bluuebunny/crossref_metadata_2025_split huggingface dataset:
Haplotype‐based association analysis in cohort studies of unrelated individuals
Authors: Lin D.Y. 
Published: March 2004

AbstractExploring the associations between haplotypes and disease phenotypes is an important step toward the discovery of genes that influence complex human diseases. When unrelated subjects are sampled, haplotypes are often ambiguous because of the unknown gametic phase of the measured sites along a chromosome. We consider cohort studies of unrelated subjects which collect data on potentially censored ages of onset of disease along with unphased genotypes and possibly time‐varying environmental factors. We formulate the effects of haplotypes and environmental variables on the time to disease occurrence through a semiparametric Cox proportional hazards model, which can accommodate a variety of genetic mechanisms as well as gene‐environment interactions. We develop a simple and fast expectation‐maximization algorithm to maximize the likelihood for the relative risks and other parameters based on the observable data of unphased genotypes and potentially censored ages of onset. The resultant estimators are consistent, efficient, and asymptotically normal. Simulation studies show that, for practical situations, the parameter estimators are virtually unbiased, the association tests maintain type I errors near nominal levels, the confidence intervals have proper coverage probabilities, and the efficiency loss due to unknown gametic phase is small. © 2004 Wiley‐Liss, Inc.
Combined association and linkage analysis applied to the APOE locus
Authors: Beekman Marian , Posthuma Daniëlle , