International trends in hospital admission rates for asthma

Asthma-related hospital use among Finnish asthmatics of working age

The aim was to examine asthma-related use of hospital services among persons of working age (15-64 years) in Finland on the basis of hospital discharge registers over a period of 15 years. A total of 155,080 asthma-induced treatment periods and 1,270,453 hospitalisation days were observed in the working-age population during the period concerned. Although the use of hospital services was found to be smallest in the second youngest male age-group (25-34 years), the numbers of treatment periods and hospitalisation days observed among men relative to population were found to increase by age. Middle-aged (35-44) female asthmatics tend to use hospital services more often than men of the same age, but no difference was observed between the sexes in the oldest age-group (55-64 years). The long-term monitoring and guidance of asthmatics and the specialist services required should be coordinated within the basic health care system as in the case of other chronic diseases. The long-term monitoring of asthmatics should be performed by general practitioners, and in the light of the present findings special emphasis should be placed on subjects aged 35 years and older.

The cost of asthma: can it be reduced?

Asthma is a major public health problem in developed countries, where it consumes a large and increasing share of scarce health resources. Ideally, medical management should be both optimal in terms of improving the patient's quality of life, and cost-effective for society. At present, there is very little information relating to costs and economic efficiency of current asthma management. Although the true total cost of asthma is unknown, current estimates suggest it is high. The main value of recent total cost estimates is that they identify the most expensive areas of asthma costs, and ideally, formal cost-effectiveness analyses should be concentrated on these areas. Asthma is still under- or inappropriately diagnosed, and undertreated. Several national and international consensus plans for the optimal management of asthma in children and adults have been published. If these inadequacies in asthma management were corrected, using current treatment recommendations, the overall cost of asthma from both the community and patient perspective should fall. The situation requires increased use of preventative medications {sodium cromoglycate (cromolyn sodium) or inhaled corticosteroids}, more widespread use of written crisis plans, more proactive medical consultations (rather than reactive or urgent consultations), further expansion of asthma education programmes, and further education of medical practitioners about the optimum management of both long term asthma and the acute exacerbation of asthma in the patient's home, the doctor's office, the hospital emergency room and the hospital inpatient setting. The increased costs associated with these measures would be more than offset by reduced expenditure on bronchodilator drugs, less widespread use of nebulisers at home and in hospitals, reduced antibiotic usage, reduced need for expensive emergency medical care and particularly reduced utilisation of hospital resources. To ensure that resources are being directed into the most cost-effective areas of asthma care, clinical trials of asthma should include utilisation of healthcare resources as an outcome measure, and estimates of the costs of the treatment under study. In addition, since the intangible cost (quality of life) is one of the most important effects of treatment from the patient's perspective, this should be more widely used as an outcome measure in clinical trials. Ultimately, prevention of asthma is the long term goal. If the hypothesis that sensitisation to house dust mite in early infancy is a major contributor to the subsequent development of asthma, then prevention may require drastic and expensive changes to current housing.

Asthma related hospital treatment in Finland: 1972-86

BACKGROUND

The number of asthma related treatment periods in hospital has increased in many countries, particularly among children. The aim of the present investigation was to describe the use made of hospital services by asthmatic patients over a wide range in Finland.

METHODS

A total of 255,387 treatment periods for asthma that had occurred between 1972 and 1986 was collected from the discharge register maintained by the National Board of Health (diagnosis 493, International Classification of Diseases). The numbers of admissions, days in hospital, and new occurrences of asthma were calculated by sex and age in relation to the total population at the end of each year.

RESULTS

Asthma induced treatment periods in hospital in Finland were 12,860 (277 treatment periods per 100,000 inhabitants) in 1972 and 20,000 (406 per 100,000 inhabitants) in 1986. The annual increase in the number of such periods was 4.7% for men (95% confidence interval (95% CI) 3.5 to 5.9%) and 3.4% for women (2.1 to 4.7%) in relation to population. The most pronounced change was found in those aged 65 years and over, in which the number of treatment periods was found to increase annually by 7.5% (6.0 to 9.0%) for men and 4.9% (3.4 to 6.5%) for women, whereas the smallest increase was found among persons under 15 years with an annual change of 1.3% (0.2 to 2.3%) for boys and 1.1% (-0.1 to 2.4%) for girls. Although the number of asthma related treatment periods increased, that of new patients with asthma did not. An average of 114 new male asthmatic patients per 100,000 men were treated in hospitals annually between 1977 and 1986, whereas the figure for women was 115; the annual change during this 10 year period was 0.2% (-0.8 to 1.2%) for men and -0.8% (-1.8 to 0.2%) for women.

