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Biomedical subjects

D Jarvis

Publications and source records attributed to D Jarvis.

At least 19 recordsLinked to original sources
PubMed2003

Promoting safer sex among HIV-positive youth with haemophilia: theory, intervention, and outcome.

The goal of the project was to develop and evaluate theory-based interventions designed to change sexual behaviour and promote safer sex practices of HIV seropositive young men and adolescents with haemophilia to prevent transmission to sexual partners and offspring. Safer sex was defined as abstinence, consistent condom use, or 'outercourse' (intimate, non-intercourse sexual behaviour). This project utilized the Transtheoretical Model developed by Prochaska and DiClemente, which describes behaviour change as an incremental, stage-based process. The 1-year intervention protocol consisted of two individual sessions and two peer-centred activities. One hundred and four adolescents, residing in 22 states, participated. Pre- and post-intervention evaluations were conducted to measure stage progression for participants. The number who were in the action or maintenance stage of change for safer sex was significantly greater at post-test than at pre-test (79 vs. 62%, P < 0.0001). Participants also reported an increased use of outercourse. In addition, significant increases in self-efficacy and knowledge regarding safer sex were demonstrated. Following these stage-based interventions, participants were significantly more likely to be engaging in safer sex behaviours than they were previously. These intervention activities can be adapted for use with other adolescent populations and for other behaviour change goals in adolescents with haemophilia.

Adolescent↗
PubMed2003

Accident and emergency departments are still failing to assess asthma severity.

OBJECTIVES: To quantify the documentation of vital signs in children attending accident and emergency (A&E) for asthma and to assess whether indicators of severity were used appropriately. METHODS: Records of all children aged 3 to 14 attending A&E for the treatment of asthma in four London hospitals over a three month period were examined for documentation of heart rate, respiratory rate, peak expiratory flow rate, oxygen saturation, and fraction of inspired oxygen. The relation between severity indicators and whether the child was admitted or not was examined. RESULTS: There were 255 attendances in 229 children. Heart rate, respiratory rate, and oxygen saturation were recorded on most attendances (94.5%, 85.5%, and 96.8%) but fraction of inspired oxygen and peak flow were recorded in few children (48.6% and 48.5%). Heart rate and respiratory rate were higher and oxygen saturation lower in children who were admitted compared with those who were not. CONCLUSIONS: Assessment of airways obstruction is inadequate in children but when measured may be used appropriately to guide admission. There is a need for interventions to improve assessment of children attending A&E for asthma.

Adolescent↗
PubMed2003

Volcanic ash and respiratory symptoms in children on the island of Montserrat, British West Indies.

BACKGROUND: In July 1995 the volcano on the West Indian island of Montserrat erupted after being inactive for several hundred years. Since then, clouds of ash have been released intermittently from the volcano. Some of this ash is <10 micro m in diameter and therefore respirable. Concerns were raised that the particles might cause respiratory problems. AIMS: To evaluate whether ashfalls had any effect on the respiratory health of children in Montserrat. METHODS: A survey of asthma diagnoses, respiratory symptoms, exercise induced bronchoconstriction (EIB), and current and previous exposure to volcanic ash was carried out in schools in Montserrat during February 1998. RESULTS: Questionnaire information was available for nearly 80% of the 443 children on the school rolls. The prevalence of wheeze symptoms in the previous 12 months was 18% in children aged 12 years and under and 16% in children aged 13 years and over. In children aged 12 and under, the prevalence of wheeze was greater in those who had ever been heavily or moderately exposed to volcanic ash compared with the group who had only ever been exposed to low levels (wheeze in last 12 months: odds ratio (OR) 4.30; wheeze ever: OR 3.45). The prevalence of EIB in 8-12 year olds was about four times higher in those who were currently heavily exposed to volcanic ash (OR 3.85) compared to those currently exposed to low levels. CONCLUSIONS: Volcanic ash emissions adversely affected the respiratory health of Montserrat children. The findings emphasise the need to limit exposures of children to volcanic ash and ensure the appropriate management of respiratory symptoms.

Adolescent↗
PubMed2002

Association of body mass index with respiratory symptoms and atopy: results from the European Community Respiratory Health Survey.

