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

Time to Say Goodbye to Bronchiolitis, Viral Wheeze, Reactive Airways Disease, Wheeze Bronchitis and All That

The diagnosis and management of infants and children with a significant viral lower respiratory tract illness remains the subject of much debate and little progress. Over the decades various terms for such illnesses have been in and fallen out of fashion or have evolved to mean different things to different clinicians. Terms such as "bronchiolitis," "reactive airways disease," "viral wheeze," and many more are used to describe the same condition and the same term is frequently used to describe illnesses caused by completely different dominant pathologies. This lack of clarity is due, in large part, to a failure to understand the basic underlying inflammatory and associated processes and, in part, due to the lack of a simple test to identify a condition such as asthma. Moreover, there is a lack of insight into the fact that the same pathology can produce different clinical signs at different ages. The consequence is that terminology and fashions in treatment have tended to go around in circles. As was noted almost 60 years ago, amongst pre-school children with a viral LRTI and airways obstruction there are those with a "viral bronchitis" and those with asthma. In the former group, a neutrophil dominated inflammation response is responsible for the airways' obstruction whilst amongst asthmatics much of the obstruction is attributable to bronchoconstriction. The airways obstruction in the former group is predominantly caused by airways secretions and to some extent mucosal oedema (a "snotty lung"). These patients benefit from good supportive care including supplemental oxygen if required (though those with a pre-existing bacterial bronchitis will also benefit from antibiotics). For those with a viral exacerbation of asthma, characterized by bronchoconstriction combined with impaired b-agonist responsiveness, standard management of an exacerbation of asthma (including the use of steroids to re-establish bronchodilator responsiveness) represents optimal treatment. The difficulty is identifying which group a particular patient falls into. A proposed simplified approach to the nomenclature used to categorize virus associated LRTIs is presented based on an understanding of the underlying pathological processes and how these contribute to the physical signs.

Asthma: A Loss of Post-natal Homeostatic Control of Airways Smooth Muscle With Regression Toward a Pre-natal State

The defining feature of asthma is loss of normal post-natal homeostatic control of airways smooth muscle (ASM). This is the key feature that distinguishes asthma from all other forms of respiratory disease. Failure to focus on impaired ASM homeostasis largely explains our failure to find a cure and contributes to the widespread excessive morbidity associated with the condition despite the presence of effective therapies. The mechanisms responsible for destabilizing the normal tight control of ASM and hence airways caliber in post-natal life are unknown but it is clear that atopic inflammation is neither necessary nor sufficient. Loss of homeostasis results in excessive ASM contraction which, in those with poor control, is manifest by variations in airflow resistance over short periods of time. During viral exacerbations, the ability to respond to bronchodilators is partially or almost completely lost, resulting in ASM being "locked down" in a contracted state. Corticosteroids appear to restore normal or near normal homeostasis in those with poor control and restore bronchodilator responsiveness during exacerbations. The mechanism of action of corticosteroids is unknown and the assumption that their action is solely due to "anti-inflammatory" effects needs to be challenged. ASM, in evolutionary terms, dates to the earliest land dwelling creatures that required muscle to empty primitive lungs. ASM appears very early in embryonic development and active peristalsis is essential for the formation of the lungs. However, in post-natal life its only role appears to be to maintain airways in a configuration that minimizes resistance to airflow and dead space. In health, significant constriction is actively prevented, presumably through classic negative feedback loops. Disruption of this robust homeostatic control can develop at any age and results in asthma. In order to develop a cure, we need to move from our current focus on immunology and inflammatory pathways to work that will lead to an understanding of the mechanisms that contribute to ASM stability in health and how this is disrupted to cause asthma. This requires a radical change in the focus of most of "asthma research."

'Recurrent lower respiratory tract infections' - going around in circles, respiratory medicine style

Recurrent lower respiratory tract infections are very common in childhood, particularly the pre-school years. The term lower respiratory tract infection [LTRI] is, as with many terms used in respiratory medicine, used very loosely and carries little more information than the often decried term 'chest infections'. LRTIs should more accurately be characterised by the type of infection [viral or bacterial], the site of infection [conducting airways, or respiratory compartment or both - bronchitis/pneumonia/bronchopneumonia], the nature of the episode [acute or acute on chronic (exacerbation)], the interaction with co-morbidities such as asthma. The limited nature of the responses of the lower airways to any insult whether it is infective or irritation due to inhaled or aspirated chemicals means that almost any aetiology can lead to cough, shortness of breath and noisy breathing. We lack good non-invasive techniques to study the nature of the inflammation in the lower airways and hence the cause of chronic and recurrent symptoms in patients is frequently mis-diagnosed.

