Underdiagnosis and undertreatment of asthma in childhood

A paper that changed my practice: S McKenzie. Cough but is it asthma? Arch Dis Child 1994;70:1-2

Most doctors can identify key papers that have influenced their approach to the management of a particular clinical problem, although sometimes the gestation period of this effect can be very prolonged. In this short review I discuss the effects of a seminal paper by Sheila Mackenzie from the early 1990s on my current approach to the diagnosis and management of chronic cough in children.

Changing trends in sex specific prevalence rates for childhood asthma, eczema, and hay fever

Numerous surveys of school-aged children have shown increasing asthma prevalence with a less publicized but noticeable change in the male to female ratio. We sought to confirm this change in the sex ratio in four questionnaire-based surveys and investigate possible explanations. Identical questionnaire surveys were performed in 1989 (n=3,390), 1994 (n=4,047), 1999 (n=3,540) and 2004 (n=1,920) in school-children aged 9-11 years. Over these 15 years the male to female ratio (M:F) significantly narrowed for wheeze (1.34 to 0.98:1 P < 0.0002), for asthma (1.74 to 1.02:1 P < 0.0001), for eczema (1.42:1 to 0.81:1 P < 0.0001) and for hay fever (1.46 to 0.93:1 P < 0.0001). The diagnosis of asthma in children with wheeze was more commonly made in boys in 1989 relative risk RR 1.32 (1.12, 1.56), even in those with accompanying eczema and/or hay fever RR 1.20 (0.99, 1.45). By 2004 this sex bias in diagnosis was no longer present, RR 1.01 (0.91, 1.12) for wheeze and 1.02 (0.85, 1.21) for those with wheeze and eczema and/or hay fever. From 1989 to 2004 no significant difference in sex distribution changes between older and younger children occurred, making secular trends in the onset of puberty in females an unlikely contributory factor. The disappearance of the bias to diagnose asthma in symptomatic males but not in females may be partly responsible for the narrowing of the sex ratio, but other factors such as those enhancing the expression of asthma and atopy in females may also be implicated.

Short-course montelukast for intermittent asthma in children: a randomized controlled trial

RATIONALE

In children, intermittent asthma is the most common pattern and is responsible for the majority of exacerbations. Montelukast has a rapid onset of action and may be effective if used intermittently.

OBJECTIVES

To determine whether a short course of montelukast in children with intermittent asthma would modify the severity of an asthma episode.

METHODS

Children, aged 2-14 years with intermittent asthma participated in this multicenter, randomized, double-blind, placebo-controlled clinical trial over a 12-month period. Treatment with montelukast or placebo was initiated by parents at the onset of each upper respiratory tract infection or asthma symptoms and continued for a minimum of 7 days or until symptoms had resolved for 48 hours.

MEASUREMENTS AND MAIN RESULTS

A total of 220 children were randomized, 107 to montelukast and 113 to placebo. There were 681 treated episodes (345 montelukast, 336 placebo) provided by 202 patients. The montelukast group had 163 unscheduled health care resource utilizations for asthma compared with 228 in the placebo group (odds ratio, 0.65; 95% confidence interval, 0.47-0.89). There was a nonsignificant reduction in specialist attendances and hospitalizations, duration of episode, and beta-agonist and prednisolone use. Symptoms were reduced by 14% and nights awakened by 8.6% (p = 0.043), and days off from school or childcare by 37% and parent time off from work by 33% (p < 0.0001 for both).

CONCLUSIONS

A short course of montelukast, introduced at the first signs of an asthma episode, results in a modest reduction in acute health care resource utilization, symptoms, time off from school, and parental time off from work in children with intermittent asthma.

Proficiency of pediatricians in the use of inhaled medication delivery systems for the management of asthma

OBJECTIVE

To evaluate the proficiency of pediatricians in the demonstration of the proper use of metered-dose inhalers (MDIs) and to assess their theoretical knowledge of inhalation devices used in the management of asthma.

DESIGN

Prospective cross-sectional survey.

SETTING

Two university-affiliated hospitals.

PARTICIPANTS

Seventy-one pediatricians and pediatric house staff.

INTERVENTION

Each pediatrician's technique was graded by two trained observers using a checklist of six essential steps recommended by national guidelines. Theoretical knowledge of asthma devices was evaluated by a written questionnaire.

RESULTS

Twenty (35.2%) pediatricians performed at least five steps correctly, 28 (39.4%) performed three or four steps correctly, and 18 (25.4%) performed two steps or less correctly. The most common errors were failure to start inhalation from functional residual capacity, failure to inhale slowly, and failure to wait at least 20 seconds before the next puff. Senior pediatricians were more skillful in the practical use of MDIs than were pediatric house staff (p = 0.03). The most common deficiencies in theoretical knowledge were related to estimation of the amount of medication in the canister (8.5% correct) and how valved holding chambers (VHCs) improve drug delivery to the lung (15.5% correct).

CONCLUSION

Pediatricians in Kuwait have significant deficiencies regarding the practical and theoretical aspects of MDIs and other inhalation devices.

The right tools at the right time

Asthma is underdiagnosed and undertreated or inappropriately treated, even though approximately 300 million people worldwide currently have the disease. While asthma in most patients can be controlled using currently available medications, in practice this rarely happens. Despite the wide availability of treatment guidelines, there are clear discrepancies between recommendations and the reality of treatment. There is excessive use of relief medications, particularly among patients with moderate-to-severe persistent asthma, coupled with a marked underuse of inhaled corticosteroids (ICS). This underuse by patients is likely to be related to anxiety about side effects and a misunderstanding about asthma. Many patients overestimate their degree of control and have a perceived lack of need for medication. Early therapeutic intervention, with optimal antiinflammatory therapy and a stepwise approach, has a positive impact on long-term outcomes, achieving suppression of airway inflammation, prompt symptom control, and restoration of pulmonary function. Even at low doses, ICS rapidly improve clinical symptoms and measures of lung function, while their long-term use markedly reduces the frequency and severity of exacerbations and asthma mortality. Although ICS monotherapy achieves successful control of persistent asthma in a significant proportion of patients, add-on therapy with a long-acting beta2-agonist provides control for most patients with moderate-to-severe persistent asthma. Fixed combination inhalers (ICS plus a long-acting beta2-agonist) have become popular, but these have drawbacks and there is the potential for overuse. In conclusion, ICS are the cornerstone of therapy for persistent asthma of all degrees of severity in adults and children, and early therapeutic intervention is recommended for optimal long-term outcome.

Symptom profile and asthma control in school-aged children

BACKGROUND

Children with poorly controlled asthma are at high risk of airway remodeling, sleep disruption, school absenteeism, and limited participation in activities.

OBJECTIVE

To determine asthma prevalence and characterize disease severity and burden in school-aged children.

METHOD

A case-finding study was conducted via a multiple-choice questionnaire and asthma algorithm. Items used for analysis include physician diagnosis of asthma, symptom severity, and health care utilization. The chi2 test was used to determine the significance of differences among cases. Logistic regression was used to evaluate the association of patient factors and asthma indicators.

RESULTS

Of the 5,417 children surveyed, 1,341 (25%) were classified as being at risk of asthma. Of these asthma cases, 55% were positive by diagnosis and algorithm (active), 10% were positive per algorithm alone (suspected), and 35% were positive per diagnosis alone (nonactive). Only 14% of all asthma cases reported experiencing no respiratory symptoms (< 1% active, 2% suspected, and 40% nonactive) compared with 75% of noncases. Also, 75% of noncases reported never missing school compared with 19%, 33%, and 54% of active, suspected, and nonactive asthma cases. African American race, Medicaid enrollment, and male sex were independent predictors of asthma risk. Similarly, African American race, Medicaid enrollment, age, and persistent asthma were independent predictors of emergency department use among asthma cases.

DISCUSSION

Prevalence of active symptoms suggestive of poor asthma control was extremely high among urban, minority children enrolled in Arkansas' largest public school district. Poor asthma control greatly affects quality of life, including school attendance and performance. Interventions should raise expectations and emphasize the importance of achieving asthma control.

