Effects of meteorological factors on daily hospital admissions for asthma in adults: a time-series analysis

The short-term effects of different cold spell definitions on asthma outpatient visits in Lanzhou, China

BACKGROUND

With global warming, most studies have focused on the health impacts of heat waves, while the health effects of cold spells, especially in developing countries, still need to be explored. Additionally, existing research on temperature extremes and asthma primarily targets severe asthma cases requiring hospitalization or emergency care, neglecting outpatients with mild symptoms. This study aimed to identify the optimal definition of cold spells in Lanzhou, China, and examine their association with outpatient asthma visits, identifying potentially vulnerable populations.

METHODS

This study collected daily asthma outpatient records, along with meteorological and air pollutant data, from January 1, 2017, to December 31, 2020, in Lanzhou, Gansu Province. Twenty-four cold spell definitions were developed using four temperature indices (daily mean, daily minimum, daily mean apparent, and daily minimum apparent temperatures), two thresholds (P10 and P5), and three durations (2, 3, and 4 days). A time-series fitted poisson generalized linear model (PGLM) and distributed lag nonlinear model (DLNM) were applied to estimate the short-term effects of cold seasons (November to March) on outpatient asthma visits, controlling for confounding factors such as humidity, air pollutants, time trends, holidays, and weekdays. Stratified analyses by sex and age were conducted to identify vulnerable populations and examine the influence of cold spell duration on asthma clinic visits.

RESULTS

Various definitions of cold spells influenced asthma outpatient visits, with similar trends observed. The model fit was best when the daily minimum apparent temperature was below the 10th percentile, and the duration was more significant than or equal to 4 days. Based on this optimal definition, for the total population, the main effect of the cold spell on asthma occurred at Lag0, Lag1, Lag6, and Lag7, with Lag7 producing the most significant effect (RR = 1.208, 95% CI: 1.052 ± 1.388). In the subgroup analyses, the cumulative effect of lag 0-7 days (Lag0-7) was higher for females and those in the 0-18 age group than for males and other age groups, respectively. In addition, the longer the duration of the cold spell from lag 3 days (Lag3) onwards, the greater its effect.

CONCLUSION

Cold spells in Lanzhou City can notably increase asthma outpatient visits, with females and individuals aged 0-18 particularly affected. Moreover, the longer a cold spell persists, the greater its impact, especially in the latter days of the event.

Meteorological factors and climate change impact on asthma: a systematic review of epidemiological evidence

OBJECTIVE

This systematic review aimed to investigate the epidemiological data about meteorological factors and climate change (CC) impact on asthma.

DATA SOURCES

A search was performed using three databases (Web of Science, Science Direct, and MEDLINE) for all relevant studies published from January 1, 2018, to December 31, 2022.

STUDY SELECTIONS

This systematic review complied with the PRISMA document's requirements, including studies related to meteorological factors and CC impact on asthma. The search included studies published in English or French language, and was based on title, abstract, and complete text. Documents not meeting inclusion requirements were excluded.

RESULTS

We identified 18 studies published in the last five years that were eligible for inclusion in this review. We found that these studies concerned European, Asian, American, and Oceanic cities. Extreme variations in temperature, humidity, wind speed, exceptional incidents like hurricanes, cold and heat waves, and seasonal shifts were strongly correlated with the worsening of asthmatic symptoms, particularly in childhood. In addition, excessive concentrations of air pollutants and aeroallergens were linked to pediatric asthma emergency hospital admissions.

CONCLUSIONS

A significant association between the consequences of CC and asthma in adults particularly in children has been demonstrated. Future research should quantify the impact of global change in climate regarding the aeroallergens' distribution in terms of geography and time. It is also necessary to research the impact of air pollution on asthmatic health, like sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and particles having an aerodynamic diameter lower than 2.5 µm (PM2.5).

The correlation between daily temperature, diurnal temperature range, and asthma hospital admissions in Lanzhou city, 2013-2020

BACKGROUND

With the backdrop of global climate change, the impact of climate change on respiratory diseases like asthma is receiving increasing attention. However, the effects of temperature and diurnal temperature range (DTR) on asthma are complex, and understanding these effects across different seasons, age groups, and sex is of utmost importance.

METHODS

This study utilized asthma hospitalization data from Lanzhou, China, and implemented a distributed lag nonlinear model (DLNM) to investigate the relationship between temperature and DTR and asthma hospitalizations. It considered differences in the effects across various seasons and population subgroups.

RESULTS

The study revealed that low temperatures immediately increase the risk of asthma hospitalization (RR = 1.2010, 95% CI: 1.1464, 1.2580), and this risk persists for a period of time. Meanwhile, both high and low DTR were associated with an increased risk of asthma hospitalization. Lower temperatures (RR = 2.9798, 95% CI: 1.1154, 7.9606) were associated with higher asthma risk in the warm season, while in the cold season, the risk significantly rose for the general population (RR = 3.6867, 95% CI: 1.7494, 7.7696), females (RR = 7.2417, 95% CI: 2.7171, 19.3003), and older individuals (RR = 18.5425, 95% CI: 5.1436, 66.8458). In the warm season, low DTR conditions exhibited a significant association with asthma hospitalization risk in males (RR = 7.2547, 95% CI: 1.2612, 41.7295) and adults aged 15-64 (RR = 9.9494, 95% CI: 2.2723, 43.5643). Children also exhibited noticeable risk within specific DTR ranges. In the cold season, lower DTR increases the risk of asthma hospitalization for the general population (RR = 3.1257, 95% CI: 1.4004, 6.9767). High DTR significantly increases the risk of asthma hospitalization in adults (RR = 5.2563, 95% CI: 2.4131, 11.4498).

CONCLUSION

This study provides crucial insights into the complex relationship between temperature, DTR, and asthma hospitalization, highlighting the variations in asthma risk across different seasons and population subgroups.

The impact of outdoor pollution and extreme temperatures on asthma-related outcomes: A systematic review for the EAACI guidelines on environmental science for allergic diseases and asthma

Air pollution is one of the biggest environmental threats for asthma. Its impact is augmented by climate change. To inform the recommendations of the EAACI Guidelines on the environmental science for allergic diseases and asthma, a systematic review (SR) evaluated the impact on asthma-related outcomes of short-term exposure to outdoor air pollutants (PM2.5, PM10, NO2, SO2, O3, and CO), heavy traffic, outdoor pesticides, and extreme temperatures. Additionally, the SR evaluated the impact of the efficacy of interventions reducing outdoor pollutants. The risk of bias was assessed using ROBINS-E tools and the certainty of the evidence by using GRADE. Short-term exposure to PM2.5, PM10, and NO2 probably increases the risk of asthma-related hospital admissions (HA) and emergency department (ED) visits (moderate certainty evidence). Exposure to heavy traffic may increase HA and deteriorate asthma control (low certainty evidence). Interventions reducing outdoor pollutants may reduce asthma exacerbations (low to very low certainty evidence). Exposure to fumigants may increase the risk of new-onset asthma in agricultural workers, while exposure to 1,3-dichloropropene may increase the risk of asthma-related ED visits (low certainty evidence). Heatwaves and cold spells may increase the risk of asthma-related ED visits and HA and asthma mortality (low certainty evidence).

Exploring the Relationship between Wind Patterns and Hospital Admissions Due to Respiratory Symptoms in Children

Respiratory disorders significantly impact adolescents' health, often resulting in hospital admissions. Meteorological elements such as wind patterns have emerged as potential contributors to respiratory symptoms. However, it remains uncertain whether fluctuations in wind characteristics over extended periods have a tangible impact on respiratory health, particularly in regions characterized by distinct annual wind patterns. Crete is situated in the central-eastern Mediterranean Sea and frequently faces southerly winds carrying Sahara Desert sand from Africa and northerly winds from the Aegean Sea. This retrospective study analyzes long-term wind direction data and their relationship to respiratory symptoms observed in children up to 14 years old admitted at the University Hospital of Heraklion between 2002 and 2010. Symptoms such as headache, dyspnea, dry cough, dizziness, tachypnea, throat ache, and earache were predominantly reported during the presence of southern winds. Fever, productive cough, and chest pain were more frequently reported during northern winds. Cough was the most common symptom regardless of the wind pattern. Southern winds were significantly associated with higher probabilities of productive or non-productive cough, headache, dyspnea, tachypnea, dizziness, earache, and throat ache. Northern winds were related to a higher incidence of productive cough. Rhinitis, asthma, allergies, pharyngitis, and sinusitis were related to southern winds, while bronchiolitis and pneumonia were associated with northern winds. These findings underscore the critical role of local climatic factors, emphasizing their potential impact on exacerbating respiratory conditions in children. Moreover, they point out the need for further research to elucidate the underlying mechanisms and develop targeted interventions for at-risk populations.

