Trends in the hospital care of acute childhood asthma 1970-8: a regional study

Trends in childhood asthma hospitalisation in three Asia Pacific countries

AIM

The study aims to examine recent childhood asthma hospitalisation rates in the Asia Pacific countries of Australia, Hong Kong and Singapore. On the background of reported decline in many countries with high asthma prevalence during late 1990s.

METHODS

Annual asthma hospitalisation (ICD9-CM: 493 or ICD10-AM: J45-46)* and population data from 1994 to 2008, of children aged 0-14 years old, were obtained from the Australian National Hospital Morbidity Database, from the Hospital Authority in Hong Kong and from the Ministry of Health in Singapore. Data were stratified in two age groups: 0-4 and 5-14 years old, and also in different periods of calendar years. Time-series regression analyses were used to examine temporal trends. Diagnostic transfer was addressed by examining bronchitis hospitalisations.

RESULTS

Significant decreases of up to 6.5% per annum in childhood asthma hospitalisation rates were found over the study period. However, the latter half of the study period showed increases in hospitalisation rates in all countries studied. No evidence of diagnostic transfer was found.

CONCLUSION

Although there has been a decrease in childhood asthma hospitalisation rates since the 1990s, a modest increase was observed from 2003 to 2008. Ongoing monitoring is required.

Pathophysiological mechanisms of asthma. Application of cell and molecular biology techniques

Asthma is a common increasing and relapsing disease that is associated with genetic and environmental factors such as respiratory viruses and allergens. It causes significant morbidity and mortality. The changes occurring in the airways consist of a chronic eosinophilic and lymphocytic inflammation, together with epithelial and structural remodeling and proliferation, and altered matrix proteins, which underlie airway wall narrowing and bronchial hyperresponsiveness (BHR). Several inflammatory mediators released from inflammatory cells such as histamine and cysteinyl-leukotrienes induce bronchoconstriction, mucus production, plasma exudation, and BHR. Increased expression of T-helper 2 (Th2)-derived cytokines such as interleukin-4 and 5 (IL-4, 5) have been observed in the airway mucosa, and these may cause IgE production and terminal differentiation of eosinophils. Chemoattractant cytokines (chemokines) such as eotaxin may be responsible for the chemoattraction of eosinophils to the airways. The initiating events are unclear but may be genetically determined and may be linked to the development of a Th2-skewed allergen-specific immunological memory. The use of molecular biology techniques on tissues obtained from asthmatics is increasing our understanding of the pathophysiology of asthma. With the application of functional genomics and the ability to transfer or delete genes, important pathways underlying the cause if asthma will be unraveled. The important outcome of this is that new preventive and curative treatments may ensue.

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.

20-year trends in the prevalence of asthma and chronic airflow obstruction in an HMO

Although asthma is on the rise in the United States and elsewhere, data on age-sex-specific patterns of change in various types of health care utilization are scarce. We report on 20-yr trends in the treated prevalence of asthma among members of a large health maintenance organization. Data are presented separately for each of six age-sex categories, and include both the treated prevalence of asthma as well as the treated prevalence of the broader category of chronic airflow obstruction (CAO), defined as asthma, chronic bronchitis, or emphysema. During the period 1967-1987 the treated prevalence of asthma and CAO increased significantly in all age-sex categories except males aged 65 and older. These patterns are in contrast to previous studies of this population that showed that increases in asthma hospitalizations and hospital-based episodes of care were limited primarily to young boys. Not only do these findings support other evidence of a real increase in asthma prevalence, but they also highlight the risks associated with drawing inferences about changing disease epidemiology based on a single type of health care utilization.

Pet ownership in the UAE: its effect on allergy and respiratory symptoms

The aim of this paper was to study the effect of pets and other domestic animals on bronchial asthma among United Arab Emirates (UAE) schoolchildren aged 6-14 years. A cross-sectional study of 850 schoolchildren living in both urban and rural areas (average age 9.36 +/- 2.11 years, 46.8% boys and 53.2% girls) was conducted using self-administered questionnaires between October 1992 and May 1993. Prevalence rate for asthma, rhinitis, wheeze, cough, and eczema in children from families with and without animals were investigated. A total of 40.7% of families studied were found to keep animals in their homes. Children from families with animals were found to have a significantly higher prevalence rate of respiratory symptoms than those without. The prevalence rate for asthma in children with animals was found to be twice that of children without (RR: 2.03; 95% CI: 1.40-2.95). The risk of having chronic cough (RR: 1.93; 95% CI: 1.21-3.10), breathlessness/chest tightness (RR: 2.53; 95% CI: 1.59-4.02), chronic wheeze (RR: 2.10; 95% CI: 1.20-3.67), allergic rhinitis (RR: 1.53; 95% CI: 1.17-2.00) was significantly higher in children with animals than in children without. Similarly, the risk of having eczema (RR: 2.55; 95%, CI: 1.74-3.75) was significantly higher among children with animals than among those without. Overall, there was a highly statistically significant difference in the prevalence of asthma, wheeze, nocturnal cough, eczema, and rhinitis between children in families with animals and those without (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Rates of admission to hospital for asthma

OBJECTIVE

To describe trends in hospital admission rates for asthma in England and Wales (1976-85), the East Anglian region (from 1976 to 1991-2), and Wales (1980-90).

