Biomedical subjects
M Abramson
Publications and source records attributed to M Abramson.
Encasement of bedding does not improve asthma in atopic adult asthmatics.
AIM: We evaluated the impact of impermeable bed covers on asthma in asthmatics with clinically relevant house dust mite (HDM) sensitization. METHODS: The study included 32 HDM-sensitized asthmatics in whom HDM allergy was considered as a significant factor in their asthma. They were randomized into either an intervention group whose bedding was encased with impermeable covers, or a control group who received cotton covers. Before and 3 and 6 months after encasement, dust samples were collected from the bedding and assayed for Der p 1. Clinical outcomes included quality of life, lung function, bronchial reactivity to methacholine, symptoms, medications and peak flow rates. RESULTS: Baseline Der p 1 levels in both the active and the placebo groups were comparable and high (19.2 vs 18.9 microg/g of dust). There was a significant reduction in Der p 1 levels in the active group after 6 months, but not in the placebo group (7.3 vs 21.9 microg/g of dust). Quality of life improved significantly in both the intervention and control groups, but there was no significant difference in the improvements between the groups. There was no significant change in lung function, symptoms, and requirements for medications. CONCLUSIONS: Encasement of bedding significantly reduced the Der p 1 levels. However, this was not sufficient to produce worthwhile clinical improvement in those in whom dust mite avoidance might well have been recommended as part of their clinical management.
Screening for lung cancer.
BACKGROUND: While population based screening for lung cancer has not been adopted by most countries, it is not clear whether sputum examinations, chest radiography or newer methods such as computed tomography are effective in reducing mortality from lung cancer. OBJECTIVES: To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality. SEARCH STRATEGY: Electronic databases (the Cochrane Central Register of Controlled Trials, MEDLINE, PREMEDLINE and EMBASE; 1966 to July 2000) ), bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials. SELECTION CRITERIA: Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest. DATA COLLECTION AND ANALYSIS: Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effects model, but for other outcomes the fixed effect model was used. MAIN RESULTS: Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT. REVIEWER'S CONCLUSIONS: The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.
Enhancing validity: what counts as an asthma attack?
BACKGROUND: Major epidemiological studies in asthma use the question: "How many attacks of asthma have you had in the last 12 months?" We set out to study what constitutes an asthma attack from the perspective of people with asthma. We also examined concordance between qualitative responses and standard quantitative measures of this question. METHODS: Individuals aged 18 to 70 years who sought care for asthma at Emergency Departments in an Australian central city, a suburban and a regional hospital were recruited. Sixty two (43 women and 19 men) participants were interviewed in depth. All interviews were taped, transcribed and thematically analyzed. Demographic data and responses to respiratory health data were also collected. FINDINGS: Widely varying responses to the question, "How many attacks of asthma have you had in the last 12 months?" were found in the quantitative data set. Comparison of quantitative and qualitative data sets showed good agreement between these two responses (intraclass correlation 0.66). People defined asthma attacks as "major" and "minor," as determined by the degree of personal control they were able to exercise. A strongly unifying description of a severe attack was that it was "out of control." Patient's recognized that upper respiratory tract infections commonly triggered major attacks. INTERPRETATION: A commonly asked question about the number of asthma attacks in the past year needs refinement in order to enhance validity. Asthma action plans should use the words "out of control" when defining a severe attack of asthma.
Choosing to attend an asthma doctor: a qualitative study in adults attending emergency departments.
BACKGROUND: Asthma treatment guidelines currently recommend a 'therapeutic partnership' to achieve best care. It is frequently assumed that individuals presenting to emergency departments with asthma do not have a good doctor-patient relationship. We asked what is the nature of patients' relationships with their doctors in those presenting to hospital emergency departments for asthma care. METHODS: A qualitative study of all consenting individuals aged 18-70 years who presented to a hospital emergency department over 2 months was carried out. Sixty-two participants (19 male) engaged in in-depth interviews which were taped, transcribed and underwent thematic analysis. Questionnaire data were also collected and asthma severity determined. RESULTS: Nearly all patients (61/62) had a doctor whom they saw for their asthma. Patients made thoughtful choices on where they sought care according to their needs. Our findings identified that perceptions of doctors' competence, listening to patients and time constraints were important influences on doctor-patient relationships. Participants had strong expectations that their personal disease experience would be acknowledged by their doctors. CONCLUSION: This group of patients had doctors who cared for their asthma. The acceptability of medical care was determined as much by patient choice as by the quality of the doctor-patient relationship.
