International trends in hospital admission rates for asthma

The epithelial barrier: The gateway to allergic, autoimmune, and metabolic diseases and chronic neuropsychiatric conditions

Since the 1960 s, our health has been compromised by exposure to over 350,000 newly introduced toxic substances, contributing to the current pandemic in allergic, autoimmune and metabolic diseases. The "Epithelial Barrier Theory" postulates that these diseases are exacerbated by persistent periepithelial inflammation (epithelitis) triggered by exposure to a wide range of epithelial barrier-damaging substances as well as genetic susceptibility. The epithelial barrier serves as the body's primary physical, chemical, and immunological barrier against external stimuli. A leaky epithelial barrier facilitates the translocation of the microbiome from the surface of the afflicted tissues to interepithelial and even deeper subepithelial locations. In turn, opportunistic bacterial colonization, microbiota dysbiosis, local inflammation and impaired tissue regeneration and remodelling follow. Migration of inflammatory cells to susceptible tissues contributes to damage and inflammation, initiating and aggravating many chronic inflammatory diseases. The objective of this review is to highlight and evaluate recent studies on epithelial physiology and its role in the pathogenesis of chronic diseases in light of the epithelial barrier theory.

Epithelial Barrier Theory: The Role of Exposome, Microbiome, and Barrier Function in Allergic Diseases

Allergic diseases are a major public health problem with increasing prevalence. These immune-mediated diseases are characterized by defective epithelial barriers, which are explained by the epithelial barrier theory and continuously emerging evidence. Environmental exposures (exposome) including global warming, changes and loss of biodiversity, pollution, pathogens, allergens and mites, laundry and dishwasher detergents, surfactants, shampoos, body cleaners and household cleaners, microplastics, nanoparticles, toothpaste, enzymes and emulsifiers in processed foods, and dietary habits are responsible for the mucosal and skin barrier disruption. Exposure to barrier-damaging agents causes epithelial cell injury and barrier damage, colonization of opportunistic pathogens, loss of commensal bacteria, decreased microbiota diversity, bacterial translocation, allergic sensitization, and inflammation in the periepithelial area. Here, we review scientific evidence on the environmental components that impact epithelial barriers and microbiome composition and their influence on asthma and allergic diseases. We also discuss the historical overview of allergic diseases and the evolution of the hygiene hypothesis with theoretical evidence.

Does the epithelial barrier hypothesis explain the increase in allergy, autoimmunity and other chronic conditions?

There has been a steep increase in allergic and autoimmune diseases, reaching epidemic proportions and now affecting more than one billion people worldwide. These diseases are more common in industrialized countries, and their prevalence continues to rise in developing countries in parallel to urbanization and industrialization. Intact skin and mucosal barriers are crucial for the maintenance of tissue homeostasis as they protect host tissues from infections, environmental toxins, pollutants and allergens. A defective epithelial barrier has been demonstrated in allergic and autoimmune conditions such as asthma, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis, coeliac disease and inflammatory bowel disease. In addition, leakiness of the gut epithelium is also implicated in systemic autoimmune and metabolic conditions such as diabetes, obesity, multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis and autoimmune hepatitis. Finally, distant inflammatory responses due to a 'leaky gut' and microbiome changes are suspected in Alzheimer disease, Parkinson disease, chronic depression and autism spectrum disorders. This article introduces an extended 'epithelial barrier hypothesis', which proposes that the increase in epithelial barrier-damaging agents linked to industrialization, urbanization and modern life underlies the rise in allergic, autoimmune and other chronic conditions. Furthermore, it discusses how the immune responses to dysbiotic microbiota that cross the damaged barrier may be involved in the development of these diseases.

Epidemiology of Asthma in Children and Adults

Asthma is a globally significant non-communicable disease with major public health consequences for both children and adults, including high morbidity, and mortality in severe cases. We have summarized the evidence on asthma trends, environmental determinants, and long-term impacts while comparing these epidemiological features across childhood asthma and adult asthma. While asthma incidence and prevalence are higher in children, morbidity, and mortality are higher in adults. Childhood asthma is more common in boys while adult asthma is more common in women, and the reversal of this sex difference in prevalence occurs around puberty suggesting sex hormones may play a role in the etiology of asthma. The global epidemic of asthma that has been observed in both children and adults is still continuing, especially in low to middle income countries, although it has subsided in some developed countries. As a heterogeneous disease, distinct asthma phenotypes, and endotypes need to be adequately characterized to develop more accurate and meaningful definitions for use in research and clinical settings. This may be facilitated by new clustering techniques such as latent class analysis, and computational phenotyping methods are being developed to retrieve information from electronic health records using natural language processing (NLP) algorithms to assist in the early diagnosis of asthma. While some important environmental determinants that trigger asthma are well-established, more work is needed to define the role of environmental exposures in the development of asthma in both children and adults. There is increasing evidence that investigation into possible gene-by-environment and environment-by-environment interactions may help to better uncover the determinants of asthma. Therefore, there is an urgent need to further investigate the interrelationship between environmental and genetic determinants to identify high risk groups and key modifiable exposures. For children, asthma may impair airway development and reduce maximally attained lung function, and these lung function deficits may persist into adulthood without additional progressive loss. Adult asthma may accelerate lung function decline and increase the risk of fixed airflow obstruction, with the effect of early onset asthma being greater than late onset asthma. Therefore, in managing asthma, our focus going forward should be firmly on improving not only short-term symptoms, but also the long-term respiratory and other health outcomes.

Management of acute respiratory diseases in the pediatric population: the role of oral corticosteroids

Respiratory diseases account for about 25% of all pediatric consultations, and 10% of these are for asthma. The other main pediatric respiratory diseases, in terms of incidence, are bronchiolitis, acute bronchitis and respiratory infections. Oral corticosteroids, in particular prednisolone, are often used to treat acute respiratory diseases given their anti-inflammatory effects. However, the efficacy of treatment with oral corticosteroids differs among the various types of pediatric respiratory diseases. Notably, also the adverse effects of corticosteroid treatment can differ depending on dosage, duration of treatment and type of corticosteroid administered — a case in point being growth retardation in long-course treatment. A large body of data has accumulated on this topic. In this article, we have reviewed the data and guidelines related to the role of oral corticosteroids in the treatment and management of pediatric bronchiolitis, wheezing, asthma and croup in the attempt to provide guidance for physicians. Also included is a section on the management of acute respiratory failure in children.

Clinical features of a paediatric asthma population in Trinidad

AIM

Clinical features and management of paediatric asthma, highly prevalent in the Caribbean, was explored in Trinidadian children.

MATERIALS

Children (2-16 years) with acute [visiting Accident and Emergency (A&E) in the past 12 months (50.2%, 120)] or stable asthma [controlled during the previous 3 months (49.8%, 119)] were studied.