Treating according to asthma control: does it work in real life?

Control-based asthma management has been incorporated in asthma guidelines for many years. This article reviews the evidence for its utility in adults, describes its strengths and limitations in real life, and proposes areas for further research, particularly about incorporation of future risk and identification of patients for whom phenotype-guided treatment would be effective and efficient. The strengths of control-based management include its simplicity and feasibility for primary care, and its limitations include the nonspecific nature of asthma symptoms, the complex role of β(2)-agonist use, barriers to stepping down treatment, and the underlying assumptions about asthma pathophysiology and treatment responses.

Effects of acupuncture-like transcutaneous electrical nerve stimulation on children with asthma

OBJECTIVE

To evaluate the effects of acupuncture-like transcutaneous electrical nerve stimulation (AL-TENS) on children with asthma.

METHODS

After an 8-week run-in period, the experimental group were assigned to treatment with AL-TENS, whereas the control group did not receive AL-TENS. A total of 43 children with asthma were recruited from a hospital and an elementary school. All the cases had been diagnosed as having asthma by physicians. The outcome measures included pulmonary function tests (PFTs), heart rate turbulence (HRT), heart rate variability (HRV), and pediatric asthma quality-of-life questionnaire (PAQLQ).

RESULTS

After 8 weeks of AL-TENS, there were no significant differences on forced vital capacity (FVC), FEV₁/FVC, and peak expiratory flows (PEFs) between the two groups. The HRT is the physiological, biphasic response of the sinus node to premature ventricular contractions. In the experimental group, the mean HRT was statistically significant between pretest and posttest. The HRV and the PAQLQ showed no difference, but in the experimental group, the subscale of the PAQLQ (particularly activity) improved significantly more than the pretest scores. Furthermore, there were no differences in PFTs and HRV after 8 weeks of AL-TENS between the two groups.

CONCLUSIONS

The PAQLQ activities of the experimental group improved significantly more than those of the control group. Reasons may include: 1) the asthma cases were stable and the cases were on stable status and 2) the degree of airway remodeling was less. It is suggested that in the future, treatment frequency and the long-term follow-up for evaluating the effects of AL-TENS on children with asthma should also be considered.

Correlation of clinical score to pulmonary function and oxygen saturation in children with asthma attack

BACKGROUND

The aim of this study is to demonstrate the importance of the relation between clinical score, pulse oximetry and spirometric tests in an asthma attack.

METHODS

In this randomized, double blind, observational study, 110 children (age 2-15 years) with an asthma attack who were admitted to emergency room were evaluated. Patient history, physical examination, clinical score and oxygen saturation were recorded in all patients; however pulmonary function tests were obtained only in 54 children who were over 5 years of age. The clinical score was derived from respiratory rate, wheezing, dyspnea and retractions.

RESULTS

Both oxygen saturation and spirometric tests were found to be significantly correlated with the clinical score in children.

CONCLUSION

The clinical score could be used for assessing the severity of the asthma attack particularly in developing countries where laboratory facilities are not available or pulmonary function tests are not feasible.

Diverging trends for lower respiratory infections in non-Aboriginal and Aboriginal children

AIM

To investigate temporal trends in admission rates for acute lower respiratory infections (ALRI) in a total population birth cohort of non-Aboriginal and Aboriginal children.

METHODS

Retrospective analysis of linked population-based data using the Western Australian Data Linkage System. All singleton live births in Western Australia between 1990 and 2000 were included. Hospital admission rates per 1000 live births for ALRI before age 2 years and linear time trends for ALRI admission rates were investigated.