Asthma and vaccination history in a young adult cohort.
BACKGROUND: It has been suggested that childhood vaccinations may be associated with the onset of asthma. We investigated the association between asthma, atopy and vaccination history in a cohort of young adults living in Melbourne, Australia. METHODS: Subjects were aged between 22 and 44 years and were surveyed by an interviewer-administered questionnaire. Questions were asked about vaccinations to measles, mumps and rubella (MMR), triple antigen (DTP), hepatitis B and Sabin polio vaccine (OPV). Atopy was assessed by skin prick testing to common aeroallergens. RESULTS: There was no significant association observed for subjects diagnosed with asthma who had received measles or MMR vaccinations compared with those who did not receive measles or MMR vaccinations (RR 1.33, 95% CI 0.98-1.80). Non-significant associations were also observed for OPV and hepatitis B vaccinations (RR 3.27, 95% CI 0.50-21.3 and RR 1.08, 95% CI 0.83-1.41, respectively). However, subjects reporting full immunisation were found to be at higher risk to asthma (RR 1.52, 95% CI 1.09-2.11) but not atopy. CONCLUSIONS: Our results show relatively weak support for the hypothesis that childhood vaccinations may lead to increased risk of asthma, but caution is advised due to possible recall bias.
Reported adverse food reactions overestimate true food allergy in the community.
OBJECTIVE: To determine the extent to which perceived adverse food reactions were associated with IgE mediated food allergy, as defined by skin prick testing (SPT). DESIGN: A cohort epidemiological study. Participants underwent SPT to five common food allergens (cow's milk, peanut mix, egg white, shrimp and whole grain wheat mix) and were asked whether they had ever suffered any food 'illness/trouble', and if so to list such food(s). A positive SPT was defined as wheal diameter of > or =3 mm. Cohen's kappa (kappa) was used to assess the agreement between SPT and self-reported reactions to food(s) which contained the allergen of interest. SETTING: Randomly selected adults who took part in the follow-up of the European Community Respiratory Health Survey (ECRHS) in 1998. SUBJECTS: The subjects were 457 adults aged 26-50 y. RESULTS: Fifty-eight (13%) adults were sensitised to at least one food allergen whilst 99 adults (22%) reported illness to food(s) nearly always. However, only seven subjects who reported illness to a food also had a positive SPT to the same food. The prevalence of adverse food reactions associated with IgE mediated allergy in the adult general population would be less than 1.5% (7/457). The agreement between SPT and self-reported illness to food(s) was poor for cow's milk (kappa=0) and wheat (kappa=0), slight for shrimp (kappa=0.16) and egg white (kappa=0.09) and fair for peanut mix (kappa=0.37). CONCLUSIONS: There was little agreement between self-reported perceived illness to food(s) known to contain the food allergen of interest, and positive SPT, suggesting that most reactions are not due to IgE mediated food allergy.
Mouldy houses influence symptoms of asthma among atopic individuals.
BACKGROUND: The influence of current levels of indoor fungi on asthma is a controversial issue that needs to be resolved in order to advise patients appropriately. OBJECTIVE: To assess the seasonal variation in indoor fungal levels and the impact of these levels on asthma among mould-sensitized individuals. METHODS: Thirty-five young adults with current asthma and sensitization to fungi were visited four times over 1 year. At each home visit a questionnaire was administered and samples of dust and air were collected. Participants also recorded information on symptoms, peak expiratory flows (PEF) and medication use. Dust samples were analysed for house dust mite allergen (Der p 1) and total fungal biomass (ergosterol). Total and genus-specific fungal propagules were identified in air samples. Seasonal variation in allergen levels and significant independent effects of fungal levels on peak flow variability (PFV) were identified by repeated measures analysis of variance. RESULTS: Significant seasonal variations were observed in viable airborne fungi, ergosterol levels in the floor dust and PFV. PFV correlated significantly with symptom scores and the dose of reliever medication. PFV was also significantly associated with smoking and visible mould. The association between visible mould and PFV was independent of season, smoking and the dose of reliever medication. However, there was no association between total fungi, specific fungi or ergosterol and PFV. Der p 1 levels had no significant influence on asthma, even in HDM-sensitized individuals. CONCLUSIONS: Mouldy homes adversely influence asthma in asthmatics sensitized to fungi.
Wheeze not current asthma affects quality of life in young adults with asthma.