RESULTS

There were more (P < 0.001) boys (71.5%) than girls. Asthma was associated with asthmatic mothers (48.5%), fathers (19.2%) and both parents (15.1%) (P < 0.001). Children's average age of first wheeze was 2.5 (standard deviation = 1.3) years; 30.1% were nebulized before 1 year. In the past 12 months, frequencies of A&E visits were once (20.6%), >1 (61.9%) and >3 times (26.4%) (P < 0.001). Sufferers of exacerbations showed negative logistic regression for age (-0.129, standard error = 0.039, P < 0.001) independent of gender. Acute asthmatics who suffered cough, fever and sore throat in the preceding week were respectively 15.2 [odds ratio (OR) = 15.2, 95% confidence interval (CI) = 6.8-34.0], 13.7 (OR = 13.7, 95% CI = 6.7-28.2) and 3.4 (OR = 3.4, 95% CI = 1.7-6.7) times more likely to suffer wheeze exacerbations than stable children. Most stable children (76.5%) inhaled corticosteroids with salbutamol reliever compared with 22.5% of acute asthmatics, whereas 40.8% of the latter group used salbutamol alone compared with 19.3% of stable children (P < 0.001).

CONCLUSION

Childhood wheeze occurs before 3 years and is associated with maternal asthma. Cough, fever and sore throat in the previous week are strongly associated with exacerbations. Defining these associations could enhance preventive approaches to combat childhood asthma.

The allergy epidemics: 1870-2010

Before the first description of hay fever in 1870, there was very little awareness of allergic disease, which is actually similar to the situation in prehygiene villages in Africa today. The best explanation for the appearance and subsequent increase in hay fever at that time is the combination of hygiene and increased pollen secondary to changes in agriculture. However, it is important to remember that the major changes in hygiene in Northern Europe and the United States were complete by 1920. Asthma in children did not start to increase until 1960, but by 1990, it had clearly increased to epidemic numbers in all countries where children had adopted an indoor lifestyle. There are many features of the move indoors that could have played a role; these include increased sensitization to indoor allergens, diet, and decreased physical activity, as well as the effects of prolonged periods of shallow breathing. Since 1990, there has been a remarkable increase in food allergy, which has now reached epidemic numbers. Peanut has played a major role in the food epidemic, and there is increasing evidence that sensitization to peanut can occur through the skin. This suggests the possibility that changes in lifestyle in the last 20 years could have influenced the permeability of the skin. Overall, the important conclusion is that sequential changes in lifestyle have led to increases in different forms of allergic disease. Equally, it is clear that the consequences of hygiene, indoor entertainment, and changes in diet or physical activity have never been predicted.

Prevalence, severity and risk factors of asthma, rhinitis and eczema in a large group of Chinese schoolchildren

BACKGROUND

There is a lack of information on the prevalence, severity and risk factors of asthma, rhinitis and eczema in Chinese children.

OBJECTIVE

To establish baseline data for a major longitudinal study of factors affecting asthma, rhinitis and eczema in a large group of children from the industrialized city of Shijiazhuang, China.

METHODS

We used the International Study of Asthma and Allergies in Childhood questionnaire and studied 10 338 children, ages 6-18, from Shijiazhuang.

RESULTS

The prevalence of childhood asthma, rhinitis and eczema is 1.2%, 13.5% and 11.8%, respectively. Boys had higher prevalence of these conditions than girls and younger children had higher prevalence of asthma and eczema but lower prevalence of rhinitis than older children. Breastfed children had lower prevalence of asthma and rhinitis, but not eczema, than non-breastfed children. Overweight children had higher prevalence of asthma and rhinitis than those who were not overweight. Children exposed to paternal smoking had higher prevalence of rhinitis and eczema than those not exposed; children exposed to pets had higher prevalence of asthma and rhinitis than those not exposed.

CONCLUSIONS

The prevalence of asthma in this study group is low, but the prevalence of rhinitis is high, and could be considered a major public health problem. The prevalence of asthma, rhinitis and eczema is generally higher in boys and younger children generally have higher prevalence of asthma and eczema but lower prevalence of rhinitis. Exposure to pets is a risk factor for rhinitis, being overweight is a risk factor for asthma and rhinitis, and exposure to parental smoking is a risk factor for asthma, rhinitis and eczema in these children.

Fifty years of pediatric asthma in developed countries: how reliable are the basic data sources?

Given the difficulties in diagnosing, or even defining, asthma in children, claims of a pediatric asthma epidemic in Canada and other developed countries are accepted with surprisingly little critical examination. We reviewed a broad range of data sources to understand how the epidemic evolved during the last 50 years and also to assess the reliability of the conclusions drawn from that data. We obtained Canadian National and Provincial data from Statistics Canada National Population Health Survey, and the British Columbia Ministry of Health respiratory database. International data were obtained by extensive review of pediatric asthma epidemiological surveys published during the last 50 years. In many developed countries, there have been three separate epidemics involving different aspects of pediatric asthma during the last 50 years: a double peaked mortality epidemic (1960s and 1980s), a hospital admission epidemic (peaked around 1990) and a steadily growing epidemic of children who report asthmatic symptoms on questionnaires. Canadian pediatric rates for asthma mortality (1-2/million/year) and hospital admission (1-2/thousand/year) are low and have fallen for the last 20 years. Rates based on questionnaire studies are high (10-15/hundred) and rose steadily over the same period. Objective reductions in asthma deaths and hospital admission likely reflect improved education and treatment programmes. Current claims of an epidemic based largely on subjective self-reported symptoms require more careful analysis. The possibility that symptom misperception, disease fashions, and poor recall, may be part of the explanation for the current high levels of self-reported symptoms deserves more attention.

Preschool asthma in Italy: prevalence, risk factors and health resource utilization

Asthma in preschool children is greatly under-diagnosed worldwide. Aim was to investigate prevalence of wheezing, and asthma risk factors, doctor diagnosis, treatment and health resource utilization in preschool children. About 1402 children (3-5 years) attending local kindergartens participated in the study. The International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire (WQ) was used with additional questions on risk factors, asthma diagnosis, treatments, resource utilization. Allergic sensitisation was evaluated by skin prick tests for the common allergens. Prevalence of "wheezing in previous 12 months" and "doctor diagnosed asthma" were 12.1% and 8.6%, respectively. 4.7% of children have had both wheezing in the last 12 months and asthma diagnosis. Significant risk factors for wheezing were rhinitis, parental history of atopy and sensitivity to mites and grass pollens. 27.3% of children with asthma diagnosis, but only 4.9% of children without diagnosis, received regular treatment during the previous year (p<0.0001). Children with more than 4 episodes of wheezing a year received more frequently an asthma diagnosis, but 68.6% were not on regular treatment. Asthma diagnosis was associated with a significant increase in control visits for wheezing (p<0.0001). The prevalence of children requiring at least one hospital emergency visit in the previous year was not different among the two groups (83.3% vs. 82.5%). In preschool children the prevalence of wheezing and asthma is elevated. Preschool asthma seems to be under-treated with few cases receiving regular therapy. The social cost of the disease at this age seems to be elevated because of the high frequency of control and emergency visits.

[Trends in hospital admissions for asthma in France, 1998-2002]

BACKGROUND

As the quality of asthma care influences hospital admission rates, we described hospitalizations for asthma and studied trends in admission rates in France from 1998 to 2002.

