25 results on '"L. Trefan"'
Search Results
2. Meta-analysis of the effects of dietary vitamin E supplementation on α-tocopherol concentration and lipid oxidation in pork
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Claudia Terlouw, Andrea Doeschl-Wilson, Lutz Bünger, J.A. Rooke, L. Trefan, B. Salmi, Catherine Larzul, J. Bloom-Hansen, Sustainable Livestock Systems Group, Scottish Agricultural College, Danish Meat Research Institute (DMRI), Station de Génétique Quantitative et Appliquée (SGQA), Institut National de la Recherche Agronomique (INRA), and Unité de Recherches sur les Herbivores (URH)
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Meat ,Swine ,Thiobarbituric acid ,medicine.medical_treatment ,alpha-Tocopherol ,TBARS ,LIPID OXYDATION ,Thiobarbituric Acid Reactive Substances ,Lipid peroxidation ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Lipid oxidation ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,medicine ,α-TOCOPHEROL ,Animals ,Tocopherol ,Food science ,Muscles ,Vitamin E ,0402 animal and dairy science ,food and beverages ,04 agricultural and veterinary sciences ,META-ANALYSIS ,Animal Feed ,040401 food science ,040201 dairy & animal science ,META-ANALYSE ,Diet ,VITAMIN E ,Longissimus ,Nonlinear Dynamics ,chemistry ,Dietary Supplements ,Animal Nutritional Physiological Phenomena ,Lipid Peroxidation ,PORK QUALITY ,Food Science - Abstract
International audience; Meta-analyses have been carried out to quantify the effect of dietary vitamin E on α-tocopherol accumulation and on lipid oxidation in porcine M. longissimus. Published results of 13 (vitamin E accumulation) and 10 (lipid oxidation) experiments respectively were used for the analyses. After a number of standardization procedures, a nonlinear relationship was found between the supplementary vitamin E and the accumulation of α-tocopherol in pork which approached a maximum value of 6.4 μg/g tissue. Pork lipid oxidation levels were described in terms of Thiobarbituric Acid Reacting Substances (TBARS) values. The statistical analysis revealed significant effect of vitamin E dose, muscle α-tocopherol concentration and supplementation time on TBARS, resulting in two prediction models for lipid oxidation. Meta-analysis has proven to be a valuable tool for combining results from previous studies to quantify the effects of dietary vitamin E. Further studies, carried out with standardized experimental protocols would be beneficial for model validation and to increase the predictive power of the derived models.
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- 2011
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3. Meta-analysis of the effect of the halothane gene on 6 variables of pig meat quality and on carcass leanness1
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J. Bloom-Hansen, Catherine Larzul, L. Trefan, B. Salmi, Jean Pierre Bidanel, and Andrea Doeschl-Wilson
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2. Zero hunger ,0303 health sciences ,Veterinary medicine ,media_common.quotation_subject ,0402 animal and dairy science ,Regression analysis ,04 agricultural and veterinary sciences ,General Medicine ,Biology ,Random effects model ,040201 dairy & animal science ,Breed ,03 medical and health sciences ,Economic factor ,Meta-analysis ,Genetics ,medicine ,Animal Science and Zoology ,Quality (business) ,Halothane ,Gene effect ,030304 developmental biology ,Food Science ,medicine.drug ,media_common - Abstract
Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss, whereas carcass quality is often characterized by lean percentage. A meta-analysis of findings relating to 3,530 pigs reported in 23 publications was carried out to assess the effects of the halothane gene, sex, breed, and slaughter weight of animals on 7 selected variables: pH at 45 min postmortem, ultimate pH, reflectance (L*-value), redness (a*-value), yellowness (b*-value), drip loss, and lean percentage. Two statistical methods were used in the meta-analysis: the method of effect size and the better known random effects model. The method of effect size was associated with Markov chain Monte Carlo techniques for implementing Bayesian hierarchical models to avoid the problems of limited data and publication bias. The results of our meta-analysis showed that the halothane genotype had a significant effect on all analyzed pork quality variables. Between-study variance was evaluated with the Cochran (1954) Q-test of heterogeneity. Meta-regression was used to explain this variance, with covariates such as breed, sex, slaughter weight, and fasting duration being integrated into different regression models. The halothane gene effect was associated with the breed effect only for the following variables: L*-value, b*-value, and drip loss. Slaughter weight contributed significantly only to the explanation of differences in ultimate pH between homozygous genotypes. In response to inconsistencies reported in the literature regarding the difference between the genotypes NN and Nn, results of the meta-analysis showed that the difference between these 2 genotypes was significant for all the analyzed variables except the a*-value.
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- 2010
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4. Meta-analysis of the effect of the halothane gene on 6 variables of pig meat quality and on carcass leanness
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B, Salmi, L, Trefan, J, Bloom-Hansen, J P, Bidanel, A B, Doeschl-Wilson, and C, Larzul
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Male ,Meat ,Genotype ,Swine ,Body Composition ,Animals ,Bayes Theorem ,Female ,Monte Carlo Method ,Biomarkers ,Markov Chains - Abstract
Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss, whereas carcass quality is often characterized by lean percentage. A meta-analysis of findings relating to 3,530 pigs reported in 23 publications was carried out to assess the effects of the halothane gene, sex, breed, and slaughter weight of animals on 7 selected variables: pH at 45 min postmortem, ultimate pH, reflectance (L*-value), redness (a*-value), yellowness (b*-value), drip loss, and lean percentage. Two statistical methods were used in the meta-analysis: the method of effect size and the better known random effects model. The method of effect size was associated with Markov chain Monte Carlo techniques for implementing Bayesian hierarchical models to avoid the problems of limited data and publication bias. The results of our meta-analysis showed that the halothane genotype had a significant effect on all analyzed pork quality variables. Between-study variance was evaluated with the Cochran (1954) Q-test of heterogeneity. Meta-regression was used to explain this variance, with covariates such as breed, sex, slaughter weight, and fasting duration being integrated into different regression models. The halothane gene effect was associated with the breed effect only for the following variables: L*-value, b*-value, and drip loss. Slaughter weight contributed significantly only to the explanation of differences in ultimate pH between homozygous genotypes. In response to inconsistencies reported in the literature regarding the difference between the genotypes NN and Nn, results of the meta-analysis showed that the difference between these 2 genotypes was significant for all the analyzed variables except the a*-value.
