Comparison of the seasonal patterns of asthma identified in general practitioner episodes, hospital admissions, and deaths

Seasonal variations and social disparities in asthma hospitalizations and outcomes

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Temporal trends of hospitalizations, comorbidity burden and in-hospital outcomes in patients admitted with asthma in the United States: Population-based study

BACKGROUND

Asthma is a prevalent chronic respiratory condition and remains a common cause for hospitalization. However, contemporary data on asthma hospitalization rates, comorbidity burden, and in-hospital outcomes are lacking.

METHODS

Survey-weighted analysis of hospitalization records with a primary diagnosis of asthma using data from the US National (Nationwide) Inpatient Sample between 2004 and 2017. Outcomes were number of hospitalizations per 100,000 population and in-hospital outcomes including receipt of ventilation, length of stay, and hospital costs. Patient and admission characteristics and comorbidity burden were examined over time. Multivariable logistic and linear regression models were fitted for over-time risks of the outcomes.

RESULTS

Among 3,098,863 asthma admissions between 2004 and 2017, mean (±SD) age was 29 (±25), 57% females, 36% White, 40% had Medicaid as primary payer. During 2004-2017, asthma hospitalizations declined from 89 to 56 per 100,000 population; length of stay remained overall stable; median (interquartile range IQR) inflation-adjusted hospital costs doubled from $8,446 (9,227) in 2004 to $17,756 (19,434) in 2017. Common comorbidities in patients admitted with asthma were hypertension and diabetes in adults, but gastroesophageal reflux disease, obstructive sleep apnoea, anemia, and obesity in children. Over time, the prevalence of mental illness increased by >50%. Severe asthma (IRR, 2.48; 95%CI: 2.27-2.72) and psychoses (IRR, 1.10; 1.05-1.14) were predictors of prolonged hospitalization. Asian/Pacific Islanders were more likely to receive ventilation (OR: 2.35; 1.73-3.20) than White patients. Hospital costs were significantly higher in females and adults with hypertension (coefficient, 1405.2; 283.1-2527.4) or psychoses (coefficient, 1978.4; 674.9-3282.0).

CONCLUSIONS

US asthma hospitalization rates fluctuated in earlier years but declined over time, which may reflect improvements in community care and declining asthma prevalence. Comorbidity burden, including mental illness, increased over time and is associated with in-hospital outcomes. This highlights the changing landscape of asthma admissions which may inform redesigning services to support pre-hospitalization asthma care and help further reduce admissions, particularly among patients with multimorbidity.

Spring is associated with increased total and allergenic fungal concentrations in house dust from a pediatric asthma cohort in New York City

Introduction

Asthma and allergy symptoms vary seasonally due to exposure to environmental sources of allergen, including fungi. However, we need an improved understanding of seasonal influence on fungal exposures in the indoor environment. We hypothesized that concentrations of total fungi and allergenic species in vacuumed dust vary significantly by season.

Objective

Assess seasonal variation of indoor fungi with greater implications related to seasonal asthma control.

Methods

We combined next-generation sequencing with quantitative polymerase chain reaction (qPCR) to measure concentrations of fungal DNA in indoor floor dust samples (n = 298) collected from homes participating in the New York City Neighborhood Asthma and Allergy Study (NAAS).

Results

Total fungal concentration in spring was significantly higher than the other three seasons (p ≤ 0.005). Mean concentrations for 78% of fungal species were elevated in the spring (26% were significantly highest in spring, p < 0.05). Concentrations of 8 allergenic fungal species were significantly (p < 0.5) higher in spring compared to at least two other seasons. Indoor relative humidity and temperature were significantly highest in spring (p < 0.05) and were associated with total fungal concentration (R2 = 0.049, R2 = 0.11, respectively).

Conclusion

There is significant seasonal variation in total fungal concentration and concentration of select allergenic species. Indoor relative humidity and temperature may underlie these associations.

Monthly and seasonal prevalence of asthma and chronic obstructive pulmonary disease in the District Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan

Background

Asthma and chronic obstructive pulmonary disease are the major airway diseases and are increasingly important causes of mortality, morbidity, and disability globally. This cross-sectional study was conducted to determine monthly and seasonal patterns of asthma and chronic obstructive pulmonary disease in the study area during 2020–2021. The data of the indoor patients for the study period were obtained from the official records maintained in the District Head Quarter teaching hospital Dera Ismail Khan.

Results

A total of 2179 cases of asthma were recorded including 1609 (73.8%) in 2020 and 570 (26.2%) in 2021, and 740 cases of the chronic obstructive pulmonary disease were also recorded in 2020. Overall asthma was highest in March with 1128 (51.8%) cases and was lowest in July with 29 (1.3%) cases. Seasonal prevalence/pattern show that asthma relatively more prevailed during winter and early spring (December through March). Out of a total of 740 cases of chronic obstructive pulmonary disease, the highest 405 (54.7%) cases were recorded in February and the lowest 0 in April. Seasonal distribution indicated that chronic obstructive pulmonary disease was relatively higher in winter (January–February).

Conclusions

Seasonal variation and pattern in prevalence exist both in asthma and chronic obstructive pulmonary disease as both indicated relatively higher prevalence in winter compared to summer and autumn.

Improving Medication Adherence in Asthma

In little over a generation, the ingenuity of scientists and clinician researchers has developed inhaled medications and pathway-specific biological agents that control the inflammation and physiology of asthma. Unfortunately, whether it is because of cost or difficulty understanding why or how to use inhaled medications, patients often do not take these medications. The consequences of poor treatment adherence, loss of control and exacerbations, are the same as if the condition remained untreated. Furthermore, poor adherence is difficult to detect without direct measurement. Together this means that poor treatment adherence is easily overlooked and, instead of addressing the cause of poor adherence, additional medicines may be prescribed. In other words, poor treatment adherence is a risk for the patient and adds cost to healthcare systems. In this article, we discuss the rationale for and the delivery of successful interventions to improve medication adherence in asthma. We contextualize these interventions by describing the causes of poor treatment adherence and how adherence is assessed. Finally, future perspectives on the design of new interventions are described.

Effect of the COVID-19 Lockdown on Asthma Biological Rhythms

Asthma has a striking temporal character, in which time-of-day, patient age, and season each influence disease activity. The extent to which rhythms in asthma activity reflect exposure to specific disease triggers remains unclear. In this study, we examined how virus mitigation strategies enacted during the COVID-19 pandemic ("lockdown measures") affected rhythms in asthma clinical activity in children. To this end, we retrospectively analyzed asthma clinical presentations in children aged <18 years to our regional academic medical center, comparing 4 years of medical records prior to COVID-19 lockdown measures with the 12 months immediately after the institution of such measures. We correlated these data to positive viral test results, febrile seizures, and allergic clinical surrogates (allergic reaction visits and Emergency Department [ED] antihistamine prescriptions, respectively) over the same time frame. In the 12 months following the institution of the COVID-19 lockdown, positivity rates for common respiratory viruses dropped by 70.2% and ED visits for asthma among children dropped by 62% compared to pre-COVID years. Lockdown suppressed seasonal variation in positive viral tests and asthma ED visits, while diurnal rhythms in asthma visits were unchanged. Asthma seasonality correlated most strongly with rhinovirus positivity both before and after the institution of COVID lockdown measures. Altogether, our data support a causal role for viruses in driving seasonal variability in asthma exacerbations in children.

Age-Dependent Reduction in Asthmatic Pathology through Reprogramming of Postviral Inflammatory Responses

Asthma is a chronic disease of childhood, but for unknown reasons, disease activity sometimes subsides as children mature. In this study, we present clinical and animal model evidence suggesting that the age dependency of childhood asthma stems from an evolving host response to respiratory viral infection. Using clinical data, we show that societal suppression of respiratory virus transmission during coronavirus disease 2019 lockdown disrupted the traditional age gradient in pediatric asthma exacerbations, connecting the phenomenon of asthma remission to virus exposure. In mice, we show that asthmatic lung pathology triggered by Sendai virus (SeV) or influenza A virus is highly age-sensitive: robust in juvenile mice (4-6 wk old) but attenuated in mature mice (>3 mo old). Interestingly, allergen induction of the same asthmatic traits was less dependent on chronological age than viruses. Age-specific responses to SeV included a juvenile bias toward type 2 airway inflammation that emerged early in infection, whereas mature mice exhibited a more restricted bronchiolar distribution of infection that produced a distinct type 2 low inflammatory cytokine profile. In the basal state, aging produced changes to lung leukocyte burden, including the number and transcriptional landscape of alveolar macrophages (AMs). Importantly, depleting AMs in mature mice restored post-SeV pathology to juvenile levels. Thus, aging influences chronic outcomes of respiratory viral infection through regulation of the AM compartment and type 2 inflammatory responses to viruses. Our data provide insight into how asthma remission might develop in children.