METHODS

Using data from the French hospital information system, admissions for asthma were defined by the J45 or J46 codes (ICD-10) as primary diagnosis, and admissions for acute respiratory failure (ARF) associated with asthma by the J96.0 code as primary diagnosis and the J45 or J46 codes as an associated diagnosis. Annual rates of admission adjusted for age and sex were calculated.

RESULTS

During the study period, the adjusted asthma admission rate decreased by 5% per year (from 10.8/10,000 in 1998 to 8.6/10,000 in 2002). A significant decrease was observed in children aged 10-14 years (-5%/year) and in older people (from -7%/year in 15-19 years old to -9%/year in people aged 50 years or more), whereas no significant decrease was seen in youngest children (-2%/year in children aged 0-1 or 5-9 years, +0.1%/year in those aged 2-4 years). Although not statistically significant, an increase in admission rate for ARF associated with asthma was observed (+5%/year).

CONCLUSION

Admission rates for asthma decreased between 1998 and 2002 in people aged 10 years and older. However, changes in coding practices or admission policies cannot be excluded and the extent to which the observed trends reflect changes in preventive care among patients with asthma remains to be assessed.

Air pollution, weather, and associated risk factors related to asthma prevalence and attack rate

Asthma is an important public health challenge. The objective of this research was to investigate the relationship of air pollution and weather to adolescent asthma prevalence and attack rate. A 6-month mass screening asthma study was conducted from October 1995 to March 1996 in Taiwan. The study population included junior high school students from throughout the country (1,139,452 students). Eighty-nine percent of students completed questionnaires (International Study of Asthma and Allergies in Childhood-ISAAC and New England Core Questionnaires) and passed a logical screening error program. Lung function data was collected to assist in the diagnosis of asthma status. From the students screened during this mass survey, a stratified random sample of 64,660 students was analyzed for asthma prevalence and attack rate. Using a regression model to compare the USEPA National Ambient Air Quality Standards 2000 (NAAQS, 2000) to asthma prevalence, this investigation found that the standards may not provide enough protection for adolescents after controlling for age, rhinitis, eczema, urban birth location, parental education level, exercise, cigarette smoking, environmental tobacco smoking, alcohol beverage consumption and weather factors. The general estimating equations (GEE) model, a repeated measurement regression model, was used to examine the relationship between the monthly asthma attack rate among asthma patients and air pollution (nitrogen oxides; nitrogen dioxide; nitric oxide; Ozone; PM10) while controlling for household smoking. The GEE model demonstrated that air pollution is related to asthma attack rate. Air pollution factors also interacted with weather parameters when related to asthma attack rate.

The global burden of asthma

There has been a sharp increase in the global prevalence, morbidity, mortality, and economic burden associated with asthma over the last 40 years, particularly in children. Approximately 300 million people worldwide currently have asthma, and its prevalence increases by 50% every decade. In North America, 10% of the population have asthma. Asthma is underdiagnosed and undertreated, although the use of inhaled corticosteroids has made a positive impact on outcomes. The increasing number of hospital admissions for asthma, which are most pronounced in young children, reflect an increase in severe asthma, poor disease management, and poverty. Worldwide, approximately 180,000 deaths annually are attributable to asthma, although overall mortality rates have fallen since the 1980s. Most asthma deaths occur in those > or = 45 years old and are largely preventable, frequently being related to inadequate long-term medical care or delays in obtaining medical help during the last attack. The financial burden on patients with asthma in different Western countries ranges from $300 to $1,300 per patient per year, disproportionately affecting those with the most severe disease. There are a number of significant barriers to reducing the burden of asthma, particularly in developing countries, where many patients have limited access to care and essential medications. The Global Initiative for Asthma has outlined a six-point patient management plan to address the effective handling of the increased number of patients in primary care. The plan focuses on patient education, written treatment plans, and ongoing communication and review with patients and their providers.

Seasonality in adult asthma admissions, air pollutant levels, and climate: a population-based study

OBJECTIVE AND BACKGROUND

Most studies of asthma seasonal variations have not examined associations of environmental risk factors and climatic changes associated with seasonality in asthma hospitalizations. This study used population-based data to examine seasonality in asthma admissions and the associated seasonality in levels of air pollutants and climatic factors during a 4-year period in Taiwan.

METHODS

A total of 126,671 asthma hospitalizations in Taiwan during 1998-2001 operationalized as monthly admissions per 100,000 population and monthly mean levels of criterion air pollutants and meteorological factors were subjected to Auto-Regressive Integrated Moving Average to test for seasonality and association between asthma admission rates and the pollutant and climatic factor levels. Owing to significant differences in seasonality between pediatric and adult age groups, this study was limited to 99,591 adult asthma cases to examine the seasonality issue as related to the criterion air pollutants and climatic factors using Spearman rank correlations.

RESULTS

Seasonal trends showed a hospitalization peak in January through March and a sharp decline beginning in April to a trough in June for both sexes. Seasonal variations in adult asthma admissions were significantly positively correlated with levels of PM10, SO2, CO, NO2, and atmospheric pressure and negatively correlated with temperature and hours of sunshine.

CONCLUSIONS

Adult asthma hospitalization propensity is highest in spring and is significantly correlated with air pollution and climate. Air quality control programs and early public warning systems on pollution and atmospheric factors are needed to enable predisposed individuals and their physicians to preempt attacks through primary and secondary preventive measures.

Urban asthma

PURPOSE OF REVIEW

To review the possible reasons why the prevalence and morbidity of asthma are greater in those living in an urban setting.

RECENT FINDINGS

Urban asthma is associated with exposure to air pollution, urban allergens, and violence. Outdoor air pollution is a particular problem in urban areas and affects children more than adults. Asthma has been shown to be exacerbated by ozone, respirable particulates, and nitrogen dioxide. Exposure to high point sources of pollutants such as heavy traffic is of particular concern. Urban allergens include cockroach, mouse, and rat. Cockroach exposure increases the risk of asthma exacerbations and may increase the risk of developing asthma. Although mouse allergen is also found in suburban homes, the concentration is a log-fold higher in inner-city homes at levels known to elicit symptoms in workers in animal facilities. Rat allergen is found in a third of inner-city homes and is associated with asthma morbidity. A recent interventional study showed that comprehensive environmental control of cockroach allergen reduced asthma morbidity. Finally, stress elicits asthma symptoms and exposure to violence is associated with greater asthma morbidity.

SUMMARY

The increase in prevalence and morbidity of asthma associated with urban living is associated with at least three plausible causative factors each of which is amenable to intervention, raising the issue of environmental justice issues: controlling air pollution in general and exposure to point sources in particular; reducing cockroach, mice, and rat infestations; and preventing violence.