CONCLUSIONS

The increase in the number of asthma related hospital treatment periods seemed attributable to the frequent treatment of the same patients. Treatment periods for persons aged 40 years or over were found to increase most, suggesting that the treatment of these asthmatic patients should be optimised and its organisation improved.

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.

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.

Are children with asthma affected by smog?

OBJECTIVE

To assess the relationship between atmospheric smog and emergency department attendances in children with asthma.

DESIGN

The number of child attendances with acute asthma was calculated retrospectively for each day of the 1989 calendar year. Daily smog data for 1989 were then obtained from the Environment Protection Authority of Victoria, and were related statistically to asthma attendances.

SETTING

The Emergency Department of the Royal Children's Hospital, Melbourne, which provides primary, secondary and tertiary level health care to the children of Victoria.

PATIENTS

All children over two years of age with acute asthma.

MAIN OUTCOME MEASURE

The number of attendances with asthma each day for the 1989 calendar year.

RESULTS

Smog alerts (smog days predicted by the Environment Protection Authority) and smog episodes (actual smog days of all types) were not significantly related to asthma attendances. A significant relationship was noted, however, between asthma attendances and days when the airborne particulate index was above the acceptable threshold. No relationship was found between asthma attendances and ozone levels (a marker of photo-oxidant smog), or between any smog index and days of unusually high asthma attendance (asthma epidemic days). All smog variables combined explained only 2.3% of the variance in asthma attendance.

CONCLUSIONS

Although the overall contribution of smog to asthma attendances in children is small, the correlation between asthma attacks and airborne particles is a hitherto unreported finding in Australia and is potentially of public health importance.

Targeting asthma care in general practice using a morbidity index

OBJECTIVES

To evaluate a morbidity index as a postal surveillance tool in defining previously diagnosed asthmatic patients needing extra education or management; to determine the accuracy of a computerised asthma register in general practice.

DESIGN

Postal questionnaire survey of asthmatic patients identified from a computer register. Questionnaire comprised three morbidity questions, two questions about current asthma status, and one about treatments.

SETTING

Urban general practice of 8400 patients linked to academic unit.

SUBJECTS

853 asthmatic patients of all ages.

MAIN OUTCOME MEASURES

Numbers of patients with low, medium, and high morbidity; associations of these groups with age, asthma status, and drugs taken.

RESULTS

Two mailings yielded 621 replies (73%); 28 patients (5%) had moved away, leaving 593 for analysis. Attempts were subsequently made to contact 20% sample of non-respondents. 234 respondents (40%) were in the "low morbidity" group, 149 (25%) in the "medium morbidity" group, and 210 (35%) in the "high morbidity" category. 53% of patients perceiving themselves as currently asthmatic (193/362) were in the high morbidity group, but 7% (11/153) who said they were no longer asthmatic and 8% (6/78) who did not believe they had ever been asthmatic were also in that group. High morbidity was also found in 10% (18/185) of those on no treatment, 38% (59/154) of those on bronchodilators alone, and 54% (119/220) of those on inhaled corticosteroids. 25 patients (4%) were wrongly identified as asthmatic; when combined with returns marked "gone away" this gave a disease register accuracy of 91%.

CONCLUSIONS

This exercise identified subgroups of previously diagnosed asthmatic patients with high morbidity in general practice who might benefit from extra education and management and revealed some misclassification on the asthma disease register.

Correlates of asthma morbidity in primary care

OBJECTIVES

To explore the morbidity of patients diagnosed as asthmatic in general practice, to examine the determinants of this morbidity, and to derive a simple morbidity screening tool for use in primary care.

DESIGN

Patient interviews, lung function measurements, and data extraction from general practice case notes.

