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Average Prevalence (average + prevalence)
Selected AbstractsThe epidemiology of contact allergy in the general population , prevalence and main findingsCONTACT DERMATITIS, Issue 5 2007Jacob Pontoppidan Thyssen A substantial number of studies have investigated the prevalence of contact allergy in the general population and in unselected subgroups of the general population. The aim of this review was to determine a median prevalence and summarize the main findings from studies on contact allergy in the general population. Published research mainly originates from North America and Western Europe. The median prevalence of contact allergy to at least 1 allergen was 21.2% (range 12.5,40.6%), and the weighted average prevalence was 19.5%, based on data collected on all age groups and all countries between 1966 and 2007. The most prevalent contact allergens were nickel, thimerosal, and fragrance mix. The median nickel allergy prevalence was 8.6% (range 0.7,27.8%) and demonstrates that nickel was an important cause of contact allergy in the general population and that it was widespread in both men and women. Numerous studies demonstrated that pierced ears were a significant risk factor for nickel allergy. Nickel was a risk factor for hand eczema in women. Finally, heavy smoking was associated with contact allergy, mostly in women. Population-based epidemiological studies are considered a prerequisite in the surveillance of national and international contact allergy epidemics. [source] Gender and Ethnic Diversity Among UK Corporate BoardsCORPORATE GOVERNANCE, Issue 2 2007Stephen Brammer This paper investigates the ethnic and gender diversity of the corporate board of UK companies, placing particular emphasis on links to board size and industry characteristics. We employ a novel dataset that covers a large sample of UK PLCs and describes a director's gender, ethnicity and position held. We find both ethnic and gender diversity to be very limited, and that diversity is somewhat less pronounced among executive positions. We find significant cross-sector variation in gender diversity, with an above average prevalence of women in Retail, Utilities, Media and Banking, while such variation in ethnic diversity is considerably less pronounced. Our evidence suggests that a close proximity to final consumers plays a more significant role in shaping board diversity than does the female presence among the industry's workforce. We argue that this shows that board diversity is influenced by a firm's external business environment and particularly an imperative to reflect corresponding diversity among its customers. [source] Schizophrenia in homeless persons: a systematic review of the literatureACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2002D. Folsom Objective:,This article systematically reviews studies of prevalence of schizophrenia in homeless persons. Method:,Medline and PsychInfo were searched using the key words: homeless person, mental illness, psychosis, and schizophrenia. The bibliographies of identified articles were also reviewed. Results:,Study designs varied considerably. The rate of schizophrenia in homeless persons reported in the 33 published reports, representing eight different countries, ranged from 2 to 45%. In the 10 methodologically superior studies, the prevalence range was 4,16% and the weighted average prevalence was 11%. In addition, rates were higher in younger persons, women and the chronically homeless. Slightly less than half of the homeless persons with schizophrenia were not currently receiving treatment. Conclusion:,Schizophrenia is much more prevalent among homeless persons than in the population at large. Future research should focus on better ways of meeting the mental health care needs of homeless people with schizophrenia. [source] Differences in spatial predictions among species distribution modeling methods vary with species traits and environmental predictorsECOGRAPHY, Issue 6 2009Alexandra D. Syphard Prediction maps produced by species distribution models (SDMs) influence decision-making in resource management or designation of land in conservation planning. Many studies have compared the prediction accuracy of different SDM modeling methods, but few have quantified the similarity among prediction maps. There has also been little systematic exploration of how the relative importance of different predictor variables varies among model types and affects map similarity. Our objective was to expand the evaluation of SDM performance for 45 plant species in southern California to better understand how map predictions vary among model types, and to explain what factors may affect spatial correspondence, including the selection and relative importance of different environmental variables. Four types of models were tested. Correlation among maps was highest between generalized linear models (GLMs) and generalized additive models (GAMs) and lowest between classification trees and