Relationship between air quality and asthma-related emergency hospital admissions in Mexico City 2017-2019

BACKGROUND

Previous studies found exposure to air pollution leads to exacerbations of asthma in paediatric and adult patients and increases asthma-related emergency hospital admissions (AREHA).

METHODS

AREHAs and levels of air pollutants (PM10, PM2.5 and NO2) were obtained from Mexico City for the period 2017-2019. A time-series approach was used to explore the relationship between air pollutants and AREHA. Relative risks of AREHA were estimated using a negative binomial regression in young children (less than 5 years) and adults (greater than 18 years).

RESULTS

There was a positive association between AREHA and PM10, PM2.5 and NO2 in adults, which remained after mutual adjustment for these pollutants. The relative risk (RR) of admission in adults increased by 3% (95% CI 1% to 4%) for a 10 µg/m3 increase in PM10, 1% (0.03% to 3%) for a 5 µg/m3 increase in PM2.5 and by 1% (0.06% to 2%) for a 5 µg/m3 increase in NO2. In contrast, in young children, AREHAs were negatively associated with PM10 after adjustment for NO2 (RR 0.97 (0.95 to 0.99) for a 10 µg/m3 and with NO2 after adjustment for PM10 and PM2.5 (RR 0.98 (0.96 to 0.99) and 0.97 (0.96 to 0.99), respectively, for a 5 µg/m3 increase in NO2). AREHAs in children were not associated with PM2.5 after adjustment for NO2.

CONCLUSIONS

Ambient air pollution, within the previous week, was associated with emergency hospital admissions for asthma to public hospitals in adults in Mexico City. The relationship in children was less consistent. Further work is needed to explore why differences between adults and children exist to inform appropriate interventions to benefit public health.

Associations between personal apparent temperature exposures and asthma symptoms in children with asthma

Ambient temperature and relative humidity can affect asthma symptoms. Apparent temperature is a measure of temperature perceived by humans that takes into account the effect of humidity. However, the potential link between personal exposures to apparent temperature and asthma symptoms has not been investigated. We conducted a panel study of 37 asthmatic children, aged 5-11 years, during an early spring season (average daily ambient temperature: 14°C, range: 7-18°C). Asthma symptoms were measured 4 times for each participant with a 2-week interval between consecutive measurements using the Childhood Asthma-Control Test (C-ACT). Average, minimum, and maximum personal apparent temperature exposures, apparent temperature exposure variability (TV), and average ambient temperature were calculated for the 12 hours, 24 hours, week, and 2 weeks prior to each visit. We found that a 10°C lower in 1-week and 2-week average & minimum personal apparent temperature exposures, TV, and average ambient temperature exposures were significantly associated with lower total C-ACT scores by up to 2.2, 1.4, 3.3, and 1.4 points, respectively, indicating worsened asthma symptoms. Our results support that personal apparent temperature exposure is potentially a stronger driver than ambient temperature exposures for the variability in asthma symptom scores. Maintaining a proper personal apparent temperature exposure could be an effective strategy for personalized asthma management.

Asthma hospitalisations and heat exposure in England: a case-crossover study during 2002-2019

BACKGROUND

Previous studies have reported an association between warm temperature and asthma hospitalisation. They have reported different sex-related and age-related vulnerabilities; nevertheless, little is known about how this effect has changed over time and how it varies in space. This study aims to evaluate the association between asthma hospitalisation and warm temperature and investigate vulnerabilities by age, sex, time and space.

METHODS

We retrieved individual-level data on summer asthma hospitalisation at high temporal (daily) and spatial (postcodes) resolutions during 2002-2019 in England from the NHS Digital. Daily mean temperature at 1 km×1 km resolution was retrieved from the UK Met Office. We focused on lag 0-3 days. We employed a case-crossover study design and fitted Bayesian hierarchical Poisson models accounting for possible confounders (rainfall, relative humidity, wind speed and national holidays).

RESULTS

After accounting for confounding, we found an increase of 1.11% (95% credible interval: 0.88% to 1.34%) in the asthma hospitalisation risk for every 1°C increase in the ambient summer temperature. The effect was highest for males aged 16-64 (2.10%, 1.59% to 2.61%) and during the early years of our analysis. We also found evidence of a decreasing linear trend of the effect over time. Populations in Yorkshire and the Humber and East and West Midlands were the most vulnerable.

CONCLUSION

This study provides evidence of an association between warm temperature and hospital admission for asthma. The effect has decreased over time with potential explanations including temporal differences in patterns of heat exposure, adaptive mechanisms, asthma management, lifestyle, comorbidities and occupation.

LSTM model for predicting the daily number of asthma patients in Seoul, South Korea, using meteorological and air pollution data

Asthma is a common respiratory disease that is affected by air pollutants and meteorological factors. In this study, we developed models that predict the daily number of patients receiving treatment for asthma using air pollution and meteorological data. A neural network with long short-term memory (LSTM) and fully connected (FC) layers was used. The daily number of asthma patients in the city of Seoul, the capital of South Korea, was collected from the National Health Insurance Service. The data from 2015 to 2018 were used as the training and validation datasets for model development. Unseen data from 2019 were used for testing. The daily number of asthma patients per 100,000 inhabitants was predicted. The LSTM-FC neural network model achieved a Pearson correlation coefficient of 0.984 (P < 0.001) and root mean square error of 3.472 between the predicted and original values on the unseen testing dataset. The factors that impacted the prediction were the number of asthma patients in the previous time step before the predicted date, type of day (regular day and day after a holiday), minimum temperature, SO₂, daily changes in the amount of cloud, and daily changes in diurnal temperature range. We successfully developed a neural network that predicts the onset and exacerbation of asthma, and we identified the crucial influencing air pollutants and meteorological factors. This study will help us to establish appropriate measures according to the daily predicted number of asthma patients and reduce the daily onset and exacerbation of asthma in the susceptible population.

Effects of Heatwaves on Hospital Admissions for Cardiovascular and Respiratory Diseases, in Southern Vietnam, 2010-2018: Time Series Analysis

This study investigated the associations between heatwaves and daily hospital admissions for cardiovascular and respiratory diseases in two provinces in Viet Nam known to be vulnerable to droughts during 2010-2018. This study applied a time series analysis with data extracted from the electronic database of provincial hospitals and meteorological stations from the corresponding province. To eliminate over-dispersion, this time series analysis used Quasi-Poisson regression. The models were controlled for the day of the week, holiday, time trend, and relative humidity. Heatwaves were defined as the maximum temperature exceeding P90th over the period from 2010 to 2018 during at least three consecutive days. Data from 31,191 hospital admissions for respiratory diseases and 29,056 hospitalizations for cardiovascular diseases were investigated in the two provinces. Associations between hospital admissions for respiratory diseases and heatwaves in Ninh Thuan were observed at lag 2, with excess risk (ER = 8.31%, 95% confidence interval: 0.64-16.55%). However, heatwaves were negatively associated with cardiovascular diseases in Ca Mau, which was determined amongst the elderly (age above 60), ER = -7.28%, 95%CI: -13.97--0.08%. Heatwaves can be a risk factor for hospital admission due to respiratory diseases in Vietnam. Further studies need to be conducted to assert the link between heat waves and cardiovascular diseases.

SARS-CoV-2 phase I transmission and mutability linked to the interplay of climatic variables: a global observation on the pandemic spread

The study aims to determine the impact of global meteorological parameters on SARS-COV-2, including population density and initiation of lockdown in twelve different countries. The daily trend of these parameters and COVID-19 variables from February 15th to April 25th, 2020, were considered. Asian countries show an increasing trend between infection rate and population density. A direct relationship between the time-lapse of the first infected case and the period of suspension of movement controls the transmissivity of COVID-19 in Asian countries. The increase in temperature has led to an increase in COVID-19 spread, while the decrease in humidity is consistent with the trend in daily deaths during the peak of the pandemic in European countries. Countries with 65°F temperature and 5 mm rainfall have a negative impact on COVID-19 spread. Lower oxygen availability in the atmosphere, fine droplets of submicron size together with infectious aerosols, and low wind speed have contributed to the increase in total cases and mortality in Germany and France. The onset of the D614G mutation and subsequent changes to D614 before March, later G614 in mid-March, and S943P, A831V, D839/Y/N/E in April were observed in Asian and European countries. The results of the correlation and factor analysis show that the COVID-19 cases and the climatic factors are significantly correlated with each other. The optimum meteorological conditions for the prevalence of G614 were identified. It was observed that the complex interaction of global meteorological factors and changes in the mutational form of CoV-2 phase I influenced the daily mortality rate along with other comorbid factors. The results of this study could help the public and policymakers to create awareness of the COVID-19 pandemic.