The childhood asthma epidemic

A case of delayed rather than mistaken diagnosis

Wheezing in Chinese schoolchildren: disease severity distribution and management practices, a community-based study in Hong Kong and Guangzhou

BACKGROUND

Asthma is a common chronic disease and information on its management practices at the community level is helpful in identifying problems and improving asthma care.

OBJECTIVE

To assess the severity status and management of the asthma symptom of wheeze of children at the community level in Hong Kong (HK) and Guangzhou (GZ).

METHODS

Cross-sectional study of children aged 10 years using the International Study of Asthma and Allergic disease in Childhood (ISAAC Phase II protocol). Asthma management and lung function were assessed in 178 (98 from HK and 80 from GZ) randomly selected children with wheeze over the past 12 months.

RESULTS

Eighty-three percent, 11%, 6% and 0% of children suffered from intermittent, mild persistent, moderate persistent and severe persistent asthma, respectively, according to the frequency of their symptoms. Addition of spirometric parameter only changed the asthma severity classification in 2.8% of children. Medications were used by 30.6% and 71.3% of children for wheeze in HK and GZ, respectively. In HK, inhaled beta(2)-agonist (73.3% among the drug users) was the commonest medication used followed by inhaled corticosteroid (ICS) (23.3%). In GZ, inhaled beta(2)-agonist was used by 75.4% of children, but use of ICS (26.3%), oral beta(2)-agonist (26.3%), oral theophylline (45.6%), oral ketotifen (36.8%) and oral steroid (35.1%) were also common. ICS was only used by 11.4% of children with persistent asthma. Ten percent and 18.7% of children in HK and GZ, respectively, had emergency department visits, while 16.3% and 11.6% of children in HK and GZ, respectively, had missed school secondary to asthma over the past 1 year.

CONCLUSIONS

Most children in the community had intermittent asthma and addition of lung function to symptoms did not significantly affect classification of asthma severity. Significant morbidity was seen even in this group of children with mostly intermittent and mild persistent asthma.

Prevalence of asthma, eczema and allergic rhinitis: two surveys, 6 years apart, in Kota Bharu, Malaysia

OBJECTIVE

This study was undertaken to determine the prevalence of asthma, eczema, and allergic rhinitis in school children in Kota Bharu, Malaysia, and in so doing to determine the differences in symptom prevalence rates of asthma, and atopic diseases in Kota Bharu school children between 1995 and 2001.

METHODOLOGY

In two studies (1995 and 2001), year one primary school (PS) pupils (6-7 years old) and secondary school (SS) year two pupils (13-14 years old) were randomly selected from the district of Kota Bharu, Kelantan, Malaysia. In 1995, 3939 PS children and 3116 SS children participated, and in 2001 3157 PS children and 3004 SS children participated. The Phase I International Study of Asthma and Allergies in Childhood prevalence written questionnaire and video questionnaire (only shown to SS children) were used in both studies.

RESULTS

The written questionnaire showed no significant changes in the prevalence (1995, 2001) of ever wheeze (8.3%, 6.9%P = 0.06), current wheeze (5.4%, 4.3%P = 0.08), exercise-induced wheeze (EIW; 3.9%, 3.7%P = 0.63), and rhinoconjunctivitis (4.6%, 5%P = 0.42) among PS children. The prevalence of flexural itchy rash increased from 14% to 17.6% (P = 0.004) and night cough decreased from 20.4% to 17.5% (P = 0.005). There were also no significant changes in these symptoms among SS children (1995, 2001): ever wheeze (10.7%, 12%P = 0.37), current wheeze (6.8%, 5.7%P = 0.20), EIW (9.9%, 11.6%P = 0.28), night cough (21.6%, 24%P = 0.39), rhinoconjunctivitis (11%, 15%P = 0.11), and flexural itchy rash (12%, 13%P = 0.11). The video questionnaire showed no significant changes in the prevalence of symptoms in the previous 12 months (1995 vs 2001) for wheeze at rest (3.8%, 2.8%P = 0.12), EIW (6.9%, 8.8%P = 0.32), waking with wheeze (1.7%, 1.7%P = 1.0), and severe wheeze (2.1%, 3%P = 0.12). Night cough in the previous 12 months increased significantly from 5.1% to 8.3% (P = 0.007).

CONCLUSION

Although asthma and atopic disorders are common in this country, the results revealed no major changes in the prevalence rates of these diseases over a period of 6 years.

Prevalence estimates of asthma or COPD from a health interview survey and from general practitioner registration: what's the difference?

BACKGROUND

The aim of this study was to compare prevalence estimates of asthma or chronic obstructive pulmonary disease (COPD) derived from self-report in a health interview survey and from general practitioners' (GPs') medical records, and to explain any differences.

METHODS

the presence of asthma or COPD was measured by self-report in a random sample of 104 general practices in the Netherlands (n = 19 685) participating in the second Dutch National Survey of General Practice (DNSGP-2). This was compared with the presence of GP-diagnosed asthma or COPD in the same population as recorded using the International Classification of Primary Care by their GPs during a 12-month period. Gender, age, health insurance, ethnic background, educational level, tobacco exposure, and other symptoms and conditions were evaluated as explanatory variables using logistic models.

RESULTS

The prevalence of self-reported asthma or COPD (9.7%) was almost twice as high as the prevalence based on GP information (5.2%). The medical records of patients who reported having asthma or COPD, without having a diagnosis in their medical records, usually included other respiratory conditions. Patients reporting no asthma or COPD but whose medical records carried a diagnosis of asthma or COPD, were relatively older (P < 0.01) and tended to be exposed to smoking in their home (P < 0.05).

CONCLUSIONS

Two methods for estimating prevalence of asthma or COPD yielded different results: compared with GP medical records, self-reported prevalence shows an overestimation in people who suffer from other respiratory conditions and an underestimation in elderly persons living in a smoky environment.

Asthma epidemiology: has the crisis passed?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Infectious triggers of asthma

There is abundant evidence that asthma is frequently exacerbated by infectious agents. Several viruses have been implicated in the inception and exacerbation of asthma. Recent attention has been directed at the role of infections with the atypical bacteria Mycoplasma pneumoniae and Chlamydia pneumoniae as agents capable of triggering asthma exacerbations and potentially as inciting agents for asthma. This article examines the evidence for interaction between specific infectious agents and exacerbations of asthma, including the immunopathology of infection-triggered asthma, and the current therapeutic options for management.

Prevalence of asthma in a Portuguese countryside town: repercussions on absenteeism and self-concept

BACKGROUND

Childhood asthma represents an increasing health problem and is the leading cause of hospital admission and absenteeism in children with chronic disease. It also compromises quality of life, eventually contributing to disturbances in self-concept. Self-concept is a recent and global perspective of "the self" and relates to skills, self-image and self-esteem. Little information is available on this topic and there are no data from Portuguese countryside towns.

OBJECTIVE

The aim of this study was to determine the prevalence of asthma among all school children in the 5th and 6th grades in a Portuguese countryside town and to establish its possible correlation with absenteeism and self-concept.

METHODS

In April 2002, two questionnaires were administered in the presence of the researcher to a group of 950 children attending different schools. The children completed the internationally renowned questionnaires: ISAAC and the Self-Concept Scale by Susan Harter.

RESULTS

Our sample (n = 818) had a mean age of 11 years (10-15 years) and a male-to-female ratio of 1/1. The cumulative prevalence of asthma was 11.9 % and that of active asthma was 8.8 %; 63.9 % of asthmatics were male and 36.1 % were female. The mean age of asthmatics was 11.34 years and 74 % had active symptoms. Comparison of this group of 97 asthmatic children with the remaining children revealed a statistically significant correlation between the presence of asthma and school absenteeism (global: p = 0.04; gymnastics: 0.05). Regarding the Self-Concept Scale a statistically significant association was found between the presence of asthma and school achievement (p = 0.027), physical appearance (p = 0.015), behavior (p < 0.000) and self-esteem (p < 0.000). No statistically significant correlations were found in social acceptance (p = 0.289) or athletic competence (p = 0.085). Asthmatic boys had higher self-concept scores than girls, except in the domain of behavior.

