Asthma treatment, perceived respiratory disability, and morbidity

No differences in physical activity in (un)diagnosed asthma and healthy controls

To establish whether asthma affects physical activity levels in children (aged 7-10 years) we evaluated physical activity levels in children with undiagnosed asthma (UDA), diagnosed asthma (DA), and healthy controls (HCs). A cross-sectional community-based study was performed which included a parental questionnaire on their child's respiratory health, and testing of airway reversibility and bronchial hyperresponsiveness (BHR). DA was defined as the parents' confirmation of a physician's diagnosis of asthma in the past 12 months. UDA was defined by asthma symptoms combined with airway reversibility or BHR in children without a physician's diagnosis of asthma. Physical activity was measured during 5 days with an accelerometer and a diary, and with the habitual activity estimation scale which reviews the physical activity during the past 2 weeks. The final study population comprised 1,614 children of whom 81 (5%) had DA, 130 (8%) UDA, and 202 HCs. Baseline FEV(1) % was lowest in children with UDA (UDA FEV(1) 94% predicted, DA FEV(1) 98% predicted, HCs FEV(1) 100% predicted). Using the three methods, no differences were found in the physical activity between children with UDA, DA, and HCs. Childhood asthma does not appear to be associated with a decreased level of daily physical activity in our study population.

Quality of life in children with undiagnosed and diagnosed asthma

This study describes the impact of undiagnosed and diagnosed asthma on quality of life in schoolchildren aged 7-10 years and their caregivers in a cross-sectional community-based study. Diagnosed asthma was defined as the parents' confirmation of a physician's diagnosis of asthma. Undiagnosed asthma was defined by asthma symptoms combined with airway reversibility or bronchial hyperresponsiveness. Quality of life was evaluated in all children with asthma and a sample of healthy controls by the Pediatric Asthma Quality of Life Questionnaire, and by the Paediatric Asthma Caregiver's Quality of Life Questionnaire. We studied the impact of breathing problems on school absence. Compared with healthy controls, quality of life scores among children and their caregivers were lower if the child had asthma (P < 0.05), with lowest scores in diagnosed asthma (P < 0.05 compared with undiagnosed asthma). Children with asthma reported more school absence (P < 0.05), with highest absence rate in those with diagnosed asthma. In conclusion, both undiagnosed and diagnosed asthma have a significant impact on the quality of life of both children and their caregivers.

Is childhood asthma still underdiagnosed and undertreated in Istanbul?

BACKGROUND

Childhood asthma is reported to be underdiagnosed and undertreated worldwide. The purpose of the present study was to investigate the rate of underdiagnosis and undertreatment among children diagnosed with asthma in a tertiary reference center in Turkey.

METHODS

A questionnaire survey was carried out among the parents of 1134 patients diagnosed with asthma in a tertiary reference outpatient clinic.

RESULTS

Mean age of the patients was 4.9 years (range 1-17 years). Of these children 45.5% had recurrent asthma attacks (average 4.8 attacks per year) and 24.7% had only the symptom of vigorous fits of coughing. Although they had been symptomatic for 29.6 months, only 41.1% were diagnosed as having asthma before admission to the clinic. In this study group 61.3% had received some form of asthma treatment, but only 21.1% of all patients were treated according to the guidelines. The rate of treatment according to guidelines was lower in the children under 6 years of age than older children (18.8 vs 24.2%, respectively, P = 0.02).

CONCLUSIONS

Underdiagnosis and undertreatment of childhood asthma still seem to be a major problem in the management of childhood asthma, especially in preschool children, even after the recommendations of guidelines.

Issues in identifying asthma and estimating prevalence in an urban school population

This article first presents salient issues related to identifying children in urban schools who might benefit from asthma services. It discusses a brief questionnaire for identifying cases and problems in estimating asthma prevalence. Subsequently, results of case detection in 14 urban schools are presented and discussed in light of these issues. The questionnaire was employed with parents of 4,653 African-American children in Detroit. Results suggest that determining number, type, and frequency of symptoms may be necessary to ascertain prevalence of asthma. Using only number and type produced a rate of asthma of 25%. Adding frequency provided a more conservative estimate of 19%. About 9% of children exhibiting symptoms of asthma had no physician diagnosis. Only 25% with symptoms reflecting mild persistent, 35% with moderate persistent, and 26% with severe persistent disease had prescriptions for anti-inflammatory medicine. Further, 23% of children with asthma-like symptoms had no prescription for asthma medicine of any type.