RESULTS

ALRI admission rates were 7.5 (95% confidence interval (CI) 7.2-7.7) times higher in Aboriginal than non-Aboriginal children (337 vs. 45 per 1000 live births); pneumonia rates were 13.5 (95% CI 12.8-14.4) times higher and bronchiolitis rates were 5.8 (95% CI 5.3-6.0) times higher. ALRI admission rates rose in non-Aboriginal children (<12 months, 6%/year, P<0.002; 12-23 months, 11%/year, P<0.001) but declined in Aboriginal children aged 12-23 months (4%/year, P=0.003). Bronchiolitis rates rose in all children, especially non-Aboriginal infants aged <12 months (13%/year, P<0.001), while pneumonia rates rose in non-Aboriginal children but declined in Aboriginal children. Declines in bronchitis and asthma were also noted.

CONCLUSION

There has been an increase in incidence of bronchiolitis before age 12 months. For children aged 12-23 months a diagnostic shift from asthma and bronchitis to bronchiolitis and changes in health service utilisation are likely explanations for diverging temporal trends. The continuing disparity between Aboriginal and non-Aboriginal children needs to be addressed and appropriate preventative measures for ALRI, and in particular bronchiolitis, are urgently needed.

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.

Hospitalization rates as outcome indicators of national medicinal drug policies: the example of gastrointestinal ulcer

National medicinal drug policies are employed around the world as a means of maximizing the benefits of medication use. An essential component to the implementation of these policies is their concurrent evaluation, which informs future policy implementation and strategic directions. The overall effect of the policy can be measured by monitoring changes in health outcomes and hospitalization rates for conditions that can be managed with appropriate medication use have been proposed as a potential outcome indicator of national medicinal drug policies. In this paper, a method for establishing the validity of this indicator is described. The method enables suitable conditions to be identified and takes into account potential confounding factors. To demonstrate this a case study of hospitalization rates for gastrointestinal ulcer is presented. The analysis shows that hospitalization rates are suitable as outcome indicators of quality medication use where the hospitalization rate is not confounded by changes in the population profile, disease prevalence and severity, diagnosis, hospital based policies, coding practices, environmental factors or hospital based treatments, but is responsive to changes in the utilization of medication. This method could be used in many countries for determining relevant and valid indicators for monitoring health outcomes.

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.

Asthma education programme in Russia: educating patients

To address the recent rise in asthma morbidity and mortality in Russia, an intervention study was conducted to improve asthma diagnosis, treatment and prevention. US recommendations for asthma management were adapted for use in educating Moscow families with children with asthma. Two hundred and fifty-two children with asthma aged 4-14 years receiving health care in eight Moscow public health clinics together with their parents were enrolled in the study to see whether US teaching manuals for asthma management would be acceptable and effective in Russia. Children at four of the clinics with recent asthma attacks were randomly assigned to either the education or control group to test if patient education and guided asthma care would improve outcomes for patients. Modern medications were made available to both groups to see if training in the US guidelines was necessary to get physicians to use the medications. Children with recent asthma attacks at the other four clinics were defined as comparison group 1 to control for the possible effect of medication availability. All children at the eight clinics who had no asthma attacks composed comparison group 2 to see if the outcomes for these children would change over time. One-year follow-up results showed significant improvement in asthma self-management skills of children and parents, in terms of asthma treatment, only among those in the education group. Significant increases were observed in the subgroup of children in the education group using anti-inflammatory drugs for asthma control. Children in the education group had markedly increased peak flow rates and reduced daily peak flow variability as compared to control and comparison groups. There was a significantly greater reduction in doctor visits by the education group of children compared to control. Presumably, changes in parents' and children's behaviour in terms of asthma treatment and prevention skills, proper treatment of the disease and access to medications could be responsible for reducing asthma morbidity in children.

The decline in asthma hospitalisations in persons aged 0-34 years in New Zealand

AIMS

Hospitalisation rates for asthma for the 0-14 year and five-34 year age ranges have been examined from 1969 to 1993 to determine whether the rise observed between the 1960s and 1980s has continued into the 1990s.

RESULTS

In the 0-14 age range, hospitalisations peaked in 1986 then fell by 18.7% by 1993. There was a corresponding rise in hospitalisation rates for acute bronchitis/bronchiolitis and it is possible that the fall in asthma hospitalisations in this age range is at least partly explained by diagnostic transfer. On the other hand, the trends in the five-34 age range appear unlikely to be explained by diagnostic transfer. The rate peaked in 1986 and fell by 34.7% by 1993, with most of the decline occurring after 1989. This in part parallels the trends in mortality in this age range, which saw a sudden fall in the death rate in 1989.