The Retrospective Analysis of Google Queries Related to Cardiovascular Diseases Symptoms in the Years 2004-2019

The Internet enables immediate access to health-related information. We aimed to rank the complaints related to cardiovascular diseases among Google users globally and locally as well as investigate secular and seasonal trends in the years 2004 to 2019. We used Google Trends (GT) to identify and analyze course over time and regional interest of seven topics: "Chest pain," "Cyanosis," "Edema," "Orthopnea," "Palpitation," "Shortness of breath," and "Syncope." We analyzed secular trends using the seasonal Mann-Kendall test and seasonal variation using time series decomposition. We calculated the interest of all topics in proportion to the relative search volume (RSV) of "Chest Pain." Globally the most popular topics were: "Edema" (proportion to RSV of "Chest pain," 1.39), "Chest pain" (1.00), and Syncope (0.71). "Chest pain" was predominately searched in n  = 25 countries, while "Edema" in n  = 24, "Syncope" in n  = 9, and "Shortness of breath" in n  = 3. The RSV of all topics increases over time and the most dynamically for "Chest pain" (4.30 RSV/year), "Shortness of breath" (3.87 RSV/year), and "Palpitations" (3.69 RSV/year). Interest in "Chest pain," "Cyanosis," "Orthopnea," "Palpitations," and "Syncope" peaks in fall and winter, while interest in "Edema" in midsummer and "Shortness of breath" in April. Google users were particularly interested in "Edema," "Chest pain," and "Syncope." The interest in cardiovascular diseases-related symptoms increases over time and presents explicable seasonal variations. The Internet plays the acquisition of health-related information; thus, professionals should create and recommend evidence-based information sources for their patients.

Using Bayesian time-stratified case-crossover models to examine associations between air pollution and "asthma seasons" in a low air pollution environment

Many areas of the United States have air pollution levels typically below Environmental Protection Agency (EPA) regulatory limits. Most health effects studies of air pollution use meteorological (e.g., warm/cool) or astronomical (e.g., solstice/equinox) definitions of seasons despite evidence suggesting temporally-misaligned intra-annual periods of relative asthma burden (i.e., “asthma seasons”). We introduce asthma seasons to elucidate whether air pollutants are associated with seasonal differences in asthma emergency department (ED) visits in a low air pollution environment. Within a Bayesian time-stratified case-crossover framework, we quantify seasonal associations between highly resolved estimates of six criteria air pollutants, two weather variables, and asthma ED visits among 66,092 children ages 5–19 living in South Carolina (SC) census tracts from 2005 to 2014. Results show that coarse particulates (particulate matter <10 μm and >2.5 μm: PM_10-2.5) and nitrogen oxides (NO_x) may contribute to asthma ED visits across years, but are particularly implicated in the highest-burden fall asthma season. Fine particulate matter (<2.5 μm: PM_2.5) is only associated in the lowest-burden summer asthma season. Relatively cool and dry conditions in the summer asthma season and increased temperatures in the spring and fall asthma seasons are associated with increased ED visit odds. Few significant associations in the medium-burden winter and medium-high-burden spring asthma seasons suggest other ED visit drivers (e.g., viral infections) for each, respectively. Across rural and urban areas characterized by generally low air pollution levels, there are acute health effects associated with particulate matter, but only in the summer and fall asthma seasons and differing by PM size.

Burden of preschool wheeze and progression to asthma in the UK: Population-based cohort 2007 to 2017

BACKGROUND

Wheeze is one of the most common symptoms of preschool children (age 1-5 years), yet we have little understanding of the burden in the United Kingdom.

OBJECTIVES

We sought to determine prevalence and pattern of physician-confirmed preschool wheeze, related health care utilization, and factors associated with progression to school-age asthma.

METHODS

We used nationally representative primary and secondary care electronic medical records between 2007 and 2017 to identify preschool children with wheeze. Factors associated with asthma progression were identified in a nested cohort of children with follow-up from age 1 to 2 years, until at least age 8 years.

RESULTS

From 1,021,624 preschool children, 69,261 were identified with wheeze. Prevalence of preschool wheeze was 7.7% in 2017. Wheeze events were lowest in August and highest in late-autumn/early-winter. During median follow-up of 2 years (interquartile range, 1.2-4.0 years), 15.8% attended an emergency department, and 13.9% had a hospital admission, for a respiratory disorder. The nested cohort with prolonged follow-up identified 15,085 children; 35.5% progressed to asthma between age 5 and 8 years. Of children with preschool wheeze, without an asthma diagnosis, 34.9% were prescribed inhaled corticosteroids and 15.6% oral corticosteroids. The factors most strongly associated with progression to asthma were wheeze frequency and severity, atopy, prematurity, maternal asthma severity, and first reported wheeze event occurring in September.

CONCLUSIONS

Preschool wheeze causes considerable health care burden, and a large number of children are prescribed asthma medication and have unplanned secondary care visits. Multiple factors influence progression to asthma, including first wheeze event occurring in September.

Exacerbation Patterns in Adults with Asthma in England. A Population-based Study

RATIONALE

Asthma is heterogeneous and knowledge on exacerbation patterns is lacking. Previous studies have had a relatively short follow-up or focused on severe disease.

OBJECTIVES

To describe exacerbation patterns over a prolonged follow-up in a population that includes patients of all disease severity.

METHODS

We used electronic health care records to identify patients with asthma aged 18-55 years and their exacerbations from 2007 to 2015. A cohort with greater than or equal to 7 years of data was used to describe exacerbation patterns by asthma severity defined by medication use. Effect estimates for risk factors were calculated for sporadic (single year of exacerbations) and recurrent (>1 yr) exacerbation patterns, using logistic regression. In a nested case-control design, the association between a history of exacerbations, spanning 5 years, and a future exacerbation was examined.

MEASUREMENTS AND MAIN RESULTS

A total of 51,462 patients were eligible for the 7-year cohort; 64% had no exacerbations. Of those who exacerbated, 51% did so only once; exacerbation frequency increased with disease severity. Only 370 patients (0.7%) were characterized by a frequent-exacerbator phenotype (yearly exacerbations), of whom 58% had mild/moderate asthma. Exacerbation risk factors were not uniquely associated with a particular exacerbation pattern. A past exacerbation increased the risk of a future exacerbation more than all other factors, although this effect dissipated over 5 years.

CONCLUSIONS

During 7 years of follow-up, exacerbations occur in around one-third of patients. Of those who exacerbate, half do not do so again; the timing of future exacerbations is largely unpredictable. Just 2% exhibit a frequent-exacerbator phenotype. Past exacerbation patterns are the most informative risk factor for predicting future exacerbations.

Do hospital admission rates increase in colder winters? A decadal analysis from an eastern county in England

Background

The aim of the study was to measure the effect of colder winters compared to warmer winters on hospital admission rates in Suffolk County.

Methods

The setting of this study was Suffolk County in eastern England. The period of the study was financial years 2003/04-2012/13. The study was an analytic ecological study. Analysis involved calculation of rate ratios of hospital admission rates in colder winters compared to warmer winters, in all persons and the elderly.

Results

The main finding of the study was that all rate ratios for hospital admission rates in colder winters compared to warmer winters were significantly raised with effects of 2-5%. Rate ratios for all admissions in persons of all ages and persons aged 65 years and over were, respectively, 1.02 (99% confidence interval (CI): 1.01, 1.03; P < 0.001) and 1.02 (99% CI: 1.01, 1.04; P < 0.001). Rate ratios for emergency admissions in persons of all ages and persons aged 65 years and over were, respectively, 1.05 (99% CI: 1.03, 1.06; P < 0.001) and 1.04 (99% CI: 1.01, 1.06; P < 0.001).

Conclusion

In Suffolk County, hospital admission rates are significantly raised in colder winters compared to warmer winters. This evidence may be useful in planning hospital services.

Monitoring epidemiological trends in back to school asthma among preschool and school-aged children using real-time syndromic surveillance in England, 2012-2016

BACKGROUND : Back to school (BTS) asthma has been previously reported in children; however, its epidemiology and associated healthcare burden are unclear. We aimed to describe the timing and magnitude of BTS asthma using surveillance data from different health services in England. METHODS : Asthma morbidity data from emergency department attendances and general practitioner (GP) consultations between April 2012 and December 2016 were used from national syndromic surveillance systems in England. Age-specific and sex-specific rates and time series of asthma peaks relative to school term dates were described. The timing of a BTS excess period and adjusted rates of asthma relative to a baseline period were estimated using cumulative sum control chart plots and negative binomial regression. RESULTS : BTS asthma among children aged below 15 years was most pronounced at the start of the school year in September. This effect was not present among those aged 15 years and above. After controlling for sex and study year, the adjusted daily rate of childhood GP in-hours asthma consultations was 2.5-3 times higher in the BTS excess period, with a significantly higher effect among children aged 0-4 years. A distinct age-specific pattern of sex differences in asthma presentations was present, with a higher burden among males in children and among females aged over 15 years. CONCLUSION: We found evidence of a BTS asthma peak in children using surveillance data across a range of healthcare systems, supporting the need for further preventative work to reduce the impact of BTS asthma in children.