- Published
- 2010
5. Meta-analysis of effects of dietary vitamin E and post slaughter storage conditions on changes of redness (a*) of pork
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J. Blom-Hansen, J.A. Rooke, Andrea Doeschl-Wilson, Catherine Larzul, Lutz Bünger, L. Trefan, B. Salmi, C. Terlouw, Sustainable Livestock Systems Group, Scottish Agricultural College, Danish Meat Research Institute (DMRI), Station de Génétique Quantitative et Appliquée (SGQA), Institut National de la Recherche Agronomique (INRA), Unité de Recherches sur les Herbivores (URH), and University of Edinburgh
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pig ,Cultural Studies ,Mixed model ,Lightness ,Animal breeding ,colour ,[SDV]Life Sciences [q-bio] ,medicine.medical_treatment ,Biology ,Dietary vitamin ,chemistry.chemical_compound ,0404 agricultural biotechnology ,alpha-tocopherol ,medicine ,redness ,pork quality ,[INFO]Computer Science [cs] ,Statistical analysis ,Food science ,meta analysis ,vitmamin e ,Longissimus dorsi ,Vitamin E ,0402 animal and dairy science ,Religious studies ,04 agricultural and veterinary sciences ,040401 food science ,040201 dairy & animal science ,chemistry ,alpha-Tocopherol - Abstract
A meta-analysis was carried out to quantify the effects of dietary vitamin E and storage conditions on colour changes of pork from M. longissimus dorsi. After standardisation procedures, redness of pork (CIE colour specification a*), one of the most important objective colour attributes, was used as an indicator for colour changes in this analysis. The analysis was based on results from five experiments, which met selection criteria. Analysis of changes of other objective colour attributes, lightness (L*) and yellowness (b*) was not possible due to lack of published data. The statistical analysis (using mixed models) found significant effects of tissue α-tocopherol concentration in M. longissimus dorsi, simplified supplemented vitamin E levels as well as storage time and storage light on redness of pork and its changes over time. The relationship between redness and α-tocopherol concentration was found to be linear, and between redness and storage time was non-linear (third degree polynomial) in one model. This model suggested that an increase of 1 μg of α-tocopherol in the muscle led to an expected increase a* value of 0.11. Another model identified significant interactions about 0.28 between α-tocopherol concentration and storage time in late storage periods. A third model found a significant difference of −0.48 between predicted a* values at lower (≤50 IU/kg feed) and higher supplemented vitamin E levels (≥100 IU/kg feed). The models predicted an initial increase for 3 days, a stable period for 5 days and then a decrease for a* values over storage time. The a* values were significantly lower by about 1.4 when samples were exposed to light in the models, the effect of light found to be constant over time. Further studies, carried out with standardized methods, are needed to increase the predictive power of the derived models and to validate the models for other muscles.
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- 2010
6. Trends in antipsychotic prescribing to children and adolescents in England: cohort study using 2000-19 primary care data.
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Radojčić MR, Pierce M, Hope H, Senior M, Taxiarchi VP, Trefan L, Swift E, and Abel KM
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- Male, Female, Child, Humans, Adolescent, Cohort Studies, Drug Prescriptions, England epidemiology, Practice Patterns, Physicians', Primary Health Care, Antipsychotic Agents therapeutic use, Autism Spectrum Disorder drug therapy
- Abstract
Background: The prescription of antipsychotics to children and adolescents has been increasing worldwide. We described up-to-date trends in antipsychotic prescribing and identified likely indications in a contemporary English cohort., Methods: We used a large primary care database, the Clinical Practice Research Datalink (CPRD) Aurum database, and we included all children and adolescents aged 3-18 years in the database and registered in England between Jan 1, 2000, and Dec 31, 2019, excluding those whose gender was recorded as indeterminate. Participants were followed up until the earliest of Dec 31, 2019, June 30 of the year they turned 18 years, their death, when they transferred from the primary care practice, or when the practice left the database. Data were not collected on ethnicity. We recorded antipsychotic prescriptions using the date a prescription was issued. As CPRD prescriptions are not linked to indications, we developed an algorithm to ascertain the most likely indication associated with participants' first antipsychotic prescription using clinical codes. We reported prescribing trends as annual period prevalence and the rate of first antipsychotic prescription, and we used joinpoint regression analysis to identify changes in the outcome trend. We stratified prevalence estimates by age group, gender, and Index of Multiple Deprivation quintiles, we reported frequencies of likely indications associated with incident prescriptions, and we explored clinical preference for typical versus atypical antipsychotics within deprivation quintiles., Findings: Between Jan 1, 2000, and Dec 31, 2019, we included 7 216 791 children and adolescents, of whom 3 480 730 (48·2%) were girls and 3 736 061 (51·8%) were boys, with a mean age at the start of follow-up of 7·3 years (SD 4·9; range 3-18). Median follow-up was 4·1 years (IQR 1·5-8·5). 19 496 (0·3%) individuals received 243 529 antipsychotic prescriptions over follow-up, including 225 710 (92·7%) atypical and 17 819 (7·3%) typical antipsychotic prescriptions. The annual period prevalence of antipsychotic prescriptions rose from 0·057% (95% CI 0·052-0·063%) in 2000 to 0·105% (0·100-0·111%) in 2019. From joinpoint analyses, the period prevalence of all antipsychotic prescriptions increased by an average of 3·3% per year (2·2-4·9%) and the rate of first prescriptions increased by 2·2% per year (1·7-2·7%). The most likely indications of the first identified antipsychotic prescriptions were for autism spectrum disorder (2477 [12·7%]), non-affective psychosis (1669 [8·6%]), anxiety disorders (1466 [7·5%]), ADHD (1391 [7·1%]), depression (1256 [6·4%]), and conduct disorders (1181 [6·1%])., Interpretation: The observed increase in antipsychotic prescriptions over 20 years results from the accumulation of repeated prescriptions to the same individuals combined with an increase in new prescriptions. These findings highlight the need for continued monitoring of trends in antipsychotic use and, although this was not examined in this paper, the findings highlights the need for better information about long-term antipsychotic safety., Funding: None., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)
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- 2023
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7. Primary care clinical management following self-harm during the first wave of COVID-19 in the UK: population-based cohort study.