SUBJECTS

300 asthmatic patients aged 5 to 65 years randomly selected from the repeat prescribing registers of three general practices in the Southampton area.

MAIN OUTCOME MEASURES

Reported morbidity using a calculated index based on three questions (Are you in a wheezy or asthmatic condition at least once per week; Have you had time off work or school in the past year because of your asthma; Do you suffer from attacks of wheezing during the night?); mean forced expiratory volume in one second and mean peak expiratory flow (over a seven day period); diurnal variation in peak flow; and the relation of the morbidity index to lung function.

RESULTS

Mean forced expiratory volume in one second was 67% predicted (SD 18.4), mean peak expiratory flow was 80% predicted (SD 18.9), and mean diurnal variation was 10% (SD 7.7). 76 subjects were classified as having low morbidity, 95 medium, and 125 high. The morbidity index was significantly associated with forced expiratory volume in one second, mean peak expiratory flow rate, and diurnal variation (p less than 0.05); it was not significantly associated with inhaler technique or use of prophylaxis.

CONCLUSIONS

There was a large burden of persisting morbidity across all ages of patients diagnosed as asthmatic in the three well resourced practices studied. The use of the morbidity index may help to target the asthmatic patients needing more attention by concentrating on those reporting medium to high morbidity.

Evaluation of the properties and reliability of a clinical severity scale for acute asthma in children

The inter-observer agreement (reliability) and validity of a clinical asthma severity scale (ASS) derived from separate scores of wheeze, heart rate and accessory muscle use (each on a 4-point scale) were studied in 60 children aged between 6 months and 17 years (mean 5.4 years). Independent assessments of these clinical parameters were made by two paediatricians, and they also rated patients as having a mild, moderate, severe or very severe acute episode (clinical judgement rating, CJR). Oxygen saturation (SaO2) was measured concurrently by a Biox 3700 pulse oximeter and readings were categorized as mild (SaO2 greater than or equal to 94%), moderate (91-93%) and severe (less than 91%). Agreement between clinicians was assessed by the weighted kappa statistic (kappa W). Agreement for the ASS score compared to the severity grade obtained from SaO2 was slight (kappa W = 0.34) and compared to CJR the kappa W was 0.55. An ASS score of moderate or worse (greater than 3) had sensitivity of 97% and specificity of 50% for prediction of admission. The maximum frequency and duration of nebulizer therapy following admission were significantly greater for severe patients than for moderate patients. Length of hospital stay did not reflect the ASS score in the emergency department but total duration of functional disability increased with ASS score. The substitution of an adjusted heart rate score for the raw heart rate score used in ASS detracted from scale performance. The ASS is an imprecise but reasonable quantitative measure of the severity of an acute episode of asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Hospital admission rates and the prevalence of asthma symptoms in 20 local authority districts

Representative samples of 20-44 year old men living in 20 local authority districts in England were surveyed in 1986 by postal questionnaire and asked about symptoms associated with asthma and treatment for asthma. Regional health authorities provided information on all hospital discharges of men of the same age living in the same districts. Specific information was also provided on discharges where the primary cause of admission was for asthma. Admission rates for asthma were related to the prevalence of night time breathlessness and independently to the all cause admission rate for men of the same age. Admission rates were not significantly related to prescription rates of either corticosteroids or beta 2 agonists for symptomatic men. This lack of association is hard to interpret without further information on variation in the severity of disease. These data show that admission rates for asthma are not dictated solely by health service characteristics, such as availability of beds or the "style" of the physician, but also reflect need. More research is required on how best to reduce the local prevalence and severity of asthma.

Prevalence of asthma among 12 year old children in New Zealand and South Wales: a comparative survey

A survey of 12 year old schoolchildren was carried out in New Zealand and South Wales, the same questionnaire and exercise provocation test being used. The prevalence of a history of asthma at any time was higher in New Zealand (147/873, 17%) than in South Wales (116/965, 12%). The New Zealand children were also more likely than the Welsh children to have a history of "wheeze ever" (27% versus 22%), and wheeze brought on by running (15% versus 10.5%). The sex ratio of asthmatic and wheezy children was very similar in the two countries. A history of hospital admission for chest trouble was twice as common in New Zealand as in South Wales. An exercise test produced a fall in peak expiratory flow rate of 15% or more in more New Zealand children (12.2%) than Welsh children (7.7%). These results suggest that the prevalence of childhood asthma is higher in New Zealand than in South Wales.

