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Cases Used (case + used)
Selected AbstractsAn SPH shell formulation for plasticity and fracture analysis in explicit dynamicsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2008B. Maurel Abstract This paper introduces a new modeling method suitable for the simulation of shell fracture under impact. This method relies on an entirely meshless approach based on the smoothed particle hydrodynamics (SPH) method. The paper also presents the SPH shell formulation being used as well as the different test cases used for its validation. A plasticity model of the global type throughout the thickness is also proposed and validated. Finally, in order to illustrate the capabilities of the method, fracture simulations using a simplified fracture criterion are presented. Copyright © 2008 John Wiley & Sons, Ltd. [source] Association between pacifier use and breast-feeding, sudden infant death syndrome, infection and dental malocclusionINTERNATIONAL JOURNAL OF EVIDENCE BASED HEALTHCARE, Issue 6 2005Ann Callaghan RN RM BNurs(Hons) Executive summary Objective, To critically review all literature related to pacifier use for full-term healthy infants and young children. The specific review questions addressed are: What is the evidence of adverse and/or positive outcomes of pacifier use in infancy and childhood in relation to each of the following subtopics: ,breast-feeding; ,sudden infant death syndrome; ,infection; ,dental malocclusion. Inclusion criteria, Specific criteria were used to determine which studies would be included in the review: (i) the types of participants; (ii) the types of research design; and (iii) the types of outcome measures. To be included a study has to meet all criteria. Types of participants,The participants included in the review were healthy term infants and healthy children up to the age of 16 years. Studies that focused on preterm infants, and infants and young children with serious illness or congenital malformations were excluded. However, some total population studies did include these children. Types of research design, It became evident early in the review process that very few randomised controlled trials had been conducted. A decision was made to include observational epidemiological designs, specifically prospective cohort studies and, in the case of sudden infant death syndrome research, case,control studies. Purely descriptive and cross-sectional studies were excluded, as were qualitative studies and all other forms of evidence. A number of criteria have been proposed to establish causation in the scientific and medical literature. These key criteria were applied in the review process and are described as follows: (i) consistency and unbiasedness of findings; (ii) strength of association; (iii) temporal sequence; (iv) dose,response relationship; (v) specificity; (vi) coherence with biological background and previous knowledge; (vii) biological plausibility; and (viii) experimental evidence. Studies that did not meet the requirement of appropriate temporal sequencing of events and studies that did not present an estimate of the strength of association were not included in the final review. Types of outcome measures,Our specific interest was pacifier use related to: ,breast-feeding; ,sudden infant death syndrome; ,infection; ,dental malocclusion. Studies that examined pacifier use related to procedural pain relief were excluded. Studies that examined the relationship between pacifier use and gastro-oesophageal reflux were also excluded as this information has been recently presented as a systematic review. Search strategy, The review comprised published and unpublished research literature. The search was restricted to reports published in English, Spanish and German. The time period covered research published from January 1960 to October 2003. A protocol developed by New Zealand Health Technology Assessment was used to guide the search process. The search comprised bibliographic databases, citation searching, other evidence-based and guidelines sites, government documents, books and reports, professional websites, national associations, hand search, contacting national/international experts and general internet searching. Assessment of quality, All studies identified during the database search were assessed for relevance to the review based on the information provided in the title, abstract and descriptor/MeSH terms, and a full report was retrieved for all studies that met the inclusion criteria. Studies identified from reference list searches were assessed for relevance based on the study title. Keywords included: dummy, dummies, pacifier(s), soother(s), comforter(s), non-nutritive sucking, infant, child, infant care. Initially, studies were reviewed for inclusion by pairs of principal investigators. Authorship of articles was not concealed from the reviewers. Next, the methodological quality of included articles was assessed independently by groups of three or more principal investigators and clinicians using a checklist. All 20 studies that were accepted met minimum set criteria, but few passed without some methodological concern. Data