Effects of air pollution on moderate and severe asthma exacerbations

Background: Few studies have evaluated the impact of air pollution levels on the severity of exacerbations. Thus, we compared the relative risks posed by air pollutant levels on moderate and severe exacerbations.Methods: Exacerbation episodes of 618 from 143 adult asthmatics were retrospectively collected between 2005 and 2015 in a tertiary hospital of Korea. Air pollution GPS data for the location closest to each patient's home were obtained from the national ambient monitoring station. The relative impacts of air pollutants on asthma exacerbations were evaluated via a time-trend controlled symmetrical, bidirectional, case-crossover design using conditional logistic regression models on the day of the exacerbation (T-0) and up to 3 days before the exacerbation (T-1-T-3).Results: Overall asthma exacerbation were associated with O₃ levels in summer and winter (OR: 1.012[1.003-1.02] and 1.009[1.003-1.016]), SO₂ levels in spring and summer (OR: 1.009[1-1.018] and 1.02[1.006-1.035]) and NO₂ levels in winter (OR: 1.007[1.003-1.011]). Analyses of the temporal relationship between O₃ concentrations and exacerbations demonstrated that 63.2% of episodes in the summer occurred when the O₃ concentrations on T-1 were significantly higher than those on control days, while 51% of exacerbation episodes in the winter occurred. Severe and moderate exacerbations were similarly associated with O₃ levels in winter (OR: 1.012 [1.003-1.02] vs. 1.01 [0.999-1.021], p > 0.05) and in summer (OR: 1.006 [1.002-1.009] vs. 1.009 [1.003-1.016], p > 0.05).Conclusions: Asthma exacerbations may be associated with the seasonal elevation of O₃, SO₂ and NO₂ levels in summer and winter with the similar relative risk between moderate and severe exacerbations.

Seasonal fluctuation of lung function in cystic fibrosis: A national register-based study in two northern European populations

Background

Many risk factors for lung disease in cystic fibrosis (CF) display a seasonal pattern yet it is unclear whether this is reflected in seasonal fluctuations in lung function.

Methods

We conducted a longitudinal study using CF registries in Denmark and the UK. 471 individuals with a median of 104 FEV₁ measurements per person and 7586 individuals with a median of nine FEV₁ measures per person were included from Denmark and the UK respectively. We estimated the effect of seasonality on percent predicted FEV₁ trajectories using mixed effects models whilst adjusting for clinically important covariates.

Results

We found no significant cyclical seasonal variation in lung function in either country. The maximum variation in percent predicted FEV₁ around the yearly average was estimated to be 0.1 percentage points (95%CI 0 to 0.21) and 0.14 percentage points (95%CI 0 to 0.29) in Denmark and the UK, respectively. When considering possible step-like changes between the four seasons, we found that lung function was higher in spring compared to winter in the UK (0.34 percentage points, 95%CI 0.1 to 0.59) though the difference was not of clinical significance.

Conclusion

In both the UK and Denmark there may be small seasonal changes in lung function but this effect is not of clinical importance.

•

It is not well understood how the four seasons affect lung function in CF.

•

We performed a longitudinal analysis in the UK and Danish CF populations.

•

Forty years of data were included in a comprehensive mixed effects models.

•

The seasonal variation was small and not clinically important.

Temporal and spatial associations between influenza and asthma hospitalisations in New York City from 2002 to 2012: a longitudinal ecological study

OBJECTIVES

To determine whether asthma hospitalisations of children and adults in the five boroughs of New York City are correlated with influenza hospitalisations temporally and spatially.

DESIGN

A longitudinal ecological study.

INCLUSION CRITERIA

We reviewed the Statewide Planning and Research Cooperative System's records of hospitalisations in Manhattan, Bronx, Queens, Brooklyn and Staten Island from 2002 to 2012. All hospitalisations with a primary diagnosis of either asthma or influenza were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes.

METHODS

A time-series regression analysis was performed using aggregate monthly counts of influenza hospitalisations as predictors of asthma hospitalisations. Time-series regression models were also applied to different age groups and boroughs to examine the magnitude of influenza and asthma correlations across strata. The per cent excess risk was also calculated across age groups and boroughs.

RESULTS

Time-series analysis of the overall population revealed a significant positive correlation between influenza and asthma hospitalisations (p=0.011). When stratifying by age, there was a significant positive correlation between asthma and influenza hospitalisations for individuals 18 and older (p<0.01), and no significant correlation found for age groups younger than 18. Percentages of excess risk of influenza-related asthma hospitalisations also increased with increasing age with adults 18-44, 45-64 and 65+ having excess risk percentages of 2.9%, 3.4% and 4%, respectively. Time-series analysis by location revealed positive significant correlations between asthma and influenza hospitalisations in Brooklyn (p=0.03) and Manhattan (p<0.01). Manhattan and Brooklyn had a 2.5% and 1.6%, respectively, percentage of excess risk of influenza-related asthma hospitalisations.

CONCLUSION

Influenza and asthma hospitalisations are significantly associated at the population level among adults. These associations vary by age and geographical location. Influenza prevention strategies targeting adult populations, particularly individuals living in Manhattan and Brooklyn, have the potential for meaningful reduction of influenza-related asthma hospitalisations.

Open-label, cluster randomised controlled trial and economic evaluation of a brief letter from a GP on unscheduled medical contacts associated with the start of the school year: the PLEASANT trial

BACKGROUND

Asthma is seasonal with peaks in exacerbation rates in school-age children associated with the return to school following the summer vacation. A drop in prescription collection in August is associated with an increase in the number of unscheduled contacts after the school return.

OBJECTIVE

To assess whether a public health intervention delivered in general practice reduced unscheduled medical contacts in children with asthma.

DESIGN

Cluster randomised trial with trial-based economic evaluation. Randomisation was at general practice level, stratified by size of practice. The intervention group received a letter from their general practitioner (GP) in late July outlining the importance of (re)taking asthma medication before the return to school. The control group was usual care.

SETTING

General practices in England and Wales.

PARTICIPANTS

12 179 school-age children in 142 general practices (70 randomised to intervention).

MAIN OUTCOME

Proportion of children aged 5-16 years who had an unscheduled contact in September. Secondary endpoints included collection of prescriptions in August and medical contacts over 12 months (September-August). Economic endpoints were quality-adjusted life-years gained and health service costs.

RESULTS

There was no evidence of effect (OR 1.09; 95% CI 0.96 to 1.25 against treatment) on unscheduled contacts in September. The intervention increased the proportion of children collecting a prescription in August by 4% (OR 1.43; 95% CI 1.24 to 1.64). The intervention also reduced the total number of medical contacts between September-August by 5% (incidence ratio 0.95; 95% CI 0.91 to 0.99).The mean reduction in medical contacts informed the health economics analyses. The intervention was estimated to save £36.07 per patient, with a high probability (96.3%) of being cost-saving.

CONCLUSIONS

The intervention succeeded in increasing children collecting prescriptions. It did not reduce unscheduled care in September (the primary outcome), but in the year following the intervention, it reduced the total number of medical contacts.

TRIAL REGISTRATION NUMBER

ISRCTN03000938; Results.

Retrospective observational study of emergency department syndromic surveillance data during air pollution episodes across London and Paris in 2014

INTRODUCTION

Poor air quality (AQ) is a global public health issue and AQ events can span across countries. Using emergency department (ED) syndromic surveillance from England and France, we describe changes in human health indicators during periods of particularly poor AQ in London and Paris during 2014.

METHODS

Using daily AQ data for 2014, we identified three periods of poor AQ affecting both London and Paris. Anonymised near real-time ED attendance syndromic surveillance data from EDs across England and France were used to monitor the health impact of poor AQ.Using the routine English syndromic surveillance detection methods, increases in selected ED syndromic indicators (asthma, difficulty breathing and myocardial ischaemia), in total and by age, were identified and compared with periods of poor AQ in each city. Retrospective Wilcoxon-Mann-Whitney tests were used to identify significant increases in ED attendance data on days with (and up to 3 days following) poor AQ.