BACKGROUND: There are several reports showing that obese adults report more respiratory symptoms suggestive of asthma than those who are not obese. OBJECTIVE: To determine the association of body mass index with respiratory symptoms and atopy in young adults METHOD: Information collected from 15,454 participants in the European Community Respiratory Health Survey, a multicentre cross-sectional survey of young adults, was analysed to determine the association of body mass index with respiratory symptoms and atopy. RESULTS: Men and women with a body mass index of greater than 30 were at an increased risk of wheeze with shortness of breath compared with those with a body mass of 20-24.99 (OR in men 1.85, 95% confidence interval 1.41-2.42; OR in women 2.03, 95% confidence interval 1.59-2.58). Similar associations were observed for other symptoms suggestive of asthma. Body mass index was not associated with 'hayfever or nasal allergies', specific IgE to house dust mite, grass or cat or with total IgE in men or women. CONCLUSION: Reported associations of body mass index with symptoms suggestive of asthma are unlikely to be explained by a higher risk of atopy in the obese. Alternative explanations must be sought.

Adult↗
PubMed2002

Early exposure to children in family and day care as related to adult asthma and hay fever: results from the European Community Respiratory Health Survey.

BACKGROUND: The literature indicates that early exposure to children in the family and to day care permanently influences the development of allergic disease. A study was undertaken to examine the associations of family size and day care with adult asthma and hay fever and to determine whether these associations are mediated through specific IgE production and whether they vary with allergic predisposition. METHODS: 18,530 subjects aged 20-44 years from 36 areas predominantly in the market economies participated in the European Community Respiratory Health Survey and provided information through interviewer-led questionnaires. 13,932 subjects gave blood samples for measurement of specific IgE. RESULTS: Hay fever was less common in subjects with many siblings (OR=0.92; 95% CI 0.90 to 0.95 per sib). There was a U-shaped relationship between asthma and number of siblings (quadratic effect of siblings, pwheeze=0.014, pFEV(1)=0.016). In subjects without siblings but exposed to children in day care, hay fever was less common (OR=0.76; 95% CI 0.60 to 0.98) and asthma symptoms were more common (ORwheeze=1.48; 95% CI 1.12 to 1.95). Adjustment for specific IgEs did not alter these associations. The inverse association of hay fever with siblings was found in sensitised subjects (OR=0.89; 95% CI 0.84 to 0.94) and in those with parental allergy (OR=0.91; 95% CI 0.85 to 0.97), but not in subjects without such a predisposition (OR=1.02; 95% CI 0.97 to 1.09). CONCLUSION: Subjects exposed to many children at home or in day care experienced less hay fever and more asthma in adulthood. Microbial challenge through children may contribute to a non-allergic immunological development giving less hay fever but more airways infections predisposing to asthma. These effects were not mediated through production of specific IgE. The protective effect of siblings on hay fever was particularly strong in those with an allergic predisposition.

Adult↗
PubMed2002

Relation of bronchial responsiveness to body mass index in the ECRHS. European Community Respiratory Health Survey.

BACKGROUND: There is substantial evidence for an association between symptoms of asthma and overweight or obesity. However, a study that reported no association between bronchial responsiveness (BHR) and body mass index (BMI) suggested that the relation of symptoms to obesity was due to increased diagnosis of asthma. The relation of BHR to BMI was therefore investigated in a large multicentre study. METHODS: Data were obtained for 11,277 participants in stage II of the European Community Respiratory Health Survey (ECRHS). BHR to methacholine was analysed in relation to BMI adjusted for a number of factors known to be associated with BHR, including baseline lung function and allergen sensitisation, and combined across 34 centres using random effects meta-analysis. RESULTS: BHR increased with increasing BMI in men (ECRHS slope changed by -0.027 for each unit increase in BMI, 95% confidence interval -0.044 to -0.010, p=0.002), but the relation in women was weak (-0.014, 95% CI -0.033 to 0.005, p=0.14). There was no evidence for an interaction of sex with BMI (p=0.41). CONCLUSIONS: BHR is related to BMI in the ECRHS. This suggests that the association is not due to greater diagnosis or perception of symptoms in obese people compared with those of normal weight. The data do not support the finding by some studies of a relation between asthma and obesity in women but not in men.