The childhood asthma epidemic

A case of delayed rather than mistaken diagnosis

Prevalence of asthma among Qatari schoolchildren: International Study of Asthma and Allergies in Childhood, Qatar

The aim of the present study is to determine the prevalence of asthma and allergic diseases among schoolchildren aged 6-14 years in the State of Qatar, based on a questionnaire designed by the International Study of Asthma and Allergy in Childhood (ISAAC). A cross-sectional study of 3,283 school children living in both urban and rural areas (average age, 9.03 +/- 1.99 years; 52.3% boys and 47.7% girls) was conducted between February 2003-February 2004. The population sample had a high prevalence of diagnosed asthma (19.8%), allergic rhinitis (30.5%), eczema (22.5%), and chest infection (11.9%). The frequency of asthma, allergic rhinitis, and eczema among parents reflected the same pattern as seen in their children. Overall, males had more asthma, allergic rhinitis, and chest infections than females. In general, the prevalence rate of asthma and allergic rhinitis decreased with age. The prevalence rate of asthma was significantly higher in mothers (11.8%) than in fathers (9.0%), but the frequency of allergic rhinitis symptoms was comparable (mothers, 18.5%; fathers, 17.5%). The prevalence rate of asthma (19.8%) in Qatari schoolchildren is very close to that in the neighboring Gulf country, Oman (20.7%), and higher than in some developing countries. Genetic factors related to the high rates of consanguinity may play an important role in the high prevalence rates noted in the Qatari population, but changes in lifestyle and environmental factors cannot be discounted as possible causes of the high prevalence noted in this study.

Asthma epidemiology: has the crisis passed?

PURPOSE OF REVIEW

Asthma is a difficult, resource-intensive disease that can result in symptoms, hospitalization and, in rare cases, death. In the past few decades, there has been an abundance of evidence showing the prevalence of asthma to be increasing in certain regions. However, reports have recently emerged suggesting that asthma prevalence has stabilized. This has led to debate among researchers whether increases in asthma prevalence have come to an end. We reviewed recent literature in search of answers to the ongoing debate on whether the asthma crisis is over.

RECENT FINDINGS

In contrast with past reports, several recent studies have reported a stabilization of asthma prevalence. However, based on repeated cross-sectional studies, findings regarding the stabilization of asthma prevalence have been inconsistent, especially when considering the heterogeneity of the disease, which can result in a variety of patterns concerning asthma diagnosis, symptoms, and allergic sensitization. Temporal trends considering physician visits, hospitalizations, and mortality have been more consistent, with stabilizing and decreasing patterns of asthma burden in recent years.

SUMMARY

Because reasons for the original increases in asthma prevalence remain unclear, an explanation for the apparent stabilization of asthma prevalence reported in some studies also remains elusive. This is compounded by the difficulty in defining asthma accurately in population studies and inconsistencies in the results of prevalence estimation among repeated cross-sectional studies. Efforts should be made to continue monitoring asthma prevalence and to begin monitoring asthma prevalence in regions where environmental and social changes are occurring.

[Severe asthma in the general population: definition and prevalence]

RATIONALE

Severe asthma is a real public health problem because of its consequences on patients and its economic cost. Nevertheless, few epidemiological studies have focussed on severe asthma. The aim of this state of the art review is to describe the criteria used to estimate asthma severity and to assess the prevalence of severe asthma from population-based epidemiological studies.

OBSERVATIONS

Asthma severity has been defined in various ways in epidemiology, with criteria based on symptoms, hospitalisation, ventilatory function, discomfort caused by asthma attacks, and treatment. A high variability in the prevalence of severe asthma is observed, resulting mostly from the lack of standardisation in the phenotypes used, but also from a real geographical heterogeneity. Nevertheless, the prevalence of severe asthma may be reasonably estimated between 1 and 3% of the general population, both in children and adults.

CONCLUSION

Data from the literature show a lack of standardisation of the severe asthma phenotype. Further epidemiological studies are needed to understand the geographical variability in severe asthma prevalence.

Predictors of short-term hospital readmissions of asthmatic children

BACKGROUND

The admission rate for bronchial asthma has increased dramatically all over the world. Part of this increase in hospital admissions is due to patient readmission.

OBJECTIVE

To determine the risk factors associated with short-term hospital readmission of pediatric patients with asthma within two months of the last hospital admission.

METHODS AND SETTING

A retrospective case-control study using the registration books of both admissions and discharges to identify patient groups. All hospital records of patients admitted from August 1998 through December 2002 at Aseer Central Hospital, southwestern Saudi Arabia were reviewed. Patients who were admitted during this period of study and readmitted to hospital within two months were used as the study group (n=28) and those patients admitted within the same period but not readmitted within two months constituted the control group (n=45). Demographic variables, route of admission, patient's previous medical history, clinical assessment, hospital treatment as well as discharge treatment were obtained and entered for analysis.

RESULTS

Twenty-eight patients were readmitted within two months of their discharge from hospital (17 boys and 11 girls). Seventy percent of these were less than four years of age. Significant predictors of readmission were: prior history of asthma admission (adjusted OR 2.21,95% CI 1.08-9.10), neonatal intensive care graduate (adjusted OR 4.44,95% CI 1.67-9.34), bronchopulmonary dysplasia (adjusted OR 3.06,95% CI 2.01-7.95), recurrent aspiration (adjusted OR 1.96,95% CI 1.08-4.27), duration of asthma symptoms more than five days (adjusted OR 0.15,95% CI 0.03-0.42), moderate to severe clinical assessment (adjusted OR 1.12,95% CI 1.01-2.94), positive X-ray findings (adjusted OR 0.04,95%CI 0.011-0.230), intensive care admission (adjusted OR 1.96,95%CI 1.08-4.63), mechanical ventilation (adjusted OR 0.010,95%CI 0.002-0.130), intravenous steroids (adjusted OR 0.104 ,95%CI 0.016-0.321).

CONCLUSION

Prior neonatal intensive care unit admission, bronchopulmonary dysplasia, history of previous asthma admissions, recurrent aspirations, intensive care unit admission, intravenous steroids, positive X-ray findings and mechanical ventilation were significant predictors of asthma short-term hospital readmissions.

Comparative study of different inhaler devices in asthmatic children

BACKGROUND

The inhaler is an important drug delivery system in the treatment of asthma, but inhaler technique is often inadequate. We assessed technique in children diagnosed with asthma, comparing the performance of three devices.

PATIENTS AND METHODS

In a cross-sectional survey, 523 children (271 boys, 252 girls, ages 5 to 12 years; mean+/-SD 7.53+/-1.79 years) demonstrated inhalation technique according to Netherlands Asthma Foundation criteria during a first visit to a primary care clinic in Abha, Saudi Arabia. Patients used the device with which they were most familiar (either pMDI, Turbuhaler or Diskus).

RESULTS

Two hundred children (38% of total population) used a pMDI, while 323 (62% of total population) used one of the dry powder inhalers 173 (58%) the Turbuhaler and 150 (47%) the Diskus. Only 49 children (25% of the total population) completed the assessment without making a mistake. The remaining 474 (75% of the total population) performed one or more manuevers poorly. Only 80 children who used an MDI (40% of those using the device) completed 50% or more of the maneuvers correctly compared with 111 (69% of those using the device) and 100 (67% of those using the device) of those using the Turbuhaler and Diskus, respectively (P=0.001 for comparison of MDI with dry powder inhalers). Children whose mothers had intermediate school or higher education performed better than those whose mothers had less education (P=0.001). The father's education had no bearing on performance with the inhaler.