Associations of Emergency Department Visits for Asthma with Precipitation and Temperature on Thunderstorm Days: A Time-Series Analysis of Data from Louisiana, USA, 2010-2012

BACKGROUND

Studies of thunderstorm asthma to understand risk factors using high-resolution climate data and asthma outcomes on a large scale are scarce. Moreover, thunderstorm asthma is not well studied in the United States.

OBJECTIVES

We examined whether climate parameters involved in thunderstorms are associated with emergency department (ED) visits for acute asthma attacks in the United States.

METHODS

We analyzed 63,789 asthma-related, daily ED visits for all age groups, and thunderstorm-associated climate data in Louisiana during 2010 through 2012. We performed time-series analyses using quasi-Poisson regression models with natural cubic splines of date, parish, holiday, day of week, season, daily maximum concentrations of ozone (O3) and fine particulate matter [PM ≤2.5μm in aerodynamic diameter (PM2.5)], and daily mean pressure, precipitation, and temperature. Because of a significant interaction effect between temperature and lightning days on asthma-related visits, we performed stratified analyses by days with/without lightning or thunderstorm (defined by any lightning and precipitation).

RESULTS

On thunderstorm days, higher asthma-related ED visits were associated with higher daily mean precipitation [relative risk (RR)=1.145 per 1 g/m2/s (95% CI: 1.009, 1.300)] and lower daily mean temperature [RR=1.011 per 1°C change (1.000-1.021)] without carry-over effect to the next non-thunderstorm day. These higher risks were found mainly among children and adults <65 years of age. We observed similar results on lightning days. However, we did not find similar associations for non-thunderstorm or non-lightning days. Daily maximum O3 and PM2.5 levels were not significantly associated with asthma ED visits on thunderstorm days.

DISCUSSION

Higher precipitation and lower temperature on thunderstorm days appear to contribute to asthma attacks among people with asthma, suggesting they should consider taking precautions during thunderstorms. EDs should consider preparing for a potential increase of asthma-related visits and ensuring sufficient stock of emergency medication and supplies for forecasted severe thunderstorm days. https://doi.org/10.1289/EHP10440.

The association between outdoor allergens - pollen, fungal spore season and high asthma admission days in children and adolescents

Periods when asthma admissions peaks have serious implications for asthma sufferers and hospitals. We assessed the association between aeroallergen exposure and childhood asthma peak periods during two grass pollen seasons using the Melbourne Air Pollen Children and Adolescent Health (MAPCAH) study conducted in Melbourne, Australia. Two peak periods were identified. Effect modifications by atopy and sex were considered. All pollen 2 days prior was associated with increased odds of these peak periods. Same day fungal spores, but not pollen, were important. Grass at lag 2 was associated with increased odds 1.03 (95%CI 1.01, 1.05) as was the same day Alternaria 1.02 (1.00, 1.04) per spore/m³ for boys. In addition to pollen, fungal spores particularly Alternaria may result in days of high exacerbations during pollen seasons. Further guidance is needed to better prepare families/carers with information about the increased risk of asthma attacks in children prior to pollen seasons.

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

Background

Studies 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.

Methods

We 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.

Results

From 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).

Conclusions

There 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01960-8.

Effects of air temperature on the number of ambulance calls for asthma during cold season in Nur-Sultan- the second coldest capital in the world

Deleterious effect of cold on overall mortality is well-established. We studied associations between the air temperature and the number f ambulance calls for asthma in Nur-Sultan, Kazakhstan – the second coldest capital in the world. Daily counts of ambulance calls for asthma in Nur-Sultan for the cold seasons (October-March) 2006–2010 were obtained from the Municipal Ambulance Station. Associations between the number of calls and mean and minimum apparent temperatures (average for lags 0–15) were studied using first-order Poisson auto-regression models controlling for wind speed and effects of month, year, weekends and holidays. Altogether, there were 7373 ambulance calls for asthma during the study period. An inverse association between minimum apparent temperature and the number of calls was observed for the age-group 60 years and older. A decrease of the minimum apparent temperature by 1°C was associated with an increase in the number of calls by 1.7% (95% CI: 0.1%-3.3%) across the whole temperature spectrum. No associations in other age groups were found. Our results suggest an inverse association between the average 15-day lag minimum apparent temperature and the number of ambulance calls during the cold season in Nur-Sultan, but this is limited to the oldest age-group.

Optimised deep neural network model to predict asthma exacerbation based on personalised weather triggers

Background - Recently, there have been attempts to develop mHealth applications for asthma self-management. However, there is a lack of applications that can offer accurate predictions of asthma exacerbation using the weather triggers and demographic characteristics to give tailored response to users. This paper proposes an optimised Deep Neural Network Regression (DNNR) model to predict asthma exacerbation based on personalised weather triggers. Methods - With the aim of integrating weather, demography, and asthma tracking, an mHealth application was developed where users conduct the Asthma Control Test (ACT) to identify the chances of their asthma exacerbation. The asthma dataset consists of panel data from 10 users that includes 1010 ACT scores as the target output. Moreover, the dataset contains 10 input features which include five weather features (temperature, humidity, air-pressure, UV-index, wind-speed) and five demography features (age, gender, outdoor-job, outdoor-activities, location). Results - Using the DNNR model on the asthma dataset, a score of 0.83 was achieved with Mean Absolute Error (MAE)=1.44 and Mean Squared Error (MSE)=3.62. It was recognised that, for effective asthma self-management, the prediction errors must be in the acceptable loss range (error<0.5). Therefore, an optimisation process was proposed to reduce the error rates and increase the accuracy by applying standardisation and fragmented-grid-search. Consequently, the optimised-DNNR model (with 2 hidden-layers and 50 hidden-nodes) using the Adam optimiser achieved a 94% accuracy with MAE=0.20 and MSE=0.09. Conclusions - This study is the first of its kind that recognises the potentials of DNNR to identify the correlation patterns among asthma, weather, and demographic variables. The optimised-DNNR model provides predictions with a significantly higher accuracy rate than the existing predictive models and using less computing time. Thus, the optimisation process is useful to build an enhanced model that can be integrated into the asthma self-management for mHealth application.

Patterns of medical care utilization according to environmental factors in asthma and chronic obstructive pulmonary disease patients

BACKGROUND/AIMS

Weather and air pollution are associated with the exacerbation of respiratory diseases. We investigated patterns of medical care use according to meteorological factors and air pollution in patients with asthma or chronic obstructive pulmonary disease (COPD).

METHODS

We analyzed the medical care utilization patterns of patients with asthma or COPD registered in the Korea Health Insurance Review and Assessment database for the period 2007 to 2013. The patterns were divided into hospitalization and emergency department (ED) use.

RESULTS

The medical care use of patients with asthma or COPD increased when the mean temperature and relative humidity were lower, and the temperature difference and atmospheric pressure were greater. Medical care use increased with the concentrations of particulate matter and ozone. Among age groups, sensitivity to pollutants was greatest in patients aged ≥ 65 years. The effect of being elderly was greater for asthma than for COPD, with a higher hospitalization rate. ED utilization affected by environmental factors was significantly greater for females and hospitalization was significantly more common for males.

CONCLUSION

Meteorological factors and air pollutants were shown to contribute to increased medical care utilization by patients with asthma and COPD, particularly elderly patients. The overall effect was greater for COPD, but the effect in elderly patients was greater for asthma. In addition, the patterns of change in medical care use due to environmental factors differed according to sex.

Mortality and morbidity of asthma and chronic obstructive pulmonary disease associated with ambient environment in metropolitans in Taiwan

Background

This study investigated risks of mortality from and morbidity (emergency room visits (ERVs) and outpatient visits) of asthma and chronic obstructive pulmonary disease (COPD) associated with extreme temperatures, fine particulate matter (PM_2.5), and ozone (O₃) by sex, and age, from 2005 to 2016 in 6 metropolitan cities in Taiwan.