RESULTS

Almost 1.5 million ED attendances were recorded during the study period (27 February 2014 to 1 October 2014). Significant increases in ED attendances for asthma were identified around periods of poor AQ in both cities, especially in children (aged 0-14 years). Some variation was seen in Paris with a rapid increase during the first AQ period in asthma attendances among children (aged 0-14 years), whereas during the second period the increase was greater in adults.

DISCUSSION

This work demonstrates the public health value of syndromic surveillance during air pollution incidents. There is potential for further cross-border harmonisation to provide Europe-wide early alerting to health impacts and improve future public health messaging to healthcare services to provide warning of increases in demand.

Influence of the Scandinavian climate pattern on the UK asthma mortality: a time series and geospatial study

OBJECTIVE

It is well known that climate variability and trends have an impact on human morbidity and mortality, especially during the winter. However, there are only a handful of studies that have undertaken quantitative investigations into this impact. We evaluate the association between the UK winter asthma mortality data to a well-established feature of the climate system, the Scandinavian (SCA) pattern.

METHODS

Time series analysis of monthly asthma mortality through the period of January 2001 to December 2015 was conducted, where the data were acquired from the UK's Office for National Statistics. The correlations between indices of important modes of climate variability impacting the UK such as the North Atlantic Oscillation as well as the SCA and the asthma mortality time series were computed. A grid point correlation analysis was also conducted with the asthma data with sea level pressure, surface wind and temperature data acquired from the European Centre for Medium-Range Weather Forecasts.

RESULTS

We find that sea level pressure and temperature fluctuations associated with the SCA explain ~20% (>95% CL) of variance in the UK asthma mortality through a period of 2001-2015. Furthermore, the highest winter peak in asthma mortality occurred in the year 2015, during which there were strong northwesterly winds over the UK that were the result of a sea level pressure pattern similar to that associated with the SCA.

CONCLUSIONS

Our study emphasises the importance of incorporating large-scale geospatial analyses into future research of understanding diseases and its environmental impact on human health.

Interventions for autumn exacerbations of asthma in children

BACKGROUND

Asthma exacerbations in school-aged children peak in autumn, shortly after children return to school following the summer holiday. This might reflect a combination of risk factors, including poor treatment adherence, increased allergen and viral exposure, and altered immune tolerance. Since this peak is predictable, interventions targeting modifiable risk factors might reduce exacerbation-associated morbidity and strain upon health resources. The peak occurs in September in the Northern Hemisphere and in February in the Southern Hemisphere.

OBJECTIVES

To assess the effects of pharmacotherapy and behavioural interventions enacted in anticipation of school return during autumn that are designed to reduce asthma exacerbations in children during this period.

SEARCH METHODS

We searched the Cochrane Airways Group Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, reference lists of primary studies and existing reviews, and manufacturers' trial registries (Merck, Novartis and Ono Parmaceuticals). We searched databases from their inception to 1 December 2017, and imposed no restriction on language of publication.

SELECTION CRITERIA

We included all randomised controlled trials comparing interventions aimed specifically at reducing autumn exacerbations with usual care, (no systematic change in management in preparation for school return). We included studies providing data on children aged 18 years or younger.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently screened records identified by the search and then extracted data and assessed bias for trials meeting the inclusion criteria. A third review author checked for accuracy and mediated consensus on disagreements. The primary outcome was proportion of children experiencing one or more asthma exacerbations requiring hospitalisation or oral corticosteroids during the autumn period.

MAIN RESULTS

Our searches returned 546 trials, of which five met our inclusion criteria. These studies randomised 14,252 children to receive either an intervention or usual care. All studies were conducted in the Northern Hemisphere. Three interventions used a leukotriene receptor antagonist, one used omalizumab or a boost of inhaled corticosteroids, and the largest study, (12,179 children), used a medication reminder letter. Whilst the risk of bias within individual studies was generally low, we downgraded the evidence quality due to imprecision associated with low participant numbers, poor consistency between studies, and indirect outcome ascertainment.A US study of 513 children with mild/severe asthma and allergic sensitisation was the only study to provide data for our primary outcome. In this study, the proportion of participants experiencing an exacerbation requiring oral corticosteroids or hospital admission in the 90 days after school return was significantly reduced to 11.3% in those receiving omalizumab compared to 21.0% in those receiving placebo (odds ratio 0.48, 95% confidence interval 0.25 to 0.92, moderate-quality evidence). The remaining studies used alternative exacerbation definitions. When data from two leukotriene receptor antagonist studies with comparable outcomes were combined in a random-effects model, there was no evidence of an effect upon exacerbations. There was no evidence that a seasonal medication reminder letter decreased unscheduled contacts for a respiratory diagnosis between September and December.Four studies recorded adverse events. There was no evidence that the proportion of participants experiencing at least one adverse event differed between intervention and usual care groups. Lack of data prevented planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Seasonal omalizumab treatment from four to six weeks before school return might reduce autumn asthma exacerbations. We found no evidence that this strategy is associated with increased adverse effects other than injection site pain, but it is costly. There were no data upon which to judge the effect of this or other seasonal interventions on asthma control, quality of life, or asthma-related death. In future studies definitions of exacerbations should be provided, and standardised where possible. To investigate possible differential effects according to subgroup, participants in future trials should be well characterised with respect to baseline asthma severity and exacerbation history in addition to age and gender.

PLEASANT: Preventing and Lessening Exacerbations of Asthma in School-age children Associated with a New Term - a cluster randomised controlled trial and economic evaluation

BACKGROUND

Asthma episodes and deaths are known to be seasonal. A number of reports have shown peaks in asthma episodes in school-aged children associated with the return to school following the summer vacation. A fall in prescription collection in the month of August has been observed, and was associated with an increase in the number of unscheduled contacts after the return to school in September.

OBJECTIVE

The primary objective of the study was to assess whether or not a NHS-delivered public health intervention reduces the September peak in unscheduled medical contacts.

DESIGN

Cluster randomised trial, with the unit of randomisation being 142 NHS general practices, and trial-based economic evaluation.

SETTING

Primary care.

INTERVENTION

A letter sent (n = 70 practices) in July from their general practitioner (GP) to parents/carers of school-aged children with asthma to remind them of the importance of taking their medication, and to ensure that they have sufficient medication prior to the start of the new school year in September. The control group received usual care.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of children aged 5-16 years who had an unscheduled medical contact in September 2013. Supporting end points included the proportion of children who collected prescriptions in August 2013 and unscheduled contacts through the following 12 months. Economic end points were quality-adjusted life-years (QALYs) gained and costs from an NHS and Personal Social Services perspective.

RESULTS

There is no evidence of effect in terms of unscheduled contacts in September. Among children aged 5-16 years, the odds ratio (OR) was 1.09 [95% confidence interval (CI) 0.96 to 1.25] against the intervention. The intervention did increase the proportion of children collecting a prescription in August (OR 1.43, 95% CI 1.24 to 1.64) as well as scheduled contacts in the same month (OR 1.13, 95% CI 0.84 to 1.52). For the wider time intervals (September-December 2013 and September-August 2014), there is weak evidence of the intervention reducing unscheduled contacts. The intervention did not reduce unscheduled care in September, although it succeeded in increasing the proportion of children collecting prescriptions in August as well as having scheduled contacts in the same month. These unscheduled contacts in September could be a result of the intervention, as GPs may have wanted to see patients before issuing a prescription. The economic analysis estimated a high probability that the intervention was cost-saving, for baseline-adjusted costs, across both base-case and sensitivity analyses. There was no increase in QALYs.

LIMITATION

The use of routine data led to uncertainty in the coding of medical contacts. The uncertainty was mitigated by advice from a GP adjudication panel.

CONCLUSIONS

The intervention did not reduce unscheduled care in September, although it succeeded in increasing the proportion of children both collecting prescriptions and having scheduled contacts in August. After September there is weak evidence in favour of the intervention. The intervention had a favourable impact on costs but did not demonstrate any impact on QALYs. The results of the trial indicate that further work is required on assessing and understanding adherence, both in terms of using routine data to make quantitative assessments, and through additional qualitative interviews with key stakeholders such as practice nurses, GPs and a wider group of children with asthma.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN03000938.

FUNDING DETAILS

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 93. See the HTA programme website for further project information.

Predicting the frequency of extreme air quality events

A new method for predicting the frequency of extreme air quality events is proposed. The method is based on knowing the number of times a pollutant is measured at different concentrations during a period of data collection and fitting this data to a Weibull-type function. Extrapolation of the function to higher concentrations then allows the frequency of extreme events that did not occur during the collection period to be predicted, albeit with an unspecified uncertainty. Prediction of the frequency of events over a given concentration, which was exceeded during the period of data collection, has also been performed assuming Poisson statistics. The assumption of Poisson statistics enables the provision of an uncertainty statement to accompany the prediction. The methods are trialled on a data set of daily average PM₁₀ mass concentrations recorded at Marylebone Road in London between 2007 and 2016, inclusive. Using the method it was predicted that a daily average PM₁₀ mass concentration of over 100 μg m^-3, corresponding to the highest UK Daily Air Quality Index band, should be expected once in just over three years and this agreed well with real observations, demonstrating the utility of this new technique.

