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Selected AbstractsLatent Class Model Diagnosis from a Frequentist Point of ViewBIOMETRICS, Issue 1 2003Anton K. Formann Summary. This is in response to Garrett and Zeger (2000, Biometrics56, 1055,1067) who, within the Bayesian framework, developed mainly graphical methods for latent class model diagnosis. Possible problems with this approach, and with its application to both generated and empirical data, are pointed out. The impact of the proposed tools cannot be understood by their reader, as no comparisons are made to results obtainable using established methods for latent class model diagnosis; this applies especially to overall goodness-of-fit tests, for which alternatives (bootstrap, Rudas-Clogg-Lindsay index of fit) are mentioned. Further, in one case of generated data, the methods proposed by Garrett and Zeger seem to give problematic results as to identifiability; in the case of the empirical data on major depression, they lead to accepting a suboptimal three-class model. In the latter case, one can be rather sure that an identifiable, well-fitting latent class model could have been identified,if Garrett and Zeger had also considered restricted latent class models. [source] Adjusting for mortality effects in chronic toxicity testing: Mixture model approachENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2000Shin Cheng David Wang Abstract Chronic toxicity tests, such as the Ceriodaphnia dubia 7-d test are typically analyzed using standard statistical methods such as analysis of variance or regression. Recent research has emphasized the use of Poisson regression or more generalized regression for the analysis of the fecundity data from these studies. A possible problem in using standard statistical techniques is that mortality may occur from toxicant effects as well as reduced fecundity. A mixture model that accounts for fecundity and mortality is proposed for the analysis of data arising from these studies. Inferences about key parameters in the model are discussed. A joint estimate of the inhibition concentration is proposed based on the model. Confidence interval estimation via the bootstrap method is discussed. An example is given for a study involving copper and mercury. [source] Oro-facial injuries in Central American and Caribbean sports games: a 20-year experienceDENTAL TRAUMATOLOGY, Issue 3 2005Enrique Amy Abstract,,, Dental services in sports competitions in the Games sponsored by the International Olympic Committee are mandatory. In every Central American, Pan American and Olympic Summer Games, as well as Winter Games, the Organizing Committee has to take all the necessary measures to assure dental services to all competitors. In all Olympic villages, as part of the medical services, a dental clinic is set up to treat any dental emergency that may arise during the Games. Almost every participating country in the Games has its own medical team and some may include a dentist. The major responsibilities of the team dentist as a member of the national sports delegation include: (i) education of the sports delegation about different oral and dental diseases and the illustration of possible problems that athletes or other personnel may encounter during the Games, (ii) adequate training and management of orofacial trauma during the competition, (iii) knowledge about the rules and regulations of the specific sport that the dentist is working, (iv) understanding of the anti-doping control regulations and procedures, (v) necessary skills to fabricate a custom-made and properly fitted mouthguard to all participants in contact or collision sports of the delegation. This study illustrates the dental services and occurrence of orofacial injury at the Central American and Caribbean Sports Games of the Puerto Rican Delegation for the past 20 years. A total of 2107 participants made up the six different delegations at these Games. Of these 279 or 13.2% were seen for different dental conditions. The incidence of acute or emergency orofacial conditions was 18 cases or 6% of the total participants. The most frequent injury was lip contusion with four cases and the sport that experienced more injuries was basketball with three cases. [source] Overview and Perspectives of Employment in People with EpilepsyEPILEPSIA, Issue 2005Hanneke M. De Boer Summary:, Even though it is now the viewpoint of the majority of professionals working in epilepsy care that most people with epilepsy should and can perform on the labor market as does anybody else, research tells a different story. Most figures concerning employment rates of people with epilepsy indicate that they do not perform as well on the labor market as others do. Although both research figures and research groups vary, generally unemployment rates are higher for people with epilepsy than for the general population. Early studies showed that the situation for people with epilepsy was rather grim. Later studies showed similar outcomes. Unemployment rates vary between groups and countries. Research shows that being employed is an important ingredient of the quality of life of people with epilepsy. The World Health Organization also recognizes the importance of employment as a part of social health, and therefore, improving the quality of life. It is important to know the perspectives on the labor market for people with epilepsy and what the possible problems are. I describe a Dutch research project and give an overview of the findings concerning the employment and consequent employability of people with epilepsy and questions pertaining to employment and epilepsy. Possible interventions [i.e., public education and employment programs for people with epilepsy with the aim to improve the (re)integration of people with epilepsy into the labor market, thus improving the quality of life of (potential) employees with epilepsy], are described extensively. [source] The effect of health changes and long-term health on the work activity of older CanadiansHEALTH ECONOMICS, Issue 10 2005Doreen Wing Han Au Abstract Using longitudinal data from the Canadian National Population Health Survey (NPHS), we study the relationship between health and employment among older Canadians. We focus on two issues: (1) the possible problems with self-reported health, including endogeneity and measurement error, and (2) the relative importance of health