CONCLUSIONS

New Zealand is not only benefiting from a marked fall in asthma deaths, but is also benefiting from a marked decline in asthma hospitalisations in young adults, and probably also in children.

The prediction of hospital admission in children with acute asthma

OBJECTIVE

To determine whether a single assessment of children at the time of presentation to the emergency department would discriminate accurately between those requiring admission and those who could be managed at home and to examine the appropriateness of these decisions.

METHODOLOGY

Fifty-three children were assessed using a table recommended by Australian and New Zealand respiratory paediatricians, which categorizes children as probably being able to manage at home (group 1), may need admission to hospital (group 2) and certainly need admission to hospital (group 3) on the basis of oximetry, presence of wheeze and pulsus paradoxus.

RESULTS

Nine out of 11 children assigned to group 1 were managed at home and 15/17 who were predicted to require admission were admitted. No individual component of the assessment dominated the decision made. Of the 25 children allocated to group 2, 18 were admitted.

CONCLUSIONS

The method employed was highly predictive of outcome for half of the children who presented with asthma. However, 25/53 (47%) were assigned by the table to a recommendation for further assessment; this limits its usefulness.

The asthma health outcome indicators study

Health outcomes have become an important public health policy focus in Australia. The New South Wales Health Department's Health Outcomes Program includes asthma as one of its priority areas. This study combined a survey of a non-random sample of 14 asthma researchers and clinicians and the results of a literature review to determine the current status and validity of outcome indicators used in relation to asthma. A written questionnaire was used to present individual patient, clinical trial, school intervention and public health scenarios, and respondents were asked to nominate asthma outcome indicators they would use in each scenario as well as their estimate of the indicators' validity. The results provide a critical appraisal of a variety of asthma outcome indicators with regard to their repeatability, and their concurrent and predictive validity.

Increased asthma hospitalizations among registered Indian children and adults in Saskatchewan, 1970-1989

We investigated asthma morbidity in children and adults among Registered Indians in Saskatchewan using hospitalization data for 1970-1989. In Registered Indians, significant increases were observed in the asthma hospitalization rates from 1979 to 1989 in boys and girls under 4 years, boys aged 5-14 years, and female adults aged 15-34 years respectively. In children under 4 years, the asthma hospitalization rates increased from 12.7 per 1000 in 1979 to 21.7 per 1000 in 1989. Asthma hospitalizations were higher among Indian boys than girls in the age group 0-4 years but this was reversed in the age groups 15-34 and 35-64 years. When compared with other Saskatchewan populations, the Indian population in age groups 0-4 and 35-64 years had significantly increased risk for hospitalization for asthma. Even though asthma was reported to be rare among Indians before 1975, we observed increases in asthma morbidity in recent years among Indian children and young adults.

Effect of readmissions on increasing hospital admissions for asthma in children

BACKGROUND

Previous studies have reported increases in the number of hospital admissions for asthma in children. The aim of the present study was to examine the effect of readmissions on these increased hospital admissions and to investigate gender differences in asthma readmissions.

METHODS

The Provincial Government of Saskatchewan provides universal health care to its residents. Hospital admissions data for asthma were obtained from the Saskatchewan Health Department for all 134 hospitals in the province between 1980 and 1989. Age-specific and sex-specific hospital admission rates for asthma were calculated for each calendar year using first admissions and all admissions. The ratio between the number of readmissions and all admissions in a year was defined as the readmission rate for that year.

RESULTS

Although rates based on all admissions for asthma were greater than rates based on first admissions, trends and sex differences were similar for the two rates. Despite the higher hospital admission rates for boys aged 10-14 years, girls in this age group had higher readmission rates for asthma from 1981 to 1989 (odds ratio (OR) 1.6 for girls; 95% confidence intervals (CI) 1.3 to 1.9). Similar increases were observed in readmission rates for asthma among children aged 5-9 years from 1985 to 1989 (OR 1.3 for girls; 95% CI 1.1 to 1.5).

