthening of primary care policies in Brazil was able to reduce hospitalizations for ACSC and it is necessary to further strengthen these practices to improve people's health care.

Association Between Changes in Timing of Spring Onset and Asthma Hospitalization in Maryland

Ongoing climate change is affecting the health of communities across the globe. While direct consequences, including morbidity and mortality tied to increases in the frequency of extreme weather events, have received significant attention, indirect health effects, particularly those associated with climate change-driven disruptions in ecosystems, are less understood. To investigate how ongoing changes in the timing of spring onset related to climate change are associated with rates of asthma hospitalization in Maryland. This cross-sectional study of 29 257 patients with asthma used general additive (quasi Poisson) and mixed-effect (negative binomial) models to investigate the association between changes in the timing of spring onset, detected using satellite observations, and the risk of asthma hospitalization in Maryland from 2001 to 2012. Data analysis was conducted from January 2016 to March 2019. Phenology data, derived from the National Aeronautics and Space Administration's Moderate Resolution Imaging Spectroradiometer, were used to calculate location-specific median dates for start of season from 2001 to 2012. How the start of season for a given year and location deviated from the long-term average was calculated and categorized as very early, early, normal, or late. Daily asthma hospitalization in Maryland during the spring season (ie, March to May). There were 108 358 total asthma hospitalizations during the study period, of which 29 257 (27.0%; 14 379 [49.1%] non-Hispanic black patients; 17 877 [61.1%] women) took place during springtime. In the unadjusted model, very early (incident rate ratio [IRR], 1.17; 95% CI, 1.07-1.28) and late (IRR, 1.07; 95% CI, 1.00-1.15) onset of spring were associated with increased risk of asthma hospitalization. When the analysis was adjusted for extreme heat events and concentrations of particulate matter with an aerodynamic diameter less than 2.5 μm, the risk remained significant for very early spring onset (IRR, 1.10; 95% CI, 1.02-1.20) but not for late spring onset (IRR, 1.03; 95% CI, 0.97-1.11). These results suggest that ongoing changes in the timing of spring onset, which are related to climate variability and change, are associated with asthma hospitalization. Given the high burden of allergic diseases and the number of individuals sensitized to tree pollen, these findings serve as a wake-up call to public health and medical communities regarding the need to anticipate and adapt to the ongoing changes in the timing and severity of the spring allergy season.

Asociación entre la utilización de broncodilatadores de corta duración y el riesgo de hospitalización por asma en condiciones de práctica clínica habitual en una cohorte poblacional

ObjectiveTo determine the number of short-acting beta-agonists (SABA) canisters dispensed in a pharmacy during one year that is associated with higher asthma hospitalization risk in the same period in patients with active asthma. Multi-centre cross-sectional descriptive design. LocationPrimary care, MAJORICA cohort including sociodemographic, clinical and electronic prescription system data coded during clinical practice from 68,578 patients with COPD and asthma in the Balearic Islands. ParticipantsA total of 7,648 patients older than 18 years with active asthma, who got any SABA canister from the pharmacy during the 2014-2015 period were included. COPD patients were excluded. Main measurementsAsthma hospitalization, respiratory medication, tobacco, co-morbidities, age and gender. ResultsMean age 47 years, 38% women, 23.2% active smokers. Seventy-seven patients (1%) were admitted for asthma exacerbation in the study period. Patients who received more than 8 SABA containers per year increased the risk of hospitalization (OR 2.81; 95% CI 1.27-6.24). Severity by therapeutic step and amount of inhaled corticosteroids, as well as heart failure and sleep apnea were also significantly associated with hospitalization. ConclusionsThere is a significant association between the risk of hospitalization and the higher number of SABA canisters dispensed from the pharmacy. The number of canisters/year that best defines a higher risk of hospitalization is≥8 and could be used to identify asthma at risk.

Emergency department visit count: a practical tool to predict asthma hospitalization in children

Objectives: Resource limitations and low rates of follow-up with primary care providers currently limit the impact of emergency department (ED)-based preventative strategies for children with asthma. A mechanism to recognize the children at highest risk of future hospitalization is needed to target comprehensive preventative interventions at discharge. The primary objective of this study was to determine whether frequency of ED visits predicts future asthma hospitalization in children.Methods: Children aged 2–16.99 years with asthma ED visits between 2012 and 2015 were identified through health administrative data. Survival analysis using Kaplan–Meier estimator and multivariable Cox regression models with time-varying covariates were used to quantify the number of ED visits in the previous year that would best predict hospitalization risk in the following year, after adjustment for age, sex, and presentation severity.Results: We identified 2669 patients with 3300 asthma ED visits. ED visit count was an independent predictor of future hospitalization risk (p < 0.001), demonstrating a dose-dependent response. Compared with zero previous visits, the adjusted hazard of future hospitalization in children with one visit or two or more visits was 2.9 (95% CI 1.6–5.0) and 4.4 (95% CI 1.9–10.4), respectively.Conclusions: ED visit count is a reliable predictor of future asthma hospitalization risk. Future studies could aim to validate these findings to support using ED visit count as a practical and objective tool to predict the children at the highest risk of future hospitalization and therefore, those who may benefit most from ED-based preventative interventions.