GAMs or GLMs. Correlation between Random Forests (RFs) and GAMs was the same as between RFs and classification trees. Spatial correspondence among maps was influenced the most by model prediction accuracy (AUC) and species prevalence; map correspondence was highest when accuracy was high and prevalence was intermediate (average prevalence for all species was 0.124). Species functional type and the selection of climate variables also influenced map correspondence. For most (but not all) species, climate variables were more important than terrain or soil in predicting their distributions. Environmental variable selection varied according to modeling method, but the largest differences were between RFs and GLMs or GAMs. Although prediction accuracy was equal for GLMs, GAMs, and RFs, the differences in spatial predictions suggest that it may be important to evaluate the results of more than one model to estimate the range of spatial uncertainty before making planning decisions based on map outputs. This may be particularly important if models have low accuracy or if species prevalence is not intermediate. [source] An ecological law and its macroecological consequences as revealed by studies of relationships between host densities and parasite prevalenceECOGRAPHY, Issue 3 2001Per ArnebergArticle first published online: 30 JUN 200 Epidemiological models predict a positive relationship between host population density and abundance of macroparasites. Here I test these by a comparative study. I used data on communities of four groups of parasites inhabiting the gastrointestinal tract of mammals, nematodes of the orders Oxyurida, Ascarida, Enoplida and Spirurida, respectively. The data came from 44 mammalian species and represent examination of 16 886 individual hosts. I studied average prevalence of all nematodes within an order in a host species, a measure of community level abundance, and considered the potential confounding effects of host body weight, fecundity, age at maturity and diet. Host population density was positively correlated with parasite prevalence within the order Oxyurida, where all species have direct life cycles. Considering the effects of other variables did not change this. This supports the assumption that parasite transmission rate generally is a positive function of host population density. It also strengthens the hypothesis that host densities generally act as important determinants of species richness among directly transmitted parasites and suggests that negative influence of such parasites on host population growth rate increase with increasing host population density among host species. Within the other three nematode orders, where a substantial number of the species have indirect life cycles, no relationships between prevalence and host population density were seen. Again, considering the effects of other variables did not affect this conclusion. This suggests that host population density is a poor predictor of species richness of indirectly transmitted parasites and that effects of such parasites on host population dynamics do not scale with host densities among species of hosts. [source] Identification of ,hot spots' of obesity and being underweight in early pregnancy in LiverpoolJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 3 2009J. C. Abayomi Abstract Background: Obesity and being underweight in pregnancy are related to an increased risk of maternal and foetal morbidity, yet their prevalence is often unknown. The present study aimed to identify neighbourhoods with a higher than average prevalence or ,hot spots' of obesity and/or being underweight among first trimester pregnant women. Methods: A database was compiled consisting of postcode, height and weight for 7981 women who had booked-in for antenatal care between July 2004 and June 2005 at Liverpool Women's Hospital. Body mass index (BMI) was calculated and women were categorised accordingly. Postcodes for 6865 cases across Merseyside were converted to geolocations (pin-points on a map) using conversion software (http://www.census.ac.uk/cdu/). Results: There was a very high prevalence of being overweight (27%) and obesity (17%); 3.8% of women were underweight and probably malnourished (BMI < 18.5 kg m,2); and a further 10.7% of women were possibly malnourished (BMI < 20.0 kg m,2. Deriving case density from the geolocations allowed visualisation and identification of six neighbourhoods with above average levels of obesity and three neighbourhoods had marked concentrations of both being underweight and obesity. Conclusions: These neighbourhoods, particularly those identified as ,hot spots' for both being underweight and obesity, include some of the most deprived wards in the UK. As dietetic intervention may help to promote optimal weight gain during pregnancy and improve dietary intake for pregnant women and their families, primary health care providers should target these localities with a high prevalence of low and high BMI as a priority. [source] Systematic review: the epidemiology of eosinophilic oesophagitis in adultsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2010R. J. Sealock Summary Background, The epidemiology of eosinophilic oesophagitis (EoE) in adults remains unclear. Aim, To estimate the prevalence and incidence of EoE through a systematic review of published literature. Methods, We conducted systematic literature searches in PubMed in September 2009. Studies were excluded if they contained any participants below 18 years of age, published in languages other than English, or had no exact reporting of prevalence or incidence rates. Results, Nine studies fulfilled the criteria; one evaluated a population-based sample, one examined patients referred from a defined geographical region and seven studies examined the prevalence in a total of 6018 patients in clinic or hospital settings. The lowest prevalence was reported in population-based studies (4 and 0.23 per 1000), followed by studies of unselected patients (1.0%, 6.5%) and highest in the other five clinic/hospital based studies (2.2,48.2%). Men were more affected in seven of eight studies (64.5,100%). The sample size weighted average prevalence from the population-based studies was 0.03%. For studies evaluating symptomatic patients, it was 2.8%. Conclusions, The prevalence of EoE in adults varies considerably based on the study sampling frame: high in dysphagia patients, quite low in population-based studies and intermediate among unselected endoscopy patients. [source] Systematic review: the extra-oesophageal symptoms of gastro-oesophageal reflux disease in childrenALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2009V. TOLIA Summary Background, Extra-oesophageal symptoms are thought to be common, atypical symptoms of gastro-oesophageal reflux disease (GERD) in children. Aim, To investigate the prevalence of GERD in children with extra-oesophageal symptoms or of extra-oesophageal symptoms in children with GERD, and the effect of GERD therapies on extra-oesophageal symptoms. Methods, A systematic review of articles in PubMed and EMBASE. Results, We identified 18 relevant articles. The pooled weighted average prevalence of GERD in asthmatic children was 23%, compared with 4% in healthy controls from the same five studies. The majority of studies evaluating the relationship between apparent life-threatening event (ALTE) and GERD did not suggest a causal relationship. Seven studies reported that respiratory symptoms, sinusitis and dental erosion were significantly more prevalent in children with GERD than in controls. Data from pharmacotherapeutic trials were inconclusive and provided no support for a causal relationship between GERD and extra-oesophageal symptoms. Conclusions, Possible associations exist between GERD and asthma, pneumonia, bronchiectasis, ALTE, laryngotracheitis, sinusitis and dental erosion, but causality or temporal association were not established. Moreover, the paucity of studies, small sample sizes and varying disease definitions did not allow firm conclusions to be drawn. Most trials of GERD therapies showed no improvement in extra-oesophageal symptoms in children. [source] Global map of the prevalence of symptoms of rhinoconjunctivitis in children: The International Study of Asthma and Allergies in Childhood (ISAAC) Phase ThreeALLERGY, Issue 1 2009N. Aït-Khaled Background:, Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) measured the global patterns of prevalence and severity of symptoms of rhinoconjunctivitis in children in 1993,1997. Methods:, International Study of Asthma and Allergies in Childhood Phase Three was a cross-sectional survey performed 5,10 years after Phase One using the same methodology. Phase Three covered all of the major regions of the world and involved 1 059 053 children of 2 age groups from 236 centres in 98 countries. Results:, The average overall prevalence of current rhinoconjunctivitis symptoms was 14.6% for the 13- to 14-year old children (range 1.0,45%). Variation in the prevalence of severe rhinoconjunctivitis symptoms was observed between centres (range 0.0,5.1%) and regions (range 0.4% in western Europe to 2.3% in Africa), with the highest prevalence being observed mainly in the centres from middle and low income countries, particularly in Africa and Latin America. Co-morbidity with asthma and eczema varied from 1.6% in the Indian sub-continent to 4.7% in North America. For 6- to 7-year old children, the average prevalence of rhinoconjunctivitis symptoms was 8.5%, and large variations in symptom prevalence were also observed between regions, countries and centres. Discussion:, Wide global variations exist in the prevalence of current rhinoconjunctivitis symptoms, being higher in high vs low income countries, but the prevalence of severe symptoms was greater in less affluent countries. Co-morbidity with asthma is high particularly in Africa, North America and Oceania. This global map of symptom prevalence is of clinical importance for health professionals. [source] | ||||||||||