extraction, To meet the requirements of the Joanna Briggs Institute, reasons for acceptance and non-acceptance at each phase were clearly documented. An assessment protocol and report form was developed for each of the three phases of review. The first form was created to record investigators' evaluations of studies included in the initial review. Those studies that failed to meet strict inclusion criteria were excluded at this point. A second form was designed to facilitate an in-depth critique of epidemiological study methodology. The checklist was pilot tested and adjustments were made before reviewers were trained in its use. When reviewers could not agree on an assessment, it was passed to additional reviewers and discussed until a consensus was reached. At this stage, studies other than cohort, case,control and randomised controlled trials were excluded. Issues of clarification were also addressed at this point. The final phase was that of integration. This phase, undertaken by the principal investigators, was assisted by the production of data extraction tables. Through a process of trial and error, a framework was formulated that adequately summarised the key elements of the studies. This information was tabulated under the following headings: authors/setting, design, exposure/outcome, confounders controlled, analysis and main findings. Results, With regard to the breast-feeding outcome, 10 studies met the inclusion criteria, comprising two randomised controlled trials and eight cohort studies. The research was conducted between 1995 and 2003 in a wide variety of settings involving research participants from diverse socioeconomic and cultural backgrounds. Information regarding exposure and outcome status, and potential confounding factors was obtained from: antenatal and postnatal records; interviews before discharge from obstetric/midwifery care; post-discharge interviews; and post-discharge postal and telephone surveys. Both the level of contact and the frequency of contact with the informant, the child's mother, differed widely. Pacifier use was defined and measured inconsistently, possibly because few studies were initiated expressly to investigate its relationship with breast-feeding. Completeness of follow-up was addressed, but missing data were not uniformly identified and explained. When comparisons were made between participants and non-participants there was some evidence of differential loss and a bias towards families in higher socioeconomic groups. Multivariate analysis was undertaken in the majority of studies, with some including a large number of sociodemographic, obstetric and infant covariates and others including just maternal age and education. As might be expected given the inconsistency of definition and measurement, the relationship between pacifier use and breast-feeding was expressed in many different ways and a meta-analysis was not appropriate. In summary, only one study did not report a negative association between pacifier use and breast-feeding duration or exclusivity. Results indicate an increase in risk for a reduced overall duration of breast-feeding from 20% to almost threefold. The data suggest that very infrequent use may not have any overall negative impact on breast-feeding outcomes. Six sudden infant death syndrome case,control studies met the criteria for inclusion. The research was conducted with information gathered between 1984 and 1999 in Norway, UK, New Zealand, the Netherlands and USA. Exposure information was obtained from a variety of sources including: hospital and antenatal records, death scene investigation, and interview and questionnaire. Information for cases was sought within 2 days after death, within 2,4 weeks after death and in one study between 3 and 11 years after death. Information for controls was sought from as early as 4 days of a nominated sudden infant death syndrome case, to between 1 and 7 weeks from the case date, and again in one study some 3,11 years later. In the majority of the studies case ascertainment was determined by post-mortem. Pacifier use was again defined and measured somewhat inconsistently. All studies controlled for confounding factors by matching and/or using multivariate analysis. Generally, antenatal and postnatal factors, as well as infant care practices, and maternal, family and socioeconomic issues were considered. All five studies reporting multivariate results found significantly fewer sudden infant death syndrome cases used a pacifier compared with controls. That is, pacifier use was associated with a reduced incidence of sudden infant death syndrome. These results indicate that the risk of sudden infant death syndrome for infants who did not use a pacifier in the last or reference sleep was at least twice, and possibly five times, that of infants who did use a pacifier. Three studies reported a moderately sized positive association between pacifier use and a variety of infections. Conversely, one study found no positive association between pacifier use at 15 months of age and a range of infections experienced between the ages of 6 and 18 months. Given the limited number of studies available and the variability