The effect and burden modification of heating on adult asthma hospitalizations in Shijiazhuang: a time-series analysis

BackgroundPrevious studies have found associations between asthma morbidity and air pollution especially in young population, (PLoS One 12:e0180522, 2017; Can J Public Health 103:4-8, 2012; Environ Health Perspect 118:449-57, 2010; Am J Respir Crit Care Med 182:307-16, 2010; J Allergy Clin Immunol 104:717-22, 2008; J Allergy Clin Immunol 104:717-22, 1999; Environ Res 111:1137-47, 2011) but most of them were conducted in areas with relatively low air pollutant level. Moreover, very few studies have investigated the effect and burden modification of heating season during which the ambient air pollution level is significantly different from that during non-heating season in north China.ObjectivesThis study aimed to evaluate the effect and burden modification of heating on short-term associations between adult asthma hospitalizations and ambient air pollution in the north China city of Shijiazhuang.MethodsGeneralized additive models combined with penalized distributed lag nonlinear models were used to model associations between daily asthma hospitalizations and ambient air pollutants from 1 January 2013 to 16 December 2016 in Shijiazhuang city, adjusting for long-term and seasonality trend, day of week, statutory holiday, daily mean air pressure and temperature. Attributable risks were calculated to evaluate the burden of asthma hospitalizations due to air pollutants exposure. The effect of pollutants on hospitalization and the attributable measures were estimated in heating and non-heating season separately and the comparisons between the two seasons were conducted.ResultsAll pollutants demonstrated positive and significant impacts on asthma hospitalizations both in heating season and non-heating season, except for O3 in heating season where a negative association was observed. However, the differences of the pollutant-specific effects between the two seasons were not significant. SO2 and NO2 exposure were associated with the heaviest burden among all pollutants in heating season; meanwhile, PM10 and PM2.5 were associated with the heaviest burden in heating season.ConclusionsIn conclusion, we found evidence of the effect of ambient air pollutants on asthma hospitalizations in Shijiazhuang. The central heating period could modify the effects in terms of attributable risks. The disease burden modification of heating should be taken into consideration when planning intervention measures to reduce the risk of asthma hospitalization.

Asthma vs. PM2.5: A Bridge Between Health and Environmental Surveillance.

Asthma vs. PM2.5: A Bridge Between Health and Environmental Surveillance.

Long-term use of Chinese herbal medicine therapy reduced the risk of asthma hospitalization in school-age children: A nationwide population-based cohort study in Taiwan

BackgroundClinical trials have indicated some traditional Chinese medicine formulas reduce airway hyperresponsiveness and relieve asthma symptoms. This study investigated Chinese herbal Medicine (CHM) for childhood asthma and clarified the relationship between CHM use and consequent asthma hospitalization by a population-based cohort study. MethodsWe used the data of one million individuals randomly selected from Registry of Beneficiaries of the National Health Insurance Research Database. Patients aged less than 18 years and diagnosed as asthma were followed from 2000 to 2012 and divided into the CHM group and the non-CHM group. Cox proportional hazard regression model was conducted to estimate the adjusted hazard ratio (aHR) of the two groups, and the Kaplan-Meier survival curve was used to determine the association between CHM cumulative days and consequent asthma hospitalization. ResultsOf the total of 33,865 patients, 14,783 (43.6%) were included in the CHM group, and 19,082 (56.4%) were included in the non-CHM group. After adjustment for gender, age, comorbidities, and total numbers of asthma medication, CHM users had a lower risk of asthma hospitalization than non-CHM users (aHR: 0.90, 95% confidence interval [CI]: 0.83–0.95). Children older than 6 years who used CHM therapy for more than 180 days exhibited a reduction of 29% for the risk of consequent asthma hospitalization (aHR: 0.71, 95% CI: 0.51–0.98). ConclusionChildren aged 6–18 years who used more than 6 months CHM therapy reduced the risk of consequent asthma hospitalization. Long-term CHM therapy has benefit in school-age children with asthma.

Effects of personal air pollution exposure on asthma symptoms, lung function and airway inflammation.