CONCLUSIONS

Twelve percent of the population studied was asthmatic. In asthmatic children, absenteeism was higher and self-concept was lower for almost all domains, except social acceptance and athletic achievement, probably due to overprotection.

The pattern of commoner health problems among basic school children, gezira state, Sudan

BACKGROUND

The lack of baseline information on the magnitude of health problems among school children is considered one of the factors of the unsatisfactory status of school health in Sudan. Availability of such data from schools will help in the health promotion of school children.

OBJECTIVE

To determine the proportions of the commoner diseases or health problems among Wad Medani basic school children (males and females) at the end of the school year 2000-2001.

METHOD

This is a cross-sectional study conducted on 3862 basic school children (males and females).They were selected by multi-stage stratified proportional random sampling according to their sex and localities. A pre-designed pre-tested questionnaire was used to collect data which were then tabulated and statistically analyzed.

RESULTS

The study revealed that 77.9% of the study group had malaria, 33% of them had sore throat, 26.4% suffered from psychosocial problems that affected their school performance. Dental carries 24.5%, diarrhea attacks 17.5%, oxyuris worm 16.8%, pneumonia 11.5, measles infection 12.4%, asthma 9.2% and visual defects 8.9%. Some of these problems were related to the poor quality of school environment including sanitation and poor nutritional services. These findings should be considered in planning school health programmes. Appropriate interventions to reduce these problems through improving school environment and raising the awareness of the school community towards such problems is recommended.

Prevalence and risk factors of asthma among wad medani basic school children, gezira state, Sudan

OBJECTIVES

Childhood asthma is said to be under-estimated and under-diagnosed in tropical countries including Sudan. The prevalence of asthma worldwide is increasing. The objective of this study was to determine the prevalence and the trigger factors of asthma among Wad Medani basic school children.

METHODS

A cross-sectional study was conducted during school year 2000-2001. The study group was selected by stratified proportional random sampling according to their age, sex and localities.Data was collected utilizing a pre-tested questionnaire addressing the history of asthma and its trigger factors (sample-2, 2002).

RESULTS

The results revealed that asthma is the ninth of the most common diseases among the school children, having a prevalence of 9.2% (sample 1) and 17.9% (sample 2), the main trigger factors of which are dust, cold bats, exercise and smoke respectively.

CONCLUSION

Asthma among school children is a common problem that should be considered when planning preventive school health programmes.

Development of a questionnaire weighted scoring system to target diagnostic examinations for asthma in adults: a modelling study

Background

Identification and treatment of unrecognised asthmatics in the community is important for improving the health of the individual and minimising cost and quality of life burden. It is not practical to offer clinical diagnostic assessment to whole communities, and a simple tool such as a questionnaire is required to identify a smaller target group. Conventional questionnaire screening methods which separate individuals into positive and negative categories have resulted in large numbers of individuals requiring clinical assessment. This study has therefore developed and tested a weighted scoring system that prioritises those most urgently in need, based on their questionnaire responses.

Methods

A stratified random sample of adult respondents to a general practice postal questionnaire survey were categorised 'asthmatic' or 'non-asthmatic' according to three expert physicians' opinions. Based on this categorisation, logistic regression was used to derive weights reflecting the relative importance of each question in predicting asthma, allowing calculation of weighted scores reflecting likelihood of asthma. Respondents scoring higher than a chosen threshold would be offered diagnostic examination.

Results

Age and presence of wheeze were most influential (weight 3) and overall weighted scores ranged from -1 to 13. Positive predictive values (PPV) were estimated. For example, setting the threshold score at nine gave an estimated PPV for asthma diagnosis of 93.5%, a threshold score of seven corresponded to PPV 78.8%. PPV estimates were supported by examining 145 individuals from a new survey.

Conclusion

Weighted scoring of questionnaire responses provides a method for evaluating the priority level of an individual 'at a glance', minimising the resource wastage of examining false positives.

Validation of a multistage asthma case-detection procedure for elementary school children

OBJECTIVE

The purpose of this study was to validate a 3-stage asthma case-detection procedure for elementary school-aged children.

METHODS

The study was performed in 10 elementary schools in 4 inner-city school systems, with a total enrollment of 3539 children. Results of the case-detection procedure were compared with the diagnosis of an asthma specialist study physician, to determine the sensitivity and specificity of the case-detection procedure.

RESULTS

Ninety-eight percent of children returned the asthma symptoms questionnaires, and 79% of those children consented to additional testing. Results indicated that the 3-stage procedure had good validity, with sensitivity, specificity, and predictive value of 82%, 93%, and 93%, respectively. A 2-stage procedure using questionnaires and spirometry had similar validity, with sensitivity, specificity, and predictive value of 78%, 93%, and 93%, respectively. However, given the time and expense associated with the 2- or 3-stage procedure and the difficulty of obtaining physician follow-up evaluation of the case-detection diagnosis, schools may prefer to use a 2-item questionnaire that has a lower sensitivity (66%) but higher specificity (96%) and predictive value (95%).

CONCLUSIONS

Case-detection programs are generally well received by school personnel and can identify children with unrecognized or undiagnosed disease, as well as those with a current diagnosis but poorly controlled disease. This study yields substantial information regarding the validity, yield, and specific types of children who might be identified with the use of such procedures. For the choice of the method of case detection used in a school, the strengths and weaknesses of each procedure, as well as the resources available for case detection, physician referral, and follow-up procedures, must be considered.

How accurate is diagnosis of asthma in a general practice database? A review of patients' notes and questionnaire-reported symptoms

BACKGROUND

Planned care of patients with chronic diseases in primary care depends on being able to identify them. A recorded label of asthma does not necessarily mean that the patient is currently symptomatic, and failure to record the diagnosis may influence future care.

AIM

To determine the degree of under- and over-reporting of the diagnosis of asthma for patients aged 16-55 years inclusive in one large general practice.

DESIGN

A questionnaire validated for the detection of bronchial hyper-reactivity was sent to all patients recorded as having asthma and their matched controls. Patients with a diagnosis of asthma and symptomatic bronchial hyper-reactivity were considered to have asthma. Evidence of asthma in the written and computer records was sought for two groups: patients with asthma and without symptoms of bronchial hyper-reactivity, and controls with symptoms of bronchial hyper-reactivity.

SETTING

A semi-rural group practice with 14 830 patients.

METHOD

Questionnaires were sent to 833 patients and 831 controls matched by age and sex.

RESULTS

Response rates were 79.1% (659/833)for patients with asthma and 70.6% (587/831) for control patients. Of the patients with asthma who replied, 60.5% (399/659) had symptomatic bronchial hyper-reactivity. Of those with asthma and a negative bronchial hyper-reactivity status (based on the questionnaire), 190/260 (73.1%) were considered to have had asthma when diagnosed, on review of their primary care records. There was no evidence to suggest asthma in 45 (17.3%) of the 260 patients who had a negative bronchial hyper-reactivity status. Of the control patients, 41 (7.0%) of the 587 responders had symptomatic bronchial hyper-reactivity and nine of these may have asthma. By extrapolation, we estimate that there were possibly another 99 patients with symptoms of asthma, who had not been labelled as having asthma, and 362 patients with symptoms of bronchial hyper-reactivity who had not reported them to their doctors or had not had them recognised.

CONCLUSIONS

There is an 89.4% chance that a patient recorded as having asthma has, or has had, asthma.

[Chronic cough in childhood]

INTRODUCTION

Although less frequent than viral induced recurrent cough; chronic cough remains a sometimes difficult to resolve diagnostic tool.

STATE OF THE ART

Most authors estimate that a cough can by considered as chronic after three weeks of duration. Few papers have been published concerning etiologic diagnosis of chronic cough in childhood but these indicate the same main causes as in adults: cough variant asthma, postnasal drip syndrome, gastro-esophageal reflux. Nevertheless, each age bracket presents specific diagnosis: malformations between zero and one year, psychogenic cough in adolescents.