Methods

The distributed lag non-linear model was employed to assess age (0–18, 19–39, 40–64, and 65 years and above), sex-cause-specific deaths, ERVs, and outpatient visits associated with extreme high (99^th percentile) and low (5^th percentile) temperatures and PM_2.5 and O₃ concentrations at 90^th percentile. Random-effects meta-analysis was adopted to investigate cause-specific pooled relative risk (RR) and 95% confidence intervals (CI) for the whole studied areas.

Results

Only the mortality risk of COPD in the elderly men was significantly associated with the extreme low temperatures. Exposure to the 90^th percentile PM_2.5 was associated with outpatient visits for asthma in 0–18 years old boys [RR = 1.15 (95% CI: 1.09–1.22)]. Meanwhile, significant elevation of ERVs of asthma for females aged 40–64 years was associated with exposure to ozone, with the highest RR of 1.21 (95% CI: 1.05–1.39).

Conclusions

This study identified vulnerable subpopulations who were at risk to extreme events associated with ambient environments deserving further evaluation for adaptation.

The short-term associations of chronic obstructive pulmonary disease hospitalizations with meteorological factors and air pollutants in Southwest China: a time-series study

Chronic obstructive pulmonary disease (COPD) is the fourth major cause of mortality and morbidity worldwide and is projected to be the third by 2030. However, there is little evidence available on the associations of COPD hospitalizations with meteorological factors and air pollutants in developing countries/regions of Asia. In particular, no study has been done in western areas of China considering the nonlinear and lagged effects simultaneously. This study aims to evaluate the nonlinear and lagged associations of COPD hospitalizations with meteorological factors and air pollutants using time-series analysis. The modified associations by sex and age were also investigated. The distributed lag nonlinear model was used to establish the association of daily COPD hospitalizations of all 441 public hospitals in Chengdu, China from Jan/2015-Dec/2017 with the ambient meteorological factors and air pollutants. Model parameters were optimized based on quasi Akaike Information Criterion and model diagnostics was conducted by inspecting the deviance residuals. Subgroup analysis by sex and age was also performed. Temperature, relative humidity, wind and Carbon Monoxide (CO) have statistically significant and consistent associations with COPD hospitalizations. The cumulative relative risk (RR) was lowest at a temperature of 19℃ (relative humidity of 67%). Both extremely high and low temperature (and relative humidity) increase the cumulative RR. An increase of wind speed above 4 mph (an increase of CO above 1.44 mg/m³) significantly decreases (increases) the cumulative RR. Female populations were more sensitive to low temperature and high CO level; elderly (74+) populations are more sensitive to high relative humidity; younger populations (< = 74) are more susceptible to CO higher than 1.44 mg/m³. Therefore, people with COPD should avoid exposure to adverse environmental conditions of extreme temperatures and relative humidity, low wind speed and high CO level, especially for female and elderly patients who were more sensitive to extreme temperatures and relative humidity.

Changes in ambient temperature increase hospital outpatient visits for allergic rhinitis in Xinxiang, China

BACKGROUND

The effect of ambient temperature on allergic rhinitis (AR) remains unclear. Accordingly, this study aimed to explore the relationship between ambient temperature and the risk of AR outpatients in Xinxiang, China.

METHOD

Daily data of outpatients for AR, meteorological conditions, and ambient air pollution in Xinxiang, China were collected from 2015 to 2018. The lag-exposure-response relationship between daily mean temperature and the number of hospital outpatient visits for AR was analyzed by distributed lag non-linear model (DLNM). Humidity, long-time trends, day of the week, public holidays, and air pollutants including sulfur dioxide (SO2), and nitrogen dioxide (NO2) were controlled as covariates simultaneously.

RESULTS

A total of 14,965 AR outpatient records were collected. The relationship between ambient temperature and AR outpatients was generally M-shaped. There was a higher risk of AR outpatient when the temperature was 1.6-9.3 °C, at a lag of 0-7 days. Additionally, the positive association became significant when the temperature rose to 23.5-28.5 °C, at lag 0-3 days. The effects were strongest at the 25th (7 °C) percentile, at lag of 0-7 days (RR: 1.32, 95% confidence intervals (CI): 1.05-1.67), and at the 75th (25 °C) percentile at a lag of 0-3 days (RR: 1.15, 95% CI: 1.02-1.29), respectively. Furthermore, men were more sensitive to temperature changes than women, and the younger groups appeared to be more influenced.

CONCLUSIONS

Both mild cold and mild hot temperatures may significantly increase the risk of AR outpatients in Xinxiang, China. These findings could have important public health implications for the occurrence and prevention of AR.

Effect of Ambient Temperature on Daily Nebulized Asthma Hospital Visits in a Tropical City of Dhaka, Bangladesh

The acute effect of temperature on asthma morbidity in Bangladesh is not well understood. As climate varies extensively in different parts of the world, the relation between temperature and asthma might also differ. We investigated the association between temperature and asthma-related hospital visits in the tropical city of Dhaka. We analyzed information from a total of 5989 asthma patients who received ambulatory care in the form of nebulized medication at the National Asthma Center in Mohakhali, Dhaka from February to November 2013. A time-stratified case-crossover study was conducted to estimate the effect of daily temperature, with consideration of delayed effects and possible confounders such as relative humidity and political strikes. An inverse association was observed between temperature and the number of hospital visits. The effect was delayed for approximately a week. A degree centigrade decrease in mean temperature (averaged across lags 0-6) was associated with an increase of approximately 4.5% (95% CI 1.5, 7.5) in all asthma visits. The association was evident in adult males but marginal in elderly males. A positive association (lag 0) was observed among adult females, whereas no association was observed among children. Strikes significantly modified the effect among the elderly. Findings suggest temperature declines affect asthma outcomes in a warm climate, and this effect can be delayed and vary by sex and age group.

Summer storms and their effects on the spectrum and quantity of airborne bioparticles in Bratislava, Central Europe

A thunderstorm is a risk factor for severe respiratory allergy or asthma attacks in patients suffering from pollen/spore allergy. This study aimed to investigate the changes in the spectrum and quantity of pollen and fungal spores in the air of Bratislava during summer storms as well as the impact of selected environmental parameters on these changes. Pollen/spore samples were collected using a Burkard volumetric aerospore trap during summer 2016. To identify those types of pollen/spores that may harm human health during the storm episodes, we analysed how the concentration of individual bioparticles in the air changed during pre-storm/storm/post-storm periods. The effect of environmental variables on the concentration of selected pollen/spore types was evaluated through Spearman's correlation analysis. The results of our study suggest that thunderstorm-related respiratory allergy symptoms in the study area may be caused by (1) spores of Myxomycetes, the airborne concentration of which increases due to an increase in wind speed during the pre-storm period; (2) ruptured pollen and Diatripaceae spores, the concentration of which increases due to increase in precipitation and relative air humidity, respectively, during the storm period; and (3) spores of Fusarium and Leptosphaeria, the concentration of which increases due to increase in precipitation and air temperature, respectively, during the post-storm period.

The response ranges of pulmonary function and the impact criteria of weather and industrial influence on patients with asthma living in Vladivostok

PURPOSE

To determine the response of pulmonary function (PF) to the influence of environmental factors in patients with different levels of asthma control.

MATERIALS AND METHODS

Patients with controlled (136 people) and uncontrolled (96 people) asthma living in the conditions of monsoon climate and technogenic pollution in Vladivostok were examined. Discriminant analysis that provides the basis for dividing initial data into classes, as according to standards and expert estimates, was used to calculate ranges of PF response in asthma patients. The selection of discriminant functions with the highest values of constant and coefficient made it possible to identify the optimal quantitative ranges.

RESULTS

Analysis of the discriminant value of Wilks' lambda (α) has shown that the intensity of PF response to climatic and technogenic factors varies depending on level of disease control (controlled asthma - α = 0.67-0.79, uncontrolled asthma - α =0.05-0.44). The criteria and ranges of PF response also differ depending on level of disease control. In controlled asthma, PF response reflects an adaptive-compensatory dependence. The reaction to the environmental factors is rather weak; therefore, it could be detected by only more sensitive examination method (body plethysmography). In uncontrolled asthma, the response to the influence of environment quality is active and could be clearly identified by spirography.