BACKGROUND: A study was undertaken to investigate quality of life in asthma, defined by differing criteria, to see which may be most appropriate in epidemiological studies. METHODS: The 426 adults were participants in the follow up phase of the European Community Respiratory Health Survey (ECRHS) in Melbourne. As part of the laboratory visit, participants completed the SF-36 quality of life questionnaire, a detailed respiratory questionnaire, and underwent lung function testing. RESULTS: Both the physical component summary and the mental component summary scores were significantly worse in those with wheeze in the previous 12 months than in those without wheeze. Only the mental component summary score was significantly worse in those with current asthma than in those without. In contrast, in those with current asthma or bronchial hyperreactivity only, neither of the summary scales was significantly different between cases and controls. CONCLUSIONS: Quality of life is severely impaired in individuals with wheeze in the previous 12 months while individuals with current asthma or bronchial hyperreactivity alone did not appear to have significantly reduced quality of life.
European Community Respiratory Health Survey calibration project of dosimeter driving pressures.
Two potential sources of systematic variation in output from Mefar dosimeters, the system used in the European Community Respiratory Health Survey (ECRHS) study have been evaluated: individual nebulizer characteristics and dosimeter driving pressure. Output variation from 366 new nebulizers produced in two batches for the second ECRHS were evaluated, using a solute tracer method, at a fixed driving pressure. The relationship between dosimeter driving pressure was then characterized and between-centre variation in dosimeter driving pressure was evaluated in an Internet-based survey. A systematic difference between nebulizers manufactured in the two batches was identified. Batch one had a mean+/-SD output of 7.0+/-0.8 mg x s(-1) and batch two, 6.3+/-0.7 mg x s(-1) (p<0.005). There was a wide range of driving pressures generated by Mefar dosimeters as set, ranging between 70-245 kPa, with most outside the quoted manufacturer's specification of 180+/-5%. Nebulizer output was confirmed as linearly related to dosimeter driving pressure (coefficient of determination (R2)=0.99, output=0.0377 x driving pressure-0.4151). The range in driving pressures observed was estimated as consistent with a variation of about one doubling in the provocative dose causing a 20% fall in forced expiratory volume in one second. Systematic variation has been identified that constitutes potentially significant confounders for between-centre comparisons of airway responsiveness in the European Community Respiratory Health Survey, with the dosimeter driving pressure representing the most serious issue. This work confirms the need for appropriate quality control of both nebulizer output and dosimeter driving pressure, in laboratories undertaking field measurements of airway responsiveness. In particular, appropriate data on driving pressures need to be collected and factored into between-centre comparisons. Comprehensive collection of such data to optimize quality control is practicable and has been instigated by the organizing committee for the European Community Respiratory Health Survey II.
Current indoor allergen levels of fungi and cats, but not house dust mites, influence allergy and asthma in adults with high dust mite exposure.
We assessed the influence of current indoor levels of fungi, house dust mite allergen (Der p 1), and cat allergen (Fel d 1) on sensitization and asthma in adults. A total of 485 adults answered a questionnaire and had skin prick tests and lung function tests. Dust and air samples were collected from their bedrooms. The dust was analyzed for Der p 1, Fel d 1, and fungal biomass (ergosterol). Fungal propagules were measured in air samples. Current asthma was defined as having wheezed during the past 12 mo plus bronchial hyperreactivity (BHR) to methacholine. High exposure to total airborne fungi was associated with increased BHR, but perhaps paradoxically with a lower risk of being sensitized to fungi. Ergosterol levels in floor dust were a risk factor both for being sensitized to fungi and having wheezed within the last year. High Fel d 1 levels in floor dust were found to increase the risk of being sensitized to cats and in beds to increase the risk of current asthma. Although Der p 1 levels in homes were high, people exposed to high Der p 1 levels in floor dust were less likely to be sensitized to house dust mites or to have wheezed within the past year. Current indoor levels of fungi and Fel d 1, but not Der p 1, influenced sensitization and asthma in adults with high dust mite exposure.
Screening for lung cancer.
BACKGROUND: The effectiveness of screening for lung cancer with chest radiography, sputum cytology or spiral CT has not been established. OBJECTIVES: To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality. SEARCH STRATEGY: Electronic databases, bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials. SELECTION CRITERIA: Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest. DATA COLLECTION AND ANALYSIS: Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effect model, but for other outcomes the fixed effect model was used. MAIN RESULTS: Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT. REVIEWER'S CONCLUSIONS: The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.