PERSPECTIVES

New techniques as induced sputum studies helps to refine chronic cough diagnosis in childhood (after 7 years). Eosinophilic bronchitis, associated or not to bronchial hyperresponsiveness has important therapeutic consequences because associated with a favourable response to corticosteroids. Other techniques will be developed in the future (exhaled NO for example).

CONCLUSIONS

Chronic cough in childhood must be investigated from an anatomic point of view and on frequency arguments. Control and removal of the cough will only be obtained if a precise diagnosis and a suitable treatment are reached.

Increase in diagnosed asthma but not in symptoms in the European Community Respiratory Health Survey

BACKGROUND

Information on the epidemiology of asthma in relation to age is limited and hampered by reporting error. To determine the change in the prevalence of asthma with age in young adults we analysed longitudinal data from the European Community Respiratory Health Survey.

METHODS

A self-administered questionnaire was completed by 11 168 randomly selected subjects in 14 countries in 1991-3 when they were aged 20-44 years and 5-11 years later from 1998 to 2003. Generalised estimating equations were used to estimate net change in wheeze, nocturnal tightness in chest, shortness of breath, coughing, asthma attacks in the last 12 months, current medication, "diagnosed" asthma, and nasal allergies.

RESULTS

Expressed as change in status per 10 years of follow up, subjects reporting asthma attacks in the previous 12 months increased by 0.8% of the population (95% CI 0.2 to 1.4) and asthma medication by 2.1% (95% CI 1.6 to 2.6), while no statistically significant net change was found in reported symptoms. Reported nasal allergies increased, especially in the youngest age group.

CONCLUSIONS

As this cohort of young adults has aged, there has been an increase in the proportion treated for asthma but not in the proportion of those reporting symptoms suggestive of asthma. Either increased use of effective treatments has led to decreased morbidity among asthmatic subjects or those with mild disease have become more likely to label themselves as asthmatic.

The prevalence of allergic asthma and rhinitis in children of Polichni, Thessaloniki

AIM

To define the prevalence of asthma and rhinitis in primary school children in the Polichni Municipality of the city of Thessaloniki.

METHODS AND RESULTS

The parents of 2005 students living in the area of Polichni completed a questionnaire for the detection of pulmonary disease in childhood. Of 493 children who gave positive answers to the questions about allergies, asthma and rhinitis, 203 were excluded after an interview with the parents, because they suffered from either atopic dermatitis or drug allergy or had normal lgE levels. Of the remaining children, 290 were further examined: methacholine test was positive in 109, exercise test was positive in 67, nasal provocation test with histamine was positive in 244, and rhinodilation test with tramazoline was positive in 206. Skin prick tests were positive in 142 children (90 to grass-cereal pollen, 66 to acarea and 59 to Parietaria officinalis).

CONCLUSIONS

We found that 168 children suffered from rhinitis, 84 from both asthma and rhinitis concurrently and 38 from asthma alone. Only 37 % of the parents knew that their children suffered from asthma, while even fewer (32 %) knew that their children had rhinitis. The prevalence of asthma was 6.1 % and that of rhinitis was 12.6 % among children aged 9-12 years in the area of Polichni, Thessaloniki. Childhood rhinitis and asthma seem to be frequently underdiagnosed and undertreated.

Increasing asthma awareness among physicians: impact on patient management and satisfaction

Our objective was to investigate the impact of increased asthma awareness among primary care physicians on the asthma control and satisfaction of their patients. Physicians attended an asthma education session with emphasis on patient-physician partnership followed by 4 month monitored follow-up of patients aged 5-44 years with mild to moderate asthma. Findings were compared with a group of patients whose physician attended the session but did not participate in the follow-up and two other control groups. The study included pediatricians and general practitioners of Maccabi Healthcare Services and their patients. Asthma symptoms were rated by patients and physicians. Data on drug prescription and use were derived from the Maccabi central database. Patient response and satisfaction and physician satisfaction were evaluated by telephone interviews. Mean asthma symptom score improved from 2.0 to 1.1 in the study group of patients (p < 0.001). The use of reliever drugs decreased concomitantly with a rise in controller drugs in all patients. An improvement in asthma status was reported by 64% of the study patients and 39% of non-participating patients (p = 0.007). Fifty-eight percent of the patients rated their competence to deal with asthma as high before the intervention compared to 62% of the participating and 55% of the non-participating patients after the intervention (p = 0.002). Most physicians claimed that simply increasing their awareness on asthma led to beneficial results in their patients. Physician education followed by monitored follow-up enhanced asthma control and patient satisfaction. Nevertheless, physician education alone appears to have a significant isolated impact on asthma control.

The natural history of asthma in a primary care cohort

BACKGROUND

We examined the natural history of asthma in a primary care cohort of patients 10 years after the cohort was stratified for asthma risk by responses to a questionnaire and bronchial hyperresponsiveness (BHR) testing.

METHODS

Children and young adults who were born between 1967 and 1979 within 1 of 4 affiliated family practices of the Nijmegen Department of Family Medicine, The Netherlands, were asked to participate in an asthma study in 1989. Of 926 patients available, 581 (63%) agreed to participate. Their family physicians' diagnoses of upper and lower respiratory tract disease and asthma were prospectively collected during the next 10 years and were analyzed.

RESULTS

BHR or the presence of asthma symptoms at screening did not result in a significantly disproportionate number of physician visits during the next 10 years for 4 or more upper or lower respiratory tract infections when compared with patients who did not have these findings at the beginning of the study. The presence of asthma symptoms correlated with an increased risk of an asthma diagnosis or allergic rhinitis in the group of patients who did not have asthma diagnosed at start of the study. One half of the known asthmatic patients at the onset of the study (21 of 44) had no further visits to their physicians for treatment of asthma during the next 10 years.

CONCLUSIONS

In primary care, BHR testing has limited value in predicting subsequent respiratory tract disease for patients who have asthma diagnosed by a physician. The use of symptom questionnaires can be of clinical use in predicting asthma.

Assessment of respiratory symptoms and asthma prevalence in a U.S.-Mexico border region

The authors studied children who were 10-12 yr of age and who resided in sister cities in a U.S.-Mexico border region to determine the prevalence of asthma and respiratory symptoms. The relationship of symptoms to ambient levels of particulate matter less than 10 microm in diameter (PM10), and to several indoor environmental conditions, was assessed. The study was conducted in the border cities of Ambos Nogales (Nogales, Arizona [United States], and Nogales, Sonora [Mexico]). At the beginning of the 11-wk study, during the autumn of 1996, 631 students and their parents completed baseline questionnaires. While in school, the children completed daily symptom diaries and daily peak expiratory flow maneuvers. PM10 values and daily temperatures were also measured. The authors found that the prevalence of self-reported asthma among 5th-grade students was comparable on both sides of the border (i.e., 7.6% on the Arizona side and 6.9% on the Sonora side). Wheezing was a frequent complaint (29.5-35.6%), as was cough (16.8-29.6%). Smoking in the home was common on both sides of the border, and it was associated with a greater occurrence of self-reported asthma and respiratory complaints. Increased respiratory symptoms were also associated with increased ambient PM10 levels. The prevalence of respiratory symptoms such as wheezing and frequent cough among all children in this study, combined with the limitations inherent in self-reporting, suggest that asthma may actually be more prevalent than has been previously reported.

Comparing asthma care provided to Medicaid-enrolled children in a Primary Care Case Manager plan and a staff model HMO

OBJECTIVE

To examine differences in selected processes of asthma care provided to Medicaid-enrolled children in a state-administered Primary Care Case Manager (PCCM) plan and a staff model health maintenance organization (HMO).

METHODS

Retrospective cohort study assessing performance on 6 claims-based processes of care measures that reflect aspects of pediatric asthma care recommended in national guidelines. Analyzed Medicaid and HMO claims and encounter data for 2365 children with asthma in the Massachusetts Medicaid program in 1994.