DESIGN

Descriptive study.

SETTING

Hospitals in England and Wales; hospitals in the East Anglian Regional Health Authority; hospitals in Wales.

MAIN OUTCOME MEASURES

Hospital admissions for asthma as principal diagnosis in England and Wales (Hospital In-patient Enquiry, 1976-85), for the East Anglian region (Hospital In-patient Enquiry, 1976-7; Hospital Activity Analysis, 1978-86; Regional Information System, 1987-8 to 1991-2), and for Wales (Hospital Activity Analysis, 1980-90).

RESULTS

Rates for England and Wales as a whole showed a steady upward trend throughout the period examined. Rates in East Anglia, though they were similar to the national trends in the early years, showed a peak in 1985 (for males and females) with some indication of a decline in rates thereafter. Rates for Wales showed an upward trend until 1988 (for both males and females) after which they showed a decline.

CONCLUSIONS

Interpretation of the East Anglian trends is made more difficult by the change in England in 1987 of the system for the collection of hospital admission data. The fact that the rates for the East Anglian region seem to decline before this change and other considerations suggest that the observed trends, although partly reflecting the disruption of the coding during the changeover in systems, may not be entirely artefactual. The possible roles of diagnostic transfer and changes in the delivery of care, asthma treatment, admission and readmission policies, and the severity and prevalence of asthma in changing admission rates are considered. The changing trends in admission rates for East Anglia and Wales reflect recently published trends for mortality from asthma in England.

Prevalence of asthma among Emirates school children

The aim of this study was to determine the prevalence of asthma among United Arab Emirates school children aged 6-14 years. A cross-sectional study of 850 school children living in both urban and rural areas (average age 9.36 +/- 2.11 years, 46.8% boys and 53.2% girls) was conducted using self-administered questionnaires between October 1992 and May 1993. The population sample had a high prevalence rate of diagnosed asthma (13.6%), breathlessness or tightness in chest (9.7%), allergic rhinitis (22.9%), and nocturnal cough (8.9%). Allergic rhinitis was the most frequently seen respiratory illness when compared to other respiratory symptoms. The frequency of asthma, allergic rhinitis and eczema among parents reflected the same pattern as that seen in the children. Prevalence rate of asthma was not significantly higher in fathers (5.9%) than in mothers (5.3%). The differences between the sexes were not significant in any of the age group studied for any of the allergic conditions, except for diagnosed asthma in which the prevalence rate in males was significantly higher than that in females. On the whole, the prevalence rate of all the conditions increased with age. But the frequency of allergic rhinitis symptoms was significantly higher in mothers (16%) than in fathers (10.8%). These results are consistent with those obtained in neighbouring gulf countries and are higher than those of some developed countries, but the differences are not statistically significant.

Asthma at the interface: bridging the gap between general practice and a district general hospital

A clinic supervised by a nurse, using principles originally developed in general practice, was established in the paediatric department of a district general hospital. A randomised controlled study was conducted comparing children admitted with asthma or attending outpatients who were given a patient education programme and self management plan (intervention group) with a control group. The study comprised 91 patients aged 3-14 years admitted for asthma or attending a hospital outpatient department from November 1989 to November 1990. Seventy seven patients completed the study and kept diaries for a median of 283 days. Patients in the intervention group had significantly less restriction of activity (95% confidence interval (CI) -0.27 to -0.01) and fewer episodes of peak flow below 30% of best (95% CI 0.03 to 1.17). Patients in the intervention group were more likely to make the correct response to an acute exacerbation of their asthma than the control group (71% v 47%, 95% CI 9.51 to 39.1). The intervention group had fewer school absences and fewer home visits by a general practitioner. There was an increase in the readmission rate for the intervention group. A subgroup of patients who self managed by doubling their use of inhaled steroids during an exacerbation performed better than those patients who only increased their bronchodilator or were managed on salbutamol or sodium cromoglycate alone. Improvements in patient follow up and the structure of the self management plans used, particularly changing the peak flow level at which inhaled steroids are doubled, may further improve the outcome of patients attending the asthma clinic.

