PubMed Health⌕ Search

Biomedical subjects

M I Asher

Publications and source records attributed to M I Asher.

At least 19 recordsLinked to original sources
PubMed2005

The international study of asthma and allergies in childhood (ISAAC): phase three rationale and methods.

The International Study of Asthma and Allergies in Childhood (ISAAC) programme commenced in 1991 to study the aetiology of asthma, allergic rhinoconjunctivitis and atopic eczema in children in different populations using standardised methodology and facilitating international collaboration. ISAAC Phase One (1992-1996) found marked differences in the prevalence of symptoms of asthma and allergic disease throughout the world which have not been explained by the current understanding of these diseases. ISAAC Phase Two (1998-2004) uses intensive investigations to further examine the potential role of risk and protective factors that may contribute to the international difference observed in Phase One. Phase Three (2000-2003) essentially represents a repeat of Phase One, in which more detailed standardised data are obtained to enable the time trends of symptom prevalence to be determined as well as the development of a more comprehensive 'world map'. The ISAAC Phase Three rationale and methods are described in this paper. With over 280 centres in 106 countries, we anticipate that ISAAC Phase Three will comprehensively determine the prevalence of symptoms of asthma and allergic disease worldwide, explore recent time trends in the prevalence of these symptoms and cast new light on the aetiology of asthma and allergic disease.

Asthma↗
PubMed2003

Paediatric bronchiectasis in the twenty-first century: experience of a tertiary children's hospital in New Zealand.

OBJECTIVE: Despite its decline in developed countries, bronchiectasis appeared to be a common diagnosis in Auckland, New Zealand children. The aims of this study were: to document the number of children in Auckland with bronchiectasis, their severity, clinical characteristics and possible aetiologies; to assess whether there was a relationship between ethnicity and poverty; and to estimate a crude bronchiectasis prevalence rate for New Zealand. METHODS: A retrospective review of the case histories of all children attending a tertiary children's hospital in Auckland with bronchiectasis diagnosed by high-resolution chest computed tomography (CT) scan, during the period 1998-2000 was undertaken. Data collected included patient demographics, number of hospitalizations pre- and post-diagnosis, lung function tests, radiology and investigations. The New Zealand deprivation 1996 index was applied to the data to obtain a measure of socio-economic status. RESULTS: Bronchiectasis was found to be common, with an estimated prevalence of approximately one in 6000 in the Auckland paediatric population. It was disproportionately more common in the Pacific Island and Maori children. In Pacific Island children, bronchiectasis not caused by cystic fibrosis was nearly twice as common in the general population than cystic fibrosis. Socio-economic deprivation and low immunization rates may be significant contributing factors. The bronchiectasis seen was extensive. Ninety-three percent had bilateral disease and 64% had involvement of four or more lobes on chest CT scan. A wide range of comorbidities and underlying aetiologies were evident. CONCLUSIONS: Paediatric bronchiectasis in Auckland, New Zealand, is common but underresourced. Only the most severe cases are being recognized, providing a significant challenge for paediatric health professionals.

Administration, Inhalation↗
PubMed2003

Agreement between written and video questions for comparing asthma symptoms in ISAAC.

Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) has reported the prevalence of asthma, rhinitis and eczema symptoms in children. In 99 centres from 40 countries, a total of just under 317,000 13-14-yr-old children also completed a video questionnaire, showing the symptoms and signs of asthma. This first video sequence has been compared to the ISAAC written question asking about current wheezing to explore variations in agreement and the contribution of each questionnaire to wheezing prevalence between centres, by region and language groups. In general, responses to the video questionnaire gave a lower prevalence than the siritten questionnaire and responses were closely correlated. The overall proportion of agreement was high, mean 0.89. but unbalanced, with good negative agreement but poor positive agreement. Chance corrected agreement using Cohen's kappa coefficient, was generally low, with onl 20 centres with kappa >0.4. The contribution of each questionnaire to wheezing prevalence also varied between centres and suggests that written questions about wheezing are variably understood and interpreted by 13-14 yr olds. International comparisons of wheezing and its audiovisual presentation suggest that adolescents interpret a written question about wheezing differently from its audiovisual presentation and that this interpretation shows variation between centres. This relationship and the interpretation of both written and audiovisual presentation of symptoms requires further study in order to better predict asthma.