CONCLUSIONS

The climatic and technogenic environment of Vladivostok causes strong pathogenic impact on patients with uncontrolled asthma. The effects of dust fraction 0-1 μm, deeply penetrating into respiratory organs, and day-to-day variability of wind speed, which induces weather sensitivity, are particularly adverse.

Effects of Floods on the Incidence of Acute Hemorrhagic Conjunctivitis in Mengshan, China, from 2005 to 2012

This study aimed to examine the association between floods and the morbidity of acute hemorrhagic conjunctivitis (AHC) in Mengshan, China. Relying on the longitudinal data, a generalized additive model (GAM) was applied to quantify the relationship between the morbidity of AHC and floods from 2005 to 2012, controlling for other meteorological variables. Years lived with disability (YLDs) and attributable YLDs were used as the measure of the burden of AHC because of the floods. Multivariable analysis showed that floods were significantly associated with an increased risk of the morbidity of AHC (rate ratio [RR] = 2.136, 95% CI: 2.109-2.163). The total YLDs per 1,000 in Mengshan was 0.2001, although the value in females was higher than that in males (0.2351 versus 0.1686). The YLD per 1,000 of AHC in Mengshan was highest between the ages of 5 and 14 years (0.6530), followed by the age of 0-4 years (0.3325). The attributable YLD per 1,000 of AHC due to the floods in Mengshan was 0.0434 (95% CI: 0.0425-0.0442). Our study confirms that floods have significantly increased the risks of AHC in the selected study area. Females and youngsters may be the vulnerable populations to develop the flood-related disease.

Distance Education to Improve the Quality of Asthma Treatment in Primary Health Care

Objective: The mere dissemination of standard care recommendations has been insufficient to improve clinical results in patients with asthma. The objective of the present study was to evaluate the clinical effectiveness of a multifaceted asthma distance education for primary care providers. Methods: Cluster randomized controlled trial. Full primary care teams were included if they had access to telehealth support and free basic asthma treatment. Before randomization, selected teams indicated asthma patients between 5-45 years old for inclusion. The intervention group received three interactive online sessions, printed educational material, reminders, booklet for patients, and frequent stimulus to use consulting services. The control group received no intervention. Symptomfree days per two weeks was the primary result. Controlled asthma, unscheduled asthma doctor visits, and preventive inhaled corticosteroid use were the secondary results. Six months after intervention, the results were compared with baseline data using generalized estimating equations for repeated measures and clustering effect. Results: Were enrolled 71 primary care teams and 443 individuals. Most patients (60.3%) were female, and 44% were younger than 12 years old. The attendance of interactive sessions by the teams was 50%. The odds ratio (OR) for additional symptom-free day was 1.31 (95%CI 0.61-2.82; p=0.49). For the secondary results, the results were: controlled asthma OR 1.29 (95%CI 0.89-1.87; p=0.18); unscheduled asthma doctor visits OR 0.81 (95%CI 0.60-1.10; p=0.17); and preventive inhaled corticosteroid use OR 1.02 (95%CI 0.71-1.47; p=0.91). Conclusions: Multifaceted distance education in asthma care for primary care providers was not effective to improve patients’ results. Telemedicine needs to deal with significant obstacles in professional education. ClinicalTrials.gov registry: NCT01595971. 

Impact of weather conditions on childhood admission for wheezy chest and bronchial asthma

Background: Climate change represents a possible threat to patients with bronchial asthma. The purpose of this study was to investigate any association between specific meteorological conditions and the rate of hospital admission for bronchial asthma and wheezy chest. Methods: A retrospective study was conducted to observe the effects of changes in some meteorological variables on children aged 1-13 years with bronchial asthma and wheezy chest. Data were obtained from hospital registries for the study period involving all patients admitted with the diagnosis of wheezy chest and bronchial asthma. The meteorological data were obtained from the Iraqi World Meteorological Organization and Seismology and consisted of the mean monthly values of humidity, rain, temperature, dust, wind, and thunderstorms. The correlation between the mean monthly admission for bronchial asthma and changes in weather variables were investigated. Results: There were 1043 admissions for asthma or wheezy chest (7.76%). Out of all asthma cases, 75% (n=783) were 1-5 years, while 25% (n=260) were 6-13 years. Male patients predominate 67.8%, with a male to female ratio of 2:1. Hospital admissions for asthma and wheezy chest showed a seasonal variation especially for younger children. Higher monthly admission rates were associated with high relative humidity, rain, increase in wind speed, and lower temperature, whereas rising dust and thunderstorms did not show notable effects on children's admission for asthma. Conclusion: The findings suggested that changes in weather conditions, especially high relative humidity and cold weather, may trigger asthma attacks especially in younger children, and thus protective measures are recommended for at risk children.

Incidence of the Acute Symptom of Chronic Periodontal Disease in Patients Undergoing Supportive Periodontal Therapy: A 5-Year Study Evaluating Climate Variables

Although patients under supportive periodontal therapy (SPT) have a stable periodontal condition, the acute symptom of chronic periodontal disease occasionally occurs without a clear reason. Therefore, in the present study, to obtain a better understanding of this relationship in patients undergoing SPT, we hypothesized that the acute symptom of chronic periodontal disease might be affected by climate factors. We conducted a questionnaire study and carried out oral examinations on patients undergoing SPT who had been diagnosed as having the acute symptom of chronic periodontal disease. We collected climate data from the local climate office in Okayama city, Japan. We predicted parameters that affect the acute symptom of chronic periodontal disease with unidentified cause and divided patients into high and low groups in terms of climate predictors. Then we defined the cut-off values of parameters showing significant differences in the incidence of the acute symptom of chronic periodontal disease. The incidence of the acute symptom of chronic periodontal disease with unidentified cause was significantly different when the cases were classified according to the maximum hourly decrease in barometric pressure (1.5 and 1.9 hPa) (p = 0.04 and p = 0.03, respectively). This suggests that climate variables could be predictors of the acute symptom of chronic periodontal disease. Therefore, gaining a better understanding of these factors could help periodontal patients undergoing SPT prepare to avoid the acute symptom of chronic periodontal disease.

Effects of Meteorological Factors on Hospitalizations in Adult Patients with Asthma: A Systematic Review

Background

Environmental factors such as weather variables contribute to asthma exacerbation. The impact of meteorological factors on asthma-related hospital admissions (HAs) or emergency department visits (EDVs) has been assessed in the literature. We conducted a systematic review to establish a conclusion of whether these findings from the literature are consistent and generalizable or if they vary significantly by certain subgroups.

Objective

This study aims to review the effect of meteorological variables on asthma HAs and EDVs in adults, to identify knowledge gaps and to highlight future research priorities.

Method

A systematic search was conducted in electronic databases such as PubMed, Embase, and CINAHL. All studies published in English were screened and included if they met the eligibility criteria. Two independent reviewers assessed the quality of the studies and extracted the data. The available evidence was summarized and presented using a harvest plot.

Results

Our initial search returned a total of 3887 articles. After screening titles, abstracts, and full texts, 16 studies were included. Thirty-one percent of the included studies (5/16) found that temperature was the only factor associated with asthma hospitalization or EDVs. Six studies (37%) found that both temperature and relative humidity were associated with HAs. Four studies (25%) identified thunderstorms as a possible factor associated with asthma hospitalization in adults.

Conclusion

Our review suggests that HAs and EDVs due to asthma are associated with many meteorological factors. Among the articles included in this review, changing temperature is the most commonly studied variable. We did not find studies that measured barometric pressure, weather phenomena, or the effect of tornados. To develop effective strategies to protect subjects at risk, further studies are required.