CONCLUSIONS

(1) low-cost procedures can be used in schools to identify children with suspected undiagnosed and undertreated asthma; (2) prevalence estimates for asthma in the group of urban school children studied are among the highest in the United States; and (3) asthma is undertreated in this sample.

Development of a drug treatment-based severity measure in childhood asthma

Valid measures of severity are crucial in asthma pharmacoepidemiological research. This study reports the development and validation of a severity measure in childhood asthma for application to health care administrative data. A drug treatment-based asthma severity measure was developed following the stepped care approach to treatment, and this was applied to a cohort of 16,862 children who met a case definition for asthma drug prescription use between January 1995 and March 1996. Assessments were made of the measure's reliability, validity, and responsiveness to change over time. The drug treatment-based asthma severity measure classified 42% of children as having mild asthma, 37% as having moderate asthma, 19% as having moderate-severe asthma, and 2% as having severe asthma. Agreement on severity classification between two successive time periods was excellent (kappa = 0.82). Children classified as having severe asthma were significantly more likely than children with mild-moderate asthma to have previous asthma hospitalizations, to visit asthma specialists, to have high physician utilization, and to require hospital critical care. They were more likely to be reclassified as having severe asthma 2 years later. These findings show that a drug treatment-based severity measure in childhood asthma, which can be applied to prescription data, has good reliability and validity, and is responsive to changes in asthma severity over time.

Diagnostic and treatment behaviour in children with chronic respiratory symptoms: relationship with socioeconomic factors

BACKGROUND

The prevalence and severity of asthma is believed to increase with increasing socioeconomic deprivation. The relationship between asthma diagnosis, symptoms, diagnostic accuracy, and socioeconomic deprivation as determined by Townsend scores was determined in Sheffield schoolchildren.

METHODS

All 6021 schoolchildren aged 8-9 years in one school year in Sheffield were given a parent respondent survey based on International Survey of Asthma and Allergies in Childhood (ISAAC) questions.

RESULTS

5011/6021 (83.2%) questionnaires were returned. Postcode data were available in 4131 replies (82.4%) and were used to assign a composite deprivation score (Townsend score). Scores were divided into five quintiles, with group 1 being least and group 5 being most deprived. A positive trend was observed from group 1 to group 5 for the prevalence of wheeze in the previous 12 months, wheeze attacks >or=4/year, nocturnal wheeze and cough (all p<0.001), cough and/or wheeze "most times" with exertion (p<0.03), current asthma (p<0.001), and significant asthma symptoms (p<0.001). No significant trend was observed for lifetime wheeze or attacks of speech limiting wheeze. There were no significant trends in the prevalence of current asthmatic children without significant symptoms (overdiagnosis) or children with significant asthma symptoms but no current asthma diagnosis (underdiagnosis) across the social groups. There was a significant negative trend in the ratio of asthma medication to asthma diagnosis from least to most deprived groups (p<0.001).

CONCLUSIONS

Asthma morbidity and severity increase according to the level of socioeconomic deprivation. This may be due to differences in environment, asthma management, and/or symptom reporting. Diagnostic accuracy does not vary significantly across deprivation groups but children living in areas of least deprivation and taking asthma medication are less likely to be labelled as having asthma, suggesting diagnostic labelling bias.

Effect of intravenous pamidronate on bone mineral density in adults with cystic fibrosis

BACKGROUND

Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis. The aim of this study was to assess the effect of intravenous pamidronate on BMD in these subjects.

METHODS

Patients were invited to participate if they had a BMD Z score of -2 or less in the lumbar spine, proximal femur, or distal forearm. Patients were randomised to receive either 30 mg intravenous pamidronate every 3 months + 1 g calcium daily (pamidronate group) or 1 g calcium daily (control group). All pancreatic insufficient patients were prescribed oral vitamin D supplements.