Efficacy, results, and complications of mechanical ventilation in children with status asthmaticus

We have conducted a retrospective survey of 79 children out of a total hospital asthmatic patient population of 2,412, admitted over a 32 month period to the ICU for the management of severe status asthmaticus. All patients were in severe respiratory distress with CO2 retention; 19 required mechanical ventilation due to increasing fatigue and worsening bronchospasm, having failed to respond to either inhaled or IV bronchodilator therapy. All patients were ventilated at slow rates (less than 12 min) and their airway pressure (Paw) was deliberately kept below 45 cmH2O, while accepting a PaCO2 in the 45-60 mmHg range, as long as the pH was compensated. Although two patients developed pneumothoraces while on positive pressure ventilation, these were resolved without incidents. Five patients who had mediastinal or subcutaneous air leaks prior to intubation did not develop pneumothoraces. Following the initiation of mechanical ventilation, IV beta-agonist therapy was increased in order to reverse the bronchospasm and reduce the duration of mechanical ventilation. Mean duration of intubation was 42 hours. Fourteen of the 19 patients were weaned and extubated within 48 hours. All patients survived without sequelae. We conclude that a degree of controlled "hypoventilation" by deliberately choosing Paw less than 45 cmH2O can be successfully used to ventilate children with severe status asthmaticus with a reduced rate of pressure-related complications.

Racial inequalities in childhood asthma

Mortality and hospital admission rates for asthma are higher in Maoris and Pacific Islander children than in European children. These ethnic differences are not explained by ethnic differences in asthma prevalence, the characteristics of the disease or admission criteria. There are major ethnic differences in asthma drug management both in the community and at the time of discharge from hospital. In particular Polynesians were less likely to receive prophylactic therapy and this factor probably accounts for ethnic differences in mortality and admission rates. Possible explanations for the ethnic differences in medical management are discussed.

Predicting the need for hospitalization in children with acute asthma

In an attempt to identify factors which influence the decision of physicians to admit patients with acute asthma to the hospital, we studied prospectively 200 children (age 5.6 +/- 3.1 years, mean +/- SD) presenting to our emergency room with acute asthma. The children were assessed on arrival, and on disposition from the Emergency Room by one of the investigators. After obtaining historic data, a clinical score was assigned, and oxygen saturation and pulmonary function were measured. Of the 134 (67 percent) children who were discharged home from the Emergency Room, five returned within seven days and one was subsequently admitted. The clinical score on disposition was the sole variable found to best predict the decision for hospitalization (sensitivity 73 percent, specificity 95 percent). Of the variables obtained at presentation, the resulting decision tree found the clinical score to predict the decision for hospitalization (sensitivity 79 percent, specificity 75 percent). When the individual components of the clinical score were analyzed, the degree of dyspnea, as assessed by the investigator, was chosen as the rule to predict the hospitalization decision (sensitivity 88 percent, specificity 71 percent). We conclude that the decision with respect to the need for hospitalization in acute childhood asthma, is in practice based mainly on careful clinical evaluation. Pulmonary function and SaO2 measurements, although helpful adjuncts in the assessment of acute asthma, do not appear to contribute to the identification of patients who need hospital admission.

Mechanical ventilation of paediatric patients with asthma: short and long term outcome

In the 7 years from 1982 to 1988, 10,639 children with acute asthma were admitted to the Royal Children's Hospital, Melbourne. Of these, 262 children (2%) were treated in the Intensive Care Unit. Twenty-seven required mechanical ventilation on 34 occasions, being 0.3% of hospital asthma admissions. Five patients died, four due to brain death following respiratory arrest prior to intubation. The main complications were (i) barotrauma, which occurred in five patients on seven occasions (20%); (ii) a reversible myopathy which occurred in three patients treated with high dose corticosteroids and muscle relaxants. Follow-up of patients ventilated in intensive care revealed that all but one of the initial survivors was alive 1-5 years later, all patients required subsequent readmission to hospital for treatment of acute asthma and 78% had persistent rather than episodic asthma. Although uncommon, an episode of ventilation has a major impact on the family's understanding and future management of acute asthma.

Long term outcome of ventilated asthmatics

Over a 25 year period, 31 asthmatic children received artificial ventilation for acute asthma at Alder Hey Children's Hospital on 48 occasions. Altogether 47 episodes occurred from 1971-89, with no decline in the number of episodes per year (mean 2.5) over this period. Eight children died during intermittent positive pressure ventilation (IPPV), and of the 23 survivors, three further children had subsequently died from asthma. Seventeen children were followed up for more than a year after IPPV. Sixteen still had symptoms of asthma and over half had symptoms every day. Ten cooperated with pulmonary function tests: mean forced expiratory volume in one second was 83% of predicted and geometric mean provocative histamine concentration (PC20) was 2.1 mg/ml. Since the follow up study a fourth patient had died from asthma. IPPV continues to be required for a small number of asthmatic children each year. The survivors remain a high risk group with significant continuing morbidity and mortality.

Childhood bronchial asthma in a desert country

A 3 year-study of emergency room visits (total 50,300) to the paediatric clinic of the main teaching hospital in Kuwait revealed that the rates of bronchial asthmatic attacks increased significantly from 8.8% of all visits during the 1st year to 14.9% during the 3rd year. The seasonal distribution of asthmatic attacks showed maximum rates during the winter and minimum values in the summer, giving a very close inverse correlation to temperature and direct correlation to relative humidity. A similar, excellent correlation was seen between asthmatic attacks and upper respiratory infections. Occurrence of atmospheric pollen, which characteristically shows a bi-annual pattern i Kuwait, was not found to correlate with asthma attack rates. Neither was there any demonstrable effect of dust storms on the frequency of asthmatic attacks in the children. Independent of season, the boy to girl ratio among the asthma cases was remarkably constant, around 2:1.

Respiratory symptoms and asthma in primary school children in Kuala Lumpur

In a cross-sectional study of 7 to 12-year-old primary school children in Kuala Lumpur, the prevalence of chronic cough and/or phlegm, persistent wheeze, and doctor-diagnosed asthma were 8.0%, 8.0% and 8.7%, respectively. The prevalence of asthma (defined as persistent wheeze and/or doctor-diagnosed asthma) was 13.8%. 4.3% experienced at least one episode of chest illness that resulted in inactivity for at least 3 days in the previous year. The mean age of commencement of symptoms in the doctor-diagnosed asthma group was 2.75 years. The prevalence of chronic cough and/or phlegm and persistent wheeze were highest among Indian children (p less than 0.05). More Malays had been diagnosed as having asthma than the other ethnic groups but the differences were not statistically significant. The patients' fathers' low levels of education were associated with chronic cough and/or phlegm (p less than 0.05) but not with other complaints. Asthma was significantly more common among boys than girls. No age differences were noted. Further analysis showed that persistent wheeze and doctor-diagnosed asthma were associated with increased likelihood of other respiratory illnesses or doctor-diagnosed allergy before the age of 2 years.

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.

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.

Nedocromil sodium and placebo in the treatment of bronchial asthma. A multicenter, double-blind, parallel-group comparison

The efficacy of nedocromil sodium (4 mg twice daily by inhalation) in treating bronchial asthma was assessed by double-blind, placebo-controlled group comparison in 69 adults from three centers. The patients (34 active, 35 placebo) had a history of bronchial asthma with at least 15 percent reversibility. Inhaled corticosteroids, used by 22 and 24 subjects in the active and placebo groups respectively, were discontinued before the study, in which a two-week baseline was followed by six weeks of treatment. Two-weekly clinic assessments of lung function, symptoms and final opinions of treatment were significantly (p less than 0.05 p less than 0.001) in favor of nedocromil sodium. Daily diary cards showed a similar trend with significant drug effects seen after the third week. Blood and urine samples showed no abnormalities and the majority of patient withdrawals (five from nedocromil sodium and six from placebo treatment) were due to worsening asthma. Overall, we found nedocromil sodium to be well tolerated and effective in the management of bronchial asthma.

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.

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.

Morbidity and mortality of asthma

Morbidity and mortality of asthma has been on the upswing since the 1960s, as marked by increased hospitalizations with asthma since the early 1980s. This has not been explained adequately. The possibility of change in the natural history or increased exposure to environmental irritant chemicals or allergens has been suggested by some. There probably has been better recognition and diagnosis of asthma by distinguishing it from bronchitis, recurrent croup, and bronchiolitis in children. Despite evidence to suggest that this is the case, there are still some missing factors. The increase in asthma mortality is more understandable when one considers the fact the management of asthma has changed greatly in the past two decades. The use of corticosteroids orally, parenterally, and by inhalation has been a double-edged sword. There is no doubt that many asthmatics have a much improved sense of well-being and have lived more normal lives due to the use of corticosteroids. The inability of some patients, parents, or physicians to perceive impending respiratory difficulty, however, may result in underuse of drugs, including corticosteroids, leading to increased mortality. Other factors have led to increased mortality from asthma in recent years, and they include arrhythmias with combinations of theophylline, beta-agonists, and hypoxia. The psychological factors attendant to adolescence and psychological problems are probably quite important in the recent upsurge in asthma deaths in the 15- to 25-year age group. Many deaths are occurring outside of the hospital environment and may be largely preventable. There must be increased awareness by the patient, the family, and the physician. In view of the increased hospitalizations, the total number of deaths is not increasing at an alarming rate, yet it is necessary to make all of us who care for asthmatics aware and take corrective action as soon as we are aware of an asthmatic with respiratory problems.

Prevalence of respiratory symptoms, bronchial hyperresponsiveness and atopy in schoolchildren living in the Villawood area of Sydney

Respiratory symptoms, bronchial hyperresponsiveness (BHR) and atopic status were measured in 1,217 schoolchildren, aged 8 to 12 years, living in the Villawood area of the city of Sydney. The findings are compared to those from studies previously conducted, using identical protocols, in the inland town of Wagga Wagga and in the coastal town in Belmont, NSW. There was a higher prevalence of respiratory symptoms in Villawood and Wagga Wagga (40%) than in Belmont (29%). The prevalence of BHR was 15% in Villawood and Belmont and 20% in Wagga Wagga. However, the distribution of severity of BHR was similar in each study town, reflecting the same pattern of responsiveness. The percentage of children who were atopic was higher in Villawood (44%) than in inland Wagga Wagga (39%) or coastal Belmont (40%). Children in the three areas differed in their reactions to the predominant allergen groups. There were more children who were reactive to grass pollens in the inland area and more children who were reactive to house dust mites in the coastal area. Children in Villawood had a high prevalence of reactivity both to house dust mites and to grass pollens. The Villawood children who were born in Australia had a higher prevalence of respiratory symptoms, of BHR and of atopy than the foreign-born children.

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.

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.

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.

Asthma education by community child health nurses

A randomised controlled study of an educational programme for children with asthma and their families was carried out by community child health nurses. Three hundred and sixty eight children aged 2 to 14 years were enrolled in the study after admission to hospital for asthma. The intervention group was visited monthly by a nurse for six months. The subjects were assessed six months later by a postal, self administered questionnaire. European children in the intervention group were taking significantly more drugs for the treatment of asthma six months after the index admission to hospital than those in the control group (mean (SD) intake 2.7 (1.1) v 2.1 (1.0), respectively). In particular, they were using more theophylline (56.6% v 37.0%) and inhaled steroids (34.9% v 21.0%). There was no difference between the groups for parental reports of improvement, of missed schooling, and in severe attacks of asthma of not responding to the usual treatment at home. European children in the intervention group used the hospital services for severe attacks of asthma more than controls (34.2% v 10.5%). There were more re-admissions in the European intervention group in the subsequent six months after the index admission than in the control group (mean (SD) 0.51 (0.97) v 0.29 (0.65). Re-admission continued to be higher in the 12 months after the nurse had stopped visiting (0.81 (1.65) v 0.25 (0.65]. There was no difference in the duration of hospital stay between the intervention and control groups. For Polynesian children there was no difference between the groups for any outcome measures.

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.