Adolescent↗
PubMed2001

The burden of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema in children and adolescents in six New Zealand centres: ISAAC Phase One.

AIM: To describe the burden of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema in children in six New Zealand centres. METHODS: The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One was undertaken in Auckland, Bay of Plenty, Hawke's Bay, Wellington, Nelson and Christchurch during 1992-1993. In each centre, approximately 3,000 six to seven year old children and 3,000 thirteen to fourteen year old adolescents were studied, a total of 37,592 participants. Both age groups answered written questionnaires and the adolescents a video questionnaire about asthma symptoms. RESULTS: The prevalences of symptoms were high, for asthma 25% and 30%, allergic rhinoconjunctivitis 10% and 19%, and atopic eczema 15% and 13% in each age group respectively. More than 40% of participants had symptoms in the last year of at least one condition, most commonly asthma. There were no significant differences among regions, except for six to seven year olds in Nelson who had significantly lower prevalences of some symptoms of asthma and allergic rhinoconjunctivitis. CONCLUSIONS: Asthma and allergies are common in New Zealand, with resultant morbidity and cost. However, there is little regional variation with the exception of lower rates in Nelson children. Explanations for these findings will be the subject of further studies.

Adolescent↗
PubMed2001

Current controversies: sinus disease and the lower airways.

This review explores the literature dealing with the relation between the upper and lower airways, including the possible link between chronic sinus disease and asthma, and between chronic sinus disease and cough. Imaging studies, microbiology, epidemiology, animal studies, and effects of treatment are discussed. Available studies do not prove that upper airway disease directly causes lower airway pathology. Allergic rhinitis causing nasal blockage needs treatment, as does symptomatic sinus disease. Where there is concurrent disease of the upper and lower airways, both conditions need to be treated adequately. Further research is required to establish the relation between upper and lower airways, and animal models may help to unravel the mechanisms and impact of treatment. Randomized, blinded, controlled trials are needed in both children and adults to assess therapies of chronic sinusitis and the response of asthma.

Asthma↗
PubMed2001

A review of cough in children.

Cough is a very common symptom of respiratory disease and reason for parents to seek medical attention. The article presents broad clinical guidelines on the approach to childhood cough and discusses current controversies of the management of cough in children.

Adult↗
PubMed2001

Diet and asthma, allergic rhinoconjunctivitis and atopic eczema symptom prevalence: an ecological analysis of the International Study of Asthma and Allergies in Childhood (ISAAC) data. ISAAC Phase One Study Group.

Several studies have suggested that the increasing prevalence of symptoms of asthma, rhinitis and eczema, could be associated with dietary factors. In the present paper, a global analysis of prevalence rates of wheeze, allergic rhinoconjunctivitis and atopic eczema was performed in relation to diet, as defined by national food intake data. Analyses were based on the International Study of Asthma and Allergies in Childhood (ISAAC) data for 6-7 and 13-14 yr old children. Symptoms of wheeze, allergic rhinoconjunctivitis and atopic eczema symptom prevalence were regressed against per capita food intake, and adjusted for gross national product to account for economic development. Dietary data were based on 1995 Food and Agriculture Organisation of the United Nations data for 53 of the 56 countries that took part in ISAAC phase I (1994/1995). The 13-14 year age group showed a consistent pattern of decreases in symptoms of wheeze (current and severe), allergic rhinoconjunctivitis and atopic eczema, associated with increased per capita consumption of calories from cereal and rice, protein from cereals and nuts, starch, as well as vegetables and vegetable nutrients. The video questionnaire data for 13-14 yr olds and the ISAAC data for 6-7 yr olds showed similar patterns for these foods. A consistent inverse relationship was seen between prevalence rates of the three conditions and the intake of starch, cereals, and vegetables. If these findings could be generalised, and if the average daily consumption of these foods increased, it is speculated that an important decrease in symptom prevalence may be achieved.

Adolescent↗
PubMed2001

Immunization and symptoms of atopic disease in children: results from the International Study of Asthma and Allergies in Childhood.