RESULTS

After 6 months of treatment the pamidronate group (n=13) showed a significant increase in absolute BMD compared with the control group (n=15) in the lumbar spine (mean difference 5.8% (CI 2.7% to 8.9%)) and total hip (mean difference 3.0% (CI 0.3% to 5.6%)). However, the pamidronate group showed a reduction in BMD compared with the control group in the distal forearm (mean difference -1.7% (CI -3.7% to 0.3%)). The use of pamidronate was associated with a high incidence of bone pain in non-corticosteroid treated individuals.

CONCLUSION

Intravenous pamidronate increases axial BMD in adults with cystic fibrosis, but the high incidence of bone pain associated with this treatment might limit its use.

Increasing prevalence of asthma diagnosis and symptoms in children is confined to mild symptoms

BACKGROUND

The prevalence of childhood asthma is increasing but few studies have investigated trends in asthma severity. We investigated trends in asthma diagnosis and symptom morbidity between an eight year time period in a paired prevalence study.

METHODS

All children in one single school year aged 8-9 years in the city of Sheffield were given a parent respondent questionnaire in 1991 and 1999 based on questions from the International Survey of Asthma and Allergy in Children (ISAAC). Data were obtained regarding the prevalence of asthma and wheeze and current (12 month) prevalences of wheeze attacks, speech limiting wheeze, nocturnal cough and wheeze, and exertional symptoms.

RESULTS

The response rates in 1991 and 1999 were 4580/5321 (85.3%) and 5011/6021 (83.2%), respectively. There were significant increases between the two surveys in the prevalence of asthma ever (19.9% v 29.7%, mean difference 11.9%, 95% confidence interval (CI) 10.16 to 13.57, p<0.001), current asthma (10.3% v 13.0%, mean difference 2.7%, 95% CI 1.44 to 4.03, p<0.001), wheeze ever (30.3% v 35.8%, mean difference 5.7%, 95% CI 3.76 to 7.56, p<0.001), wheeze in the previous 12 months (17.0% v 19.4%, mean difference 2.5, 95% CI 0.95 to 4.07, p<0.01), and reporting of medication use (16.9% v 20%, mean difference 3.0%, 95% CI 1.46 to 4.62, p<0.001). There were also significant increases in reported hayfever and eczema diagnoses.

CONCLUSIONS

Diagnostic labelling of asthma and lifetime prevalence of wheeze has increased. The current 12 month point prevalence of wheeze has increased but this is confined to occasional symptoms. The increased medication rate may be responsible for the static prevalence of severe asthma symptoms. The significant proportion of children receiving medication but reporting no asthma symptoms identified from our 1999 survey suggests that some children are being inappropriately treated or overtreated.

Recognition of asthmatic symptoms in the pediatric age group

Asthma produces substantial morbidity in childhood. Under-diagnosis may lead to inappropriate treatment and prolonged periods of illness and absence from school. The results of a recent International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire study in Malta showed a higher prevalence of wheezy symptoms in the Central North Region. The present study was carried out to test the null hypothesis that there is no correlation between potential exposure to pediatricians (measured as pediatric private clinics/1000 childhood population/week) and percentage of children aged 13-15 years of age responding positively in the questionnaire to having had wheezy symptoms. A significant, positive correlation was found between potential exposure to pediatricians and percentage of children aged 13-15 years responding positively to having had wheeze in the previous year (p=0.009). A negative correlation was also found for severity of asthma (>12 attacks in the previous 12 months) and potential exposure to pediatricians (p=0.01). This is the first report of potential exposure to pediatricians influencing the regional incidence of asthma on a national basis. This skew may be caused by the greater exposure of pediatricians to patients with severe forms of asthma in a hospital setting, and hence a higher index of suspicion for the milder forms of the disease. Asthma may be less severe in regions where there are a greater number of pediatricians because of recognition of the condition with appropriate treatment and/or prophylaxis.

What do parents of wheezy children understand by "wheeze"?

BACKGROUND

Reported wheeze is the cornerstone of asthma diagnosis.

AIMS

To determine what parents understand by wheeze.

METHODS

Two studies were undertaken: (1) Parents of clinic attendees with reported wheeze (n=160) were asked by questionnaire what they understood by "wheeze" and how they knew their child was wheezy. Responses were compared to definitions of wheeze in 12 epidemiology studies and their response options. (2) The extent of agreement of parents' reports (n=139) of acute wheezing in their children and clinicians' findings of "wheeze" and "asthma" was examined.