RESULTS

There were no plan differences in asthma primary care visits, asthma pharmacotherapy or follow-up care after asthma hospitalization. Children in the HMO were only 54% as likely (confidence interval [CI]: 0.37-0.80; P<.01) as those in the PCCM plan to experience an asthma emergency department (ED) visit or hospitalization. HMO-enrolled children were only half as likely (CI: 0.38-0.64; P<.001) to meet the National Committee for Quality Assurance (NCQA) definition for persistent asthma and only 32% as likely (CI: 0.19-0.56; P<.001) to have prior asthma ED visits or hospitalizations relative to children in the PCCM plan. Controlling for case mix and other covariates, children in the HMO were 2.9 times as likely (CI: 1.09-7.78; P<.05) as children in the PCCM plan to receive timely follow-up care (within 5 days) after an asthma ED visit and 1.8 times as likely (CI: 1.05-3.01; P<.05) as those in the PCCM plan to receive a specialist visit during the year.

CONCLUSIONS

In this study, the HMO served a less sick pediatric asthma population. After controlling for case mix, the staff model HMO provided greater access to asthma specialists and more timely follow-up care after asthma ED visits relative to providers in the state-administered PCCM plan. Further understanding of the impact of these differences on clinical outcomes could guide asthma improvement efforts.

Assessment of the diagnosis and prevalence of asthma in Australian indigenous children

BACKGROUND AND OBJECTIVE

Although the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire has been used in many countries and has been validated previously, it has not been used in Australian Indigenous communities. We endeavoured to assess its performance when administered in Aboriginal and Torres Strait Islander communities.

METHODS

In a cross-sectional study, we assessed the ISAAC's questionnaire when administered face-to-face in Indigenous communities in the Torres Strait region, Australia.

RESULTS

Comparing responses to the questionnaire with clinical assessment of 260 Indigenous children by a pediatric respiratory physician, sensitivity (87%) was high, but specificity (51%) and positive predictive value (33%) were low. Using a logistic regression model, we determined which questions were most useful in predicting a clinical diagnosis of asthma. Using a predictive equation, asthma was detected with 79% sensitivity and 77% specificity, and the calculated weighted estimate of asthma prevalence in the region was 16.3%.

CONCLUSION

Our findings reveal that although the ISAAC questionnaire is a reasonably sensitive tool for both epidemiologic and clinical studies of asthma in Indigenous communities, its value is enhanced when used in conjunction with a predictive model. We have also shown that asthma is prevalent in the Torres Strait region.

Who gets diagnosed with asthma? Frequent wheeze among adolescents with and without a diagnosis of asthma

OBJECTIVE

1). To describe the factors associated with not receiving an asthma diagnosis among children with frequent wheezing symptoms and 2). to determine risk factors for frequent wheezing in the population.

METHODS

The North Carolina School Asthma Survey provided self-reported questionnaire data on respiratory health from 122 829 children ages 12 to 18 years enrolled in 499 public middle schools in North Carolina during the 1999-2000 school year. Questions from the International Survey of Allergies and Asthma in Childhood were used to estimate the prevalence of asthma and wheezing-related illness and associated factors.

RESULTS

Factors independently associated with undiagnosed frequent wheezing versus asymptomatic children included female gender (odds ratio [OR]: 1.45; 95% confidence interval [CI]: 1.35-1.54), current smoking (OR: 2.60; 95% CI: 2.43-2.79), exposure to household smoke (OR: 1.59; 95% CI: 1.50-1.70), low socioeconomic status (OR: 1.52; 95% CI: 1.42-1.63), and African American (OR: 1.25; 95% CI: 1.15-1.34), Native American (OR: 1.35; 95% CI: 1.11-1.62), and Mexican American (OR: 1.32; 95% CI: 1.17-1.48) race/ethnicity. Urban residence showed a weak negative association (OR: 0.91; 95% CI: 0.85-0.96). A similar pattern of results was observed for analyses comparing odds of undiagnosed frequent wheeze versus diagnosed asthmatics. Report of allergies was less likely in frequent wheezers (70%) compared with diagnosed asthmatics (86%), but much higher than in asymptomatic children (36%). Thirty-three percent of children with undiagnosed frequent wheezing reported 1 or more physician visits in the last year for wheezing or breathing problems compared with 71% of children with diagnosed asthma, and 4% in asymptomatic children. The prevalence of any inhaler use in the past 12 months was 12% for undiagnosed frequent wheezers versus 78% for diagnosed asthmatics. The proportion of undiagnosed frequent wheezers with fair or poor self-rated health (23%) was slightly higher than diagnosed asthmatics (20%) and much higher than asymptomatic children (4%).

CONCLUSIONS

In one of the largest adolescent asthma surveys ever reported in the United States, undiagnosed frequent wheezing was independently associated with female gender, current smoking, exposure to household smoke, low socioeconomic status, allergies, and African American, Native American, and Mexican American race/ethnicity. Children with undiagnosed frequent wheezing were not receiving adequate health care for their asthma-like illness. Clinicians who treat adolescents should consider asking adolescents specifically about wheezing. This information may assist primary care physicians in identifying children with undiagnosed asthma in need of treatment.

Hospital attendance prediction tool also identifies impaired quality of life in adults with asthma in general practice

STUDY OBJECTIVE

To assess the ability of an adult risk screening questionnaire (RSQ), previously shown to predict attendance at hospital emergency departments, to identify impaired quality of life in adult patients with asthma in general practice.

DESIGN

Baseline data from an RCT of asthma clinics in general practice, using the St. George Respiratory Questionnaire (SGRQ) to measure quality of life.

SETTING

Twelve general practices in Adelaide, Australia.

RESULTS

A total of 184 adult asthmatics were recruited, with a mean (standard deviation) age of 50.3 years (16.6 years). Age, gender, weight, number of comorbidities, smoking status, FEV1 and percent predicted FEV1 (pre-and post-bronchodilator), peak flow (pre and post), and RSQ were independently related to SGRQ scores. After adjusting for potential confounders, an RSQ score predictive of hospital attendance was also associated with an average increase (worsening) in SGRQ total score of 11.9 (95% CI: 7.6, 16.3), an average increase in activity score of 9.0 (2.5, 15.5), symptom score of 14.8 (8.6, 21.0), and impact score of 13.1 (8.6, 17.6). These represent clinically significant differences.

CONCLUSION

An RSQ score predictive of hospital attendance should alert the general practitioner to explore and address symptom, activity, and impact domains associated with impaired quality of life in adult asthma.

Long-term outcomes in paediatric asthma

Over the years the aims of asthma management have changed markedly from effective prednisolone treatment of symptoms and exacerbations towards more use of continuous prophylactic treatment. With our new understanding of the disease and its management definition of the aims of treatment and assessment of optimal asthma control have become much more complex. Even in times of evidence-based medicine our asthma management is based upon findings of effects on various outcomes in somewhat short-term (<1 year) controlled studies. However, assumptions about long-term effects upon the basis of findings in such studies should be made with great caution. Good examples of this are studies which assess the risk of systemic effects and clinical adverse effects of inhaled corticosteroids. From such studies it has become clear that systemic effects detected in short-term trials may have no predictive value of long-term adverse effects. Thus steroid-induced changes in lower leg growth rates assessed by knemometry do not predict long-term statural growth. Moreover, steroid-induced changes in statural growth over 1 year are not predictive of effects upon attained adult height. In contrast, reduced growth caused by uncontrolled asthma disease also seems to affect attained adult height adversely. These findings suggest that long-term outcomes should play a larger role when future asthma management strategies are decided. Some important long-term outcomes of asthma management in children include cure or remission of the disease, prevention of complications of the disease (airway remodelling, adverse effects upon growth/adult height, peak bone mineral density, physical impairment and psychosocial development) or its pharmacological management (adverse effects upon adult height, peak bone mineral density). More controlled long-term studies (several years) are needed to provide a better understanding of how these outcomes are best achieved.

Schoolboys with bronchial asthma in Al-Khobar City, Saudi Arabia: are they at increased risk of school absenteeism?

The objective of this cross-sectional study was to determine the mean period of school absenteeism (MPSA) among asthmatic Saudi schoolboys of Al-Khobar City and to determine the factors associated with the absenteeism. The methodology included the distribution of a self-administered questionnaire, which was completed by the parents of 1482 schoolboys who satisfied the selection criteria of the study. The prevalence rate of questionnaire-diagnosed asthma (QDA) was 9.5% (141/1482). The MPSA among questionnaire-diagnosed asthmatic boys (QDAs) was 13.6 +/- 3.4 days compared to 3.7 +/- 2.2 days among non questionnaire-diagnosed asthmatic boys (non QDAs). Among QDAs, the MPSA was associated significantly and positively with those who were younger, and with decreasing levels of socioeconomic class, histories of pets at home, presence of a currently smoking family member (father or both parents), visit to a hospital emergency room, and admission to hospital. It was significantly and negatively associated with concomitant use of prophylactic medication(s), including those used appropriately. The QDAs from middle and lower socioeconomic classes showed less use of prophylactic medication(s) but more histories of visits to an emergency room and of admissions to hospital. The multiple linear regression equation for the total period of school absenteeism (TPSA) during the 1995 academic year was generated. Asthmatic school children have a higher MPSA compared to their non asthmatic classmates. The risk of suffering the impacts of this disease is shown to be particularly increased among QDAs belonging to less socioeconomically advantaged families.

Towards excellence in asthma management (TEAM): a populational disease-management model

Asthma management is not always optimal, and deficiencies such as inadequate treatment and insufficient patient education are often reported. Towards Excellence in Asthma Management (TEAM) is a four-phase disease management program of the Quebec Asthma Education Network (QAEN), to be carried out over a 5-year period. The program aims to achieve a continuous improvement of asthma management by caregivers and patients. The first phase, completed in January 2000, consisted of determining the actual level of asthma-associated morbidity and mortality in various Quebec regions. The second phase, which began in September 1999, included three parts: 1. Definition of the burden of asthma, taking into account the socioeconomic consequences of the disease and the quality of life of the patients, 2. Comparison of current medical practices with the Canadian Asthma Consensus Guidelines for adult and pediatric populations, 3. Evaluation of the level of compliance with medical treatment and with the environmental changes recommended to asthmatic patients. This phase is carried out via a cohort study of physicians, mainly general practitioners and pediatricians, generating a patient cohort study, in addition to substudies evaluating specific aspects of asthma care. Once the care gap is identified, it will be possible to define, apply, and evaluate a series of interventions for physicians, other health professionals, and patients. The interventions will be particularly targeted at regions where asthma incidence and morbidity are higher. We hope that this model of disease management will progressively reduce the burden associated with asthma, and potentially other chronic diseases, and will result in the more effective use of health services.

Prevalence of wheeze, bronchial hyper-responsiveness and asthma in the elderly Chinese

BACKGROUND

Asthma is a common health problem affecting patients of all ages. Because of the ease of sampling, epidemiological studies have concentrated mainly on the paediatric and general population.

OBJECTIVE

This study aimed to determine the prevalence of wheeze, bronchial hyper-responsiveness and asthma amongst our elderly population and deduce any clinical and laboratory risk factors that might identify elderly asthmatics at an earlier stage.

METHODS

Two thousand and thirty-two elderly Chinese aged > or = 70 years, randomly selected from a registered list of all recipients of Old Age and Disability Allowances in Hong Kong, were administered a questionnaire on lung health. Two hundred and fifty subjects were invited to attend our laboratory for skin tests and pulmonary function tests and 179 agreed. Of these, 173 (96.6%) and 176 (98.3%) had eosinophil count and serum IgE levels measured, respectively. Two definitions of asthma were used: (1) bronchial hyper-responsiveness (BHR) plus current wheeze, and (2) history of wheezing without previous diagnostic labels of emphysema or chronic bronchitis.

RESULTS

Fifteen patients (out of 179: 8.4%) reported wheezing over the past 1 year. Fifty-one patients (28.5%) demonstrated BHR on spirometry or histamine challenge tests. Seven patients had both symptoms of wheezing and evidence of BHR. The prevalence of asthma using this definition is therefore 3.9% (95% CI 1.6-7.9%). Nine patients had symptoms of wheezing without previous diagnostic labels of chronic bronchitis or emphysema and, using this definition, the prevalence is 5.0% (95% CI 2.3-9.3%). Using multiple logistic regression studies, sex, social class, age, smoking habits, serum IgE levels and eosinophil counts did not predict a diagnosis of asthma using either definition. We found no association between a positive skin test and any respiratory symptoms or illnesses including asthma.

CONCLUSION

Wheeze, bronchial hyper-responsiveness and asthma are prevalent amongst our elderly population. However, there were no identifiable demographic and laboratory risk factors in this study that may help us predict a diagnosis of asthma.

Inadequate asthma treatment practices and noncompliance in Israel

Childhood asthma morbidity and mortality are increasing despite improvements in asthma therapy. The changes over the past decade in the guidelines for treatment of children with severe asthma have led to a reduction in admissions and readmissions to the pediatric intensive care unit (PICU). The Israeli medical infrastructure is exemplary in its capability of extending appropriate medical services to its entire population. Our objective was to look at the background of preventive maintenance treatment and treatment during an acute episode in children admitted to PICUs with severe asthma, and to identify areas that could be targeted for change. A 5-year retrospective chart audit on acute asthma admissions was conducted in two PICUs of general community hospitals representative of the provision of medical care in Israel. The prehospitalization preventive management and acute treatment prior to PICU admission were evaluated, and the number of admissions and readmissions was recorded. The index admission was the first episode of acute asthma for only 3% of the children: 25% of patients required readmission, and 15% of these to the PICU. In spite of a proven history of acute exacerbations of the disease, only 60% were on continuous treatment between attacks, and 29% of them had abruptly discontinued treatment, most of them shortly before the onset of the index attack. Inhaled steroids were used as maintenance and preventive treatment by less than one-third of the children, with the other two-thirds receiving mainly beta-2 agonists drugs. In conclusion, an unacceptably large proportion of asthmatic children do not receive the recommended maintenance and preventive treatment because of poor compliance, lack of education, or insufficient healthcare provision. This has probably led to avoidable recurrences of acute asthma exacerbations and unnecessary use of PICU facilities. These findings suggest that steps for implementing recommended guidelines and an educational program are needed.

The Melbourne Asthma Study: 1964-1999

A group of children with a past history of wheezing was randomly selected from the Melbourne community at the age of 7 years in 1964, and a further group of children with severe wheezing was selected from the same birth cohort at the age of 10 years. These subjects have been followed prospectively at 7-year intervals, with the last review in 1999, when their average age was 42 years. Eighty-seven percent of the original cohort who were still alive participated in the 1999 review. This study showed that the majority of children who had only a few episodes of wheezing associated with symptoms of a respiratory infection had a benign course, with many ceasing to wheeze by adult life. Most who continued with symptoms into adult life were little troubled by them. Conversely, those children with asthma mostly continued with significant wheezing into adult life, and the more troubled they were in childhood, the more likely symptoms continued. There was a loss in lung function by the age of 14 years in those with severe asthma, but the loss did not progress in adult life. The childhood asthma had been treated before the availability of inhaled steroids. There was no significant loss of lung function in those with milder symptoms.

A multi-stage asthma screening procedure for elementary school children

This paper describes an asthma screening procedure developed to identify children with asthma for an intervention study. Students were classified into three categories based on questionnaire responses (previous asthma, suspected asthma, and no evidence of asthma). Those classified as suspected asthma by questionnaire underwent further testing, including spirometry and exercise challenge. Using the questionnaire alone, the measured asthma prevalence was 32%; the addition of spirometry and step testing reduced this estimate to 9.89%. The diagnosis of asthma was confirmed in 96% of children who saw the study physician. This screening procedure can identify school children with suspected undiagnosed asthma.