Adult↗
PubMed2002

Asthma characteristics in cleaning workers, workers in other risk jobs and office workers.

Several studies have demonstrated an excess risk for asthma among cleaning workers. The aim of this analysis was to compare clinical, immunological and functional characteristics associated with asthma in cleaners and other occupational groups. Cleaners, workers exposed to high molecular weight (MW) agents, workers exposed to low MW agents, and office workers were identified from an international community-based epidemiological study. Influence of sex, smoking, age and atopy on the relationships with asthma was investigated. Rates of respiratory symptoms, bronchial hyperresponsiveness, atopic sensitisation and lung function were compared between asthmatics from the four groups (case-case analysis). The risk for asthma in workers exposed to low MW agents was higher among nonatopics than among atopics. Case-case analysis showed no major differences in asthma characteristics between cleaners and workers exposed to high or low MW agents. Asthmatic cleaners had less atopy, more chronic bronchitis and a lower lung function as compared to office workers. Asthma in cleaning workers showed many similarities with that in workers known to be at risk for occupational asthma. Atopic sensitisation did not seem to play an important role in cleaning-related asthma.

Adult↗
PubMed2001

Does living on a farm during childhood protect against asthma, allergic rhinitis, and atopy in adulthood?

Recent studies of children suggest that factors encountered in a farm environment might protect against the development of allergy. However, it remains uncertain whether living on a farm in childhood is associated with a decreased risk of atopic diseases in adulthood. We analyzed data from 6,251 randomly selected adults 20 to 44 yr of age participating in the European Community Respiratory Health Survey (ECRHS). Subjects answered a detailed questionnaire and underwent specific IgE measurements to five allergens. After adjustment for potential confounders, including pet exposure in childhood, number of siblings, severe respiratory infection in childhood, and parental history of allergy, living on a farm in childhood was associated with a reduced risk of atopic sensitization in adulthood (OR = 0.76, CI 95% = 0.60-0.97). Compared with other adults, those who had lived on a farm as a child were less frequently sensitized to cat (OR = 0.63, CI 95% = 0.41-0.96) and to Timothy grass (OR = 0.68, CI 95% = 0.50-0.94), and were at lower risk of having nasal symptoms in the presence of pollen (OR = 0.80, CI 95% = 0.64-1.02). The protective effect of farming environment in childhood observed in this population-based sample of young adults provides evidence in favor of the hypothesis that environmental factors encountered in childhood may have a lifelong protective effect against the development of allergy.

Adult↗
PubMed2001

Dissolved organic carbon losses from grazed grasslands under different management regimes.

Dissolved organic matter (DOM) is fundamental to many biogeochemical processes in soils and natural waters. Despite the large number of studies reporting on DOM losses from forest soils and in surface waters there is little published data on exports from managed grasslands. The objective of our study was to determine the extent of short-term exports of dissolved organic carbon (DOC) from managed grazed grasslands and to evaluate the influence of fertilizer management and drainage regime. DOC discharged from grazed grassland plots, with a range of management strategies. was determined over 2 months. Total export varied from 42 to 118 kgCha(-1), and was greater from some plots than literature estimates for annual losses from all catchment types. There was a significant (P = 0.048) positive correlation between DOC export and rates of nitrogen application for treatments with no artificial drainage. Increased dry matter production arising from increased fertilizer-N inputs is suggested as an important factor in this relationship. DOC export was significantly (P = 0.032) reduced by artificial drainage and adsorption of DOC to soil surfaces and the restriction of decomposition due to waterlogging are suggested as two possible explanations.

Agriculture↗
PubMed2001

Determinants of cough in young adults participating in the European Community Respiratory Health Survey.