OBJECTIVES: This study tested the hypothesis that immunization is related to the prevalence of atopic disease in childhood. METHODS: We used data from the International Study of Asthma and Allergies in Childhood to perform an ecologic analysis of national and local immunization rates for tuberculosis, diphtheria and tetanus toxoids and pertussis (DTP), and measles and prevalence of atopic disease symptoms (asthma, allergic rhinoconjunctivitis, and atopic eczema). RESULTS: In 13- to 14-year-old children, there were significant negative associations with local birth-year immunization rates for DTP and measles but none with rates for tuberculosis. No associations were found in 6- to 7-year-old children. No associations with national immunization rates were found. CONCLUSIONS: International variations in childhood atopic diseases are unlikely to be explained by variations in immunization.

Adolescent↗
PubMed2000

Costs and effectiveness of spacer versus nebulizer in young children with moderate and severe acute asthma.

OBJECTIVE: To compare the costs and effectiveness of albuterol by metered dose inhaler (MDI) and spacer versus nebulizer in young children with moderate and severe acute asthma. DESIGN: Randomized, double-blind, placebo-controlled trial in an emergency department at a children's hospital. The participants were children 1 to 4 years of age with moderate to severe acute asthma. Patients assigned to the spacer group received albuterol (600 microg) by MDI by spacer (AeroChamber) followed by placebo by nebulizer (n = 30). The nebulizer group received placebo MDI by spacer followed by 2.5 mg albuterol by nebulizer (n = 30). Treatments were repeated at 20-minute intervals until the patient was judged to need no further doses of bronchodilator, or a total of 6 treatments. RESULTS: Clinical score, heart rate, respiratory rate, auscultatory findings, and oxygen saturation were recorded at baseline, after each treatment, and 60 minutes after the last treatment. Baseline characteristics and asthma severity were similar for the treatment groups. The spacer was as effective as the nebulizer for clinical score, respiratory rate, and oxygen saturation but produced a greater reduction in wheezing (P =.03). Heart rate increased to a greater degree in the nebulizer group (11.0/min vs 0.17/min for spacer, P <.01). Fewer children in the spacer group required admission (33% vs 60% in the nebulizer group, P =.04, adjusted for sex). No differences were seen in rates of tremor or hyperactivity. The mean cost of each emergency department presentation was NZ$825 for the spacer group and NZ$1282 for the nebulizer group (P =.03); 86% of children and 85% of parents preferred the spacer. CONCLUSION: The MDI and spacer combination was a cost-effective alternative to a nebulizer in the delivery of albuterol to young children with moderate and severe acute asthma.

Acute Disease↗
PubMed1998

The International Study of Asthma and Allergies in Childhood (ISAAC). ISAAC Steering Committee.

Despite considerable research, the aetiology of asthma and allergic disease remains poorly understood. The International Study of Asthma and Allergies In Childhood (ISAAC), was founded to maximize the value of epidemiological research into asthma and allergic disease by establishing a standardized methodology and facilitating international collaboration. It has achieved its specific aims which are to describe the prevalence and severity of asthma, rhinitis and eczema in children living in different centres and to make comparisons within and between countries; to obtain baseline measures for assessment of future trends in the prevalence and severity of these diseases; and to provide a framework for further aetiological research into genetic, lifestyle, environmental and medical care factors affecting these diseases. The ISAAC design comprises three phases. Phase One used simple core written questionnaires for two age groups, and was completed in 156 collaborating centres in 56 countries and a total of 721 601 children participated. In the 13-14 years age group 155 centres from 56 countries participated, of which 99 centres completed a video questionnaire. For the 6-7 years age group there were 91 collaborating centres in 38 countries. ISAAC Phase One has demonstrated a large variation in the prevalence of asthma symptoms in children throughout the world including hitherto unstudied populations. It is likely that environmental factors were responsible for major differences between countries. The results provide a framework for studies between populations in contrasting environments which are likely to yield new clues about the aetiology of asthma. ISAAC Phase Two will investigate possible aetiological factors, particularly those suggested by the findings of Phase One. ISAAC Phase Three will be a repetition of Phase One in the year 2000 to assess trends in prevalence.

Adolescent↗
PubMed1997

Measuring morbidity from asthma in children.