Association between glycaemic control and common infections in people with Type 2 diabetes: a cohort study

AIM

To investigate the impact of glycaemic control on infection incidence in people with Type 2 diabetes.

METHODS

We compared infection rates during 2014 in people with Type 2 diabetes and people without diabetes in a large primary care cohort in the UK (the Royal College of General Practitioners Research and Surveillance Centre database). We performed multilevel logistic regression to investigate the impact of Type 2 diabetes on presentation with infection, and the effect of glycaemic control on presentation with upper respiratory tract infections, bronchitis, influenza-like illness, pneumonia, intestinal infectious diseases, herpes simplex, skin and soft tissue infections, urinary tract infections, and genital and perineal infections. People with Type 2 diabetes were stratified by good [HbA_1c < 53 mmol/mol (< 7%)], moderate [HbA_1c 53-69 mmol/mol (7-8.5%)] and poor [HbA_1c > 69 mmol/mol (> 8.5%)] glycaemic control using their most recent HbA_1c concentration. Infection incidence was adjusted for important sociodemographic factors and patient comorbidities.

RESULTS

We identified 34 278 people with Type 2 diabetes and 613 052 people without diabetes for comparison. The incidence of infections was higher in people with Type 2 diabetes for all infections except herpes simplex. Worsening glycaemic control was associated with increased incidence of bronchitis, pneumonia, skin and soft tissue infections, urinary tract infections, and genital and perineal infections, but not with upper respiratory tract infections, influenza-like illness, intestinal infectious diseases or herpes simplex.

CONCLUSIONS

Almost all infections analysed were more common in people with Type 2 diabetes. Infections that are most commonly of bacterial, fungal or yeast origin were more frequent in people with worse glycaemic control.

Asthma-related deaths

Despite major advances in the treatment of asthma and the development of several asthma guidelines, people still die of asthma currently. According to WHO estimates, approximately 250,000 people die prematurely each year from asthma. Trends of asthma mortality rates vary very widely across countries, age and ethnic groups. Several risk factors have been associated with asthma mortality, including a history of near-fatal asthma requiring intubation and mechanical ventilation, hospitalization or emergency care visit for asthma in the past year, currently using or having recently stopped using oral corticosteroids (a marker of event severity), not currently using inhaled corticosteroids, a history of psychiatric disease or psychosocial problems, poor adherence with asthma medications and/or poor adherence with (or lack of) a written asthma action plan, food allergy in a patient with asthma. Preventable factors have been identified in the majority of asthma deaths. Inadequate education of patients on recognising risk and the appropriate action needed when asthma control is poor, deficiencies in the accuracy and timing of asthma diagnosis, inadequate classification of severity and treatment, seem to play a part in the majority of asthma deaths. Improvements in management, epitomized by the use of guided self-management systems of care may be the key goals in reducing asthma mortality worldwide.

Seasonal Patterns of Asthma in Children and Adolescents Presenting at Emergency Departments in Korea

Purpose

Seasonal variations in asthma-related hospitalizations and emergency department visits have long been recognized. This study aimed to investigate the seasonal patterns of asthma in children and adolescents who presented at emergency departments in Korea.

Methods

We analyzed the National Emergency Department Information System records from 117 emergency departments in Korea that comprised all of the patients with asthma who were aged 3-18 years and who presented at the emergency departments from 2007 to 2012. The children and adolescents were divided into 3 groups based on their ages, namely, 3-6 years, 7-12 years, and 13-18 years. The data were tabulated, and graphs were created to show the seasonal trends in the monthly numbers of emergency department visits as a consequence of asthma.

Results

A total of 41,128 subjects were identified, and the male-to-female ratio was 1:0.5. General ward admissions comprised 42.6% (n=17,524 patients) of the emergency department visits, and intensive care unit admissions comprised 0.8% (n=335 patients) of the emergency department visits. The monthly numbers of emergency department visits for asthma varied according to the season, with high peaks during fall, which was from September to November, and low levels in summer, which was from June to August.

Conclusions

Important differences in the seasonal patterns of emergency department visits for asthma were evident in children and adolescents. Identifying seasonal trends in asthma-related emergency department visits may help determine the causes and reduce the likelihood of asthma exacerbation.

Asthma: Hospitalization Trends and Predictors of In-Hospital Mortality and Hospitalization Costs in the USA (2001-2010)

BACKGROUND

In the last decade, the proportion of people with asthma in the USA grew by nearly 15%, with 479,300 hospitalizations and 1.9 million emergency department visits in 2009 alone. The primary objective of our study was to evaluate in-hospital outcomes in patients admitted with asthma exacerbation in terms of mortality, length of stay (LOS) and hospitalization costs.

METHODS

We queried the HCUP's Nationwide Inpatient Sample (NIS) between 2001 and 2010 using the ICD9-CM diagnosis code 493 for asthma (n = 760,418 patients). The NIS represents 20% of all hospitals in the USA. Multivariate logistic regression analysis was used to evaluate predictors of in-hospital mortality. LOS and hospitalization costs were also analyzed.

RESULTS

The overall LOS was 3.9 days and as high as 8.3 days in patients requiring mechanical ventilation. LOS has decreased in recent years, though it continues to be higher than in 2001. The hospitalization cost increased steadily over the study period. The overall in-hospital mortality was 1% and as high as 9.8% in patients requiring mechanical ventilation. Multivariate predictors of longer LOS, higher hospitalization costs and in-hospital mortality included increasing age and hospitalizations during the winter months. Private insurance was predictive of lower hospitalization costs and LOS as well as lower in-hospital mortality.

CONCLUSION

Asthma continues to account for significant in-hospital mortality and resource utilization, especially in mechanically ventilated patients. Age, admissions during winter months and the type of insurance are independent predictors of in-hospital outcomes.

Smoke-free legislation and the incidence of paediatric respiratory infections and wheezing/asthma: interrupted time series analyses in the four UK nations

We investigated the association between introduction of smoke-free legislation in the UK (March 2006 for Scotland, April 2007 for Wales and Northern Ireland, and July 2007 for England) and the incidence of respiratory diseases among children. We extracted monthly counts of new diagnoses of wheezing/asthma and RTIs among children aged 0–12 years from all general practices in the Clinical Practice Research Datalink during 1997–2012. Interrupted time series analyses were performed using generalised additive mixed models, adjusting for underlying incidence trends, population size changes, seasonal factors, and pandemic influenza, as appropriate. 366,642 new wheezing/asthma diagnoses and 4,324,789 RTIs were observed over 9,536,003 patient-years. There was no statistically significant change in the incidence of wheezing/asthma after introduction of smoke-free legislation in England (incidence rate ratio (IRR) 0.94, 95% CI 0.81–1.09) or any other UK country (Scotland: IRR 0.99, 95% CI 0.83–1.19; Wales: IRR 1.09, 95% CI 0.89–1.35; Northern Ireland: IRR 0.96, 95% CI 0.76–1.22). Similarly no statistically significant changes in RTI incidence were demonstrated (England: IRR 0.95, 95% CI 0.86–1.06; Scotland: IRR 0.96, 95% CI 0.83–1.11; Wales: IRR 0.97, 95% CI 0.86–1.09; Northern Ireland: IRR 0.90, 95% CI 0.79–1.03). There were no demonstrable reductions in the incidence of paediatric wheezing/asthma or RTIs following introduction of smoke-free legislation in the UK.

Association between patterns of leisure time physical activity and asthma control in adult patients

Background

Physical activity has been shown to have various health benefits in patients with asthma, especially in children. However, there are still limited data on the nature of the association between physical activity and asthma control in adults.

Objective

The objective of the current study was to determine the nature of the association between physical activity and asthma control, with particular emphasis on the intensity of the activity and seasonal variations.

Methods

643 adult patients with objectively confirmed asthma (mean age (SD)=53 (15) years, 60% women) were interviewed by telephone. Patients completed the asthma control questionnaire (ACQ), the asthma quality of life questionnaire, and a 1-year physical activity recall questionnaire to assess leisure time physical activity (LTPA).

Results

Total LTPA was related to control (β (95% CI)=−0.013 (−0.030 to 0.006)), with those doing recommended levels of LTPA being nearly 2.5 times more likely to have good control compared with inactive patients. Analysis of seasonal exercise habits found that winter LTPA (β=−0.027 (−0.048 to −0.006)) was more strongly associated with ACQ scores than summer LTPA (β=−0.019 (−0.037 to −0.001)). Adjustment for age, sex, season of assessment, inhaled corticosteroid (ICS) dose, body mass index, and current smoking status reduced the strength of the relationships.