changes and long-term health in the decision to work. We contrast estimates of the impact of health on employment using self-assessed health, an objective health index contained in the NPHS , the HUI3, and a ,purged' health stock measure. Our results suggest that health has an economically significant effect on employment probabilities for Canadian men and women aged 50,64, and that this effect is underestimated by simple estimates based on self-assessed health. We also corroborate recent US and UK findings that changes in health are important in the work decision. Copyright © 2005 John Wiley & Sons, Ltd. [source] Detecting infants in need: Are complicated measures really necessary?INFANT MENTAL HEALTH JOURNAL, Issue 4 2007Kaija Puura The object of this paper was to study how the Baby Alarm Distress Scale (ADBB), developed as a simple screening tool for front line professionals working with infants, correlates with the more detailed assessment method of the Global Rating Scale (GRS) for Mother-Infant Interaction at two and four months. A sample of 127 eight- to eleven-week-old infants was videotaped in free interaction with their mothers, and infant interaction behavior was rated with both methods by independent researchers. Compared to the GRS infant scales the sensitivity of the ADBB, using the recommended cutoff point of 5 or more, was 0.77 and specificity 0.80. In further analyses it was found that deviant ratings of two items of the ADBB, the quality of eye contact between the infant and the caregiver and assessment of the sense of relationship between the infant and the caregiver, were the items most strongly associated with poor interaction skills of the infant on the GRS. Mothers of infants found deviant in the ADBB performed more poorly in the interaction with their infants when compared to mothers of infants found healthy in the ADBB. For the purpose of detecting deviations in infant interaction skills as signs of possible problems in early parent-infant interaction the ADBB seems to be a sufficiently sensitive and specific instrument. However, the results of this study still need to be tested with larger samples and against other observation methods. [source] Mortality after care among young adult foster children in SwedenINTERNATIONAL JOURNAL OF SOCIAL WELFARE, Issue 3 2001Bo Vinnerljung This exploratory study looks at mortality after care among 13,100 former Swedish foster children, placed before their teens. Sources used are two national databases, on child welfare interventions and causes of death. Risk ratios of death for foster children are compared with those of their peers in the general population and with a comparison group, consisting of 10,668 young adults from adverse home backgrounds, who never entered foster family care before their teens. Both ex-foster children and the comparison group were young adults (19,26 years old) at time of follow-up. Results show a moderately elevated risk ratio for both groups compared with peers in the general population, mainly due to more frequent unnatural deaths, especially suicides. Time at first placement was not related to mortality among men, but there was a weak tendency of a higher risk ratio for girls placed at age 7,12. Information on time spent in care is used with caution, due to possible problems with reliability. Almost all comparisons between the foster care and the comparison group fell short of statistical significance. For foster children who had spent more than five years in care, the risk ratio tended to be higher than for foster children with shorter care experience, and similar to that of the comparison group. Foster children who had been in care for less then six years thus tended to have a lower risk ratio than the comparison group. [source] EARLY EXPERIENCE WITH CLINICAL INDICATORS IN SURGERYANZ JOURNAL OF SURGERY, Issue 6 2000B. T. Collopy Background: In 1997 a set of 53 clinical indicators developed by the Royal Australasian College of Surgeons (RACS) and the Australian Council on Healthcare Standards (ACHS) Care Evaluation Programme (CEP), was introduced into the ACHS Evaluation and Quality Improvement Programme (EQuIP). The clinical indicators covered 20 different conditions or procedures for eight specialty groups and were designed to act as flags to possible problems in surgical care. Methods: The development process took several years and included a literature review, field testing, and revision of the indicators prior to approval by the College council. In their first year 155 health-care organizations (HCO) addressed the indicators and this rose to 210 in 1998. Data were received from all states and both public and private facilities. Results: The collected data for 1997 and 1998 for some of the indicators revealed rates which were comparable with those reported in the international literature. For example, the rates of bile duct injury in laparoscopic cholecystectomy were 0.7 and 0.53%, respectively; the mortality rates for coronary artery graft surgery were 2.5 and 2.1%, respectively; the mortality rates after elective abdominal aortic aneurysm repair were 2.5 and 3.7%, respectively; and the post-tonsillectomy reactionary haemorrhage rates were 0.9 and 1.3%, respectively. Results for some indicators differed appreciably from other reports, flagging the need for further investigation; for example, the negative histology rates for appendectomy in children were 18.6 and 21.2%, respectively, and the rates for completeness of excision of malignant skin tumours were 90.7 and 90%, respectively. The significance of these figures, however, depends upon validation of the data and their reliability and reproducibility. Because reliability can be finally determined only at the hospital level they are of limited value for broader comparison. Conclusion: The process of review established for the indicator set has led to refinement of some indicators through improvement of definitions, and to a considerable reduction in the number of indicators to 29 (covering 18 procedures), for the second version of the indicators (which was introduced for use from January 1999). The clinical indicator programme, as it has with other disciplines, hopefully will provide a stimulus to the modification and improvement of surgical practice. Clinician ownership should enhance the collection of reliable data and hence their usefulness. [source] | |||||||||||||