CONCLUSION

The inhaler technique of most asthmatic children is poor, but technique is better in children who use a dry powder compared a metered-dose inhaler. The level of the mother's education is positively associated with better inhalation technique in the child.

Trends and ethnic differences in asthma hospitalization rates in Singapore, 1991 to 1998

BACKGROUND

A few reports have indicated that asthma hospitalization rates in several countries have stopped rising or started falling in the 1990s.

AIM

To describe recent trends and ethnic differences in asthma hospitalization rates in Singapore from 1991 to 1998.

METHODS

Asthma hospitalization rates in all hospitals were analyzed by age groups, sex, ethnicity, and individual years, using aggregated data for asthma (ICD-9 493 and ICD-10 J45, J46) from 1991 to 1998, when nationwide data from the Central Claims Processing System were available.

RESULTS

Between 1991 and 1998 there were a total of 37,615 hospital admissions for asthma, giving an annual average rate of 17.1 hospital admissions per 10,000 persons. Overall, the rates of asthma hospitalization fell by 28% from 21.7 per 10,000 in 1991 to 15.4 per 10,000 in 1998 (3.5% annually). The trends were broadly based across all age, sex, and ethnic groups. Hospitalizations were more common in boys than in girls aged 0 to 4 (male/female ratio 1.69), but less common in men than women aged 35 to 64 (male/female ratio 0.81). Rates of asthma hospital admissions were higher in Malays (32.8 per 10,000) and Indians (40.8 per 10,000) than Chinese (11.9 per 10,000).

CONCLUSIONS

In line with findings from several countries, there have been recent declines in rates of hospital admissions for asthma in Singapore in the 1990s. The declines were broadly based across all population subgroups and parallel previously observed declines in mortality in adults. However, considerable ethnic differences in levels of asthma hospitalization still exist.

Mortality from asthma in children and young adults in Louisiana

BACKGROUND

Asthma mortality rates have been increasing despite our improved understanding of the pathophysiology of asthma and advanced methods of treatment. Although there are many national studies of asthma mortality rates, few studies have concentrated on subnational regions such as individual states.

OBJECTIVES

We sought to determine the trends in asthma mortality in children and young adults during the last 15 years in Louisiana.

METHODS

Asthma mortality data were acquired from the Louisiana State Center for Health Statistics for the years 1983 through 1997. All asthma deaths coded International Classification of Disease, Ninth Revision 493 were included in the data set along with year, sex, and rate characteristics. State population estimates obtained from the United States Bureau of Census for three 5-year periods (1983 to 1987, 1988 to 1992, and 1993 to 1997) were used to calculate crude and adjusted mortality rates. These time periods were compared with one another and with the period 1983 to 1987, which was used as a baseline.

RESULTS

For all residents, the mortality rate increased from 0.41 deaths per 100,000 persons during the 1983 to 1987 time period to 0.49 and 0.63 deaths per 100,000 persons during 1988 to 1992 and 1993 to 1997 time periods, respectively. Mortality rates have increased in both the white and non-white populations over the 15-year study period, with the most pronounced increases among the non-white population.

CONCLUSION

Asthma mortality rates in Louisiana have increased, particularly among the non-white population, over the last 15 years, although the results are not statistically significant. When compared with other states, asthma mortality in Louisiana is lower than in the northeast and central north states.

Process of care for Medicaid-enrolled children with asthma: served by community health centers and other providers

OBJECTIVE

To compare the process of care received by Medicaid-enrolled children with asthma served by community health centers (CHCs) and other Medicaid providers.

DESIGN

Retrospective cohort study.

SETTING

Five provider types serving Massachusetts Medicaid enrollees: three provider groups--CHCs, hospital outpatient departments (OPDs), and solo/group physicians--participating in the statewide Primary Care Clinician Plan; a staff model health maintenance organization (HMO); and fee-for-service (FFS) providers.

STUDY POPULATION

Six thousand three hundred twenty-one Medicaid-enrolled children (age 2-18) with asthma assigned to one of the above provider types in 1994.

DATA

Person-level files were constructed by linking Medicaid claims, demographic and enrollment files with HMO encounter data.

METHODS

Five claims-based process of care measures reflecting aspects of care recommended in national guidelines were developed and used to analyze patterns of care across provider types, controlling for case-mix and other covariates.

RESULTS

Children served by CHCs and the HMO had significantly higher asthma visit rates compared with those served by OPDs, solo/group physicians and FFS providers. CHCs emergency department (ED) visit rates for asthma were lower than those of OPDs (P <0.001) and similar to other providers. However, CHC patients averaged more asthma hospitalizations relative to solo/group physicians or the HMO (P <0.0001). In multivariate analyses, children served by CHCs were 2.2 times as likely (95% CI, 1.02-4.91) as those served by solo/group physicians to receive a follow-up visit within 5 days of an asthma ED visit and 4.3 times as likely (95% CI, 1.45-12.68) to receive a follow-up visit within 5 days of hospital discharge. CHC patients with utilization suggestive of persistent asthma were less likely (OR, 0.28; 95% CI, 0.13-0.59) than those served by solo/group physicians to be seen by an asthma specialist. There were no significant differences in measures of asthma pharmacotherapy across providers types.

CONCLUSION

These data suggest that CHCs provide more timely follow-up care after an asthma ED visit or hospitalization relative to solo/group physicians, but diminished access to asthma specialists. There were no differences in asthma pharmacology across providers. Relatively low access to asthma specialists among children served by CHCs warrants further investigation.

Asthma hospitalization trends in Charleston, South Carolina, 1956 to 1997: twenty-fold increase among black children during a 30-year period

OBJECTIVE

The increase in asthma prevalence has been documented worldwide, affecting many races living in many different climates. Multiple studies have demonstrated that the most striking prevalence and morbidity of asthma in the United States has been in black children, but little research has determined the scale of the increase, or specifically when the disease became severe in this group. This study sought to determine exactly when the rise in asthma hospitalizations among black patients began and what the pattern of asthma hospitalizations has been in different races and age groups over a 40-year period in 1 urban area.

METHODS

A retrospective chart review of discharges from the Medical University of South Carolina was conducted from 1956 to 1997. Charts with the primary discharge diagnosis of asthma were examined for discharge date, race, and age group (0- to 4-year-olds, 5- to 18-year-olds, 19- to 50-year-olds, > or =51-year-olds). The diagnostic codes used were based on the International Classification of Diseases (ICD)-6, 1956-1957; ICD-7, 1958-1967; ICD-8, 1968-1978; and ICD-9, 1979-1997. Over the period studied, this hospital was the primary inpatient provider for children in this area, and the only provider for uninsured children. Between 1960 and 1990, the racial makeup of the area remained stable, as did the percentage of blacks living at the poverty level. The raw number of asthma discharges, rate per 10 000 discharges of the same race, and rate per 100 000 population in Charleston County were tabulated for each age group and racial category.