Long-term trends in occupational exposure.
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The rising prevalence of asthma in young Melbourne adults is associated with improvement in treatment.
BACKGROUND: Asthma is a common source of morbidity and is now recognized as a national health priority in Australia. Although a number of epidemiologic studies have been conducted in Australia to determine the prevalence of asthma in adults, it is unclear whether the prevalence is changing. OBJECTIVES: To determine the prevalence in 1998 of self-reported asthma and respiratory symptoms among young adults and changes in prevalence between 1990 and 1999. METHODS: Cross-sectional postal survey to 4,455 young adults (aged 20 to 44 years) randomly selected from the electoral rolls of the inner southeastern suburbs of metropolitan Melbourne. The survey instrument was the validated European Community Respiratory Health Survey screening questionnaire, which gathered data on self-reported respiratory symptoms, including whether asthma had been diagnosed. Identically worded questions from similar surveys conducted in 1990, 1992, and 1999 were used to compare changes in prevalence. RESULTS: A response rate of 72% was achieved in 1998 after three mailings and telephone followup. Forty-two percent reported nasal allergies, 26% wheezed within the past 12 months, and 20% ever had asthma. The prevalence of doctor-diagnosed asthma was 18%, whereas 10% reported using asthma medications within the past 12 months. Nine percent of respondents reported an asthma attack within the past 12 months. The prevalence of having ever had asthma, doctor-diagnosed asthma, and using asthma medications had increased significantly since 1990. However, the prevalence of respiratory symptoms did not significantly change over this time. CONCLUSIONS: The prevalence of asthma is likely to be rising, but the symptoms of asthma are being better managed in young Melbourne adults.
International prevalences of reported food allergies and intolerances. Comparisons arising from the European Community Respiratory Health Survey (ECRHS) 1991-1994.
OBJECTIVE: The aim of this study was to report the prevalence, type and reported symptoms associated with food intolerance. DESIGN: A cross-sectional epidemiological study involving 15 countries using standardized methodology. Participants answered a detailed interviewer-administered questionnaire and took part in blood, lung function and skin prick tests to common aeroallergens. SETTING: Randomly selected adults who took part in the second phase of the European Community Respiratory Health Survey (ECRHS). SUBJECTS: The subjects were 17280 adults aged 20-44 y. RESULTS: Twelve percent of respondents reported food allergy/intolerance (range 4.6% in Spain to 19.1% in Australia). Atopic females who had wheezed in the past 12 months, ever had asthma or were currently taking oral asthma medications were significantly more likely to report food allergy/intolerance. Participants from Scandinavia or Germany were significantly more likely than those from Spain to report food allergy/intolerance. Respondents who reported breathlessness as a food-related symptom were more likely to have wheezed in the past 12 months, to have asthma, use oral asthma medications, be atopic, have bronchial hyperreactivity, be older and reside in Scandinavia. CONCLUSION: Self-reported food allergy/intolerance differed significantly across multiple countries. The reasons for these differences were not explored in this study, but are likely to be largely due to cultural differences.
Limited (information only) patient education programs for adults with asthma.
BACKGROUND: A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. At its simplest level, education is limited to the transfer of information about asthma, its causes and its treatment. This review focused on the effects of limited asthma education. OBJECTIVES: The objective of this review was to assess the effects of limited (i.e. information only) asthma education on health outcomes in adults with asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and reference lists of articles. SELECTION CRITERIA: Randomised and controlled trials of individual asthma education involving information transfer only in adults over 16 years of age. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for missing information. MAIN RESULTS: Eleven trials were included. They were of variable quality. Limited asthma education did not reduce hospitalisation for asthma (weighted mean difference -0.03 average hospitalisations per person per year, 95% confidence interval -0.09 to 0.03). There was no effect on doctor visits, lung function and medication use. The effects on asthma symptoms were variable. There was no reduction in days lost from normal activity, but perceived asthma symptoms did improve after limited asthma education (odds ratio 0.40, 95% confidence interval 0.18 to 0.86). In one study, limited asthma education was associated with reduced emergency department visits (weighted mean difference -2.76 average visits per person per year, 95% confidence interval -4.34 to 1.18). REVIEWER'S CONCLUSIONS: Use of limited asthma education as it has been practiced does not appear to improve health outcomes in adults with asthma. However the use of information in the emergency department may be effective, but this needs to be confirmed.
Self-management education and regular practitioner review for adults with asthma.