Pattern and risk factors associated with hospital emergency visits among schoolboys with bronchial asthma in Al-Khobar

BACKGROUND

The objective of this cross-sectional study was to determine the prevalence of a history of hospital emergency visits (HHEV) among asthmatic Saudi schoolboys in the city of Al-Khobar and factors associated with such visits.

SUBJECTS AND METHODS

The methodology included the distribution of a self-administered questionnaire, which was completed by the parents of 1482 schoolboys who satisfied the selection criteria of the study.

RESULTS

The prevalence rate of questionnaire-diagnosed asthma (QDA) was 9.5%. The prevalence rate of a positive HHEV among QDA boys (QDAs0 was 65%. Positive HHEV among QDAs was associated significantly with those who were younger (P <0.00001), with decreasing levels of socioeconomic class (P <0.00001), histories of pets at home (P <0.00001), presence of a currently smoking family member (P <0.00001), and/or a smoking father (P <0.00001), with mean period of school absenteeism (P <0.00001), and previous admission to hospital (P <0.05). It was also significantly associated with concomitant use of prophylactic medication(s) (P <0.00001). The multiple linear regression equation for the total number of hospital emergency visits during the current academic year was generated.

CONCLUSION

Asthmatic school children have a relatively higher rate of HHEV compared to the normal population. Modifying the preventable factors associated with the total number of hospital emergency visits is expected to decrease the severity and the disability associated with this disease.

Environmental tobacco smoke as a risk factor for respiratory disease in children

Respiratory diseases are a frequent reason for using health care. In 1995-1996, diseases of the respiratory tract (ICD 460-519) contributed seven of the top 15 reasons for visits to physician offices among children under 15 years of age in the United States. Environmental tobacco smoke (ETS) is a wide-spread environmental pollutant that has been long linked with respiratory problems. This paper will review the available literature on the role ETS plays in respiratory diseases, including asthma. This review focuses not only on the respiratory problems caused by ETS, but also examines the influence of age at exposure on the consequences of ETS and the importance of the differing sources of ETS exposure. As ETS is a completely preventable form of environmental pollution, the success or failure of various types of interventions will also be reviewed.

Using a neural network to screen a population for asthma

PURPOSE

To use a neural network to rank a population according to individual likelihood of asthma based on their responses to a respiratory questionnaire.

METHODS

A final diagnosis of asthma can be made only after full clinical assessment but limited resources make it impossible to offer this to complete populations as part of a screening programme. Prioritisation is required so that review can be offered most promptly to those most in need. A stratified random sample of 180 from 6825 respondents to a community survey underwent clinical review. They were categorised according to likelihood of asthma by three independent experts whose opinions were combined into a single probability label for each patient. A neural network was trained to relate questionnaire responses to probability labels. The trained network was applied to the whole community to produce a ranking order based on likelihood of asthma. A screening threshold could then be set to correspond to available resources, and patients above this level with no recorded evidence of asthma diagnosis could be assessed clinically. Using the known probability labels from the training set, it was possible to derive the expected proportion of true asthmatics in any set of patients.

RESULTS

If the screening threshold had been set to capture the top 10% of the ranked population (n = 683), then 239 patients above this threshold had no evidence of diagnosis and would need assessment. Of these, it would be expected that 74% would have the diagnosis confirmed.

CONCLUSIONS

This approach allows prioritisation of a population where resources for diagnostic examination are limited.

The prevalence of asthma and heart disease in transport workers: a practice-based study

BACKGROUND

There has been widespread concern that the increasing incidence of asthma observed during the late 1980s might have arisen because of environmental pollution, and in particular vehicle pollution. The General Practice Morbidity Survey in 1991/92 (MSGP4) collected data on occupation, employment status, and smoking habit linked individually to each patient record.

OBJECTIVES

To examine whether people with occupations that have high exposure to vehicle exhaust fumes have an increased prevalence of asthma, acute respiratory infections, and ischaemic heart disease (IHD).

METHOD

Men aged 16 to 64 years were grouped by Standard Occupational Classification codes; 93,692 employed and 20,858 not-employed men were studied separately. Those with likely high occupational exposure were grouped together ('all-exposed')--the remainder occupations in corresponding chapters of the code were used as controls. We compared 12-month age and smoking standardised disease prevalence ratios for asthma, chronic obstructive pulmonary disease (COPD), acute respiratory infections (IHD), and all circulatory disorders in the all exposed and individual exposed occupations with their matching controls. Also the mean frequency of consultations per person consulting was calculated for each occupational group and disease.

RESULTS

For employed persons, the prevalence ratio (PR) for asthma in the all-exposed, (116, 95% confidence interval [95% CI] = 101-130) exceeded that for all employed persons (100); however, the difference compared with chapter-matched controls (PR = 97, 95% CI = 92-103), was not statistically significant. Results for COPD were similar. Prevalence ratios in motor mechanics, a high-exposure group, were 98 (95% CI = 70-127) 96 (95% CI = 70-123) for asthma and COPD respectively. Among the employed, prevalence ratios for IHD in all but one of the individual occupation groups examined did not differ from the average, however among those not employed the ratio in the all-exposed (PR = 152, 95% CI = 128-174) exceeded that in the controls (PR = 112, 95% CI = 104-120).

CONCLUSION

Occupational groups exposed to motor vehicle pollution have a marginally increased prevalence of asthma compared with working males generally, though not compared with occupation matched controls. This study has demonstrated a methodology for using GP data to examine occupation-related disease. This could be used in future by augmenting GP data with occupation and smoking information.

Diagnosing pediatric asthma: validating the Easy Breathing Survey

OBJECTIVE

To determine the sensitivity, specificity, and predictive value of a simple, self-administered questionnaire for the diagnosis of asthma in children.

STUDY DESIGN

A questionnaire specifically designed to assist primary care providers in making a diagnosis of asthma in children was developed and administered in 4 different primary care and subspecialty clinics, validated, and then used as part of an asthma management program called Easy Breathing. Asthma diagnoses were made according to recommended National Asthma Expert Panel Guidelines.

RESULTS

Four questions on the survey were shown to be sensitive and specific for asthma. The sensitivity was greater for all levels (mild, moderate, and severe) of persistent asthma than for mild, intermittent asthma. A positive response to any 1 of the 4 questions was over 94% sensitive for asthma; a negative response to all 4 questions was 55% specific for ruling out asthma.

CONCLUSIONS

Patient responses to 4 specific respiratory symptom questions can assist primary care providers in diagnosing asthma in children. Primary care providers serving pediatric populations at high risk for asthma should consider asking patients or their parents these 4 questions regarding asthma symptoms on a regular basis.

School attendance and school performance: a population-based study of children with asthma

OBJECTIVE

To analyze school attendance and school achievement as outcomes of the care of children with asthma.

METHODS

A previously identified Rochester, Minnesota, cohort of children with asthma and age- and sex-matched children without asthma were studied. School attendance, standardized achievement test scores, grade point average, grade promotion, and class rank of graduating students for children with asthma and control subjects were obtained from the Rochester Public School system.

RESULTS

Children with asthma (n = 92) and age- and sex-matched non-asthmatic control subjects with 640 school-years of observation were studied. Children with asthma had 2.21 (95% CI, 1.41 to 3.01) more days absent than children without asthma. There was no significant difference in standardized achievement test scores (reading percentile difference 1.22% [95% CI, -3.68 to 6.12], mathematics percentile difference 2.36% [95% CI, -2.89 to 7.60], language percentile difference 2.96% [95% CI, -4.03 to 7.15]). There was no significant difference in grade point average, grade promotion, or class rank of graduating students.

CONCLUSION

In this community, although children with asthma had 2 excess days of absenteeism, the school performance of children with asthma was similar to that of children without asthma.