CONCLUSIONS

Readmissions for asthma do not seem to explain the increasing trend in hospital admissions for asthma in children. In children aged 10-14 years girls had higher hospital readmission rates for asthma than boys, and further studies are required to find factors related to the increased readmissions among girls in this age group.

Changes in asthma severity in Manitoba

OBJECTIVE

To assess changes in the severity of physician-diagnosed asthma between 1983 and 1988.

DESIGN

Cross-sectional studies examining the frequency of markers of asthma severity: hospitalizations, ICU admissions, hospital emergency department visits, multiple physician contacts, and referrals to specialists in patients aged 0 to 14 years, 14 to 34 years, and > or = 35 years separately.

SETTING

Physicians' claims data from the universal Provincial Health Insurance Plan for fiscal years 1983 and 1988.

PATIENTS

All patients with the diagnosis of asthma, bronchitis, and COPD identified from the Manitoba Health database.

MEASUREMENTS

The markers of severity were related to the prevalence of patients seeing a physician and receiving a diagnostic label of asthma, COPD, or bronchitis.

RESULTS

The number of patients with physician-diagnosed asthma increased by 36.4% over the 5 years. In 1983, 11% of asthmatics were hospitalized during the year and 8% were hospitalized in 1988 (-2.5%; 95% confidence interval [CI], -3.2 to -1.8%). During both years, about 75% of the patients hospitalized were in hospital once only. Mean and median duration of hospital stay declined. The percentage of asthmatics seen in the hospital emergency departments declined slightly in all age groups, the total being 21% in 1983 and 18% in 1988 (-3.5%; 95% CI, -4.5 to -2.5%). About one third of the patients with asthma were seen only once by a physician during both of the years examined, 43 to 45% of them being seen on three or more occasions during both years. Referrals to specialists for all asthmatics increased from 12 to 14% (1.9%; 95% CI, 1.0 to 2.8%) from 1983 to 1988. This was almost entirely due to an increase from 11 to 16% (5.1%; 95% CI, 4.0 to 6.2%) in the youngest age group, an increase not accompanied by an increase in any other marker of severity. Changes in asthma severity were similar to changes in the severity in patients with bronchitis and COPD.

CONCLUSION

No increase in severity of asthma was seen between 1983 and 1988, but the prevalence of the diagnostic label of asthma increased substantially.

Trends in chronic obstructive pulmonary disease mortality in Australia

OBJECTIVE

To examine trends in mortality from chronic obstructive pulmonary disease in the Australian population from 1964 to 1990.

DESIGN

Review of national data on deaths from chronic obstructive pulmonary disease. We calculated direct annual age-standardised mortality rates for women and men (based on the 1976 age distribution of the Australian population), cumulative mortality rates and future mortality trends. Age-standardised mortality rates based on the world standard population were calculated and compared with mortality rates from lung cancer.

RESULTS

Male age-standardised mortality increased 1.6-fold from 1964 to 1970 and subsequently declined. In 1990 the male mortality rate was 5% less than in 1964. Female age-standardised mortality has shown a 2.6-fold increase from 1964 to 1990.

CONCLUSIONS

Chronic obstructive pulmonary disease seems likely to be a major health problem in Australia for many years to come. If present trends continue, female mortality from chronic obstructive pulmonary disease may equal male mortality by the middle of the next decade.

Has the prevalence of asthma symptoms increased in Australian children?

This paper estimates whether an increase has occurred in the prevalence of asthma symptoms and diagnosed asthma in Australian children over the past two decades. Seventeen population-based studies undertaken in Australia since 1969 were reviewed. Inclusion criteria were studies using population samples of children aged 5-12 years, with standardized questionnaire measurements. Data from serial National Health Surveys were also examined for trends in recent and chronic asthma. The prevalence of recent (12 month) and cumulative wheeze increased, showing a significant correlation with year of study (r = 0.78 and r = 0.79, respectively). Diagnosed asthma showed a smaller but still significant increase (r = 0.65). The trends observed indicated that diagnosed asthma and reported wheeze have increased by almost 1% per year over the past two decades. Data since 1980 have provided estimates of bronchial hyperreactivity (BHR), but no trend was observed. Substantial increases were noted in the National Health Surveys, with recent asthma prevalence in children aged 5-14 increasing from 3.3% in 1983 to 8.3% in 1989, and chronic asthma prevalence increasing from 4.5% in 1977 to 15.2% in 1989. The findings of this review suggest an increase in the prevalence of asthma symptoms in children, but these observations could also be explained by changes in diagnostic fashion and an increased awareness of asthma symptoms.