Conclusions

Data indicate that higher levels of LTPA are associated with better levels of asthma control in adult patients with asthma, and that this seems to be more pronounced among asthmatics who do the recommended levels of exercise.

Impact of a multi-trigger intervention on seasonal patterns of asthma symptoms in inner city children

OBJECTIVES

Peaks in childhood asthma symptoms and asthma morbidity occur universally in the fall and late winter/early spring. This study examines whether there is a time of the year best suited to implement environmental interventions to attenuate this pattern.

METHODS

From September 2006 to June 2010, mid-Atlantic inner-city children asthmatics with 1 asthma-related hospitalization (IP) or 2 emergency (ED) visits the year prior to enrollment received 5 in-home self-management education sessions which included multi-trigger avoidance techniques and supplies. Children's daily asthma symptoms were recorded for 12 months by caregivers.

RESULTS

One-hundred and thirty-six children (48%) completed 12 months of symptoms diaries. Symptom days were reduced by 4.5 days at 12 months follow-up (p < 0.001). Symptom severity improved with a decreased severity score of 29.0 to 7.9 at month 12 (p < 0.001). Sixty-one percent of patients with ≥2 ED visits at baseline dropped to 0-1visits (p < 0.001). Eighty percent of patients with ≥1 IP visits dropped to 0 visits at 12 months (p < 0.001). Patients who received intervention in the summer months had half the average monthly symptoms score (10.8) as those who received intervention in the spring months (20.8). When controlling for environment and morbidity, the summer enrolled group had a significantly lower (p = 0.021) symptom score than those in other seasons.

CONCLUSION

Home self-management/environmental interventions for this cohort appear to have the greatest effect for those receiving the intervention in the summer and fall. The largest impact occurs in the summer cohort. Further studies with a control group are necessary to confirm these findings.

Outdoor fungi and child asthma health service attendances

Asthma is a significant global public health issue. Severe asthma exacerbations can be triggered by environmental factors and require medical care from health services. Although it is known that fungal exposure may lead to allergic sensitization, little is understood about its impact on asthma exacerbations. This review aims to examine whether outdoor fungi play a significant role in child asthma exacerbations. Systematic search of seven electronic databases and hand searching for peer-reviewed studies published in English, up to 31 August 2013. Inclusion criteria were study population aged <18 yr, diagnosis of asthma, attended a health service; outdoor fungi exposure was reported. Quality and risk of bias assessments were conducted. Due to significant heterogeneity, meta-analysis was not conducted. Of the 1896 articles found, 15 were eligible. Findings were not consistent, possibly due to methodological variations in exposure classifications, statistical methods and inclusion of confounders. Cross-sectional studies found no or weak associations. All but one time series studies indicated an association that varied between fungal species. Increasing evidence indicates that asthmatic children are susceptible to asthma exacerbations when exposed to outdoor fungal spores. There is limited understanding of the contributions of different fungal species. Research is needed to investigate interactions of outdoor fungi with pollen, air pollutants and respiratory viruses.

Health problems and the health care provider choices: a comparative study of urban and rural households in Egypt

OBJECTIVE

To assess families' health problems and the health facility choices in an urban and a rural district in Egypt.

METHODS

A cross-sectional descriptive study with a multi-stage random sample of 948 urban and 401 rural households was undertaken in a district of Cairo and rural Giza. Data was collected through interviews. The questionnaire addressed health problems and the use of health services within the fortnight prior to the survey. A follow-up of a sub-sample of 285 urban and 114 rural households was carried out 2-3weeks after the first interview to assess the outcome of complaints. The EPi Info Statistical Package was used for analysis and comparing urban and rural families.

RESULTS

Over 60% of urban and 78.8% of rural families had health complaints - respiratory, gastrointestinal and musculoskeletal. Outpatient clinics in public hospitals were the first choice for 49.7% of urban families and 23% of rural, while 25.7% of urban and 42.8% of rural families visited private clinics. Over half of the families with complaints recover from their illnesses within a fortnight.

CONCLUSION

Urban families have less health complaints than rural; however, rural families recover sooner. Families bypass often public primary health care services. Urban families overuse outpatient clinics in public hospitals.

Prophylactic effectiveness of suplatast tosilate in children with asthma symptoms in the autumn: a pilot study

BACKGROUND

Exacerbations of bronchial asthma usually occur in the autumn. To our knowledge, however, the effectiveness of drugs for preventing exacerbations of asthma in the autumn has not been studied previously, except for leukotriene receptor antagonists and Omalizmab.

METHODS

This study compared the prophylactic effectiveness of suplatast tosilate with that of mequitazine in children with asthma symptoms, which is usually exacerbated in the autumn. The study group comprised 27 children aged 2 to 15 years who required treatment for asthmatic attacks during the past year and tested positive at least for mite allergen in the preceding autumn. The subjects were randomly assigned to receive either suplatast or mequitazine. The primary endpoint of this study was the number of days without symptoms during the 8 weeks of treatment. In addition, the Japanese Pediatric Asthma Control Program (JPAC) scores were also recorded every 2 weeks in each group.

RESULTS

Overall, 14 patients received suplatast, and 13 received mequitazine for 8 weeks from September through early October. During follow-up, the number of days without symptoms and the total JPAC scores did not differ significantly between the groups. However, as compared with weeks 1 to 2 of treatment, the mean number of days without symptoms during weeks 7 to 8 increased significantly in only the suplatast group (8.6 vs. 11.5 days; p = 0.004).

CONCLUSIONS

Our results suggest that short-term additional treatment with suplatast is useful for preventing asthma symptoms in children with asthma, which is usually exacerbated in the autumn.

Smartphone and tablet self management apps for asthma

BACKGROUND

Asthma is one of the most common long-term conditions worldwide, which places considerable pressure on patients, communities and health systems. The major international clinical guidelines now recommend the inclusion of self management programmes in the routine management of patients with asthma. These programmes have been associated with improved outcomes in patients with asthma. However, the implementation of self management programmes in clinical practice, and their uptake by patients, is still poor. Recent developments in mobile technology, such as smartphone and tablet computer apps, could help develop a platform for the delivery of self management interventions that are highly customisable, low-cost and easily accessible.

OBJECTIVES

To assess the effectiveness, cost-effectiveness and feasibility of using smartphone and tablet apps to facilitate the self management of individuals with asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Register (CAGR), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, Global Health Library, Compendex/Inspec/Referex, IEEEXplore, ACM Digital Library, CiteSeer(x) and CAB abstracts via Web of Knowledge. We also searched registers of current and ongoing trials and the grey literature. We checked the reference lists of all primary studies and review articles for additional references. We searched for studies published from 2000 onwards. The latest search was run in June 2013.

SELECTION CRITERIA

We included parallel randomised controlled trials (RCTs) that compared self management interventions for patients with clinician-diagnosed asthma delivered via smartphone apps to self management interventions delivered via traditional methods (e.g. paper-based asthma diaries).

DATA COLLECTION AND ANALYSIS

We used standard methods expected by the Cochrane Collaboration. Our primary outcomes were symptom scores; frequency of healthcare visits due to asthma exacerbations or complications and health-related quality of life.

MAIN RESULTS

We included two RCTs with a total of 408 participants. We found no cluster RCTs, controlled before and after studies or interrupted time series studies that met the inclusion criteria for this systematic review. Both RCTs evaluated the effect of a mobile phone-based asthma self management intervention on asthma control by comparing it to traditional, paper-based asthma self management. One study allowed participants to keep daily entries of their asthma symptoms, asthma medication usage, peak flow readings and peak flow variability on their mobile phone, from which their level of asthma control was calculated remotely and displayed together with the corresponding asthma self management recommendations. In the other study, participants recorded the same readings twice daily, and they received immediate self management feedback in the form of a three-colour traffic light display on their phones. Participants falling into the amber zone of their action plan twice, or into the red zone once, received a phone call from an asthma nurse who enquired about the reasons for their uncontrolled asthma.We did not conduct a meta-analysis of the data extracted due to the considerable degree of heterogeneity between these studies. Instead we adopted a narrative synthesis approach. Overall, the results were inconclusive and we judged the evidence to have a GRADE rating of low quality because further evidence is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. In addition, there was not enough information in one of the included studies to assess the risk of bias for the majority of the domains. Although the other included study was methodologically rigorous, it was not possible to blind participants or personnel in the study. Moreover, there are concerns in both studies in relation to attrition bias and other sources of bias.One study showed that the use of a smartphone app for the delivery of an asthma self management programme had no statistically significant effect on asthma symptom scores (mean difference (MD) 0.01, 95% confidence interval (CI) -0.23 to 0.25), asthma-related quality of life (MD of mean scores 0.02, 95% CI -0.35 to 0.39), unscheduled visits to the emergency department (OR 7.20, 95% CI 0.37 to 140.76) or frequency of hospital admissions (odds ratio (OR) 3.07, 95% CI 0.32 to 29.83). The other included study found that the use of a smartphone app resulted in higher asthma-related quality of life scores at six-month follow-up (MD 5.50, 95% CI 1.48 to 9.52 for the physical component score of the SF-12 questionnaire; MD 6.00, 95% CI 2.51 to 9.49 for the mental component score of the SF-12 questionnaire), improved lung function (PEFR) at four (MD 27.80, 95% CI 4.51 to 51.09), five (MD 31.40, 95% CI 8.51 to 54.29) and six months (MD 39.20, 95% CI 16.58 to 61.82), and reduced visits to the emergency department due to asthma-related complications (OR 0.20, 95% CI 0.04 to 0.99). Both studies failed to find any statistical differences in terms of adherence to the intervention and occurrence of other asthma-related complications.