RESULTS

Over the time period examined, there has been a progressive increase in asthma hospitalizations in black individuals of all age groups and in whites under 18 years. The most striking increase has been in black children 0 to 18 years old (figure). The increase either as raw values or as a rate per 100 000 began around 1970, and was linear. This increase in black children discharged with asthma as a rate per 100 000 population was 20-fold: the rate increased from 18 in 1970 to 370 in 1997. Asthma discharges as a rate per 10 000 black children discharged increased by 24-fold from 1960 to 1997. Total discharges from the hospital increased from 49 000 to 128 000 per year over this period. Blacks made up only 28% of discharges in 1957, but that proportion increased to 56% in 1960 and remained relatively stable over the following 35 years. The increase seen in white children 0 to 18 years of age as a rate per 100 000 population was 5-fold and began around 1980. Both increases seem to be consistent over the time period studied, and continued to 1997. [figure: see text].

CONCLUSIONS

Among a predominantly poor black population living in a southern US city, there has been a steady increase in childhood asthma hospitalizations over the past 30 years. A significant although less dramatic rise has occurred in white children. Over this time period, although there have been many changes in lifestyle that could have contributed to this rise, there have been no major changes in housing conditions for poor patients. In addition, Medicaid coverage for children in South Carolina did not change significantly until 1999. The time course of these increases parallels increases reported in other Western populations, suggesting that there must be 1 or more common factors contributing to the rise. Many explanations have been offered for the changes in incidence and severity of asthma. The scale of the change, time course, and linearity of the increase in this study represent a challenge to many of the hypotheses proposed to explain this epidemic.

Outcome of asthma in children and adolescents at a specialty-based care program

BACKGROUND

Asthma remains a major cause of morbidity for children despite national guidelines.

OBJECTIVE

To evaluate outcome from a structured specialty-based care program.

METHODS

Comparison of previous and subsequent years for children ranging from infancy to adolescence who entered a specialty clinic program at a university hospital serving a widely dispersed patient population. One hundred fifty-seven patients previously receiving primary care for their respiratory symptoms were seen during the study period; 23 were lost to followup, 15 were excluded because of other serious concurrent medical problems, and 119 were available for outcome analysis. Evaluation included historical data base from a structured interview, evaluation of pulmonary physiology, and allergy skin testing. Treatment decisions were evidence-based. Patient and/or family education was targeted at decision-making. Toll-free telephone access to the specialty service was provided around the clock. Frequency of unscheduled medical care, hospitalizations, sleep disturbance, activity interference, attainment of defined criteria for control, and medication use were quantified.

RESULTS

Seven hundred thirty-five acute care visits were reduced to 47, and 99 hospitalizations were decreased to 10 (P < 0.001 for both). Nocturnal symptoms and exercise limitation decreased significantly (P < 0.001 for both). All criteria for control of asthma were met in 89% of 75 without tobacco smoke exposure and 50% of 44 with exposure (P < 0.0001 for the difference in outcome). Frequent antibiotic use for respiratory symptoms were eliminated after entering the program. Maintenance medications were not used in 72 with an intermittent pattern of viral respiratory infection-induced asthma. Inhaled corticosteroid use increased from 38 to 68% among 47 subjects with a chronic pattern.

CONCLUSIONS

Morbidity from asthma is largely prevented with often less, but better selected, medication than had been occurring in previous primary care. These data have implications for revised guidelines directed at primary care physicians.

The relationship between asthma severity, family functioning and the health-related quality of life of children with asthma

This study compared the health-related quality of life (HRQL) of 236 children with mild or moderate/severe asthma with that of a large representative sample of children in the general community. The study also examined the relationship between the HRQL of children with asthma and their demographic characteristics, asthma severity and family functioning. Children with asthma had a significantly poorer HRQL than other children in the community. Amongst the children with asthma, parents reported that children living in single-parent families had poorer physical health, mental health and social functioning than children in two-parent families. There was a significant relationship between the mental health of children with asthma and family functioning but no significant relationship between their physical health and family functioning. These findings suggest that the domains comprising the HRQL of children with asthma are related to both disease and non-disease factors. A better understanding of these relationships will facilitate the development of new interventions to help children with asthma.

Benefit from the inclusion of self-treatment guidelines to a self-management programme for adults with asthma

This study assessed the long-term efficacy of adding self-treatment guidelines to a self-management programme for adults with asthma. In this prospective randomized controlled trial, 245 patients with stable, moderate to severe asthma were included. They were randomized into a self-treatment group (group S) and a control group (group C). Both groups received self-management education. Additionally, group S received self-treatment guidelines based on peak expiratory flow (PEF) and symptoms. Outcome parameters included: asthma symptoms, quality of life, pulmonary function, and exacerbation rate. The 2-yr study was completed by 174 patients. Both groups showed an improvement in the quality of life of 7%. PEF variability decreased by 32% and 29%, and the number of outpatient visits by 25% and 18% in groups S and C, respectively. No significant differences in these parameters were found between the two groups. After 1 yr, patients in both groups perceived better control of asthma and had more self-confidence regarding their asthma. The latter improvements were significantly greater in group S as compared to group C. There were no other differences in outcome parameters between the groups. Individual self-treatment guidelines for exacerbations on top of a general self-management programme does not seem to be of additional benefit in terms of improvements in the clinical outcome of asthma. However, patients in the self-treatment group had better scores in subjective outcome measures such as perceived control of asthma and self-confidence than patients in the control group.

Drug therapy approaches in the treatment of acute severe asthma in hospitalised children

Acute severe paediatric asthma remains a serious and debilitating disease throughout the world. The incidence and mortality from asthma continue to increase. Early, effective and aggressive outpatient therapy is essential in reducing symptoms and preventing life-threatening progression. When complications occur or when the disease progresses to incipient respiratory failure, these children need to be managed in a continuous care facility where aggressive and potentially dangerous interventions can be safely instituted to reverse persistent bronchospasm. The primary drugs for acute severe asthma include oxygen, corticosteroids, salbutamol (albuterol) and anticholinergics. Second-line drugs include heliox, magnesium sulfate, ketamine and inhalational anaesthetics. Future therapies may include furosemide, leukotriene modifiers, antihistamines and phosphodiesterase inhibitors. This review attempts to explore the multitude of medications available with emphasis on pharmacology and pathophysiology.

[Epidemiology of respiratory allergy in children]

Epidemiology of paediatric respiratory allergic disorders allows the approach to causal and preventive risk factors by studying groups or sub groups of children in different locations and under different conditions. This is, however, complicated by the lack of consensus on disease definitions, which renders comparisons between studies difficult. Atopy is usually defined by the presence of positive skin tests (wheal size of at least a mean diameter > or = 3 mm), by the presence of specific IgE, or by the presence of increased total IgE (> or = 100 UI/mL). Infantile asthma is not well defined, complicated by the high prevalence of bronchiolitis; one thus questions between wheezing or wheezy bronchitis. Prevalence is high: among early wheezers, two populations will be defined by the medium term evolution: transient wheezers and persistent wheezers. Risk factors for these two conditions are different. Childhood asthma may be defined by the diagnosis of asthma (specific but fairly non-sensitive), by asthmatic symptoms (wheezing, waking by an attack of shortness of breath) (sensitive but not very specific), or by the combination of symptoms and airway hyperresponsiveness. The ISAAC study has standardised a questionnaire to assess the prevalence of asthma. The preliminary results show that there are wide variations across the world. The prevalence is low in Africa and Asia, intermediate in Europe, and high in Anglo-Saxon countries. The prevalence of asthma has gradually increased over the past 20 years in developed countries. Asthma and atopy are closely associated in children. Risk factors are genetic, associated with sex and environmental factors. Among these, allergic sensitisation is associated with the degree of exposure to allergens. Westernization of way of life is associated with increased prevalence of atopy, allergic rhinitis and asthma. Atopy seems inversely correlated to certain infections. Passive smoking is clearly associated with early wheezing. This and atmospheric pollution aggravate childhood asthma. However, the inducing role of pollution on asthma is still controversial.