There is evidence that air pollution increases the risk of asthma hospitalizations and healthcare utilization, but the effects on day-to-day asthma control are not fully understood. We undertook a prospective single-centre panel study to test the hypothesis that personal air pollution exposure is associated with asthma symptoms, lung function and airway inflammation. Thirty-two patients with a clinical diagnosis of asthma were provided with a personal air pollution monitor (Cairclip NO2 /O3 ) which was kept on or around their person throughout the 12-week follow-up period. Ambient levels of NO2 and particulate matter were modelled based upon satellite imaging data. Directly measured ozone, NO2 and particulate matter levels were obtained from a monitoring station in central Leicester. Participants made daily electronic records of asthma symptoms, peak expiratory flow and exhaled nitric oxide. Spirometry and asthma symptom questionnaires were completed at fortnightly study visits. Data were analysed using linear mixed effects models and cross-correlation. Cairclip exposure data were of good quality with clear evidence of diurnal variability and a missing data rate of approximately 20%. We were unable to detect consistent relationships between personal air pollution exposure and clinical outcomes in the group as a whole. In an exploratory subgroup analysis, total oxidant exposure was associated with increased daytime symptoms in women but not men. We did not find compelling evidence that air pollution exposure impacts on day-to-day clinical control in an unselected asthma population, but further studies are required in larger populations with higher exposure levels. Women may be more susceptible than men to the effects of air pollution, an observation which requires confirmation in future studies.

Application of a Time-Stratified Case-Crossover Design to Explore the Effects of Air Pollution and Season on Childhood Asthma Hospitalization in Cities of Differing Urban Patterns: Big Data Analytics of Government Open Data.

Few studies have assessed the lagged effects of levels of different urban city air pollutants and seasons on asthma hospitalization in children. This study used big data analysis to explore the effects of daily changes in air pollution and season on childhood asthma hospitalization from 2001 to 2010 in Taipei and Kaohsiung City, Taiwan. A time-stratified case-crossover study and conditional logistic regression analysis were employed to identify associations between the risk of hospitalization due to asthma in children and the levels of air pollutants (PM2.5, PM10, O3, SO2, and NO2) in the days preceding hospitalization. During the study period, 2900 children in Taipei and 1337 in Kaohsiung aged ≤15 years were hospitalized due to asthma for the first time. The results indicated that the levels of air pollutants were significantly associated with the risk of asthma hospitalization in children, and seasonal effects were observed. High levels of air pollution in Kaohsiung had greater effects than in Taipei after adjusting for seasonal variation. The most important factor was O3 in spring in Taipei. In children aged 0–6 years, asthma was associated with O3 in Taipei and SO2 in Kaohsiung, after controlling for the daily mean temperature and relative humidity.

Climate and Health in Maryland:

Maryland’s response to climate change has included creation of the Maryland Commission on Climate Change in 2007, and initiatives across many State agencies. The Commission coordinates these initiatives through the State Climate Action Plan. The Maryland Department of Health has partnered with the School of Public Health at the University of Maryland College Park to develop the 2016 Climate and Health Profile report, which estimates the health impacts of climate change in Maryland. Using historical health data and climate model projections, the report found that climate change will have a disproportionate impact on certain populations across the state. For example, extreme heat and extreme precipitation events during summer months increased the risk of hospitalization for asthma in Maryland by 22% and 11% respectively. But the extreme heat related risk for asthma hospitalization was more pronounced among non-Hispanic whites (33%) than non-Hispanic blacks (20%). Based on these findings, the Department and School have begun to engage with community organizations and various stakeholders to develop interventions and adaptations aimed at increasing resilience and mitigating some of the health impacts. Through these partnerships and projects, Maryland is using health data, climate projections, and the State Climate Action Plan to assist local communities and regional partners in climate adaptation activities.

Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city

Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4–5-day lag. When grass pollen concentrations were categorized into Met Office pollen ‘alert’ levels, ‘very high’ days (vs. ‘low’) were associated with increased admissions 2–5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20–1.78) at 3 days. Increased admissions were also associated with ‘high’ versus ‘low’ pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures.

STROBE-compliant article: Is continuity of care associated with avoidable hospitalization among older asthmatic patients?

Continuity of care (COC) has a proven relationship with health care outcomes. However, evidence regarding an association between COC and avoidable hospitalization for elderly patients with asthma is insufficient.A retrospective cohort study was performed using Taiwanese National Health Insurance claim data from 2004 to 2013. Patients were retrospectively followed for 2 years; the COC index (COCI) for asthma was measured in the 1st year, and avoidable hospitalization for asthma and follow-up time were determined in the subsequent year. Cox proportional hazards regression was employed to examine hazard ratios (HRs) between COC and avoidable hospitalization for asthma after adjustment for confounding factors. Adjusted HR (aHR) was also calculated by stratifying each variable to investigate whether the effect of COC on hospitalization for asthma was avoidable and how this varied across levels of COCI.Of 3356 patients included in this study, 1648 patients (49%) had a COCI of 1, and the average COCI was 0.73. Compared with patients with high COC (COCI = 1), those with low COC (COCI < 0.5) had a significantly higher risk of avoidable hospitalization for asthma (aHR = 2.68; 95% confidence interval [CI]: 1.55–4.63). In addition, after stratified analysis, we determined that COC plays a much more important role for patients who were women, had low insurance premiums, and had no comorbidities.High continuity of ambulatory asthma care is linked to a reduced risk of avoidable hospitalization for asthma in elderly asthmatic patients.