Time trends in respiratory symptoms in childhood over a 24 year period

Two cross sectional surveys, 24 years apart, using the same respiratory questionnaire, were carried out to examine changes in prevalence rates of cough, phlegm, and wheeze and to relate changes in wheeze to objective peak expiratory flow rates (PEFRs). The surveys were done in towns in southern and northern England and South Wales in schoolchildren aged 6.0-7.5 years; n = 1655 in 1966 and n = 2323 in 1990. Parents reported on winter cough and winter phlegm (early morning or day/night) and wheeze; PEFRs were also measured. The proportion of children reported as wheezing on most days or nights increased from 3.9% to 6.1% (95% confidence interval (CI) for increase -0.2 to 4.6), with a smaller increase in the prevalence of those who had ever wheezed. The proportion of children with day or night time cough increased from 21.1% to 33.3% (95% CI for increase 3.8 to 20.6) and the proportion with day or night time phlegm increased from 5.8% to 10.0% (95% CI for increase 0.4 to 8.0). Smaller increases in the prevalence of persistent cough (from 9.0% to 12.4%) and persistent phlegm (from 2.4% to 3.5%) were also observed, while morning cough and morning phlegm showed little change. The increases in cough and phlegm were apparent in subjects with and without a history of wheeze. Both absolute and proportional changes in symptom prevalence were generally greater in the north than in the south. Similar social class trends were seen in each survey. The mean difference in PEFR between subjects with and without wheeze was smaller in 1990 than in 1966, but this result could be influenced by a greater proportion of subjects receiving antiasthmatic treatment in the 1990 survey. These apparent increases in the prevalence of persistent wheeze, day and night time cough and phlegm, occurring over a period during which outdoor air pollution levels have decreased substantially, deserve further investigation.

Temporal trends in hospital-based episodes of asthma care in a health maintenance organization

Studies reporting increased asthma hospitalizations and mortality in the United States and abroad have heightened concern about the changing epidemiology of asthma. We studied 20-yr patterns of acute asthma care occurring at two large community hospitals among members of a large health maintenance organization. The presentation focuses on the conceptualization and operationalization of an "episode" of asthma care, defined as a collection of encounters (emergency room visits, urgency care visits, and hospital admissions) that cluster in time, as well as on changes in episode rates over time. We found a statistically significant increase in asthma episodes among boys younger than 5 yr of age that continued unabated from 1967 to 1987 despite a drop in asthma hospitalization rates starting in 1985. We hypothesize that this difference may reflect a change in emergency room management practices and not a true change in the underlying epidemiology of asthma. The concept of an episode of acute asthma care has not been studied in the literature and represents a potentially useful methodologic innovation. Particularly in the context of managed health care systems, studies of such episodes may be less sensitive than studies of hospital admissions to changes in the organization and delivery of acute asthma care, and thus may be better suited for studying changes in the epidemiology of asthma.

Twenty year trends in hospital discharges for asthma among members of a health maintenance organization

We examined trends in hospitalizations for asthma from 1967 to 1987 among members of a large health maintenance organization. During this time asthma discharges increased significantly among children, and especially among boys under the age of 5 years. Ninety-five percent of the increase in discharges among boys was explained by a corresponding increase in the number of boys who were hospitalized. Increased readmissions did not account for the rise. Changes in the International Classification of Diseases coding of asthma and diagnostic shift by physicians accounted for only part of the increase. A decline in hospitalizations since 1984 may reflect changes in the management of asthma in the emergency room and not a decline in severe asthma episodes.

The experience of asthma

A group of seven asthmatics were identified from family practice, following administration of a questionnaire, as expressing feelings of stigma or pessimism concerning their condition. They were interviewed in depth, using interpretive research methods, concerning their experience of asthma. Interpretive research uses qualitative methods to explore the emotions, feelings and meaning of the event of interest. All the interviews were transcribed verbatim by the principal researcher and analyzed by the technique of immersion and crystallization. The picture of asthma that emerged for the participants in this study gave rise to the concept of a dynamic model to illustrate their asthma experience. The model showed asthma as a continuum from diagnosis to final acceptance. The transition phase included a need to integrate knowledge, experience and self-awareness before progressing to acceptance and control. A mentoring relationship greatly facilitated resolution of the transition phase. Progress along the continuum was accompanied by diminishing fear. Another important theme to emerge was the fact that tiredness and physical limitations were common feelings, irrespective of the severity of the asthma in medical terms. The implications of this research for health workers is that they have much to contribute in assisting asthmatics to gain control over their condition, particularly in respect to understanding what knowledge concerning their condition is relevant to asthmatics and in understanding the potential benefit to asthmatics of a mentoring relationship.

Immunohistochemical characterization of the cellular infiltration in asthmatic bronchi

Bronchial biopsies obtained from 16 asthmatic patients and six normal subjects were analyzed by immunohistochemistry. In the asthmatic patients, the total numbers of macrophages infiltrating the airway mucosa were increased. Many of the macrophages had the phenotypic characteristics of blood monocytes. HLA Class II antigen was expressed on infiltrating cells and airway epithelial cells. In biopsies from the asthmatics there was a significant increase in activated eosinophils, but not in neutrophils. There was also a significant increase in the numbers of T-lymphocytes in the asthmatics, but very few B-lymphocytes were detected. These results suggest that lung macrophages may have a central role to play in the mechanisms of the chronic immune-mediated inflammatory response seen in the airway mucosa of asthmatic patients.