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Steeg S, Carr M, Trefan L, Ashcroft D, Kapur N, Nielsen E, McMillan B, and Webb R
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- Cohort Studies, Humans, Primary Health Care, Retrospective Studies, SARS-CoV-2, United Kingdom epidemiology, COVID-19, Self-Injurious Behavior epidemiology, Self-Injurious Behavior psychology, Self-Injurious Behavior therapy
- Abstract
Objectives: A substantial reduction in self-harm recorded in primary care occurred during the first wave of COVID-19 but effects on primary care management of self-harm are unknown. Our objectives were to examine the impact of COVID-19 on clinical management within 3 months of an episode of self-harm., Design: Retrospective cohort study., Setting: UK primary care., Participants: 4238 patients with an index episode of self-harm recorded in UK primary care during the COVID-19 first-wave period (10 March 2020-10 June 2020) compared with 48 739 patients in a prepandemic comparison period (10 March-10 June, 2010-2019)., Outcome Measures: Using data from the UK Clinical Practice Research Datalink, we compared cohorts of patients with an index self-harm episode recorded during the prepandemic period versus the COVID-19 first-wave period. Patients were followed up for 3 months to capture subsequent general practitioner (GP)/practice nurse consultation, referral to mental health services and psychotropic medication prescribing. We examined differences by gender, age group and Index of Multiple Deprivation quintile., Results: Likelihood of having at least one GP/practice nurse consultation was broadly similar (83.2% vs 80.3% in the COVID-19 cohort). The proportion of patients referred to mental health services in the COVID-19 cohort (4.2%) was around two-thirds of that in the prepandemic cohort (6.1%). Similar proportions were prescribed psychotropic medication within 3 months in the prepandemic (54.0%) and COVID-19 first-wave (54.9%) cohorts., Conclusions: Despite the challenges experienced by primary healthcare teams during the initial COVID-19 wave, prescribing and consultation patterns following self-harm were broadly similar to prepandemic levels. We found no evidence of widening of digital exclusion in terms of access to remote consultations. However, the reduced likelihood of referral to mental health services warrants attention. Accessible outpatient and community services for people who have self-harmed are required as the COVID-19 crisis recedes and the population faces new challenges to mental health., Competing Interests: Competing interests: NK reports grants and personal fees from the UK Department of Health and Social Care, the National Institute of Health Research (NIHR), the National Institute for Health and Care Excellence (NICE) and the Healthcare Quality and Improvement Partnership, outside the submitted work; works with NHS England on national quality improvement initiatives for suicide and self-harm; is a member of the advisory group for the National Suicide Prevention Strategy of the Department of Health and Social Care; has chaired NICE guideline committees for Self-harm and Depression; and is currently the Topic Advisor for the new NICE Guidelines for self-harm. All other authors declare no competing interests., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)
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- 2022
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8. Visualisation and optimisation of alcohol-related hospital admissions ICD-10 codes in Welsh e-cohort data.
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Trefan L, Akbari A, Morgan JS, Farewell DM, Fone D, Lyons RA, Jones Hywel M, and Moore SC
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- Cohort Studies, Ethanol, Hospitals, Humans, Hospitalization, International Classification of Diseases
- Abstract
Introduction: The excessive consumption of alcohol is detrimental to long term health and increases the likelihood of hospital admission. However, definitions of alcohol-related hospital admission vary, giving rise to uncertainty in the effect of alcohol on alcohol-related health care utilization., Objectives: To compare diagnostic codes on hospital admission and discharge and to determine the ideal combination of codes necessary for an accurate determination of alcohol-related hospital admission., Methods: Routine population-linked e-cohort data were extracted from the Secure Anonymised Information Linkage (SAIL) Databank containing all alcohol-related hospital admissions (n,= 92,553) from 2006 to 2011 in Wales, United Kingdom. The distributions of the diagnostic codes recorded at admission and discharge were compared. By calculating a misclassification rate (sensitivity-like measure) the appropriate number of coding fields to examine for alcohol-codes was established., Results: There was agreement between admission and discharge codes. When more than ten coding fields were used the misclassification rate was less than 1%., Conclusion: With the data at present and alcohol-related codes used, codes recorded at admission and discharge can be used equivalently to identify alcohol-related admissions. The appropriate number of coding fields to examine was established: fewer than ten is likely to lead to under-reporting of alcohol-related admissions. The methods developed here can be applied to other medical conditions that can be described using a certain set of diagnostic codes, each of which can be a known sole cause of the condition and recorded in multiple positions in e-cohort data., Competing Interests: Conflict of interests: The authors declare that they do not have any conflict of interest.
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- 2021
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9. Mental health selection: common mental disorder and migration between multiple states of deprivation in a UK cohort.
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Greene G, Gartner A, Farewell D, Trefan L, Davies AR, Bellis MA, and Paranjothy S
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- Adult, Aged, Female, Health Services Accessibility statistics & numerical data, Humans, Male, Middle Aged, Poverty statistics & numerical data, Socioeconomic Factors, Wales, Young Adult, Health Services Needs and Demand statistics & numerical data, Healthcare Disparities statistics & numerical data, Mental Health statistics & numerical data, Residence Characteristics statistics & numerical data, Social Class
- Abstract
Objectives: To assess whether the direction of movement along the social gradient was associated with changes in mental health status., Design: Longitudinal record-linkage study using a multistate model., Setting: Caerphilly, Wales, UK between 2001 and 2015., Participants: The analytical sample included 10 892 (60.8% female) individuals aged 18-74 years., Primary and Secondary Outcome Measures: Deprivation change at lower super output area level using the 2008 Welsh Index of Multiple Deprivation. Mental health was assessed in 2001 and 2008 using the Mental Health Inventory subscale of the short-form 36 V.2., Results: Mental health selection was shown whereby individuals with common mental health disorders were less likely to move to areas of lower deprivation but more likely to move to areas of greater deprivation., Conclusion: Poor mental health seems to drive health selection in a similar way to poor physical health. Therefore, funding targeted at areas of higher deprivation should consider the demand to be potentially higher as individuals with poor mental health may migrate into that area., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2020
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10. Drinking beer, wine or spirits - does it matter for inequalities in alcohol-related hospital admission? A record-linked longitudinal study in Wales.