Hospital admissions and attendances for asthma--a true increase?

OBJECTIVE

To compare the ratio of hospital admissions for asthma to total hospital admissions and to admissions for non-asthma respiratory conditions, over an 11-year period, to see if there has been a true increase in admissions for asthma or merely a change in diagnostic labelling. A similar comparison was made for presentations with asthma and non-asthma respiratory conditions to the accident and emergency department.

DESIGN AND SETTING

A case review of all patients with a confirmed diagnosis of respiratory disease admitted to hospital or attending the accident and emergency department at the Camperdown Children's Hospital between 1979 and 1989.

RESULTS

There was a 98% increase in the number of patients admitted with a confirmed diagnosis of asthma. While the ratio of admissions for asthma to total admissions increased from 0.053 in 1979 to 0.09 in 1989, the ratio of admissions for non-asthma respiratory conditions to total admissions remained relatively constant. The ratio of attendances for asthma to total accident and emergency attendances rose from 0.017 in 1979 to 0.072 in 1989, whereas the ratio of attendances for non-asthma respiratory conditions to total accident and emergency attendances had a maximum variation of 0.065 to 0.09.

CONCLUSIONS

These results suggest that there has been a major increase in the number of cases of asthma being treated at this hospital and that this is a true increase, perhaps representing increased severity, rather than a change in diagnostic labelling.

Crisis in asthma care

Reports of increases in both hospitalizations and deaths due to asthma have provided a sense of crisis in asthma care. This article examines issues concerning this sense of crisis. The authors review current trends in prevalence, morbidity, hospitalization, and mortality from asthma and examine possible reasons for changes that have occurred. A review of data suggesting that asthma can result in irreversible, chronic airway obstruction is presented. Finally, the authors discuss the role of the primary care physician in the management of asthma.

Primary staphylococcal pneumonia in childhood: a review of 69 cases

Primary staphylococcal pneumonia is a rapidly progressive illness with well-described clinical and radiological features and a significant mortality rate. This retrospective study of cases diagnosed over a 20 year period at a tertiary paediatric hospital was undertaken to document the epidemiology and assess the management and mortality of the disease. The survey demonstrated that far fewer patients are being seen than formerly and confirmed that this is a disease primarily affecting infants and Aboriginal children. The initial radiological features were not diagnostic in the majority of cases but typical changes appeared in most at some time during the illness. The use of surgical drainage was not associated with a decrease in the duration of fever or length of hospital stay. The mortality rate has improved but remains significant.

Accuracy of asthma death statistics in Australia

Asthma mortality statistics issued by the Australian Bureau of Statistics (ABS) were compared with clinical data from a survey of asthma mortality. Deaths in Victoria from May 1986 to April 1987 containing 'asthma' in Parts 1 or 2 of the death certificate (N = 405) were reviewed. For each subject, the cause of death attributed by the Victorian Asthma Mortality Survey was compared with the ABS cause of death, by age and sex of the subject. Information on 393 of the 405 deaths investigated by the Victorian Asthma Mortality Survey was analysed. The ABS estimate of the total number of asthma deaths in Victoria was 47 per cent higher than the estimate of the Victorian Asthma Mortality Survey. In subjects under 50 years of age the two estimates were within 10 per cent. The difference between the estimates increased with age at death for persons over 50 years old and was equivalent for males and females. If the assessment by the Victorian Asthma Mortality Survey of the number of deaths due to asthma is accepted as accurate, then the ABS estimate of asthma deaths was reliable for those under 50 years of age. In those who died at an older age, the ABS significantly overestimated the number of deaths due to asthma in Victoria.

Prevalence of asthma in adults in Busselton, Western Australia

OBJECTIVE

To estimate whether the prevalence of asthma in adults increased over a nine year interval.

DESIGN

Serial cross sectional studies of the population with a protocol that included both subjective and objective measurements.