Use of a management plan for treating asthma in an emergency department

A standardised management protocol has been developed for the assessment and treatment of adults with acute asthma attending an emergency department. The management protocol consists of an assessment sheet for recording essential features of the history and examination findings and a flow diagram with guidelines for initial management that were based on spirometric recordings. The protocol was introduced at Wellington Hospital in 1986. The effect of this intervention was assessed by analysing emergency department records during the three months before and one year after the introduction of the protocol. The use of the assessment sheet improved history taking and led to the increased use of serial measures of airflow obstruction and improved documentation of follow up arrangements. The provision of management guidelines influenced the emphasis of management, including an increased use of corticosteroids intravenously and more frequent use of an additional dose of nebulised bronchodilator. In the light of the initial experience the protocol has been modified and its use either in an emergency department or in general practice is recommended.

Trends and district variations in the hospital care of childhood asthma: results of a regional study 1970-85

Trends and district variations in the pre-hospital and hospital care of children aged 0-14 years admitted with acute asthma were surveyed in all 13 districts of a health region by examining case notes for 1970, 1978, and 1985. From 1970 to 1985 there was a substantial increase in admissions and some reduction of hospital stay. Over this time adrenergic drugs remained the most frequently used treatment with a large shift towards selective beta2 agonists administered by nebulisation. Use of corticosteroids fell in the under 5s with a decrease in the parenteral route of administration but rose in the 5-14 age group with an increase in the oral route of administration. There was an increase the use of oral xanthines but this was outweighed by falls in the use of suppositories and in parenteral administration. The use of antibiotics became less frequent and that of sedatives and antihistamines fell to almost nil. There were also important changes in other aspects of management, notably an increase in the use of lung function tests (from 3% to 70%) and falls in the use of chest radiographs, blood tests, bacteriology, and physiotherapy. In nearly all aspects of management there were significant and often very extreme variations in practice between districts, which were unlikely to be explained by differences in morbidity. These variations would be a suitable focus for medical audit, with the aim of establishing which treatment regimens have the best outcome and avoiding unnecessary cost and discomfort. Because early hospital drug treatment is closely related to the type of treatment given before admission such audit activities would need to include general practitioners.

Has the prevalence of asthma increased in children? Evidence from the national study of health and growth 1973-86

OBJECTIVES

To estimate changes in the prevalence of reported symptoms of respiratory disease and reported diagnoses of asthma and bronchitis in primary school children in England between 1973 and 1986.

DESIGN

Mixed longitudinal survey.

SETTING

Representative sample of English primary schools in 22 areas.

PARTICIPANTS

15,000 Boys and 14,156 girls each studied at least once between 1973 and 1986.

DATA COLLECTED

Whether, according to the parent or guardian, the child had wheezed, wheezed on most days or nights, or had attacks of bronchitis or asthma in the past year.

RESULTS

Within age groups trends in successive annual cohorts showed an increasing prevalence of asthma for each annual birth cohort (boys, 6.9%, p less than 0.001; girls, 12.8%, p less than 0.001) and of wheeze on most days or nights (boys, 4.3% per cohort, p less than 0.001; girls, 6.1% per cohort, p less than 0.001) and a falling prevalence of bronchitis (boys, -4.7% per cohort, p less than 0.001; girls, -5.8% per cohort, p less than 0.001). There was a smaller increase in the prevalence of wheeze whether or not it occurred on most days or nights, and this increase was significant only among the girls (boys, 1.0% per cohort, p greater than 0.05; girls, 1.7% per cohort, p less than 0.05). Although the rate of increase of "asthma" was greater than the rate of decrease in "bronchitis," the baseline prevalence of asthma was much lower than that of bronchitis, and the total proportion of children with either diagnosis declined slightly over the whole period. The main change was an increase in the proportion of children whose parents stated that they had persistent wheeze and yet did not have a report of either "asthma" or "bronchitis."

CONCLUSIONS

These results suggest that there has been a true increase in morbidity that is not simply due to changes in diagnostic fashion. The increase is large enough to explain much if not all of the increase in admission to hospital and mortality, and it underlines the importance of an understanding of the aetiology of asthma in tackling the causes of the recent increase.