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Gartner A, Trefan L, Moore S, Akbari A, Paranjothy S, and Farewell D
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- Adult, Alcoholic Intoxication epidemiology, Alcoholism, Beer statistics & numerical data, Female, Health Surveys, Humans, Longitudinal Studies, Male, Middle Aged, Public Policy, Residence Characteristics, Social Class, Wales, Wine statistics & numerical data, Alcohol Drinking epidemiology, Alcoholic Beverages statistics & numerical data, Hospitalization statistics & numerical data, Socioeconomic Factors
- Abstract
Background: Alcohol-related harm has been found to be higher in disadvantaged groups, despite similar alcohol consumption to advantaged groups. This is known as the alcohol harm paradox. Beverage type is reportedly socioeconomically patterned but has not been included in longitudinal studies investigating record-linked alcohol consumption and harm. We aimed to investigate whether and to what extent consumption by beverage type, BMI, smoking and other factors explain inequalities in alcohol-related harm., Methods: 11,038 respondents to the Welsh Health Survey answered questions on their health and lifestyle. Responses were record-linked to wholly attributable alcohol-related hospital admissions (ARHA) eight years before the survey month and until the end of 2016 within the Secure Anonymised Information Linkage (SAIL) Databank. We used survival analysis, specifically multi-level and multi-failure Cox mixed effects models, to calculate the hazard ratios of ARHA. In adjusted models we included the number of units consumed by beverage type and other factors, censoring for death or moving out of Wales., Results: People living in more deprived areas had a higher risk of admission (HR 1.75; 95% CI 1.23-2.48) compared to less deprived. Adjustment for the number of units by type of alcohol consumed only reduced the risk of ARHA for more deprived areas by 4% (HR 1.72; 95% CI 1.21-2.44), whilst adding smoking and BMI reduced these inequalities by 35.7% (HR 1.48; 95% CI 1.01-2.17). These social patterns were similar for individual-level social class, employment, housing tenure and highest qualification. Inequalities were further reduced by including either health status (16.6%) or mental health condition (5%). Unit increases of spirits drunk were positively associated with increasing risk of ARHA (HR 1.06; 95% CI 1.01-1.12), higher than for other drink types., Conclusions: Although consumption by beverage type was socioeconomically patterned, it did not help explain inequalities in alcohol-related harm. Smoking and BMI explained around a third of inequalities, but lower socioeconomic groups had a persistently higher risk of (multiple) ARHA. Comorbidities also explained a further proportion of inequalities and need further investigation, including the contribution of specific conditions. The increased harms from consumption of stronger alcoholic beverages may inform public health policy.
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- 2019
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11. Epidemiology of alcohol-related emergency hospital admissions in children and adolescents: An e-cohort analysis in Wales in 2006-2011.
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Trefan L, Gartner A, Alcock A, Farewell D, Morgan J, Fone D, and Paranjothy S
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- Adolescent, Child, Cohort Studies, Female, Humans, Incidence, Length of Stay, Male, Wales epidemiology, Alcohol Drinking epidemiology, Emergency Service, Hospital, Hospitalization
- Abstract
Objective: Harmful levels of alcohol consumption in young people are prevalent and of increasing public concern in the western world. Rates of alcohol-related emergency hospital admissions in children and young people between 10 to 17 years were described, and the reasons for these admissions and their association with socio-demographic factors were examined., Methods: E-cohort data were extracted from the Secure Anonymised Information Linkage Databank, which contained alcohol-related emergency hospital admissions (N = 2968) from 2006 to 2011 in children and adolescents aged 10 to 17 years in Wales. A generalised linear mixed model was fitted using a log-link with a population offset to the data to calculate incident rate ratios (IRRSs)., Results: There was a general decreasing trend from 2006 to 2011 in the number and rate of alcohol-related emergency hospital admissions; the mean age of admission was 15.4 (standard deviation 1.4) years. In each of the four youngest age groups (10-13,14,15,16 years), females had higher IRRs than males. Males had slightly higher IRR compared to females only in the oldest age group (17 years). IRRs increased with increasing deprivation. The majority (92%) of the admissions lasted one day and most of the admissions (70%) occured during the last three days of the week with a peak on Saturday. The length of stay in hospital was longer in cases when self-harm were present. Multiple admissions showed high prevalance of serious self-harm cases in females. The number of admissions with injuries and falls were higher for males than females., Conclusion: Female children and adolescents were more likely to be admitted to hospital for alcohol-related reasons. These data illustrate the significant burden of alcohol-related harm in young people and highlight the need for interventions and policies that promote safe drinking practices among young people to prevent future alcohol-related harm during the life-course., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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12. Electronic Longitudinal Alcohol Study in Communities (ELAStiC) Wales - protocol for platform development.
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Trefan L, Akbari A, Paranjothy S, Farewell DM, Gartner A, Fone D, Greene J, Evans A, Smith A, Adekanmbi V, Kennedy J, Lyons RA, and Moore SC
- Abstract
Introduction: Excessive alcohol consumption has adverse effects on health and there is a recognised need for the longitudinal analysis of population data to improve our understanding of the patterns of alcohol use, harms to consumers and those in their immediate environment. The UK has a number of linkable, longitudinal databases that if assembled properly could support valuable research on this topic., Aims and Objectives: This paper describes the development of a broad set of cross-linked cohorts, e-cohorts, surveys and linked electronic healthcare records (EHRs) to construct an alcohol-specific analytical platform in the United Kingdom using datasets on the population of Wales.The objective of this paper is to provide a description of existing key datasets integrated with existing, routinely collected electronic health data on a secure platform, and relevant derived variables to enable population-based research on alcohol-related harm in Wales. We illustrate our use of these data with some exemplar research questions that are currently under investigation., Methods: Record-linkage of routine and observational datasets. Routine data includes hospital admissions, general practice, and cohorts specific to children. Two observational studies were included. Routine socioeconomic descriptors and mortality data were also linked., Conclusion: We described a record-linked, population-based research protocol for alcohol related harm on a secure platform. As the datasets used here are available in many countries, ELAStiC provides a template for setting up similar initiatives in other countries. We have also defined a number of alcohol specific variables using routinely-collected available data that can be used in other epidemiological studies into alcohol related outcomes. With over 10 years of longitudinal data, it will help to understand alcohol-related disease and health trajectories across the lifespan., Competing Interests: Conflict of interest: The authors declare that they do not have any conflict of interest.
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- 2019
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13. A comparison of four different imaging modalities - Conventional, cross polarized, infra-red and ultra-violet in the assessment of childhood bruising.