SETTING

Busselton, Western Australia.

SUBJECTS

A random sample of 553 subjects aged 18-55 years in 1981, and of 1028 subjects aged 18-55 years in 1990.

MAIN OUTCOME MEASURES

Respiratory symptoms measured by self administered questionnaire, bronchial responsiveness measured by bronchial challenge with histamine, and allergy measured by skin prick tests.

RESULTS

Symptoms with increased prevalence were those with significant association with allergy in this population. Recent wheeze increased from 17.5% to 28.8% (p < 0.001) and diagnosed asthma increased from 9.0% to 16.3% (p < 0.001). The increase was greatest in subjects less than 30 years old. The prevalence of shortness of breath coming on at rest and of hay fever also increased significantly, but the prevalence of shortness of breath on exertion, chronic cough, bronchial hyperresponsiveness, current asthma (defined as recent wheeze plus bronchial hyperresponsiveness), and allergy did not increase. The severity of bronchial responsiveness did not change significantly in any symptom group.

CONCLUSIONS

Young adults showed a significant increase in reporting of symptoms related to allergy but not in the prevalence of current asthma. The increase in symptoms may be due to increased awareness of asthma in this community, to changed treatment patterns, or to increased exposures to allergens.

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.

Air quality and respiratory disease in Newcastle, New South Wales

OBJECTIVE

To investigate respiratory illnesses in the Newcastle region, their change over time, and their geographic relationship to industrialised areas.

DESIGN

We analysed admissions to public hospitals by postcode area in the Newcastle region, for all causes and for all the various respiratory causes, for the years 1979-1988. Comparisons were made between the State of New South Wales and the Newcastle area, and between geographic areas within Newcastle. Changes over the 10-year period were noted.

RESULTS

For both all causes and respiratory causes, admission rates to Newcastle hospitals, 1979-1988, were significantly lower than those for the rest of New South Wales in 1986. There was a correlation between living in the industrial part of the city and hospital admission for all causes and respiratory causes. There was also a correlation between mean disposable family income and hospital admissions, with those areas with the higher incomes having lower admission rates. Over the 10 years studied there was a statistically significant decline in admissions for respiratory causes, both in absolute terms and after controlling for changes in admissions for all causes. In children aged 0-14 years a significant increase in admissions for asthma occurred between 1979 and 1988, which could not be explained by diagnostic shift.

CONCLUSIONS

On the basis of hospital statistics, the members of the Newcastle population seem little different from those in the remainder of New South Wales. From 1979-1988, the efforts by industry, with the support of the community, to reduce industrial pollution have been accompanied by a reduction in hospital admission rates for respiratory diseases in general and for chronic obstructive lung disease in older people. Other contributing factors include reduced smoking rates and improved medical management. Correlations between geographic location and respiratory admission rates may be a manifestation of social class rather than poor air quality, although a contribution from the latter cannot be discounted. A concomitant rise in asthma admission rates in children aged 0-14 is likely to be unrelated to any change in air quality.

The cost of asthma in New South Wales

OBJECTIVE

To determine the economic cost of asthma to the New South Wales community.

DESIGN

Direct costs (both health-care and non-health-care) plus indirect costs (loss of productivity) were estimated from various sources to assess retrospectively the dollar costs of asthma. Intangible costs (such as quality of life) were not included.

SETTING

Estimates of costs were made at all levels of medical care of asthma patients, including inpatient and outpatient hospitalisations, emergency department visits, and visits to general practitioners and specialist physicians, plus costs of pharmaceuticals, nebulisers and home peak-flow monitoring devices. The cost of time lost by the patient attending for medical visits and loss of productivity due to absence from employment as a result of asthma were also included.

RESULTS

The total cost of asthma in New South Wales was $209 million in 1989. This was made up of $142 million in direct health-care costs, $19 million in direct non-health-care costs and $48 million in indirect costs.

CONCLUSION

Although we believe that our estimate is an underestimate of the true dollar cost of this disease to the community, it represents $769 per asthmatic person per year, assuming a current prevalence rate for asthma in New South Wales of 6%. The cost effectiveness of any new treatment of asthma should be estimated to ensure that the economic cost to the community does not rise unnecessarily.