Acute asthma: emergency department management and prospective evaluation of outcome

To determine the current management of acute asthma in the emergency department and to evaluate outcome we reviewed the charts of 99 patients aged 15 to 55 years who presented to the emergency department of a tertiary referral, university-affiliated hospital and were subsequently discharged with a diagnosis of acute asthma. Outcome was evaluated prospectively, with a structured questionnaire, by telephone. During the visit pulsus paradoxus was documented in four patients. Spirometry was done in 63 patients; postbronchodilator values ranged from 0.9 to 4.1 L. A total of 92 patients received inhaled bronchodilator therapy, most by wet nebulization. Sixteen patients received anticholinergic agents and three received theophylline. Ingested corticosteroids were given to 27 patients. Of the 71 patients contacted, a mean of 12 days after the visit, 26 (37%) had sought further medical attention, 19 at the emergency department; 9 had required admission. Forty-six patients reported that their condition had improved, but over 60% continued to have cough, sputum production, nocturnal waking and early-morning chest tightness. The results indicate that asthma continues to be undertreated in the emergency department and highlight the importance of routine spirometry in all patients and the need for systemic corticosteroid therapy.

Why are hospital admission and mortality rates for childhood asthma higher in New Zealand than in the United Kingdom?

New Zealand has higher mortality and hospital admission rates for asthma than England and Wales. To determine the reasons for this the available data on asthma mortality and hospital admissions from the Auckland region of New Zealand were compared with data from the South West Thames Region of England for 1979-86 and data from previous surveys on prevalence of wheeze (Auckland 1985, Croydon 1978). In addition, a survey of general practitioners was carried out to determine their approach to the management of asthma, patient simulations being used. Asthma mortality in children of European descent aged 5-14 years was 2.5 times higher in Auckland than in South West Thames. The reported lifetime, 12 month, and one month prevalences of wheeze were also higher in Auckland (by 18.5%, 32.1%, and 87.5%). Unexpectedly, the hospital admission rate for asthma in children of European descent aged 5-14 years was 5% less in Auckland than in South West Thames. Comparative studies of hospital case notes and of the replies from general practitioners showed that in Auckland the duration of illness before admission was greater and that general practitioners were less likely to admit patients with acute asthma. The overall standard of general practitioner care in Auckland was, if anything, higher than in South West Thames but in both areas there was considerable variation. On balance it was concluded that the higher mortality rate in New Zealand is explained by higher levels of morbidity rather than relative deficiencies in care. Nevertheless, the implications of the lesser use of hospital care for acute asthma observed in Auckland need further consideration.

Asthma education: the perceptions of family physicians

Education and training are important for people with asthma and for their family doctors in order to reduce the morbidity and mortality associated with the disease, but the most appropriate educational strategies have not been clarified. This study was conducted as a needs-assessment survey to examine the perceptions of 193 family physicians in Sydney (Australia) regarding various aspects of asthma management and patient education. Part of this sample of physicians were subsequently involved in a communitywide asthma education program. Although the measurement of airway function by doctors and patients is the cornerstone of the national asthma strategy in Australia, only 43% of family physicians surveyed regularly measured airway function in their offices and most considered that their patients rarely used a peak flow meter. Most physicians agreed with statements suggesting that asthma education was useful but some felt that education could be dangerous, or might result in fewer consultations by asthma patients. These results have provided clear directions for educating family physicians about optimal asthma management. They also provide some insight into potential barriers to the successful implementation of asthma education programs.

Increased paediatric admissions with asthma in Western Australia--a problem of diagnosis?

A study of hospital admissions of paediatric cases with asthma over a 17-year period (1971-1987) in Western Australia was performed retrospectively. Hospital admission rates for asthma increased in all paediatric age-groups with the most dramatic increase occurring in the youngest (zero- to four-years') age-group. This increase in hospital admissions for asthma has been accompanied by a rapid decline in admissions for other paediatric respiratory conditions that share a potential diagnostic overlap with asthma. Hospital admission rates for asthma have reached a plateau at the major paediatric teaching hospital in the State from 1977 and Statewide from 1983. Diagnostic transfer has contributed significantly to the reported increase in hospital admissions for asthma over the past two decades.

Accident and emergency department attendance by asthmatic children

Attendances at the accident and emergency department of a children's hospital for treatment of acute asthma were studied for one year to determine the characteristics of the children attending and their management. Eight hundred and twenty children, median age 5.5 years, made 1389 visits. Records were available from 1046 visits. Clinical information and assessment of the severity of the attack in the department was often inadequate. Peak flow records were available for 366 (35%). Attendances were most frequent in September and during the evening, but there was no significant day to day variation. Eight hundred and three children (78%) were self referred. Before attendance 962 (92%) had used a bronchodilator, including nebulised salbutamol (11%); 2% had taken prednisolone and 21% antibiotics. Five hundred and sixteen visits (49%) led to admission and 19% of those admitted required intravenous treatment. Probably some children who at present attend hospital for treatment of acute asthma could be managed at home, but this cannot be assumed without better understanding of the reasons for hospital attendance. More information is needed.