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Trefan L, Harris C, Evans S, Nuttall D, Maguire S, and Kemp AM
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- Child, Forensic Medicine, Humans, Image Enhancement, Image Processing, Computer-Assisted, Infrared Rays, Photography, Skin injuries, Ultraviolet Rays, Contusions diagnostic imaging, Diagnostic Imaging methods, Skin diagnostic imaging
- Abstract
Background: It is standard practice to image concerning bruises in children. We aim to compare the clarity and measurements of bruises using cross polarized, infra-red (IR) and ultra-violet (UV) images to conventional images., Methods: Children aged <11 years with incidental bruising were recruited. Demographics, skin and bruise details were recorded. Bruises were imaged by standard protocols in conventional, cross-polarized, IR and UV lights. Bruises were assessed in vivo for contrast, uniformity and diffuseness, and these characteristics were then compared across image modalities. Color images (conventional, cross polarized) were segmented and measured by ImageJ. Bruises of grey scale images (IR, UV) were measured by a 'plug in' of ImageJ. The maximum and minimum Feret's diameter, area and aspect ratio, were determined. Comparison of measurements across imaging modalities was conducted using Wilcoxon rank sum tests and modified Bland-Altman graphs. Significance was set at p < 0.05., Results: Twenty five children had 39 bruises. Bruises that were of low contrast, i.e. difficult to distinguish from surrounding skin, were also more diffuse, and less uniformity in vivo. Low contrast bruises were best seen on conventional and cross-polarized images and less distinctive on IR and UV images. Of the 19 bruises visible in all modalities, the only significant difference was maximum and minimum Feret's diameters and area were smaller on IR compared to conventional images. Aspect ratios were not affected by the modality., Conclusions: Conventional and cross-polarized imaging provides the most consistent bruise measurement, particularly in bruises that are not easily distinguished from surrounding skin visually., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2018
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14. Does selective migration alter socioeconomic inequalities in mortality in Wales?: a record-linked total population e-cohort study.
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Gartner A, Farewell D, Greene G, Trefan L, Davies A, Fone D, and Paranjothy S
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Recent studies found evidence of health selective migration whereby healthy people move to less deprived areas and less healthy people move to or stay in more deprived areas. There is no consensus, however, on whether this influences health inequalities. Measures of socio-economic inequalities in mortality and life expectancy are widely used by government and health services to track changes over time but do not consider the effect of migration. This study aims to investigate whether and to what extent migration altered the observed socioeconomic gradient in mortality. Data for the population of Wales (3,136,881) registered with the National Health Service on 01/01/2006 and follow-up for 24 quarters were individually record-linked to ONS mortality files. This included moves between lower super output areas (LSOAs), deprivation quintiles and rural-urban class at each quarter, age, sex, and date of death. Cox regression models were used to estimate the hazard ratios for the deprivation quintiles in all-cause mortality, as well as deprivation change between the start and end of the study. We found evidence of health selective migration in some groups, for example people aged under 75 leaving the most deprived areas having a higher mortality risk than those they left behind, suggesting widening inequalities, but also found the opposite pattern for other migration groups. For all ages, those who lived in the most deprived quintile had a 57% higher risk of death than those in the least deprived quintile, allowing deprivation to vary with moves over time. There was little change in this risk when people were artificially kept in their deprivation quintile of origin (54% higher). Overall, migration during the six year window did not substantially alter the deprivation gradient in mortality in Wales between 2006 and 2011.
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- 2018
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15. Risk of suicide following an alcohol-related emergency hospital admission: An electronic cohort study of 2.8 million people.
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Bowden B, John A, Trefan L, Morgan J, Farewell D, and Fone D
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- Adolescent, Adult, Aged, Aged, 80 and over, Alcoholic Intoxication therapy, Child, Cohort Studies, Electronic Health Records statistics & numerical data, Emergencies psychology, Emergency Treatment psychology, Emergency Treatment statistics & numerical data, Female, Follow-Up Studies, Humans, Male, Middle Aged, Patient Discharge statistics & numerical data, Risk Factors, Self-Injurious Behavior epidemiology, Self-Injurious Behavior psychology, Suicide psychology, Suicide, Attempted psychology, Suicide, Attempted statistics & numerical data, Young Adult, Alcoholic Intoxication epidemiology, Alcoholic Intoxication psychology, Emergencies epidemiology, Patient Admission statistics & numerical data, Suicide statistics & numerical data
- Abstract
Objective: Alcohol misuse is a well-known risk factor for suicide however, the relationship between alcohol-related hospital admission and subsequent risk of death from suicide is unknown. We aimed to determine the risk of death from suicide following emergency admission to hospital with an alcohol-related cause., Methods: We established an electronic cohort study of all 2,803,457 residents of Wales, UK, aged from 10 to under 100 years on 1 January 2006 with six years' follow-up. The outcome event was death from suicide defined as intentional self-harm (ICD-10 X60-84) or undetermined intent (Y10-34). The main exposure was an alcohol-related admission defined as a 'wholly attributable' ICD-10 alcohol code in the admission record. Admissions were coded for the presence or absence of co-existing psychiatric morbidity. The analysis was by Cox regression with adjustments for confounding variables within the dataset., Results: During the study follow-up period, there were 15,546,355 person years at risk with 28,425 alcohol-related emergency admissions and 1562 suicides. 125 suicides followed an admission (144.6 per 100,000 person years), of which 11 (9%) occurred within 4 weeks of discharge. The overall adjusted hazard ratio (HR) for suicide following admission was 26.8 (95% confidence interval (CI) 18.8 to 38.3), in men HR 9.83 (95% CI 7.91 to 12.2) and women HR 28.5 (95% CI 19.9 to 41.0). The risk of suicide remained substantial in subjects without known co-existing psychiatric morbidity: HR men 8.11 (95% CI 6.30 to 10.4) and women HR 24.0 (95% CI 15.5 to 37.3). The analysis was limited by the absence in datasets of potentially important confounding variables and the lack of information on alcohol-related harm and psychiatric morbidity in subjects not admitted to hospital., Conclusion: Emergency alcohol-related hospital admission is associated with an increased risk of suicide. Identifying individuals in hospital provides an opportunity for psychosocial assessment and suicide prevention of a targeted at-risk group before their discharge to the community.
- Published
- 2018
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16. Optimising the measurement of bruises in children across conventional and cross polarized images using segmentation analysis techniques in Image J, Photoshop and circle diameter measurements.