Impact of air pollution on hospital admissions with a focus on respiratory diseases: a time-series multi-city analysis

Together with the growing availability of data from electronic records from healthcare providers and healthcare systems, an assessment of associations between different environmental parameters (e.g., pollution levels and meteorological data) and hospitalizations, morbidity, and mortality has become possible. This study aimed to assess the association of air pollution and hospitalizations using a large database comprising almost all hospitalizations in Poland. This time-series analysis has been conducted in five cities in Poland (Warsaw, Białystok, Bielsko-Biała, Kraków, Gdańsk) over a period of almost 4 years (2014-2017, 1255 days), covering more than 20 million of hospitalizations. The hospitalizations have been extracted from the National Health Fund registries as daily summaries. Correlation analysis and distributed lag nonlinear models have been used to investigate for statistically relevant associations of air pollutants on hospitalizations, trying by various methods to minimize potential bias from atmospheric parameters, days of the week, bank holidays, etc. A statistically significant increase of respiratory disease hospitalizations has been detected after peaks of particulate matter concentrations (particularly PM2.5, between 0.9 and 4.5% increase per 10 units of pollutant increase, and PM10, between 0.9 and 3.5% per 10 units of pollutant increase), with a typical time lag between the pollutant peak and the event of 2 to 6 days. For other pollution parameters and other types of hospitalizations (e.g., cardiovascular events, eye and skin diseases, etc.), a weaker and ununiform correlations were recorded. Ambient air pollution exposure increases are associated with a short-term increase of hospitalizations due to respiratory tract diseases. The most prominent effect was recorded with the correlation of PM2.5 and PM10. There is only weak evidence indicating that such short-term associations exist between peaks of air pollution concentrations and increased hospitalizations for other (e.g., cardiovascular) diseases. The obtained information could be used to better predict hospitalization patterns and costs for the healthcare system and perhaps trigger additional vigilance on particulate matter pollution in the cities.

Effects and interaction of meteorological factors on influenza: Based on the surveillance data in Shaoyang, China

BACKGROUND

Previous studies have demonstrated that meteorological factors influence the incidence of influenza. However, little is known regarding the interactions of meteorological factors on the risk of influenza in China.

OBJECTIVE

The study aimed to evaluate the associations between meteorological factors and influenza in Shaoyang of southern China, and explore the interaction of temperature with humidity and rainfall.

METHODS

Weekly meteorological data and disease surveillance data of influenza in Shaoyang were collected from 2009 to 2012. According to the incubation period and infectious period of influenza virus, the maximum lag period was set as 3 weeks. A generalized additive model was conducted to evaluate the effect of meteorological factors on the weekly number of influenza cases and a stratification model was applied to investigate the interaction.

RESULTS

During the study period, the total number of influenza cases that were notified in the study area was 2506, with peak times occurring from December to March. After controlling for the confounders, each 5 °C decrease in minimum temperature was related to 8% (95%CI: 1-15%) increase in the number of influenza cases at a 1-week lag. There was an interaction between minimum temperature and relative humidity and the risk of influenza was higher in cold and less humid conditions than other conditions. The interaction between minimum temperature and rainfall was not statistically significant in our study.

CONCLUSIONS

The study suggests that minimum temperature is inversely associated with influenza in the study area of China, and the effect can be modified by relative humidity. Meteorological variables could be integrated in current public health surveillance system to better prepare for the risks of influenza.

Association of molds and metrological parameters to frequency of severe asthma exacerbation

Background

Sensitization to airborne molds may be a risk factor for severe asthma and direct cause of asthma exacerbation (AE).

Methods

A prospective, 1-year (April 2016-March 2017) study, done in Kuwait Allergy Centre, investigated the link between AEs with exposure to outdoor molds and the role of meteorological parameters in mold sensitized patients and compared with non-allergic asthma patients who had asthma deterioration. The total of 676 adult asthmatics with moderate-severe AEs were included and divided into atopic (85.65%) and non-atopic group. Atopy was defined by positive skin prick test (SPT) to at least one inhalant allergen. Data regarding atopy and asthma severity were collected from patient's records. Patients with symptoms and signs of acute respiratory infection and patient sensitized to indoor allergens only were excluded. Daily count of local pollens (Salsola kali, Bermuda grass) and molds (Aspergillus, Alternaria and Cladosporium) were obtained from the Aerobiology department. Daily metrological parameters (atmospheric pressure-AP, temperature-T and relative humidity-RH) were provided by Kuwait Environment Public Authority. Count of spores/m³ and weather variable are shown on weekly basis. The year circle was divided into 4 Seasons (1, 2, 3, 4) accordingly to typical desert climate.

Results

Sensitization to molds was relatively high but significantly less (25.0%) if compared to the pollens sensitization. The highest number of AEs was in season 4 for both molds and pollens sensitized patients. Seasonal patterns for both allergens were significant and positively correlated with RH and AP. In season 1 only, mold sensitized patients showed higher rate of AEs. Non-atopic patients have been less sensitive to increased RH than atopic. Negative correlation with T was similar in both atopic and non-atopic patients.

Conclusion

Despite of high rate of sensitization to molds, their significant role in triggering AE was not found in desert environment. Typical desert climate and high allergencity of local weeds outweigh the influence of the molds.

Different sensitivities to ambient temperature between first- and re-admission childhood asthma cases in Hong Kong - A time series study

OBJECTIVES

Asthma can be triggered by various factors due to different etiologies. Environmental factors remain a common trigger of asthma, especially amongst children, and such ambient exposures can be harder to avoid compared to behavioral triggers. As such, the contribution of environmental factors may be enhanced when considering repeat asthma cases compared to initial presentations. To test this hypothesis, we assessed associations between ambient temperature and hospital admissions for asthma in Hong Kong and stratified admission records into first and repeat asthma hospitalizations.

METHODS

The daily number of asthma hospitalizations among children aged 0-5 years in Hong Kong during 2007-2011 was regressed on daily mean temperature using distributed lagged nonlinear models, with adjustment for seasonal patterns, day-of-week effects, and other meteorological factors and air-pollutants. Analyses were stratified by summer/winter and by type of admission (first admission and repeated admission).

RESULTS

About 33% of the 12284 asthma hospitalizations were repeat admissions. Repeat admissions demonstrated higher sensitivity to high temperature in the summer. During this period, high temperatures were associated with increased risk of repeat admission but not with first admissions: RR (95% CI) comparing 31 °C vs. 29 °C across lags 0-15 days was 3.40 (1.26, 9.18) and 0.74 (0.31, 1.77) for repeat and first admissions respectively. In the cold season, all admissions increased with falls in temperature, with slightly stronger associations apparent for repeat admissions compared to first admission: 1.20 (1.00, 1.44) vs. 1.10 (0.96, 1.26) respectively comparing risk at 15 °C vs. 12 °C across lags 0-5 days.

CONCLUSIONS

To our knowledge, this is the first study to show stronger associations between ambient temperature and repeat asthma admissions compared to first admissions. The higher sensitivity among those experiencing repeat admissions may allow for more personalized disease management. Given the substantial differences in associations by admission type, future studies of ambient exposures on asthma should consider analyzing the two groups separately.

Climate Change and Healthcare Sustainability in the Agincourt Sub-District, Kruger to Canyons Biosphere Region, South Africa

As low-income communities are most vulnerable to climate-associated health concerns, access to healthcare will increase in importance as a key priority in South Africa. This study explores healthcare sustainability in the Agincourt sub-district, Kruger to Canyons Biosphere Region in Mpumalanga, South Africa. A rapid assessment and response methodology (RAR) was implemented, which includes the examination of previous studies conducted in the sub-district, the mapping of healthcare facilities in the area, and the implementation of a facility infrastructure and workforce capacity investigation by means of key informant (KI) interviews at eight healthcare facilities. Findings indicate that the greatest need across the facilities relate to access to medical doctors and pharmacists. None of the facilities factored climate associations with health into their clinical care strategies. The necessity to train healthcare facility staff on aspects related to climate change, health, and sustainability is highlighted. Environmental health practitioners should also be incorporated in grassroots community climate adaptation strategies. Outcomes further indicate the need for the advancement of integrated healthcare and climate adaptation strategies that focus on strengthening healthcare systems, which may include novel technological approaches such as telemedicine. Policy makers need to be proactive and pre-emptive in finding and improving processes and models to render healthcare services prepared for climate change.

A survey of ambulatory-treated asthma and correlation with weather and air pollution conditions within Taiwan during 2001-2010

Objective: This study of asthma was performed to evaluate annual trends in emergency department (ED) for 10 years. Weather and air pollution factors affecting asthma were also studied in order to identify the important factors and alert the public in advance. Methods: A survey of ambulatory-treated asthma patients was performed and the correlations with weather and air pollution factors examined in a cohort of one million patients in 2010. The fixed-cohort study analyzed trends, medical costs, and annual prevalence grouped by age and gender. Results: The number of asthma patients visiting EDs and non-emergency (non-ED) clinics significantly increased, with average annual percentage changes (AAPCs) of 2.3 and 4.6%, respectively. The average direct medical cost for EDs was increased significantly as compared with that of non-ED visits. Classification of asthma visits by hospital level indicated that local hospitals and others exhibited a significantly increasing trend (AAPC =15.3% [95% CI: 14.3-16.2]). The annual prevalence of asthma in males, females, and children was significantly increased (AAPCs of 1.5, 1.8, and 3.9%, respectively). Asthma patient hospitalizations were significantly correlated with temperature, humidity, and air pollution factors. Conclusions: The number of non-ED visits due to asthma increased, and the average direct medical cost for ED admissions also increased. Asthma patients tended to visit local hospitals primarily. Asthma visits by children increased, but a decrease was observed in adults. The number of hospitalized asthma patients was negatively correlated with temperature and humidity but positively correlated with the levels of PM_2.5, PM₁₀, and NO₂.