Recurrent accident and emergency department attendance for acute asthma in children

Asthmatic children aged over 5 years making repeated visits to the accident and emergency department of a children's hospital were compared prospectively, on the basis of a clinical questionnaire and pulmonary function tests, with a control group of outpatients with asthma to find the reasons for their repeated attendance. Recurrent attenders (n = 145) had more severe asthma than control subjects (n = 118), with greater airway obstruction at rest (FEV1 79% v 85% predicted) and bronchial lability (47% v 38%). Significantly more of the "emergency" group used pressurised aerosols and fewer dry powder inhalers to administer bronchodilators. There were no differences in prophylactic treatment. Seventy one per cent of parents in the emergency group had feared that their child would die during an attack, compared with 56% of control subjects. Eighty one per cent of children were self referred to the accident and emergency department. Most parents had found hospital to be the quickest means of obtaining treatment in an emergency. There were no differences between the two groups in parents' knowledge about asthma, home conditions, or social disadvantage. Although children who repeatedly attend hospital accident and emergency departments for treatment of acute attacks have more severe asthma than controls and show some deficiencies in treatment, the major determinant of attendance appeared to be the parents' conviction that appropriate treatment could not be obtained elsewhere.

Prevalence of respiratory symptoms among 7 and 11 year old schoolchildren and association with asthma

A new self administered questionnaire completed by parents was used to study the prevalences of wheeze, shortness of breath, and cough in 2503 Southampton schoolchildren aged 7 and 11 together with exacerbating factors and background information including treatment and diagnosis. The questionnaire had a response rate of 84% and was found to be highly repeatable with respect to current symptoms. The overall prevalences of wheeze and shortness of breath in the current year (1986) were 12.1% and 8.5% respectively. Social class, home ownership, parental smoking, and presence of a family pet were unrelated to symptom prevalence. According to the parents the overall diagnosis rate for asthma was 9.5%. In common with other studies, however, we found considerable evidence for undertreatment. The symptoms of wheeze and nocturnal and morning breathlessness occurred more commonly in boys, but this sex ratio decreased with increasing age. The prevalences of wheeze and shortness of breath were similar in the two age groups. In contrast, there were only small differences between the sexes with respect to cough whereas, among children without wheeze or shortness of breath, there was a fall in the prevalence of cough from 18.9% at 7 years to 8.7% at 11 years. When controlling for the other respiratory symptoms, wheeze was the only symptom significantly related to parental asthma. The fall in the prevalence of cough between the two age groups is unlikely to be related to changes in asthma prevalence and, when not associated with wheeze, may be an indicator of separate pathology.

Increase in hospital admissions for childhood asthma: trends in referral, severity, and readmissions from 1970 to 1985 in a health region of the United Kingdom

Admissions to hospital for childhood asthma have continued to increase, but the reasons are unknown. Because the incidence of acute asthmatic attacks in the community greatly exceeds the admission rate, this increase could be a result of changes in medical practice shifting the balance of care towards the hospital without there being any underlying change in morbidity. In the South West Thames Region (population 2.9 million) over the eight years 1978-85 the number of hospital admissions among those aged 0-4 and 5-14 rose by 186% and 56%. A random sample of case notes from all hospitals in the region was examined for evidence of changes in mode of referral, severity on admission (duration of episode, vital signs on admission), and readmission ratio. The findings indicate that there has been no reduction in severity on admission or increase in readmission rate since 1978. The findings for the 5-14 age group contrast with those from an earlier study (1970-8) in the same region, in which a substantial increase in self referral was observed together with an increase in readmissions and a reduction in the duration of the attack; pulse and respiration rates on admission have, however, remained unchanged over the 16 year period. Overall, these findings indicate that the increase in admissions cannot be satisfactorily explained by changes in medical practice alone and may be due to an increase in the number of asthmatic children experiencing severe attacks. This points to a change in the epidemiology of childhood asthma.

Trends in paediatric medical admissions

In the Oxford region from 1975 to 1985 the rate of discharge from paediatric departments, when standardised for age, rose by 88%. This increase was studied by using routinely collected data. It occurred in all age groups and was due mainly to an increase in emergency admissions for acute common childhood illnesses, particularly respiratory and gastro-intestinal diseases. There was no evidence that increasing morbidity accounted for this rise; the change was due to factors in medical care. Over the 11 years the median length of stay fell from 2.4 to 1.5 days and by 1985 40% of children were discharged within a day after admission. The increase in admissions was due to lower thresholds for admission resulting in part from the increased availability of beds because of the diminishing lengths of stay.

Asthma--still a challenge for general practice

Asthma is probably the commonest chronic disease in the United Kingdom, and its attendant morbidity extends outside the possible scope of the hospital sector. Innovations to improve the care of asthma must therefore come from general practice. The need for such care initiatives is demonstrated by the rising mortality and morbidity from this condition, and by the evidence of less than optimum treatment at both the primary and secondary care levels. This paper reviews this evidence, and considers possible solutions to the problems raised. Pragmatic guidelines are offered for the promotion of good asthma care, while the need for proper evaluative research is stressed.