- Author
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Harris C, Alcock A, Trefan L, Nuttall D, Evans ST, Maguire S, and Kemp AM
- Subjects
- Child, Child, Preschool, Forensic Pathology, Humans, Reproducibility of Results, Contusions pathology, Image Processing, Computer-Assisted, Imaging, Three-Dimensional, Software
- Abstract
Background: Bruising is a common abusive injury in children, and it is standard practice to image and measure them, yet there is no current standard for measuring bruise size consistently. We aim to identify the optimal method of measuring photographic images of bruises, including computerised measurement techniques., Methods: 24 children aged <11 years (mean age of 6.9, range 2.5-10 years) with a bruise were recruited from the community. Demographics and bruise details were recorded. Each bruise was measured in vivo using a paper measuring tape. Standardised conventional and cross polarized digital images were obtained. The diameter of bruise images were measured by three computer aided measurement techniques: Image J (segmentation with Simple Interactive Object Extraction (maximum Feret diameter), 'Circular Selection Tool' (Circle diameter), & the Photoshop 'ruler' software (Photoshop diameter)). Inter and intra-observer effects were determined by two individuals repeating 11 electronic measurements, and relevant Intraclass Correlation Coefficient's (ICC's) were used to establish reliability. Spearman's rank correlation was used to compare in vivo with computerised measurements; a comparison of measurement techniques across imaging modalities was conducted using Kolmogorov-Smirnov tests. Significance was set at p < 0.05 for all tests., Results: Images were available for 38 bruises in vivo, with 48 bruises visible on cross polarized imaging and 46 on conventional imaging (some bruises interpreted as being single in vivo appeared to be multiple in digital images). Correlation coefficients were >0.5 for all techniques, with maximum Feret diameter and maximum Photoshop diameter on conventional images having the strongest correlation with in vivo measurements. There were significant differences between in vivo and computer-aided measurements, but none between different computer-aided measurement techniques. Overall, computer aided measurements appeared larger than in vivo. Inter- and intra-observer agreement was high for all maximum diameter measurements (ICC's > 0.7)., Conclusions: Whilst there are minimal differences between measurements of images obtained, the most consistent results were obtained when conventional images, segmented by Image J Software, were measured with a Feret diameter. This is therefore proposed as a standard for future research, and forensic practice, with the proviso that all computer aided measurements appear larger than in vivo., (Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)
- Published
- 2018
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17. Radiological features of healing in newborn clavicular fractures.
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Fadell M, Miller A, Trefan L, Weinman J, Stewart J, Hayes K, and Maguire S
- Subjects
- Bony Callus physiopathology, Child Abuse diagnosis, Cross-Sectional Studies, Female, Fracture Healing physiology, Humans, Infant, Infant, Newborn, Male, Observer Variation, Radiography, Retrospective Studies, Birth Injuries diagnostic imaging, Clavicle injuries, Fractures, Bone diagnostic imaging
- Abstract
Objectives: Given the frequency of abusive fractures among infants, and the lack of research and or evidence for the phases of fracture healing seen in this age group, this study aims to describe a timetable of radiological features of fracture healing among infants in the first months of life., Methods: We completed a retrospective cross-sectional time-series study of birth-related clavicle fractures from 2006-2013. A total of 108 digital images were available for review from 61 infants. The presence or absence of four features of healing including periosteal reaction, callus formation, bridging callus and remodelling were scored by three radiologists., Results: The level of agreement between the radiologists was good to high (0.60-0.90). Features of healing were first seen at 7 days (periosteal reaction), 11 days (callus), 20 days (bridging) and 35 days (remodelling), respectively. The peak periods that each feature was present are as follows: periosteal reaction 11-42 days, callus 12-61 days, bridging 22-63 days and remodelling 49-59 days., Conclusions: Birth-associated clavicle fractures in infants follow a logical progression of healing changes. Understanding the expected progression and timing of fracture healing may be helpful as it pertains to the timing of injury in cases of abuse in infants., Key Points: • Large study describing the time frames of fracture healing in young infants. • Features of fracture healing develop in a logical progression. • Evidence provided for determining fractures are consistent with a proposed time frame. • It is of critical importance to have sound evidence for the dating of fractures.
- Published
- 2017
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18. A study of radiological features of healing in long bone fractures among infants less than a year.
- Author
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Warner C, Maguire S, Trefan L, Miller A, Weinman J, and Fadell M
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- Cross-Sectional Studies, Female, Humans, Infant, Infant, Newborn, Male, Retrospective Studies, Bone Remodeling physiology, Child Abuse diagnosis, Fracture Healing physiology, Fractures, Bone diagnostic imaging, Lower Extremity diagnostic imaging, Upper Extremity diagnostic imaging
- Abstract
Purpose: To create a timetable for dating long bone fractures in infants aged less than 1 year using previously defined radiographic signs of fracture healing., Materials and Methods: A retrospective cross-sectional time series of long bone fractures in infants aged less than 1 year was conducted from 2006 to 2013. After exclusion criteria were applied 59 digital image series were available for review from 40 infants. Utilizing published criteria for dating fractures, the presence or absence of four pre-defined features of healing was scored: periosteal reaction, callus, bridging, and remodeling. Three radiologists independently scored radiographs with a 3-point scale, marking each feature as present, absent, or equivocal. The times in days when features were first seen, peaked (feature agreed present in >40% of images), and last seen were noted. Statistical analysis using free marginal kappa was conducted., Results: The level of agreement among the three radiologists was high (0.64-0.85). The sequence in which the features were seen was: periosteal reaction range 7-130 (present in the majority of cases between 9 and 49 days); callus range 9-130 (present in the majority of cases between days 9-26); bridging range 15-130 (seen in the majority of cases between 15 and 67 days); remodeling range 51-247 days., Conclusion: This study provides a timetable of radiological features of long bone healing among young infants for the first time. Dating of incomplete long bone fractures is challenging, beyond the presence of periosteal reaction, but a consistent sequence of changes is present in complete fractures.
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- 2017
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19. Selecting children for head CT following head injury.
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Kemp A, Nickerson E, Trefan L, Houston R, Hyde P, Pearson G, Edwards R, Parslow RC, and Maconochie I
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- Accidental Falls statistics & numerical data, Accidents, Home, Accidents, Traffic statistics & numerical data, Adolescent, Age Distribution, Child, Child, Preschool, Craniocerebral Trauma epidemiology, Craniocerebral Trauma etiology, Critical Pathways, Cross-Sectional Studies, Emergency Service, Hospital statistics & numerical data, Hospitalization statistics & numerical data, Humans, Infant, Infant, Newborn, Prevalence, Skull Fractures diagnostic imaging, Skull Fractures epidemiology, Time-to-Treatment, Treatment Outcome, Unconsciousness diagnostic imaging, Unconsciousness epidemiology, United Kingdom epidemiology, Unnecessary Procedures statistics & numerical data, Craniocerebral Trauma diagnostic imaging, Patient Selection, Tomography, X-Ray Computed statistics & numerical data
- Abstract
Objective: Indicators for head CT scan defined by the 2007 National Institute for Health and Care Excellence (NICE) guidelines were analysed to identify CT uptake, influential variables and yield., Design: Cross-sectional study., Setting: Hospital inpatient units: England, Wales, Northern Ireland and the Channel Islands., Patients: Children (<15 years) admitted to hospital for more than 4 h following a head injury (September 2009 to February 2010)., Interventions: CT scan., Main Outcome Measures: Number of children who had CT, extent to which NICE guidelines were followed and diagnostic yield., Results: Data on 5700 children were returned by 90% of eligible hospitals, 84% of whom were admitted to a general hospital. CT scans were performed on 30.4% of children (1734), with a higher diagnostic yield in infants (56.5% (144/255)) than children aged 1 to 14 years (26.5% (391/1476)). Overall, only 40.4% (984 of 2437 children) fulfilling at least one of the four NICE criteria for CT actually underwent one. These children were much less likely to receive CT if admitted to a general hospital than to a specialist centre (OR 0.52 (95% CI 0.45 to 0.59)); there was considerable variation between healthcare regions. When indicated, children >3 years were much more likely to have CT than those <3 years (OR 2.35 (95% CI 2.08 to 2.65))., Conclusion: Compliance with guidelines and diagnostic yield was variable across age groups, the type of hospital and region where children were admitted. With this pattern of clinical practice the risks of both missing intracranial injury and overuse of CT are considerable., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)
- Published
- 2016
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20. Epidemiology of children with head injury: a national overview.