of results, no meaningful conclusions could be drawn. Five cohort studies and one case,control study focused on the relationship between pacifier use and dental malocclusion. Not one of these studies reported a measure of association, such as an estimate of relative risk. It was therefore not possible to include these studies in the final review. Implications for practice, It is intended that this review be used as the basis of a ,best practice guideline', to make health professionals aware of the research evidence concerning these health and developmental consequences of pacifier use, because parents need clear information on which they can base child care decisions. With regard to the association between pacifier use and infection and dental malocclusion it was found that, due to the paucity of epidemiological studies, no meaningful conclusion can be drawn. There is clearly a need for more epidemiological research with regard to these two outcomes. The evidence for a relationship between pacifier use and sudden infant death syndrome is consistent, while the exact mechanism of the effect is not well understood. As to breast-feeding, research evidence shows that pacifier use in infancy is associated with a shorter duration and non-exclusivity. It is plausible that pacifier use causes babies to breast-feed less, but a causal relationship has not been irrefutably proven. Because breast-feeding confers an important advantage on all children and the incidence of sudden infant death syndrome is very low, it is recommended that health professionals generally advise parents against pacifier use, while taking into account individual circumstances. [source] The reliability of summative judgements based on objective structured clinical examination cases distributed across the clinical yearMEDICAL EDUCATION, Issue 7 2007George R Bergus Context, Objective structured clinical examinations (OSCEs) can be used for formative and summative evaluation. We sought to determine the generalisability of students' summary scores aggregated from formative OSCE cases distributed across 5 clerkships during Year 3 of medical school. Methods, Five major clerkships held OSCEs with 2,4 cases each during their rotations. All cases used 15-minute student,standardised patient encounters and performance was assessed using clinical and communication skills checklists. As not all students completed every clerkship or OSCE case, the generalisability (G) study was an unbalanced student × (case : clerkship) design. After completion of the G study, a decision (D) study was undertaken and phi (,) values for different cut-points were calculated. Results, The data for this report were collected over 2 academic years involving 262 Year 3 students. The G study found that 9.7% of the score variance originated from the student, 3.1% from the student,clerkship interaction, and 87.2% from the student,case nested within clerkship effect. Using the variance components from the G study, the D study suggested that if students completed 3 OSCE cases in each of the 5 different clerkships, the reliability of the aggregated scores would be 0.63. The ,, calculated at a cut-point 1 standard deviation below the mean, would be approximately 0.85. Conclusions, Aggregating case scores from low stakes OSCEs within clerkships results in a score set that allows for very reliable decisions about which students are performing poorly. Medical schools can use OSCE case scores collected over a clinical year for summative evaluation. [source] Reliability of the Amsterdam Clinical Challenge Scale (ACCS): a new instrument to assess the level of difficulty of patient cases in medical educationMEDICAL EDUCATION, Issue 7 2000Gercama Introduction In problem-based medical curricula, consideration should be given to the level of difficulty of patient cases used for training and assessment. The Amsterdam Clinical Challenge Scale (ACCS) has been developed to assess the degree of difficulty of patient cases in a systematic and reproducible manner. To determine the reliability of the instrument two research questions were addressed: (1) How many judges are required, on the basis of the total score of the ACCS, to obtain a reliable estimate of the difficulty of a single case? (2) How many cases and/or how many judges are needed to reach an acceptable level of reliability of the total score of the ACCS? Method Four judges scored 36 patient scripts reflecting a wide range of patient problems encountered in general practice. Each script was scored four times. In the reliability analysis, the generalizability theory was applied. Results The results show that the judges did, indeed, use the whole range of difficulty ratings. When the ACCS is applied to a single case, eight or more judges are needed to reach an acceptable level of reliability. When more cases are involved, fewer judges are needed; for 10 or more cases one judge will be sufficient. Conclusions Given the typical length, for example of an objective structured clinical examination, the ACCS makes it possible to provide a reliable estimate of the level of difficulty of such a test with only a limited number of judges. [source] | ||||||||||