Seasonal asthma in Melbourne, Australia, and some observations on the occurrence of thunderstorm asthma and its predictability

We examine the seasonality of asthma-related hospital admissions in Melbourne, Australia, in particular the contribution and predictability of episodic thunderstorm asthma. Using a time-series ecological approach based on asthma admissions to Melbourne metropolitan hospitals, we identified seasonal peaks in asthma admissions that were centred in late February, June and mid-November. These peaks were most likely due to the return to school, winter viral infections and seasonal allergies, respectively. We performed non-linear statistical regression to predict daily admission rates as functions of the seasonal cycle, weather conditions, reported thunderstorms, pollen counts and air quality. Important predictor variables were the seasonal cycle and mean relative humidity in the preceding two weeks, with higher humidity associated with higher asthma admissions. Although various attempts were made to model asthma admissions, none of the models explained substantially more variation above that associated with the annual cycle. We also identified a list of high asthma admissions days (HAADs). Most HAADs fell in the late-February return-to-school peak and the November allergy peak, with the latter containing the greatest number of daily admissions. Many HAADs in the spring allergy peak may represent episodes of thunderstorm asthma, as they were associated with rainfall, thunderstorms, high ambient grass pollen levels and high humidity, a finding that suggests thunderstorm asthma is a recurrent phenomenon in Melbourne that occurs roughly once per five years. The rarity of thunderstorm asthma events makes prediction challenging, underscoring the importance of maintaining high standards of asthma management, both for patients and health professionals, especially during late spring and early summer.

Temperature drop and the risk of asthma: a systematic review and meta-analysis

The relationship between asthma and temperature changes remains controversial. The aim of this study was to investigate the association between temperature changes and the risk of asthma. A total of 26 studies (combined total number of subjects N > 26 million), covering 13 countries and Costa Rica, were identified by using a series of keywords in different combinations and searching the papers in PubMed, EMBSEA, Web of Science, MEDLINE, AIM, LILACS, and WPRIM before February 2016. Most of the papers were published in English. Random-effects meta-analyses were performed to evaluate the effect of temperature drop on risk of asthma. Several secondary analyses were also calculated based on stratification for different age, season, latitude, and region on risk of asthma. The odds ratio (OR) estimate between temperature drop and asthma was 1.05 (95% CI 1.02, 1.08) in the meta-analysis. For children, the overall OR was 1.09 (95% CI 1.03, 1.15). Dose-effect analyses showed stronger associations in asthma risk for each 1°1 °C decrement in short-term temperature (OR 1.055, 95% CI 1.00, 1.11). Further stratifications showed that winter (OR 1.03, 95% CI 1.01, 105) and low latitude (OR 1.72, 95% CI 1.23, 2.41) have a statistically significant association with the increased risk of asthma. Exposure of people to short-term temperature drop (per 1 °C decrement) was significantly associated with the risk of lower respiratory tract infections (LRTI) with asthma (OR 1.02, 95% CI 1.00, 1.04). Results suggest an adverse effect of temperature drop on asthma risk, especially in children and low-latitude areas. It may be opportune to consider the preventive actions against temperature drop, including simple face masks, to decrease the risk of asthma.

City housing atmospheric pollutant impact on emergency visit for asthma: A classification and regression tree approach

INTRODUCTION

Particulate matter, nitrogen dioxide (NO₂) and ozone are recognized as the three pollutants that most significantly affect human health. Asthma is a multifactorial disease. However, the place of residence has rarely been investigated. We compared the impact of air pollution, measured near patients' homes, on emergency department (ED) visits for asthma or trauma (controls) within the Provence-Alpes-Côte-d'Azur region.

METHODS

Variables were selected using classification and regression trees on asthmatic and control population, 3-99 years, visiting ED from January 1 to December 31, 2013. Then in a nested case control study, randomization was based on the day of ED visit and on defined age groups. Pollution, meteorological, pollens and viral data measured that day were linked to the patient's ZIP code.

RESULTS

A total of 794,884 visits were reported including 6250 for asthma and 278,192 for trauma. Factors associated with an excess risk of emergency visit for asthma included short-term exposure to NO₂, female gender, high viral load and a combination of low temperature and high humidity.

CONCLUSION

Short-term exposures to high NO₂ concentrations, as assessed close to the homes of the patients, were significantly associated with asthma-related ED visits in children and adults.

Meteorological parameters and pollutants on asthma exacerbation in Bangalore, India - an ecological retrospective time-series study

BACKGROUND

Literature has shown a significant association between asthma exacerbations and pollutant levels during that time. There is very limited evidence in India, especially Bangalore, for impacts of meteorological changes and pollution on asthma hospital admissions in adults. The objective was to study the impact of air pollution and meteorological parameters on asthma exacerbation in Bangalore.

METHODS

This study quantitatively analyzed the relation between acute exacerbations of asthma and related admissions to the hospital with the air pollution and the meteorological conditions during that time. Data regarding the daily hospital admissions in about 13 tertiary care centers in Bangalore, Karnataka and air pollutant levels and the meteorological conditions prevailing during each day over a year were collected from the Karnataka State pollution control board and meteorology departments, respectively.

RESULTS

An average daily asthma admission of 4.84±2.91, with clear seasonal variation and autocorrelations between meteorological parameters and pollutants was observed. Multiple linear regression analysis revealed that average temperature (p=0.005) and nitrogen dioxide (NO2) (p=0.034) were the two factors that were affecting the number of admissions. Quasi-poisson regression analysis using multi-pollutants and meteorological variables showed that particulate matter and NO2 had significant lag effect for up to 5 days (p<0.05) and rainfall for 1 day (p<0.001).

CONCLUSIONS

In Bangalore city, levels of NO2 and particulate matter, temperature, rainfall, and season increase asthma exacerbations.

Association between acute gouty arthritis and meteorological factors: An ecological study using a systematic review and meta-analysis

OBJECTIVES

The aims of this study were as follows: (1) to analyze the literature systematically regarding the seasonal and monthly variation of the occurrence of episodes of acute gouty arthritis, and (2) to investigate the relationship between the occurrence of episodes of acute gouty arthritis and meteorological parameters.

METHODS

The present authors systematically reviewed databases for articles published before November 2015. Studies with quantitative data on episodes of acute gouty arthritis by months and/or seasons were included. Meteorological data such as the highest temperature, lowest temperature, diurnal temperature range, change in mean temperature between neighboring days, relative humidity and wind speed for the geographic place(s), and study period where and when each study took place were obtained from meteorological websites.

RESULTS

Ten studies published between 1920 and 2015 were included. A meta-analysis by season showed that acute gouty arthritis occurred significantly more frequently in spring than in other seasons. Analysis by month showed an increase in episodes of acute gouty arthritis from March to July, being the highest in July. The trend reversed, and episodes of acute gouty arthritis started decreasing from July to September, being the lowest in September. The change in mean temperature between neighboring days was the only meteorological parameter that was significantly correlated with the number of monthly episodes of acute gouty arthritis.

CONCLUSIONS

Acute gouty arthritis seems to develop more frequently during the period in which the temperature increases significantly between neighboring days: spring by season and between March and July by month in the northern hemisphere.