[Chronic cough in children: etiology and decision trees]

Recurrent or chronic cough can be the symptom of a worrying condition which must be diagnosed without delay (cystic fibrosis, asthma, bronchial foreign body, bronchiectasis). Investigation of recurrent or chronic cough is based on simple principles: careful history-taking concerning the characteristics of the cough, full clinical examination to look for any associated symptoms, and auxological assessment to detect any interruption in weight increase. Only when this initial evaluation has been carried out can complementary investigations be sought. Ordinary respiratory infections that are part of the building up of immunity are predominant in coughs of children aged under 6 years and are aggravated by deleterious factors such as passive exposure to tobacco, early introduction to communal life, and urban pollution. We describe the most frequent causes of cough and their frequency according to the age of the child.

Total serum IgE and outcome in infants with recurrent wheezing

OBJECTIVE

To investigate the relation between total serum IgE at 0.5-3 and 3-6 years, and the risk of allergic sensitisation and persistent wheezing up to 8 years of age.

METHODS

Prospective follow up study of 45 infants with highly recurrent wheezing, no allergic symptoms, and negative skin tests.

RESULTS

In the last follow up year, 15 children still suffered from wheezing. Five wheeze-free and four episodically wheezing children had become sensitised. No association was found between early (0.5-3 years) IgE z scores and the recurrence of wheezing during follow up, or atopic sensitisation. IgE z scores at 3-6 years were significantly higher in children with positive skin tests (p = 0.013), but were still not associated with recurrence of wheezing.

CONCLUSIONS

In subjects with frequent early wheezing and no signs of atopy, early total serum IgE measurements are not predictive of outcome.

Genetic/environmental determinants of adult chronic obstructive pulmonary disease and possible links with childhood wheezing

Epidemiological evidence and similarities in underlying inflammatory mechanisms suggest that childhood respiratory conditions and adult onset chronic obstructive pulmonary disease (COPD) may have a common aetiology. The prevalence of COPD in the UK has been estimated to be 10% in males and 11% in females, and like asthma, is thought to have a polygenic contribution with a complex interplay between genetic and environmental factors. The only proven genetic factor so far identified in its pathogenesis is alpha1-antitrypsin deficiency, although this accounts for less than 1% of individuals with disease. Environmental exposures are significant but the observation that only 15% of smokers develop COPD and only some young children exposed in utero develop recurrent wheezing points to as yet undefined contributory genetic factors. The similarity in response to medication also suggests some features in common and a central question must be whether those adults who develop COPD had transient viral-associated wheeze (VAW) or non-specific bronchial hyperresponsiveness (BHR) in childhood? Similarities between some of the childhood wheezing syndromes and adult onset COPD invites a re-examination of possible links between the two conditions.

School boys with bronchial asthma in Al-khobar city, saudi arabia: are they at increased risk of school absenteeism?

OBJECTIVE

The objective of this cross-sectional study was to determine the mean period of school absenteeism (MPSA) among Questionnaire Diagnosed Asthmatic (QDA) Saudi schoolboys of Al-Khobar city and the factors associated with it.

METHODS

The methodology of this cross-sectional study included the distribution of a self-administered questionnaire, which was completed by the parents of 1482 schoolboys who satisfied the selection criteria of the study.

RESULTS

The prevalence rate of QDA was 9.5% (141/1482). MPSA among Questionnaire Diagnosed Asthmatic Boys (QDAs) was 13.6 ± 3.4 days compared to 3.7 ± 2.2 days among non-QDA boys (non-QDAs). Among QDAs, it was associated significantly and positively with those who were younger, with a decreasing level of socioeconomic class, history of pets at home, presence of a current smoker in the family (father or both parents), visit to a hospital emergency room, and admission to hospital. It was significantly and negatively associated with concomitant use of prophylactic medication(s), including those used appropriately. QDAs from middle and lower socioeconomic classes used less prophylactic medication(s) but had had more visits to an emergency room and had admissions to hospital. The multiple linear regression equation for the total period of school absenteeism (TPSA) during the current academic year was generated.

CONCLUSIONS

QDAs have higher MPSA compared to their non-asthmatic classmates. The impact of this disease increases particularly among QDAs belonging to lower socioeconomic families.

A simple diagnostic index for asthma

BACKGROUND

Asthma is becoming increasingly prevalent and a number of research groups are investigating its genetic and environmental basis.

OBJECTIVE

To produce a brief screening tool suitable for determining phenotype in asthma research.

METHODS

The scores from eight questions on symptoms and history were obtained from 678 adults and 244 children from high asthma-incidence caucasian families. An independent physician diagnosis was also obtained with the use of a modified NHLBI-CSGA questionnaire and pulmonary function test. Stepwise logistic regression was applied to determine which of the eight questions had greatest predictive value for asthma, and the quality of the resultant models was evaluated using an independent set of 643 adults and 239 children.

RESULTS

For adults, the most parsimonious model used responses from three of the eight questions. It had sensitivity and specificity of 0.94 and 0.96, respectively. For children, responses to two questions gave a model with sensitivity and specificity of 0.97. For both age groups, negative predictive values were above 0.87. Positive predictive values were 0.58 and 0.78 for adults and children respectively. The latter emphasize the need for conformation, by physician, of "affected" calls made by this initial screen.

CONCLUSION

The brief questionnaires described are potentially useful in a research setting, as a preliminary screening mechanism of low cost. Their use will reduce the numbers of subjects that must undergo detailed phenotyping.

Asthma screening as part of a routine school health assessment in the Australian Capital Territory

OBJECTIVE

To determine the feasibility and performance of a routine screen for childhood asthma in new entrants to primary school relative to diagnosis by a paediatrician.

DESIGN

Cross-sectional study with a validation substudy.

PARTICIPANTS AND SETTING

All 4539 new primary school entrants (mean age, 5.72 years; 95% CI, 5.71-5.74) in the Australian Capital Territory (ACT) in 1999; 180 of these children (73% of the 248 contacted) participated in the validation substudy.

MAIN OUTCOME MEASURE

Performance of the screening test relative to a paediatrician's diagnosis of current asthma (defined as a history of wheeze suggestive of a clinical diagnosis of asthma within the past 12 months) based on history and examination.

RESULTS

3748 of the 4539 new primary school entrants (83%) returned completed asthma and respiratory questions. The screening test was positive in 38% of children. Estimated sensitivity was 92% (95% CI, 75%-99%); specificity, 76% (95% CI, 72%-80%); positive predictive value, 51% (95% CI, 41%-63%); negative predictive value, 98% (95% CI, 90%-100%); positive likelihood ratio, 3.8 (95% CI, 2.8-4.8); and negative likelihood ratio, 0.14 (95% CI, 0.02-0.33).

CONCLUSIONS

It is feasible to conduct population screens for asthma that have good diagnostic test performance against a specialist paediatrician's diagnosis through school health programs. This approach could facilitate monitoring changes in asthma prevalence over time.

The socio-economics of asthma

Is it healthy to be wealthy? The answer to this simple but provocative question can be found in a wide variety of published studies, which evaluate the socio-economic equity of healthcare and the socio-economic impact of diseases. Studies have focused on avoidable mortality, race and ethnicity, environment and access to healthcare services, and many found supporting facts of the above thesis, mostly based on cardiovascular diseases. But what about asthma? Additional factors such as risk behaviours e.g. smoking, excessive use of beta-agonists or general non-compliance with asthma medication have been investigated and found to be contributing to adverse health outcomes. Prevalence and incidence of asthma is higher in people with high socio-economic status (SES), but disease severity and premature mortality is more than twice as common in populations with low SES. The key to reduce the large socio-economic impact is, therefore, to improve the management of patients with more severe diseases. Because those patients are found more often in low SES groups, new approaches such as community disease management programmes, probably provided by a multi-disciplinary care team, have to be established. Current financial incentives within the largely sectored healthcare system are counterproductive. Furthermore, a better co-ordination of the goals of public healthcare experts with those providing individual 'clinical' healthcare is needed. Clearly communicated healthcare goals are needed to create common incentives and shared visions. Cornerstones of the new disease management efforts are co-ordinated care, high quality innovative medicines and a well-educated patient. This might help improve the implementation of current asthma management knowledge into practice.