Trends in hospital admissions for childhood asthma in Oslo, Norway, 1980-95

BACKGROUND

The prevalence of asthma and quality of asthma care both influence hospital admission rates for childhood asthma. Therefore, we aimed to assess possible changes in the hospital admission rate for acute asthma in Oslo, Norway, from 1980 to 1995, as well as evaluate the possible effect of changes in asthma treatment upon hospitalization for acute asthma in this period.

METHODS

All pediatric patient records from the two municipal hospitals in Oslo from 1980 through 1995 with the discharge diagnoses (ICD-9) acute asthma, acute bronchitis/bronchiolitis, pneumonia, and/or atelectasis were thoroughly reviewed.

RESULTS

Of the 3,538 children admitted for acute asthma, 66% were boys and 75% were younger than 4 years, and the admittance rate increased significantly among children aged 0-3 years. First admissions increased throughout the study, whereas readmissions, as well as the mean duration of hospital stay, decreased significantly. Prophylactic treatment with inhaled steroids prior to admission increased over 1980-89, but stabilized thereafter. The use of a short course of systemic steroids during admission increased markedly from 1991.

CONCLUSIONS

The findings of increasing first admission rate as well as overall admission rate for acute asthma in children under 4 years of age, but decreasing readmissions as well as number of treatment days in hospital, probably reflect changes in the management of the disease, as well as an increasing prevalence of childhood asthma.

Validation of a predictive model for asthma admission in children: how accurate is it for predicting admissions?

We studied 364 index presentations to the Emergency Department of a children's hospital with a diagnosis of asthma. The admission rate for this group of children was about 31%. We developed a parsimonious multiple logistic regression model to predict asthma hospital admission based on asthma severity indicators. We then evaluated the model's predictive ability using two methods of cross-validation, using the same sample that was used for the predictive model, and using data from a split sample. The logistic regression model had a predictive accuracy of 90% (95% confidence interval 85-95%). The sensitivity and specificity were 86% and 88%, respectively. Cross-validation models confirmed that the predictive ability of the model was stable. In studies with limited sample sizes, it is possible to validate a model without setting aside a split sample for cross-validation.

Predictors of asthma severity in the elderly: results of a community survey in Northeast England

A number of risk factors for the development and severity of asthma in childhood are known. Particularly, there is information on allergens, excessive use of beta2- agonists, and indoor environmental pollutants. Similar information on elderly patients is lacking. We examined the risk factors for current asthma and for the severity of asthma in 95 elderly subjects (>65 years old) compared to 274 elderly subjects with obstructive spirometry who did not have asthma as defined by the following criteria: symptoms of episodic wheeze, cough, or chest tightness and forced expiratory volume in 1 sec/vital capacity (FEV1/VC) <70% with >15% or 200 mL reversibility in FEV1 to 200 microg salbutamol given from a metered-dose inhaler. The severity of airflow limitation was graded on the basis of the FEV1/VC ratio as mild (60%-70%), moderate (40%-60%), and severe (<40%). Asthma history was collected using the Medical Research Council respiratory questionnaire and a follow-up postal questionnaire. Data were analyzed using multiple logistic regression and the overall goodness-of-fit of the model was checked using the Hosmer-Lemeshow (HL) statistic. History of allergy (to one or more of the following allergens: cat, house dust, or grass or tree pollen) (odds ratio [OR] 25; 95% confidence interval [CI] 13-51; p = 0.0001) and history of childhood wheeze (OR 8; 95% CI 4-9; p = 0.004) were strong predictors of current asthma. Duration of wheezing, smoking history, indoor heating, history of working in coal mines, and sex were not predictors (HL 6.75, degrees of freedom [df] = 8, p = 0.56). Use of >4 puffs of salbutamol/ day (OR 5.3; 95% CI 2-14; p = 0.005), more than 10 years of asthma symptoms (OR 4.2; 95% CI 4.1-36.2; p = 0.0001), and >500 mL reversibility in FEV1 (OR 4.2; 95% CI 1.2-14.3; p = 0.05) were independent predictors of moderate to severe asthma. History of atopy was the strongest predictor of asthma in the elderly population studied. Indoor heating, presence of pets at home, sex, smoking history, and history of working in coal mines were not predictors of asthma. The severity of asthma as assessed by measurement of airflow limitation was related to the frequency of use of beta2-agonists, duration of symptoms of asthma, and increased reversibility of FEV1 to beta2-agonist.

The epidemiology of childhood asthma

Variability is the hallmark of childhood asthma. Conceptually defined as variable airflow obstruction, asthma affects individual children through a variety of clinical manifestations. Particular controversy surrounds the nature of wheezing in early infancy and its relationship to atopic asthma of later onset. Asthma prognosis is also highly variable and only to a limited extent predictable by clinical indicators in early childhood. Long-term follow-up studies suggest a complex pattern of remission and relapse as wheezy children are followed through adolescence into adult life. Similarly, the population burden of asthma is highly variable, both over time and between countries. The balance of evidence worldwide suggests a modest but sustained increase in the prevalence of asthma symptoms over the past three decades. Superimposed on this have been larger changes in diagnostic fashion and use of health services for childhood asthma in many countries. There is substantial international variation in the prevalence of asthma symptoms, and marked urban-rural differences have been reported from several African countries. These contrast with the more uniform distribution of the disease within industrialized countries, reflecting its ubiquity in affluent societies.

Prevalence of asthma, rhinitis and eczema among children in 2 Canadian cities: the International Study of Asthma and Allergies in Childhood

BACKGROUND

Wide variations in the prevalence of asthma, rhinitis and eczema have been reported between regions within Canada and between different countries. The International Study of Asthma and Allergies in Childhood (ISAAC) was developed to provide a standardized tool and methodology to ascertain the prevalence of asthma and allergies in different regions. Comparisons of prevalence rates across geographic regions and at different times may help to identify factors that contribute to the development of these conditions in individuals.

METHODS

Two Canadian centres, Hamilton and Saskatoon, participated in the ISAAC. A standard questionnaire was distributed through schools and completed by 13- and 14-year-old children and by the parents of 6- and 7-year-old children. Prevalence rates and 95% confidence intervals were calculated for asthma, wheezing, rhinitis and eczema.