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Trefan L, Houston R, Pearson G, Edwards R, Hyde P, Maconochie I, Parslow RC, and Kemp A
- Subjects
- Accidental Falls statistics & numerical data, Accidents, Traffic statistics & numerical data, Adolescent, Age Distribution, Athletic Injuries epidemiology, Child, Child Protective Services statistics & numerical data, Child, Preschool, Craniocerebral Trauma diagnostic imaging, Craniocerebral Trauma mortality, Female, Glasgow Coma Scale, Hospitalization statistics & numerical data, Humans, Infant, Infant, Newborn, Length of Stay statistics & numerical data, Male, Prevalence, Prospective Studies, Severity of Illness Index, Sex Distribution, Skull Fractures diagnostic imaging, Skull Fractures epidemiology, Skull Fractures mortality, Socioeconomic Factors, Tomography, X-Ray Computed, United Kingdom epidemiology, Craniocerebral Trauma epidemiology
- Abstract
Background: The National Confidential Enquiry describes the epidemiology of children admitted to hospital with head injury., Method: Children (<15 years old) who died or were admitted for >4 h with head injury were identified from 216 UK hospitals (1 September 2009 to 28 February 2010). Data were collected using standard proformas and entered on to a database. A descriptive analysis of the causal mechanisms, child demographics, neurological impairment, CT findings, and outcome at 72 h are provided., Results: Details of 5700 children, median age 4 years (range 0-14.9 years), were analysed; 1093 (19.2%) were <1 year old, 3500 (61.4%) were boys. There was a significant association of head injury with social deprivation 39.7/100 000 (95% CI 37.0 to 42.6) in the least deprived first quintile vs. 55.1 (95% CI 52.1 to 58.2) in the most deprived fifth quintile (p<0.01). Twenty-four children died (0.4%). Most children were admitted for one night or less; 4522 (79%) had a Glasgow Coma Scale score of 15 or were Alert (on AVPU (Alert, Voice, Pain, Unresponsive)). The most common causes of head injury were falls (3537 (62.1%); children <5 years), sports-related incidents (783 (13.7%); median age 12.4 years), or motor vehicle accidents (MVAs) (401 (7.1%); primary-school-aged children). CT scans were performed in 1734 (30.4%) children; 536 (30.9%) were abnormal (skull fracture and/or intracranial injury or abnormality): 269 (7.6%) were falls, 82 (10.5%) sports related and 100 (25%). A total of 357 (6.2%) children were referred to social care because of child protection concerns (median age 9 months (range 0-14.9 years))., Conclusions: The data described highlight priorities for targeted age-specific head injury prevention and have the potential to provide a baseline to evaluate the effects of regional trauma networks (2012) and National Institute of Health and Care Excellence (NICE) head injury guidelines (2014), which were revised after the study was completed., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)
- Published
- 2016
- Full Text
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21. Head injury from falls in children younger than 6 years of age.
- Author
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Burrows P, Trefan L, Houston R, Hughes J, Pearson G, Edwards RJ, Hyde P, Maconochie I, Parslow RC, and Kemp AM
- Subjects
- Age Distribution, Brain Injuries diagnostic imaging, Brain Injuries epidemiology, Brain Injuries etiology, Child, Preschool, Craniocerebral Trauma diagnostic imaging, Craniocerebral Trauma etiology, Cross-Sectional Studies, Female, Glasgow Coma Scale, Humans, Infant, Male, Severity of Illness Index, Skull Fractures diagnostic imaging, Skull Fractures epidemiology, Skull Fractures etiology, Tomography, X-Ray Computed, United Kingdom epidemiology, Accidental Falls statistics & numerical data, Craniocerebral Trauma epidemiology
- Abstract
Unlabelled: The risk of serious head injury (HI) from a fall in a young child is ill defined. The relationship between the object fallen from and prevalence of intracranial injury (ICI) or skull fracture is described., Method: Cross-sectional study of HIs from falls in children (<6 years) admitted to UK hospitals, analysed according to the object fallen from and associated Glasgow Coma Score (GCS) or alert, voice, pain, unresponsive (AVPU) and CT scan results., Results: Of 1775 cases ascertained (median age 18 months, 54.7% boys), 87% (1552) had a GCS=15/AVPU=alert. 19.3% (342) had a CT scan: 32% (110/342) were abnormal; equivalent to 5.9% of the overall population, 16.9% (58) had isolated skull fractures and 13.7% (47) had ICI (49% (23/47) had an associated skull fracture). The prevalence of ICI increased with neurological compromise; however, 12% of children with a GCS=15/AVPU=alert had ICI. When compared to falls from standing, falls from a person's arms (233 children (mean age 1 year)) had a significant relative OR for a skull fracture/ICI of 6.94 (95% CI 3.54 to 13.6), falls from a building (eg, window or attic) (mean age 3 years) OR 6.84 (95% CI 2.65 to 17.6) and from an infant or child product (mean age 21 months) OR 2.75 (95% CI 1.36 to 5.65)., Conclusions: Most HIs from a fall in these children admitted to hospital were minor. Infants, dropped from a carer's arms, those who fell from infant products, a window, wall or from an attic had the greatest chance of ICI or skull fracture. These data inform prevention and the assessment of the likelihood of serious injury when the object fallen from is known., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)
- Published
- 2015
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22. Meta-analysis of effects of gender in combination with carcass weight and breed on pork quality.