BACKGROUND: A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. This review was conducted to examine the strength of evidence supporting Step 6 of the Australian Asthma Management Plan: "Educate and Review Regularly"; to test whether health outcomes are influenced by education and self-management programmes. OBJECTIVES: The objective of this review was to assess the effects of asthma self-management programmes, when coupled with regular health practitioner review, on health outcomes in adults with asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and reference lists of articles. SELECTION CRITERIA: Randomised trials of self-management education in adults over 16 years of age with asthma. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for confirmation. MAIN RESULTS: Twenty-five trials were included. Self-management education was compared with usual care in 22 studies. Self-management education reduced hospitalisations (odds ratio 0.57, 95% confidence interval 0.38 to 0.88); emergency room visits (odds ratio 0.71, 95% confidence interval (0.57 to 0.90); unscheduled visits to the doctor (odds ratio 0.57, 95% confidence interval 0.40 to 0.82); days off work or school (odds ratio 0.55, 95% confidence interval 0.38 to 0. 79); and nocturnal asthma (odds ratio 0.53, 95% confidence interval 0.39 to 0.72). Measures of lung function were little changed. Self-management programmes that involved a written action plan showed a greater reduction in hospitalisation than those that did not (odds ratio 0.35, 95% confidence interval 0.18 to 0.68). People who managed their asthma by self-adjustment of their medications using an individualised written plan had better lung function than those whose medications were adjusted by a doctor. REVIEWER'S CONCLUSIONS: Training in asthma self-management which involves self-monitoring by either peak expiratory flow or symptoms, coupled with regular medical review and a written action plan appears to improve health outcomes for adults with asthma. Training programmes which enable people to adjust their medication using a written action plan appear to be more effective than other forms of asthma self-management.
Corticosteroids for acute severe asthma in hospitalised patients.
BACKGROUND: Corticosteroids are currently used routinely in the management of acute severe asthma. The optimal dose and route of administration continues to be debated. Some investigators have reported a greater benefit of higher doses of corticosteroids in the management of severe asthma, while others have not. OBJECTIVES: To determine whether higher doses of systemic corticosteroids (oral, intravenous or intramuscular) are more effective than lower doses in the management of patients with acute severe asthma requiring hospital admission. SEARCH STRATEGY: Randomised controlled trials were identified from the Cochrane Airways Group Asthma Register. In addition, primary authors and content experts were contacted to identify eligible studies. Bibliographies from included studies, known reviews and texts were also searched. SELECTION CRITERIA: Studies were selected for inclusion in the review if they met the following broad inclusion criteria: described as randomised controlled trials, included patients with acute severe asthma, compared different doses of corticosteroids (any route) in 2 or more treatment arms, and had a minimum period of follow up of 24 hours. Two reviewers independently assessed the studies for inclusion and disagreement was resolved by third party adjudication. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers if the authors were unable to verify the validity of information. Missing data were obtained from authors or calculated from other data presented in the paper. The data were analysed as weighted mean differences (WMD) for primary pulmonary function outcomes using a fixed effects model. For the purposes of the review, three broad categories of corticosteroid dose (equivalent dose of methylprednisolone in 24 hours) were defined in advance: low dose (< or = 80 mg), medium dose (> 80 mg and < or = 360 mg) and high dose (> 360 mg). There were thus 3 main comparison groups: low versus medium dose, medium versus high dose and low versus high dose. MAIN RESULTS: Nine trials were included; a total of 344 adult patients have been studied (96 with low dose, 85 with medium dose and 163 with high dose corticosteroids). Only 6 trials provided sufficient data for the meta-analysis. There were no clinically or statistically significant differences detected in % predicted FEV1 among comparison groups after 24, 48 or 72 hours. At 48 hours, the weighted mean difference was -3.3% predicted (95% confidence interval -12.4 to + 5.8) for the low vs medium dose comparison, -1. 9% predicted (95% CI -8.1 to + 4.3) for the medium vs high dose comparison and + 0.5% predicted (95% CI - 7.8 to + 8.8) for the low vs high dose comparison. There appeared to be no significant differences in side effects or rates of respiratory failure among the varying doses of corticosteroids. REVIEWER'S CONCLUSIONS: No differences were identified among the different doses of corticosteroids in acute asthma requiring hospital admission. Low dose corticosteroids (< or = 80 mg/day of methylprednisolone or < or = 400 mg/day of hydrocortisone) appear to be adequate in the initial management of these adult patients. Higher doses do not appear to offer a therapeutic advantage.