RESULTS

(1) "Sound" and "difficulty in breathing" were perceived central to "wheeze". "What you hear" was not selected by 23% (95% confidence interval (CI) 16-30%). "Whistling" was mentioned by 11% (CI 6-15%) but featured in 11 of 12 epidemiology questionnaires. (2) There was les than 50% agreement between parents' and clinicians' reports of wheeze and asthma.

CONCLUSIONS

Conceptual understandings of "wheeze" for parents of children with reported wheeze are different from epidemiology definitions. Parents' reports of acute wheeze and clinicians' findings also differ.

School absence and treatment in school children with respiratory symptoms in The Netherlands: data from the Child Health Monitoring System

STUDY OBJECTIVE

To assess the prevalence of respiratory problems, and the relation of these problems with school attendance, medicine use, and medical treatment.

DESIGN

The Child Health Monitoring System.

SETTING

Nineteen public health services across the Netherlands.

PARTICIPANTS

5186 school children aged 4-15 years, who were eligible for a routine health assessment in the 1991/1992 school year.

MAIN RESULTS

Respiratory symptoms were present in 12% of the children. Recent symptoms suggestive of asthma (wheezing or episodes of shortness of breath with wheezing in the past 12 months, or chronic cough, or a combination of these) were reported for 8%. These symptoms were most frequent in the younger children, and in children at school in towns with less than 20,000 inhabitants. Of the children with recent symptoms suggestive of asthma, 37% reported school absence for at least one week during the past 12 months, compared with 16% in children without respiratory symptoms. School absence because of respiratory illness was reported for 22%, and medicine use for respiratory problems for 38% of the children with recent symptoms suggestive of asthma. Of these children, 21% were receiving medical treatment, compared with 15% of the asymptomatic children.

CONCLUSIONS

Respiratory symptoms are a common health problem in children, and they are an important cause of school absence and medicine use. However, the percentage of children receiving medical treatment seemed quite low, indicating that proper diagnosis and treatment are probably still a problem.

Parental perceptions of access to care and quality of care for inner-city children with asthma

The objective of this study was to describe perceptions of asthma care, morbidity, and health service utilization by parents of children with asthma presenting to an inner-city emergency department (ED). A cross-sectional survey was conducted in an urban pediatric ED, with a convenience sample of 466 parents of children receiving asthma treatment during a consecutive 6-week period in late fall 1995. Parents completed a 30-item survey including sociodemographic data, source of primary medical care and asthma care for their child, selected measures of access to care, and medications used by their child in the week prior to the ED visit. Perceived quality of asthma care was measured by six items (summary score = 0-6) reported to have been performed by the child's asthma doctor: discussion of home peak flow monitoring, child-specific triggers, dogs/cats, smoke, postexacerbation calling instructions, and provision of a written asthma management plan. Functional morbidity was measured by nights of poor sleep, days of cough, and school days missed due to asthma in the previous month. Among 325 patients with previously diagnosed asthma, 308 (97%) were reported to have a source of primary medical care. Of these, 126 respondents identified their primary care provider as the child's usual source of asthma care, while 158 identified the ED as the usual source. The groups did not differ by insurance status, ethnicity, or mean age of the child. Thirty-nine percent of children with the same provider for primary and asthma care compared with 15% of children reported to receive their asthma care predominantly in the ED had used inhaled steroids or cromolyn in the week prior to the ED visit (p < .0001). Children with the same provider for primary and asthma care had a higher mean quality score than children receiving asthma care in the ED (3.7 vs. 2.8, p < 0.0001), but there was no relationship between source of asthma care and functional morbidity. The ED remains the usual source of asthma care for many inner-city children. Among parents surveyed in the ED, there was a significant relationship between source of usual asthma care and quality of care, but a relationship between usual source of asthma care and functional morbidity could not be identified.