Environmental triggers and avoidance in the management of asthma

Identifying asthma triggers forms the basis of environmental secondary prevention. These triggers may be allergenic or nonallergenic. Allergenic triggers include indoor allergens, such as house dust mites (HDMs), molds, pets, cockroaches, and rodents, and outdoor allergens, such as pollens and molds. Clinical observations provide support for the role of HDM exposure as a trigger, although avoidance studies provide conflicting results. Molds and their metabolic products are now considered to be triggers of asthma attacks. Pets, dogs, and especially cats can undoubtedly trigger asthmatic symptoms in sensitized subjects. Avoidance is difficult and rarely adhered to by families. Cockroach allergens contribute to asthma morbidity, and avoidance strategies can lead to clinical benefit. Mouse allergens are mostly found in inner-city dwellings, but their implication in asthma morbidity is debated. In the outdoors, pollens can induce seasonal asthma in sensitized individuals. Avoidance relies on preventing pollens from getting into the house and on minimizing seasonal outdoor exposure. Outdoor molds may lead to severe asthma exacerbations. Nonallergenic triggers include viral infections, active and passive smoking, meteorological changes, occupational exposures, and other triggers that are less commonly involved. Viral infection is the main asthma trigger in children. Active smoking is associated with higher asthma morbidity, and smoking cessation interventions should be personalized. Passive smoking is also a risk factor for asthma exacerbation. The implementation of public smoking bans has led to a reduction in the hospitalization of asthmatic children. Air pollution levels have been linked with asthmatic symptoms, a decrease in lung function, and increased emergency room visits and hospitalizations. Since avoidance is not easy to achieve, clean air policies remain the most effective strategy. Indoor air is also affected by air pollutants, such as cigarette smoke and volatile organic compounds generated by building and cleaning materials. Occupational exposures include work-exacerbated asthma and work-related asthma.

The Effects of Floods on the Incidence of Bacillary Dysentery in Baise (Guangxi Province, China) from 2004 to 2012

Research shows potential effects of floods on intestinal infections. Baise, a city in Guangxi Province (China) had experienced several floods between 2004 and 2012 due to heavy and constant precipitation. This study aimed to examine the relationship between floods and the incidence of bacillary dysentery in Baise. A mixed generalized additive model and Spearman correlation were applied to analyze the relationship between monthly incidence of bacillary dysentery and 14 flood events with two severity levels. Data collected from 2004 to 2010 were utilized to estimate the parameters, whereas data from 2011 to 2012 were used to validate the model. There were in total 9255 cases of bacillary dysentery included in our analyses. According to the mixed generalized additive model, the relative risks (RR) of moderate and severe floods on the incidence of bacillary dysentery were 1.40 (95% confidence interval (CI): 1.16–1.69) and 1.78 (95% CI: 1.61–1.97), respectively. The regression analysis also indicated that the flood duration was negatively associated with the incidence of bacillary dysentery (with RR: 0.57, 95% CI: 0.40–0.86). Therfore, this research suggests that floods exert a significant part in enhancing the risk of bacillary dysentery in Baise. Moreover, severe floods have a higher proportional contribution to the incidence of bacillary dysentery than moderate floods. In addition, short-term floods may contribute more to the incidence of bacillary dysentery than a long-term flood. The findings from this research will provide more evidence to reduce health risks related to floods.

Household indoor air quality and its associations with childhood asthma in Shanghai, China: On-site inspected methods and preliminary results

Few studies were conducted for associations of home environment with childhood health by on-site inspection in China. During 2013-2014, we conducted a case-control study with home inspection among 454 children (186 asthma children and 268 non-asthma children) in Shanghai, China. In this paper, we detailedly described the inspected methods and analyzed the preliminarily collected data. Except in winter, most residences meet the national standard for indoor temperature and relative humidity. Most living rooms had ≤1000ppm CO₂, whereas over half of the child's bedrooms had slightly >1000ppm CO₂ during night. Most residences had notably lower than 2500cfu/m³ airborne culturable fungi and ≤100μg/m³ formaldehyde. More than 70% of the child's bedrooms had ≤75μg/m³ PM_2.5 and ≤150μg/m³ PM₁₀. Indoor and outdoor concentrations of particulate matters had strong linear correlations (r=0.891-0.922; p-value <0.001). Most differences between cases and controls were not significant with respect to CO₂, culturable fungi, formaldehyde, and particulate matters. Before and after adjusted for potential confounders, indoor averaged concentration of CO₂ and particulate matters generally had negative associations with childhood history of doctor-diagnosed asthma in spring, summer, and autumn. Only in winter, indoor CO₂ concentration was significantly associated with the increased odds of childhood asthma. Our results indicated that air quality among most residences in Shanghai could meet the national standard for indoor air quality in warm seasons; but household air quality and ventilation status in winter should be greatly improved. We suspected that those "unexpected" negative associations could exist due to changes in lifestyle behaviors regarding indoor air quality after the child being diagnosed asthma by a doctor.

Prevalence and risk factors for asthma among children aged 0-14 years in Hangzhou: a cross-sectional survey

Background

Asthma is a global problem. Prevalence varies among different countries and cities. We aimed to obtain the prevalence, describe the characteristics, and discover factors that may relate to asthma in Hangzhou.

Methods

This cross-sectional study was conducted in Hangzhou. The subjects were children aged 14 years and younger. A control group of non-asthma children that matched in age and sex with each asthmatic patient was also randomly selected and interviewed. International Study of Asthma and Allergies in Childhood and National Epidemiology study of Asthma and Allergies in China questionnaires were used in this survey.

Results

We have questionnaired 13,877 children, and 665 (4.8 %) children were diagnosed asthma. The guardians regarded the cost of asthma management affordable in 49.4 %, tolerable in 46.9 %, and intolerable in 3.7 %. Both guardians and children have been absent from work or school due to children’s asthma.

Respiratory tract infection was the most common trigger of asthma attacks (85.1 %). Other common causes included cold air, house dust, exercise, fish and shrimp, pollen, and et al. Interestingly, we also found in children 6 years and older, some triggers happened more than that in children 5 years and younger. Those factors included exercise, emotional changes, house dust, pollen, renovation works in the home, mosquito–repellent incense and pets (all the p values were <0.05).

We compared some factors may relate to asthma development. Higher percentage of family history of asthma, personal history of allergy (atopic dermatitis, drug allergy and food allergy), comorbidities (allergic rhinitis, sinusitis, adenoidal hypertrophy, and urticaria), caesarean birth and complications ever happened during pregnancy were discovered in asthma children than in non-asthma children (all the p values were <0.05). Exclusive breastfeeding within first 6 months and keeping animals had higher percentage in non-asthma children than in asthma (both the p values were <0.05).

Inhaled corticosteroid (ICS)/ICS + long-acting beta2 agonists (LABA) was applied to 46.2 % of patients. Traditional Chinese medicine (TCM) was used in 44.2 % of asthma children, while leukotriene receptor antagonist (LTRA) was used in 36.4 % of them. The adherence scored higher in TCM than in ICS/ICS + LABA (P = 0.003) and LTRA.

Conclusions

In conclusion, we conducted an epidemiology study in Hangzhou. The prevalence of childhood asthma was 4.8 %. Asthma was an economic and social burden to both children and guardians. Risk factors of asthma development may include caesarean birth, personal history of allergy and concomitant allergic diseases. Exclusive breastfeeding within first 6 months and keeping animals might be protecting factors. TCM was really popular in China besides ICS/ICS + LABA and LTRA.

The short-term association between asthma hospitalisations, ambient temperature, other meteorological factors and air pollutants in Hong Kong: a time-series study

BACKGROUND

Previous studies have found associations between meteorological variables and asthma hospitalisations but the nature of these associations has varied and few studies have been done in subtropical areas or evaluated effect modification by age.

OBJECTIVES

This study aimed to evaluate associations between asthma hospitalisations and meteorological factors and to assess effect modification of these associations by age and season in Hong Kong.

METHODS

Poisson generalised additive models combined with distributed lag nonlinear models and piecewise linear models were used to model associations between daily asthma hospitalisations from 2004 to 2011 and meteorological factors and air pollutants, adjusting for day of week, seasonality and trend. Subgroup analyses by age and season were performed.

RESULTS

In the hot season, hospitalisations were lowest at 27°C, rose to a peak at 30°C, then plateaued between 30°C and 32°C. The cumulative relative risk for lags 0-3 days (RRlag0-3) for 30°C vs 27°C was 1.19 (95% CI 1.06 to 1.34). In the cold season, temperature was negatively associated with asthma hospitalisations. The cumulative RRlag0-3 for 12°C vs 25°C was 1.33 (95% CI 1.13 to 1.58). Adult admissions were most sensitive to temperatures in both seasons while admissions among children under 5 were least associated. Higher humidity and ozone levels in the hot season, and low humidity in the cold season were also associated with more asthma admissions.

CONCLUSIONS

People with asthma should avoid exposure to adverse conditions by limiting outdoor activities during periods of extreme temperatures, combinations of high humidity and high temperature, and low humidity and low temperature, and high ozone levels.