AUTHORS' CONCLUSIONS

The current evidence base is not sufficient to advise clinical practitioners, policy-makers and the general public with regards to the use of smartphone and tablet computer apps for the delivery of asthma self management programmes. In order to understand the efficacy of apps as standalone interventions, future research should attempt to minimise the differential clinical management of patients between control and intervention groups. Those studies evaluating apps as part of complex, multicomponent interventions, should attempt to tease out the relative contribution of each intervention component. Consideration of the theoretical constructs used to inform the development of the intervention would help to achieve this goal. Finally, researchers should also take into account: the role of ancillary components in moderating the observed effects, the seasonal nature of asthma and long-term adherence to self management practices.

Preventing and lessening exacerbations of asthma in school-age children associated with a new term (PLEASANT): study protocol for a cluster randomised control trial

BACKGROUND

Within the UK, during September, there is a pronounced increase in the number of unscheduled medical contacts by school-aged children (4-16 years) with asthma. It is thought that that this might be caused by the return back to school after the summer holidays, suddenly mixing with other children again and picking up viruses which could affect their asthma. There is also a drop in the number of prescriptions administered in August. It is possible therefore that children might not be taking their medication as they should during the summer contributing to them becoming ill when they return to school.It is hoped that a simple intervention from the GP to parents of children with asthma at the start of the summer holiday period, highlighting the importance of maintaining asthma medication can help prevent increased asthma exacerbation, and unscheduled NHS appointments, following return to school in September.

METHODS/DESIGN

PLEASANT is a cluster randomised trial. A total of 140 General Practices (GPs) will be recruited into the trial; 70 GPs randomised to the intervention and 70 control practices of "usual care". An average practice is expected to have approximately 100 children (aged 4-16 with a diagnosis of asthma) hence observational data will be collected on around 14000 children over a 24-month period. The Clinical Practice Research Datalink will collect all data required for the study which includes diagnostic, prescription and referral data.

DISCUSSION

The trial will assess whether the intervention can reduce exacerbation of asthma and unscheduled medical contacts in school-aged children associated with the return to school after the summer holidays. It has the potential to benefit the health and quality of life of children with asthma while also improving the effectiveness of NHS services by reducing NHS use in one of the busiest months of the year.An exploratory health economic analysis will gauge any cost saving associated with the intervention and subsequent impacts on quality of life. If results for the intervention are positive it is hoped that this could be adopted as part of routine care management of childhood asthma in general practice.

TRIAL REGISTRATION

Current controlled trials: ISRCTN03000938 (assigned 19/10/12) http://www.controlled-trials.com/ISRCTN03000938/.

UKCRN ID

13572.

Prevalence of asthma symptoms in schoolchildren, and climate in west European countries: an ecologic study

The aim of the present study was to estimate the associations between the prevalence of asthma symptoms in schoolchildren and meteorological variables in west European countries that participated in the International Study of Asthma and Allergies in Children (ISAAC), Phase III 1997-2003. An ecologic study was carried out. The prevalence of asthma was obtained from this study from 48 centers in 14 countries, and meteorological variables from those stations closest to ISAAC centers, together with other socioeconomic and health care variables. Multilevel mixed-effects linear regression models were used. For schoolchildren aged 6-7 years, the prevalence rate of asthma decreased with an increase in mean annual sunshine hours, showed a positive association with rainy weather, and warm temperature, and a negative one with relative humidity and physician density (PD). Current wheeze prevalence was stronger in autumn/winter seasons and decreased with increasing PD. Severe current wheeze decreased with PD. For schoolchildren aged 13-14 years, the prevalence rates of asthma and current wheeze increased with rainy weather, and these rates decreased with increased PD. Current wheeze, as measured by a video questionnaire, was inversely associated with sunny weather, and nurse density. Severe current wheeze prevalence was stronger during autumn/winter seasons, decreased with PD, and indoor chlorinated public swimming pool density, and increased with rainy weather. Meteorological factors, including sunny and rainy weather, and PD may have some effect on the prevalence rates of asthma symptoms in children from west European countries.

Methacholine challenge test results in children are season dependent

BACKGROUND

It is known that several parameters influence the positivity of a methacholine challenge (MCH), including a recent viral disease, allergies, and air pollution. Reports regarding the influence of the season upon the positivity of MCH are scarce. The aim of this study was to assess the percentage of positive MCH tests per season.

METHODS

We retrospectively evaluated all MCH tests performed in children and adults in a single center over a 30-month period. The percentage of positive tests for summer was compared with that of other seasons.

RESULTS

A total of 155 challenges were performed in children (under 20 years old) and 527 in adults. Thirty-eight percent of the tests were positive in adults and 71 % in children. The percentage of positive tests in the summer was significantly lower than the percentage of positive results during the rest of the year in children (58.5 vs. 75.4 %, respectively; p = 0.046). By contrast, there was no difference between the seasons in adults (39 vs. 38 %, respectively; p = 0.92).

CONCLUSIONS

There is a difference of 22.4 % in the percentage of positive tests in the summer months compared to the rest of the year in children, suggesting a reduction in the sensitivity of the MCH test in the hot season. We suggest that in cases where asthma is strongly suspected in a child and the MCH test was negative in the summer, one should consider repeating the MCH test in another season.

The influence of sensitisation to pollens and moulds on seasonal variations in asthma attacks

No large study has described the seasonal variation in asthma attacks in population-based asthmatics in whom sensitisation to allergen has been measured.

2637 young adults with asthma living in 15 countries reported the months in which they usually had attacks of asthma and had skin-prick tests performed. Differences in seasonal patterns by sensitisation status were assessed using generalised estimating equations.

Most young adults with asthma reported periods of the year when their asthma attacks were more common (range: 47% in Sweden to 86% in Spain). Seasonal variation in asthma was not modified by sensitisation to house dust mite or cat allergens. Asthmatics sensitised to grass, birch and Alternaria allergens had different seasonal patterns to those not sensitised to each allergen, with some geographical variation. In southern Europe, those sensitised to grass allergens were more likely to report attacks occurred in spring or summer than in winter (OR March/April 2.60, 95% CI 1.70–3.97; OR May/June 4.43, 95% CI 2.34–8.39) and smaller later peaks were observed in northern Europe (OR May/June 1.25, 95% CI 0.60–2.64; OR July/August 1.66, 95% CI 0.89–3.10). Asthmatics reporting hay fever but who were not sensitised to grass showed no seasonal variations.

Seasonal variations in asthma attacks in young adults are common and are different depending on sensitisation to outdoor, but not indoor, allergens.

Seasonal variation in asthma attacks is associated with sensitisation to pollens and moulds, but not indoor allergenshttp://ow.ly/nsuRS

Hospital admissions for childhood asthma after smoke-free legislation in England

OBJECTIVE

To assess whether the implementation of English smoke-free legislation in July 2007 was associated with a reduction in hospital admissions for childhood asthma.

METHODS

Interrupted time series study using Hospital Episodes Statistics data from April 2002 to November 2010. Sample consisted of all children (aged ≤14 years) having an emergency hospital admission with a principle diagnosis of asthma.

RESULTS

Before the implementation of the legislation, the admission rate for childhood asthma was increasing by 2.2% per year (adjusted rate ratio 1.02; 95% confidence interval [CI]: 1.02-1.03). After implementation of the legislation, there was a significant immediate change in the admission rate of -8.9% (adjusted rate ratio 0.91; 95% CI: 0.89-0.93) and change in time trend of -3.4% per year (adjusted rate ratio 0.97; 95% CI: 0.96-0.98). This change was equivalent to 6802 fewer hospital admissions in the first 3 years after implementation. There were similar reductions in asthma admission rates among children from different age, gender, and socioeconomic status groups and among those residing in urban and rural locations.