- Author
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Trefan L, Doeschl-Wilson A, Rooke JA, Terlouw C, and Bünger L
- Subjects
- Animals, Body Weight, Female, Male, Sex Characteristics, Sus scrofa growth & development, Time Factors, Meat standards, Muscle, Skeletal physiology, Sus scrofa physiology
- Abstract
Meta-analysis was performed to quantify the effects of gender in combination with carcass weight and breed on pork quality. Altogether published results from 43 references were used. The traits analyzed were pH at 45 min (pH45min) and pH at 24 h (pH24hr) postmortem, objective color attributes lightness (L*), redness (a*), and yellowness (b*; CIE color system), color and marbling scores, drip loss, intramuscular fat content (IMF), and backfat thickness (P2), as well as sensory scores of juiciness and tenderness. Data for 2 muscle types, LM and Musculus semimembranosus (SMM), were used for the analysis. Swine genders were defined as intact/entire male (EM), surgically castrated male (SM), immunocastrated male (IM), and entire female (EF). After standardization of scaled traits (color, marbling scores, juiciness, tenderness) and accounting for cold carcass weight (CW), statistical analysis was performed using mixed models where breed was included as random effect. The analysis found a general effect of gender on each trait and multiple comparisons identified significant differences among the individual genders for L* (lightness), marbling scores, IMF, P2 in LM, and pH24hr in SMM. For these traits, when genders were grouped into gender categories as "castrates" (IM, SM) and "natural genders" (EM, EF), significant differences were found among estimates related to these categories. Furthermore, significant differences were found between castrates and individual gender types, indicating that castrated animals statistically segregated regarding their pork quality and regardless of type of castration. Pork of SM/EM animals has been found to be the fattest/leanest and there is indication that IM pork has the lightest meat color. Carcass weight dependence was found to be nonlinear (quadratic) for a*, P2, and marbling scores, and linear for b* and color scores in LM and pH24hr in SMM. The analysis identified significant breed effects for all traits, with large variation in the actual magnitudes (∼10 to 100%) of breed effects among individual traits. The established CW dependencies of pork quality traits in combination with the other influencing factors investigated here provides pork producers with the opportunity to achieve desired pork quality targets for a wide range of CW (∼30 to 150 kg) under standard indoor-rearing conditions.
- Published
- 2013
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23. Bayesian meta-analysis of the effect of fasting, transport and lairage times on four attributes of pork meat quality.
- Author
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Salmi B, Trefan L, Bünger L, Doeschl-Wilson A, Bidanel JP, Terlouw C, and Larzul C
- Subjects
- Animals, Color, Hydrogen-Ion Concentration, Muscle, Skeletal chemistry, Bayes Theorem, Fasting, Meat analysis, Postmortem Changes, Swine
- Abstract
Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss. A meta-analysis based on a database built from 27 studies corresponding to a total of 6526 animals classified was carried out. The purpose of this meta-analysis was to study the effect of fasting, lairage and transport durations on four main attributes of the technological pork meat quality. A Bayesian hierarchical meta-regression approach was adopted. The results of our meta-analysis showed that fasting time had a significant effect on pH measured 24h post-mortem (pHu) and drip loss (DL) measured in longissimus muscle. While, lairage affected only the pHu in semimembranosus muscle. Interestingly, we found that DL was the lone attribute that was affected by transport time and its interaction with fasting time., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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24. Meta-analysis of the effects of dietary vitamin E supplementation on α-tocopherol concentration and lipid oxidation in pork.
- Author
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Trefan L, Bünger L, Bloom-Hansen J, Rooke JA, Salmi B, Larzul C, Terlouw C, and Doeschl-Wilson A
- Subjects
- Animal Feed, Animal Nutritional Physiological Phenomena, Animals, Muscles metabolism, Nonlinear Dynamics, Swine, Thiobarbituric Acid Reactive Substances metabolism, Diet veterinary, Dietary Supplements, Lipid Peroxidation, Meat, alpha-Tocopherol administration & dosage, alpha-Tocopherol analysis
- Abstract
Meta-analyses have been carried out to quantify the effect of dietary vitamin E on α-tocopherol accumulation and on lipid oxidation in porcine M. longissimus. Published results of 13 (vitamin E accumulation) and 10 (lipid oxidation) experiments respectively were used for the analyses. After a number of standardization procedures, a nonlinear relationship was found between the supplementary vitamin E and the accumulation of α-tocopherol in pork which approached a maximum value of 6.4 μg/g tissue. Pork lipid oxidation levels were described in terms of Thiobarbituric Acid Reacting Substances (TBARS) values. The statistical analysis revealed significant effect of vitamin E dose, muscle α-tocopherol concentration and supplementation time on TBARS, resulting in two prediction models for lipid oxidation. Meta-analysis has proven to be a valuable tool for combining results from previous studies to quantify the effects of dietary vitamin E. Further studies, carried out with standardized experimental protocols would be beneficial for model validation and to increase the predictive power of the derived models., (© 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
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25. Meta-analysis of the effect of the halothane gene on 6 variables of pig meat quality and on carcass leanness.
- Author
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Salmi B, Trefan L, Bloom-Hansen J, Bidanel JP, Doeschl-Wilson AB, and Larzul C
- Subjects
- Animals, Bayes Theorem, Biomarkers, Female, Genotype, Male, Markov Chains, Monte Carlo Method, Swine genetics, Body Composition genetics, Meat standards
- Abstract
Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss, whereas carcass quality is often characterized by lean percentage. A meta-analysis of findings relating to 3,530 pigs reported in 23 publications was carried out to assess the effects of the halothane gene, sex, breed, and slaughter weight of animals on 7 selected variables: pH at 45 min postmortem, ultimate pH, reflectance (L*-value), redness (a*-value), yellowness (b*-value), drip loss, and lean percentage. Two statistical methods were used in the meta-analysis: the method of effect size and the better known random effects model. The method of effect size was associated with Markov chain Monte Carlo techniques for implementing Bayesian hierarchical models to avoid the problems of limited data and publication bias. The results of our meta-analysis showed that the halothane genotype had a significant effect on all analyzed pork quality variables. Between-study variance was evaluated with the Cochran (1954) Q-test of heterogeneity. Meta-regression was used to explain this variance, with covariates such as breed, sex, slaughter weight, and fasting duration being integrated into different regression models. The halothane gene effect was associated with the breed effect only for the following variables: L*-value, b*-value, and drip loss. Slaughter weight contributed significantly only to the explanation of differences in ultimate pH between homozygous genotypes. In response to inconsistencies reported in the literature regarding the difference between the genotypes NN and Nn, results of the meta-analysis showed that the difference between these 2 genotypes was significant for all the analyzed variables except the a*-value.
- Published
- 2010
- Full Text
- View/download PDF
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