Cough is a common symptom that affects a large proportion of the general population. The aim of this investigation was to identify determinants of nocturnal, nonproductive and productive cough in population samples from different countries. In a cross-sectional international population survey, 18,277 subjects (20-48 yrs) from 16 countries answered an interview-led questionnaire. Total and specific immunoglobulin-E was measured and spirometry was performed. Three types of cough were defined: nocturnal, nonproductive and productive cough. The relation of the independent variables to cough was estimated by means of logistic regression for each centre or country and combined across centre or country by random-effects meta-analysis. The median prevalence of nocturnal, nonproductive and productive cough in the different centres was 30.7%, 10.2% and 10.2%, respectively. Nocturnal and nonproductive cough were related to female sex (adjusted odds ratio (OR)=2.08 and 1.27, respectively), while nocturnal and productive cough were related to rhinitis (OR=1.46 and 1.61, respectively). All three types of cough were related to asthma, tobacco smoking, environmental tobacco smoke and obesity. Females are more likely to report nocturnal and nonproductive cough than males. Cough was related to treatable disorders, like asthma and rhinitis, as well as avoidable factors, such as tobacco smoking and environmental tobacco smoke.

Adult↗
PubMed2001

The European Community Respiratory Health Survey: what are the main results so far? European Community Respiratory Health Survey II.

The European Community Respiratory Health Survey (ECRHS) was the first study to assess the geographical variation in asthma and allergy in adults using the same instruments and definitions. The database of the ECRHS includes information from approximately 140,000 individuals from 22 countries. The aim of this review is to summarize the results of the ECRHS to date. The ECRHS has shown that there are large geographical differences in the prevalence of asthma, atopy and bronchial responsiveness, with high prevalence rates in English speaking countries and low prevalence rates in the Mediterranean region and Eastern Europe. Analyses of risk factors have highlighted the importance of occupational exposure for asthma in adulthood. The association between sensitization to individual allergens and bronchial responsiveness was strongest for indoor allergens (mite and cat). Analysis of treatment practices has confirmed that the treatment of asthma varies widely between countries and that asthma is often undertreated. In conclusion, the European Community Respiratory Health Survey has shown that the prevalence of asthma varies widely. The fact that the geographical pattern is consistent with the distribution of atopy and bronchial responsiveness supports the conclusion that the geographical variations in the prevalence of asthma are true and most likely due to environmental factors.

Asthma↗
PubMed1999

The association of smoking with sensitization to common environmental allergens: results from the European Community Respiratory Health Survey.

BACKGROUND: Smoking is a risk factor for sensitization to some occupational allergens, but its association with sensitization to common environmental allergens remains unclear. OBJECTIVE: We sought to determine the association of smoking with total IgE levels and with sensitization to 3 common environmental allergens in data from the European Community Respiratory Health Survey. METHODS: A detailed smoking history and blood sample for determination of serum total IgE and specific IgE levels to house dust mite, grass, and cat allergens was obtained from 13,002 randomly selected young adults living in the areas served by 34 centers in 14 countries. Associations with smoking status and amount smoked were determined. Because there was evidence of heterogeneity between centers in the association of age, sex, and smoking with sensitization, odds ratios (ORs) were determined for each center and combined by using random-effects meta-analysis. RESULTS: Compared with lifetime nonsmokers, current smokers were at an increased risk of sensitization to house dust mite allergen (OR, 1.13; 95% confidence interval [CI], 1.02-1.26) but a decreased risk of sensitization to grass (OR, 0.76; 95% CI, 0.67-0.88) and cat allergens (OR, 0.69; 95% CI, 0.59-0.80). Exclusion of those with symptoms suggestive of current asthma strengthened the association of smoking with sensitization to house dust mite allergen (OR, 1.29; 95% CI, 1.11-1. 50). The geometric mean total IgE level was higher in smokers and was higher among those who currently smoked the most compared with those who smoked less than 5 cigarettes per day. CONCLUSION: The association between smoking and sensitization to common environmental allergens is different for different allergens.

Adult↗
PubMed1999

Role of current and childhood exposure to cat and atopic sensitization. European Community Respiratory Health Survey.