Rising asthma admissions and self referral

An eight fold rise in asthma admissions to the Royal Alexandra Hospital for Sick Children, Brighton occurred over the 15 year period 1971-85. The cause was an increase in the number of children seen, rather than increased readmission. The initial rise was associated with the introduction of nebulised salbutamol in 1976. The children concerned were mainly over 5 years old. Three years later came a larger influx of younger children. Circumstances leading to admissions were examined in a prospective study over a one year period. There were 605 admissions, 437 (72%) were self referrals. The commonest reason parents gave for preferring hospital treatment was the availability of nebuliser treatment.

Prevention of fatal asthma

Over a 32-month period, 980 calls from asthmatic patients were received at the switchboard office of a prehospital emergency care unit. A total of 90 patients (9 percent) died before receiving any medical help, and 216 (22 percent) patients were taken to the hospital with an emergency care ambulance where none of them died. We made the assumption that, when an asthmatic patient calls an emergency care unit, the attack is severe and might be fatal. A prospective study was performed during a six-month period to prevent these asthma deaths: 259 calls from asthmatic patients were received. For each emergency call from asthmatic patients, paramedical help (delay: 5.1 +/- 0.3 minutes) and an emergency care ambulance (delay: 9.7 +/- 0.6 minutes) were immediately sent. Only four patients died during this period. Emergency calls from asthmatic patients must be considered as related to a severe attack that might be fatal. Fatal asthma is often related to a severe attack that evolves rapidly. Some asthmatic patients are able to assess the severity of asthma attacks, and prehospital emergency care schemes for asthmatic patients are actually able to prevent some asthma deaths.

The severity of acute asthma attacks in children admitted to hospital

One hundred and twenty-six children admitted to hospital with an acute asthmatic episode were assessed as to the severity of their attack by the use of a clinical score. Fifty-one per cent had a score which equated with severe or very severe asthma. Frequent independent scoring indicated that observer bias was minimal. The proportion of children with severe asthma admitted to hospital in Christchurch was significantly greater than a similar study in England using the same scoring system. The rise in hospital admission rates for asthma in Christchurch is not due to an increase in the admission of children with milder forms of asthma.

Epidemiological diagnosis of asthma: methodological considerations of prevalence evaluation

Within an epidemiological survey on Chronic Obstructive Pulmonary Disease, before reporting data on the prevalence of bronchial asthma we checked the group of subjects defined as "pathological" by means of a suitable questionnaire and a group of "normals" as a control. We evaluated the sensitivity and specificity of the questionnaire, in comparison with a clinical evaluation made by two physicians and controlled the relationship among their results, non-specific bronchial hyperreactivity and skin tests. In particular the correspondence between diagnosis made by physicians from a clinical evaluation and that obtained by questionnaire was not satisfactory. We suggest the importance of employing physicians for an epidemiological approach to asthma, in absence of a valid objective criterion.

Effect of a single oral dose of prednisolone in acute childhood asthma

140 children of 184 with acute asthma entered a randomised double-blind trial of oral prednisolone (n = 67) compared with placebo (n = 73) administered soon after admission. The dose of prednisolone was 30 mg in children under 5, otherwise 60 mg. All children also received salbutamol. All had moderate or severe dyspnoea. Initial evaluation was similar for both groups. On reassessment after a few hours 20 children in the prednisolone group were fit for discharge compared with only 2 in the placebo group. There were no early reattendances. Children remaining in hospital had a shorter median duration of stay and were less likely to require further steroid therapy if they had initially received prednisolone. In acute asthma the prompt use of a single dose of oral prednisolone can reduce morbidity and the need for hospital care.

Prevalence of asthma and hay fever in England and Wales

The results concerned with the prevalence of asthma and hay fever in the large surveys of morbidity in general practice in 1970-1 and 1981-2 were compared. In data standardised for age the prevalence of asthma in men increased from 11.6 to 20.5 people consulting per 1000 population (p less than 0.001) and in women from 8.8 to 15.9 per 1000 population (p less than 0.001). Similar increases were also evident in data analysed from the 19 practices contributing to both surveys. The prevalence of asthma increased in each age group examined. Increases of similar magnitude were reported for hay fever--the prevalence in men increased from 10.8 to 19.8 people consulting per 1000 population (p less than 0.001) and in women from 10.3 to 19.7 per 1000 population (p less than 0.001) and occurred in all age groups. The prevalence of acute bronchitis was reduced significantly in the age group 5-14 and increased among the elderly. The prevalence of chronic bronchitis was reduced substantially in 1981-2. The reported increased prevalence of both asthma and hay fever represented a real increase and was not accounted for by changes in diagnostic preference. Only in the age group 5-14 was there any likelihood that some of the increased prevalence of asthma might have resulted from a reduction in the prevalence of acute bronchitis.