RESULTS

The overall response rates were 75.1% among the children 6 and 7 years old and 68.6% among those 13 and 14 years old. Among the younger children, the lifetime prevalence of asthma was 17.2% in Hamilton and 11.2% in Saskatoon; the corresponding rates among the older children were 19.2% and 12.2% respectively. The prevalence of wheezing in the 12 months before the survey in the younger group was 20.1% in Hamilton and 14.1% in Saskatoon; in the older group it was 30.6% and 24.0% respectively. The prevalence of rhinitis in the 12 months before the survey was 28.6% in Hamilton and 22.6% in Saskatoon in the younger group and 45.8% and 33.8% respectively in the older group. The prevalence of eczema was slightly higher in Saskatoon in both age groups.

INTERPRETATION

High prevalence rates of asthma, rhinitis and eczema exist among school children in Hamilton and Saskatoon, similar to rates in other Western countries. Further studies are required to determine the factors associated with the high rates in the 2 regions and possible reasons for the higher rates in Hamilton.

Structured discharge procedure for children admitted to hospital with acute asthma: a randomised controlled trial of nursing practice

BACKGROUND

Discharge planning is becoming an important part of the management of childhood asthma in hospital. Readmission to hospital, although often inevitable, might represent a failure of the opportunity for intervention presented by a brief period of supervised care in hospital.

AIM

To examine the impact of a structured, nurse-led discharge package for children admitted to hospital with acute asthma on readmission to hospital, reattendance at the accident and emergency (A&E) department, and general practitioner consultations for asthma.

METHODS

A structured nurse-led discharge package, consisting of a 20 minute patient education programme and self management plan for children with asthma was developed on the wards of a busy children's hospital. A randomised controlled trial was conducted involving 160 children aged 2-16 years admitted for asthma over a 12 month period. Readmission and A&E reattendance's over the six months after discharge from hospital were obtained from the hospital computerised information system and general practitioner consultations from practice records.

RESULTS

Children in the intervention group were significantly less likely to be readmitted to hospital in the next six months than those in the control group (12 of 80 v 30 of 80 patients), and significantly less likely to attend the A&E department (6 of 80 v 31 of 80). Significantly fewer children in the intervention group had visits to their general practitioner for problematic asthma (31 of 78 v 72 of 77 for whom data were available).

CONCLUSION

By delivering the simplest form of education and support during a child's stay in hospital, readmissions over a six month period were reduced. The programme was designed to be suitable for administration by nursing staff on the children's wards after a brief period of training.

Asthma prevalence among American Indian and Alaska Native children

OBJECTIVES

Although asthma is the most common chronic childhood illness in the United States, little is known about its prevalence among American Indian and Alaska Native (AI/AN) children. The authors used the latest available household survey data to estimate the prevalence of asthma in this population.

METHODS

The authors analyzed data for children ages 1 through 17 years from the 1987 Survey of American Indians and Alaska Natives (SAIAN) and the 1987 National Medical Expenditure Survey (NMES). At least one member of each AI/AN household included in the SAIAN was eligible for services through the Indian Health Service.

RESULTS

The weighted prevalence of parent-reported asthma was 7.06% among 2288 AI/AN children ages 1-17 (95% CI 5.08, 9.04), compared with a US estimate of 8.40% for children ages 1-17 based on the 1987 NMES (95% CI 7.65, 9.15). The AI/AN sample was too small to yield stable estimates for a comparison between AI/AN children and all US children when the data were stratified according to household income and metropolitan vs non-metropolitan residence. The unadjusted asthma prevalence rates were similar for AI/AN children and for children in the NMES sample.

CONCLUSIONS

In 1987, the prevalence of parent-reported asthma was similar for AI/AN children in the SAIAN sample and for children in the NMES sample. More recent data are needed to better understand the current prevalence of asthma among AI/AN children.

The rising trends in asthma and allergic disease

Considerable variation in the prevalence of childhood asthma and allergic conditions has been shown in previous studies. These differences may in part be attributable to methodological problems in defining childhood asthma and wheezing illnesses. However, the results of recent surveys using identical study instruments suggest that the variation in the distribution of the disease is real. In western societies serial prevalence studies have furthermore shown an increasing trend in the prevalence of childhood asthma and airway hyperresponsiveness. A concomitant increase in the prevalence of hay fever and atopic eczema has been reported by others. Moreover, hospitalization rates for childhood wheezing illnesses have increased in affluent countries suggesting that indeed the morbidity from these causes has increased in the last decades. Interestingly, areas of low prevalence of asthma and atopic conditions have recently been identified in developing countries and in Eastern Europe. In Eastern Germany where drastic changes towards westernization of living conditions have occurred after reunification an increase in the prevalence of hay fever and atopic sensitization has been documented over the last 4-5 years in children aged between 9 and 10 years of age. The prevalence of asthma and airway hyperresponsiveness, however, remained virtually unchanged in this age group. These children spent their first 3 years of life under socialist living conditions and were exposed to a western lifestyle only after their third birthday. Therefore, environmental factors may affect an individual's inherited susceptibility for the development of asthma and hay fever at different ages inducing changes in the prevalence of atopic diseases in populations in a time- and age-dependent way.

Prevalence of physician-diagnosed asthma in Saskatchewan, 1981 to 1990

STUDY OBJECTIVE

To examine trends in asthma prevalence in the Province of Saskatchewan using the Medical Claim Insurance Branch (MCIB) database.

DESIGN

For each calendar year from 1981 to 1990, first visits to physicians for asthma were identified from the MCIB database. Age- and sex-specific prevalence rates were obtained for each calendar year by dividing the number of first asthma visits by the number of subjects in the age- and sex-specific group insured by the Provincial Government of Saskatchewan in that calendar year.

RESULTS

Asthma prevalence increased in children and adults from 1981 to 1990. In the calendar year 1990, the prevalence of asthma was 5.1% in children < or = 4 years old, 4.4% in children 5 to 14 years old, 2.2% in young adults 15 to 34 years old, and 1.9% in adults 35 to 64 years old. Boys had higher asthma prevalence than girls in the age groups 0 to 4 years and 5 to 14 years, but it was reversed in older age groups, with women having greater asthma prevalence than men. Asthma diagnoses were verified by checking for asthma-related drug purchase in the Prescription Drug Plan database. Among the 0- to 4-year-old children with physician-diagnosed asthma, 57.3% purchased at least one asthma-related drug in 1981 and 72.3% purchased that in 1990. Among adults, asthma-related drug purchase was >73% in 1990.

CONCLUSIONS

Asthma prevalence increased in children and adults in the province of Saskatchewan. Reasons for the increase are not clear and further studies are required to determine factors related to the increase.

Empowering children to effectively self-manage asthma

The prevalence of childhood asthma continues to rise, despite the introduction and implementation of innovative treatment methods. Asthma is now one of the most common childhood diseases. It is widely believed that the causes of asthma are likely to be multifactorial. Education on asthma management remains primarily focused on the parents of asthmatic children. A heightened emphasis on education aimed primarily at the child is imperative if the negative trends in morbidity and mortality of childhood asthma are to be curtailed. This article examines the need to correlate educational content with the cognitive ability of the asthmatic child.