BACKGROUND: Clinical and population studies have shown that exposure and sensitization to allergens derived from furred pets, particularly cats, represent an important risk factor of allergic respiratory disease and also a significant risk factor for asthma. OBJECTIVE: In the framework of the multicenter European Community Respiratory Health Survey an analysis of the association of current and childhood exposure to cat with atopic sensitization to cat was conducted. METHODS: This study included cross-sectional data from 35 centers representing 16 countries. Altogether, 18,097 subjects were included, of whom 13,509 (75%) provided a blood sample for the measurement of specific IgE. Exposure data and data for potential confounders were extracted from an interviewer-led questionnaire. RESULTS: The prevalence of sensitization to cat (serum specific IgE >0.35 kU/L) was 9%. Among those who did not report allergic symptoms in the presence of pets or house dust, those who owned cats were significantly more likely to be sensitized to cats than were those who did not (odds ratio [95% confidence interval] 1.57 [1.20-2.06]. Childhood exposure to pets including cats was associated with lower sensitization to cats in adulthood, particularly among those with a positive family history of atopy (odds ratio [95% confidence interval] 0.68 [0.51-0.93]. Positive correlations were found between the community prevalence of cat and the prevalences of sensitization to cat, respiratory symptoms, physician-diagnosed asthma, and current asthma medication. CONCLUSIONS: Current cat ownership represents a significant risk for sensitization to cat if cats are allowed indoors. Our results support the hypothesis that childhood exposure to pets, including cats, might modulate immunologic mechanisms and reduce sensitization to cat in adulthood. The significant correlation found between the community prevalence of cat ownership and community prevalence of specific sensitization to cat represents the first documentation of such a relationship.

Adult↗
PubMed1999

Childhood environment and adult atopy: results from the European Community Respiratory Health Survey.

BACKGROUND: Previous literature has indicated that environmental exposures in childhood influence development of atopic sensitization. OBJECTIVE: We sought to study the association between childhood environment and adult atopy. METHODS: Thirteen thousand nine hundred thirty-two subjects aged 20 to 44 years from 36 areas in Europe, New Zealand, the United States, and Australia took part in the European Community Respiratory Health Survey, answering interviewer-led questionnaires and providing blood tests for measurement of specific IgE to grass, house dust mite, cat, and Cladosporium allergens. RESULTS: Atopy was negatively associated with family size (OR = 0. 93; 95% CI = 0.90-0.96 per 1 sib), partly attributable to an independent protective effect of a greater number of brothers (OR = 0.92; 95% CI = 0.89-0.95 per 1 brother). Accounting for total number of siblings, no further influence was detected for number of older or younger siblings. Bedroom sharing was associated with a lower prevalence of atopy, particularly to cat allergen. A protective effect of family size and bedroom sharing could only be detected in subjects reporting no parental allergy (family size, test for interaction P =.012). The presence of a dog in the home in childhood was negatively associated with adult atopy (OR = 0.85, 95% CI = 0. 78-0.92), an effect that remained after adjustment for parental allergy, sibling allergy, and adult pet ownership. CONCLUSION: Subjects from large families with brothers, shared bedrooms, and dogs in childhood were less often atopic as adults. Our findings are consistent with the hypothesis that infectious agents could inhibit development of atopy during childhood. However, in subjects with a strong genetic predisposition, environmental factors in childhood are possibly of less importance.

Adult↗
PubMed1999

Sensitization to individual allergens and bronchial responsiveness in the ECRHS. European Community Respiratory Health Survey.

Little is known about the relation of bronchial responsiveness (BHR) to sensitization to individual allergens, or its variation between countries. Data were obtained for BHR, specific immunoglobulin E and confounding variables from 11,215 subjects, aged 20-44 yrs at the start of the European Community Respiratory Health Survey, in 34 centres in 15 countries. The relation of BHR to sensitization to cat, house dust mite, timothy grass and Cladosporium was estimated by means of multiple regression for each centre, and combined across centres by random effects meta-analysis, controlling for baseline lung function, height, sex, season of testing, age, smoking and age/sex and age/smoking interactions. BHR was greater, on average, in those sensitized to cat (p=0.023), house dust mite (p<0.001) and timothy grass (p=0.018), but not to Cladosporium (p=0.60), and increased with degree of sensitization (p<0.001). All relations showed heterogeneity between centres, although to a lesser extent in the relation to sensitization to house dust mite. More variation in bronchial responsiveness was explained by sensitization and degree of sensitization to the individual allergens than by atopy defined as any positive test in each centre, but the relative importance of each allergen varied. The use of atopy as a single variable in relation to bronchial hyperresponsiveness may be misleading.

Adult↗