The changing frequency of childhood asthma

Hospital admission rates for childhood asthma have increased markedly in many countries since the beginning of the 1970s. Prevalence of asthma, as reported by parents or children in occasional surveys, has also increased during this period. In Montreal, 7.2 per 1000 3-year-old children were admitted to the hospital with a diagnosis of asthma in 1980-1981, whereas the rate was 11.9 per 1000 in 1984-1985. For 7-year-old children, these rates were 3.2 per 1000 and 4.8 per 1000, respectively. On the other hand, the length of hospital stay decreased steadily during this period, and the mean number of admissions per child did not show a tendency to increase. For 3- and 7-year-old children together, the prevalence of asthma, determined from health insurance data, increased by 71%, from 3.76% in 1980 to 6.45% in 1983. Prevalence of other medical conditions also increased in this community, but much less than for asthma. An increase in the incidence of the disease cannot be excluded as the cause for the changing prevalence of asthma.

Trends in the hospitalization for acute childhood asthma, 1970-84

Data from the 1970 through 1984 National Hospital Discharge Surveys indicate that the rate of hospitalization for children under 15 years old with asthma has increased at least 145 per cent while the average length of stay for children with asthma decreased by 26 per cent from 5 days in 1970 to 3.6 days in 1984. Over an analogous period (1970 to 1980), data from the National Health Interview Survey indicate that the prevalence of childhood asthma has increased by approximately 28 per cent for children 6 to 16 years of age. Several potential explanations for the hospital trend are discussed, including changes in the disease classification and information system, criteria for admission, organizational factors, changes in therapy, and changes in morbidity.

Asthma mortality in England and Wales: evidence for a further increase, 1974-84

The trend in asthma mortality has been estimated from published statistics for the years 1974-84, with account being taken of changes due to the revision of the International Classification of Diseases in 1979. Mortality rose annually by an average of 4.7% in the 5-34 year age-group (p less than 0.05), and the increased mortality since 1974 probably accounted for 408 excess deaths in the 5-64 year age-group between 1975 and 1984. No satisfactory explanation for this rise in mortality is likely until there is adequate monitoring of the prevalence and severity of asthma.

Parental knowledge and misconceptions about asthma: a controlled study

We interviewed the parents of 128 asthmatic children about their knowledge and misconceptions of asthma. Two-third or more gave correct responses to questions on aetiology and pathogenesis, pathophysiology, symptomatology, precipitants and outcome of asthma. A control group of parents of 110 children admitted to the hospital with minor surgical complaints performed equally well on the knowledge questions, except for four sub-questions: (1) allergy as an aetiologic factor in asthma (64.5% vs 83.6%, P = 0.002), (2) constriction of airways as a bodily change during an asthmatic attack (75.4% vs 91.3%, P = 0.004), (3) cough as a symptom of asthma (82.7% vs 99.2%, P less than 0.001) and (4) change in weather (81.0% vs 95.5%, P = 0.002) or cold weather (60.9% vs 74.2%, P = 0.015) as triggers of asthma. However, a significant minority of both groups of parents were found to harbour misconceptions about asthma. Between 10-20% believed that poor care, inappropriate diet during pregnancy or premature birth can predispose a child to asthma. About one-third believed that bodily changes during an asthmatic attack include loss of control or paralysis of chest muscles, infection of lungs and compression of the lungs by the stomach. Also about one-third believed that swallowing a hard object or touching a poisonous plant can set off an asthmatic attack. Some 10% believed that diarrhoea is a symptom of asthma, while 50% regarded sore throat as a symptom. Up to 40% believed in restriction of outdoor play by asthmatic children.(ABSTRACT TRUNCATED AT 250 WORDS)

Children with asthma: will nebulised salbutamol reduce hospital admissions?

To find out how many children with acute asthma responded to one or two doses of nebulised salbutamol and whether this response could be predicted 100 children were studied prospectively from two district hospitals. Twenty three children needed only one nebulised dose and 19 responded to two. Significant factors differentiating these responders from the remainder were age (24 (63%) of those aged 6 or more responded compared with only six (19%) of those aged 3 or less); regular treatment with a beta 2 sympathomimetic; and use of a rotahaler or aerosol. Those requiring more intensive treatment had faster pulse and respiratory rates on admission and one hour after the first nebulised dose. Another useful clinical sign was persistent supraclavicular indraw. Pulsus paradoxus and peak expiratory flow rate were of limited value in the younger children who had worse asthma. Of 29 children receiving intravenous treatment, 18 (62%) were aged 3 or less, whereas only two (7%) were aged 6 or over. The older children who responded initially to nebulised salbutamol could have been safely reassessed at home, which would have considerably reduced hospital admissions.

George Swift lecture. The world turned upside down: proposals for community-based undergraduate medical education

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