CONCLUSIONS

These findings confirm those from a small number of previous studies suggesting that the well-documented population health benefits of comprehensive smoke-free legislation appear to extend to reducing hospital admissions for childhood asthma.

Temporal patterns in severe hemoptysis requiring bronchial artery embolization

Background

Although some authors have suggested that there is some seasonal periodicity in hemoptysis, temporal patterns of hemoptysis have been poorly investigated. The aim of this study is to describe the temporal pattern of severe hemoptysis which required bronchial artery embolization (BAE).

Methods

All consecutive patients with at least one episode of hemoptysis which required BAE during a 13-year period were included. Recurring hemoptysis requiring BAE in a patient with previous embolization was included as a new hemoptysis event, unless it occurred within one month from the prior event. Lineal regression was applied to compute the tendency of occurrence of cases along 13 years of record data. The daily and monthly distributions of embolizations were used to study the weekly and monthly seasonal indexes.

Results

Hemoptysis requiring BAE occurred with some monthly variation demonstrated with two monthly peaks, with the first one occurring during April and the second one during November.

Conclusion

Hemoptysis occurred with two monthly peaks. This seasonal trend might be due to different prevalence of respiratory tract infections or to some weather variables. Identification of significant environmental factors could be useful to improve preventive measures.

Seasonality of medical contacts in school-aged children with asthma: association with school holidays

OBJECTIVES

To assess the seasonality of medical contacts in children with asthma, to compare England with Scotland, and to assess the impact of medication compliance on the frequency of medical contacts.

STUDY DESIGN

A retrospective study taken from the General Practice Research Database of daily medical contacts from 1999 to 2005 in a population of school-aged (5-16 years) children with a diagnosis of asthma, and age- and gender-matched controls.

PRIMARY OUTCOME MEASURE

All unscheduled medical contacts. Prescription frequency for inhaled corticosteroids over the same period was also assessed.

RESULTS

Data from 76,924 children were analyzed. There was an increase in unscheduled medical contacts for all children on return to school in September. Unscheduled medical contacts occurred almost twice as frequently in children with asthma compared with non-asthmatic children. The frequency of medical contacts in children with asthma could be predicted from the frequency of medical contacts in non-asthmatic children. In the 3 months from September to December, unscheduled medical contacts were disproportionately greater than would be predicted for children with asthma relative to non-asthmatic children in both England and Scotland. The rise in medical contacts in Scotland preceded that in England by approximately 14 days, reflecting the earlier date for returning to school. The number of prescriptions for inhaled corticosteroids decreased in August. A higher incidence of unscheduled medical contacts was noted during September in those not receiving a prescription in August.

CONCLUSIONS

Returning to school after the summer break is associated with a sharp increase in unscheduled medical contacts in school-aged children, particularly in those with asthma. This follows a decrease in the number of prescriptions for inhaled corticosteroids. It is suggested that at least part of the excess numbers of unscheduled contacts in children with asthma is because they do not maintain their inhaled corticosteroids over the summer holidays.

Childhood asthma utilization rates in a nonsmoking population of utah compared to state and national rates

Risk factors, such as parental smoking, are commonly associated with increased asthma symptoms and hospitalizations of children. Deseret Mutual Benefits Administrators (DMBA) is the health insurer for employees of The Church of Jesus Christ of Latter-day Saints and their families. Due to religious proscription, employees abstain from alcohol and tobacco use, creating a cohort of children not exposed to parental smoking. Calculation of hospitalization rates for DMBA, Utah, and the US were made in children to compare rates between a nonsmoking population and general populations. Compared to DMBA, rate ratios for asthma hospitalization and emergency department asthma visits were higher for the US and Utah. The incidence of hospital outpatient department and physician office visits was significantly greater for the US population compared to the DMBA. This study demonstrates a decreased need for health services used by children not exposed to second-hand smoke.

Human mortality seasonality in Castile-León, Spain, between 1980 and 1998: the influence of temperature, pressure and humidity

This study was carried out in the region of Castile and Leon, Spain, from 1980 to 1998 and analyzes the relationship between the number of monthly deaths caused by cardiovascular, respiratory and digestive diseases and three meteorological variables: temperature, pressure and humidity. One of the innovations in this study is the application of principal component analysis in a way that differs from its usual application: one single series representing the whole region was constructed for each meteorological variable from the series of eight weather stations. Annual and seasonal mortality trends were also studied. Cardiovascular diseases are the leading cause of death in Castile and Leon. The mortality related to cardiovascular, respiratory and digestive systems shows a statistically significant rising trend across the study period (an annual increase of 6, 16 and 4 per thousand, respectively). The pressure at which mortality is lowest is approximately the same for all causes of death (about 915 hPa), but temperature values vary greatly (16.8-19.7 degrees C for the mean, 10.9-18.1 degrees C for the minimum, and 24.1-27.2 degrees C for the maximum temperature). The most comfortable temperatures for patients with cardiovascular diseases (16.8 degrees C) are apparently lower than those for patients with respiratory diseases (18.1 degrees C), which are, in turn, lower than in the case of diseases of the digestive system (19.7 degrees C). Finally, the optimal humidity for patients with respiratory diseases is the lowest (24%) among the diseases, and the highest (51%) corresponds to diseases of the digestive system, while the optimal relative humidity for the cardiovascular system is 45%.

The Back to School asthma study: the effect of montelukast on asthma burden when initiated prophylactically at the start of the school year

BACKGROUND

Pediatric asthma hospitalizations peak in early autumn.

OBJECTIVE

To determine the effectiveness of montelukast therapy in reducing the asthma burden in children when initiated prophylactically on school return.

METHODS

This was a randomized, multicenter, double-blind, placebo-controlled study of children with asthma aged 6 to 14 years. No minimum asthma symptoms were required, and patients could continue inhaled corticosteroid (ICS) use. Montelukast, 5 mg, chewable tablet (n = 580) or matching placebo (n = 582) was taken the night before the first day of school and nightly thereafter for 8 weeks. The primary end point was the percentage of days with worsening asthma, defined by one of the following: (1) increased beta-agonist use, (2) increased daytime symptoms, (3) awake "all night," (4) oral corticosteroid rescue or increased ICS use for worsening asthma, or (5) unanticipated health care utilization.

RESULTS

The reduction in the percentage of days with worsening asthma with montelukast use versus placebo use was not significant (24.3% vs 27.2%, P = .07). Prespecified subgroup analyses demonstrated nonsignificant trends favoring montelukast therapy in boys and older children but no effect by baseline ICS use or history of cold symptoms. Post hoc analysis showed a nonsignificant trend favoring montelukast therapy in reducing worsening asthma days for children commencing school after August 15 compared with earlier commencement.

CONCLUSIONS

Montelukast use was not significantly more effective than was placebo use in reducing the percentage of days with worsening asthma when initiated at the start of the school year. The effect of montelukast treatment on the fall peak in asthma burden may depend on sex, age, and the date of school return.

Objective airway monitoring improves asthma control in the cold and flu season: a cluster randomized trial

BACKGROUND

The goals of asthma care are reductions in risk and impairment, but achieving these goals requires collaborative work between patients and their clinicians. The purpose of this study was to improve inhaled corticosteroid (ICS) adherence and asthma control by cueing therapeutic communication between patients with asthma and their primary care clinicians.

METHODS

We conducted a prospective, cluster-randomized, controlled effectiveness trial to assess the effect of providing visually standardized, interpreted peak flow graphs (CUE intervention) to patients and their clinicians on ICS adherence and asthma control. Asthma control outcomes were analyzed by season to account for seasonal variations in exacerbation frequency.

RESULTS

Although mean log-transformed ICS adherence was not significantly different between the two groups, there was a trend toward preserved adherence in the intervention group over time (P = .16). Intervention patients required fewer courses of oral steroids during winter (9% vs 23%, P < .001) and spring (3% and 17%, P < .001) compared with control subjects. Intervention patients also had fewer periods of worsening symptoms (65% vs 89%, P < .001) and fewer urgent care visits (10% vs 23%, P < .001) during winter compared with control subjects. Post hoc analysis showed significant improvement in the intervention group with respect to ICS adherence during winter months (P < .05), the likely explanation for the reduction in prednisone use and symptoms. Day-to-day peak flow variability in the intervention group fell consistently throughout the study from an average of 32% at baseline to 23% at final measurement (P < .001), indicating less airway reactivity over time.

CONCLUSIONS

Our findings provide evidence of the value of peak flow monitoring for patients with asthma during seasons of greatest vulnerability, the cold/flu season. The peak flow information apparently led to improvements in ICS adherence resulting in less need for prednisone rescue and fewer episodes of worsening symptoms.