Treatment of childhood asthma. Options and rationale for inhaled therapy

Epidemiological studies suggest the prevalence of asthma is increasing, though some remain sceptical as to the magnitude or indeed the presence of an increase. However, despite improved diagnosis and the availability of the potent drugs now available there remains considerable respiratory morbidity associated with asthma. It is clear from a number of studies that failure to deliver drugs to the lungs when using inhaler devices is a factor contributing to this high level of morbidity. Failure of drug delivery may result from the prescribing of inappropriate devices, failure to use devices appropriately or failure to comply with a treatment regimen. For most of the currently available forms of asthma therapy there are significant advantages to be gained from administering them in aerosol form. The benefits to be derived from administering these drugs as an aerosol include a rapid onset of action for drugs such as beta-agonists and a low incidence of systemic effects from drugs such as beta-agonists and corticosteroids. Over the past 25 years our understanding of the nature of asthma has changed. Though this has been reflected in the emphasis on inhaled corticosteroid therapy in recent guidelines, it has not been reflected in the range of inhaler devices available. Manufacturers continue to place drugs such as corticosteroids in the same devices as short acting beta-agonists even though the requirements for these different drug classes are very different. It is likely that this contributes to suboptimal therapeutic responses with inhaled corticosteroids. However, the variability associated with current delivery systems is relatively small compared with the variability introduced by poor compliance. There is no work currently available to indicate how the use of cheap disposable devises which do not incorporate any form of positive feedback influence compliance with inhaled steroids. Optimising aerosolised drug delivery in childhood involves consideration of the class of drugs, the particular drug within a class but more importantly, the age and abilities of the child. Devices must be selected to suit a particular child's needs and abilities. Devices utilising tidal breathing are generally used such as spacing chambers or, less commonly these days, nebulisers. A screaming or struggling child, or failure to use a closely fitting mask, reduces drug delivery to the lungs enormously. Failure to respond to inhaled therapy in early childhood may be attributable to failure of drug delivery. Drug delivery in early childhood using current devices remains more an art than a science.

Stability of respiratory symptoms in unlabelled wheezy illness and nocturnal cough

OBJECTIVE

To assess the natural history of respiratory symptoms not labelled as asthma in primary schoolchildren.

DESIGN

Repeat questionnaire survey of subgroups identified from a previous questionnaire survey after a two year delay.

SUBJECTS

The original population of 5321 Sheffield children aged 8-9 years yielded 4406 completed questionnaires in 1991(82.8%). After excluding children with a label of asthma, there were 370 children with current wheeze, 129 children with frequent nocturnal cough, and a random sample of 222 children with minor cough symptoms and 124 asymptomatic children.

RESULTS

Response rates in the four groups were 233 (63.0%), 77 (59.7%), 160 (72.1%), and 90 (72.6%) respectively. Of those who initially wheezed, 114 (48.9%) had stopped wheezing and 42 (18.0%) had been labelled as having asthma. Those with more frequent wheezing episodes (p < 0.02) and a personal history of hay fever (p < 0.01) in 1991 were more likely to retain their wheezy symptoms. In the children with frequent nocturnal cough in 1991, 20.1% had developed wheezing, 42.9% had a reduced frequency of nocturnal coughing, and 14.2% had stopped coughing altogether two years later. One sixth had been labelled as having asthma. Children with nocturnal cough were more likely to develop wheezing if they had a family history of atopy (p = 0.02). Only 3.8% and 3.3% of those with minimal cough and no symptoms respectively in 1991 had developed wheeze by 1993 (1.9% and 1.0% labelled as asthma).

CONCLUSIONS

Most unlabelled recurrent respiratory symptoms in 8-10 year olds tend to improve. Unlabelled children who have persistent symptoms have other features such as frequent wheezing attacks and a family or personal history of atopy. If a screening questionnaire were to be used to identify such children, a combination of questions should be employed.

Longitudinal study of free running exercise challenge: reproducibility

The reproducibility of free running exercise challenge has been examined in an unselected population of 8-10 year olds. Using a standardised protocol, monthly exercise tests were performed on 143 children over one year. A positive test was defined using both a 15% and 20% fall in peak expiratory flow after exercise. The mean (95% confidence interval, CI) population frequency for a positive test at 15% fall was 14.9% (6.5 to 23.3) and coefficient of variation 24.6%. For a 20% fall, the mean (95% CI) population frequency was 7.9% (2.9 to 12.9) and coefficient of variation 27.8%. Seventy two (50.3%) of the children gave at least one positive response at 15% fall. Exercise testing is not reproducible in the community setting and should not be used as a screening test. Exercise data from epidemiological studies of asthma should be interpreted with caution.