AIMS: To develop new measures of asthma morbidity which would be applicable to children with asthma of all grades of severity. METHODS: This study used a cross sectional sample of asthmatic children. Traditional asthma morbidity measures (admission to hospital, use of Emergency Room, general practitioner, after hours deputising service and ambulance) were compared with new measures (school attendance, teacher assessment, parental perception of morbidity and parents emotional response to child's asthma). RESULTS: Data was obtained for 381 children with asthma. Children with poor school attendance were found in the severe group as judged by a composite score using traditional measures (r = 0.30, p < 0.0001). A new composite morbidity score based on two questions about parental perception of severity (how often has asthma prevented participation in activities and rating of severity of asthma in general over the last year) and two questions about parent emotional response to the child's asthma (how often has your child's asthma (a) made you feel frightened and (b) stopped family activities) was developed. This new measure of asthma morbidity was correlated with the composite score using traditional morbidity measures (r = 0.43, p < 0.0001) and with school attendance (r = 0.28, p < 0.0001). CONCLUSION: These new morbidity measures are quick and easy to use, and provide an opportunity to measure asthma severity at the moderate to mild end of the severity spectrum. We recommend their use for both clinical assessment and research.

Absenteeism↗
PubMed1997

The effect of season-of-response to ISAAC questions about asthma, rhinitis and eczema in children.

BACKGROUND: To examine whether responses to questions about the lifetime prevalence and 12-month period prevalence of symptoms of asthma and allergies are affected by the season in which the questions are asked. METHODS: The international Study of Asthma and Allergies in Childhood (ISAAC) Phase One was undertaken in six New Zealand centres; in three centres the effect of season was studied. Over three school terms at least 3000 children were studied in each of two age groups per centre (6-7 years; 13-14 years), one-third in each term respectively. The ISAAC standardized written questionnaires were used to identify asthma, rhinitis and eczema symptoms. The written questionnaire in the younger age group was completed by the parent/guardian. The older age group self-completed the written questionnaire and also a video questionnaire about asthma symptoms. RESULTS: The total number of respondents was 21,437, approximately half in each age group. The season of responding had no effect on the level of response to eczema questions. For the written asthma questionnaire no season-of-response effect was present for 6-7 year olds; for 13-14 year olds there was a trend to a higher rate of positive responses by those responding in winter, but in only one question did this reach statistical significance. With the video questionnaire there was a similar trend for a higher rate of positive responses when questions were asked in winter, but this did not reach statistical significance. For rhinitis symptoms there was a statistically significant season-of-response effect in both age groups with two questions; the fewest positive responses by the winter responders. CONCLUSIONS: There was no significant effect of season-of-response to questions on eczema symptoms, and most questions on asthma symptoms. There was a season-of-response effect on responses to questions on rhinitis symptoms suggesting a recall bias relating to recency of symptoms.

Adolescent↗
PubMed1997

Worldwide variations in prevalence of symptoms of allergic rhinoconjunctivitis in children: the International Study of Asthma and Allergies in Childhood (ISAAC).

BACKGROUND: As part of the International Study of Asthma and Allergies in Childhood (ISAAC), prevalence surveys were conducted among representative samples of school children from locations in Europe, Asia, Africa, Australia, North and South America. SUBJECTS: 257,800 children aged 6-7 years from 91 centres in 38 countries, and 463,801 children aged 13-14 years from 155 centres in 56 countries. METHODS: Written symptom questionnaires were translated from English into the local language for self-completion by the 13-14-year-olds and completion by the parents of the 6-7-year-olds. Rhinitis was described as a problem with sneezing, or a runny, or blocked nose when you (your child) DID NOT have a cold or the flu. Additional questions were asked about rhinitis associated with itchy-watery eyes, interference with activities and a history of hay fever ever. RESULTS: The prevalence of rhinitis with itchy-watery eyes ("rhinoconjunctivitis") in the past year varied across centres from 0.8% to 14.9% in the 6-7-year-olds and from 1.4% to 39.7% in the 13-14-year-olds. Within each age group, the global pattern was broadly consistent across each of the symptom categories. In centres of higher prevalence there was great variability in the proportion of rhinoconjunctivitis labelled as hay fever. The lowest prevalences of rhinoconjunctivitis were found in parts of eastern Europe, south and central Asia. High prevalences were reported from centres in several regions. CONCLUSION: These results suggest substantial worldwide variations in the prevalence and labelling of symptoms of allergic rhinoconjunctivitis which require further study. These differences, if real, may offer important clues to environmental influences on allergy.

Adolescent↗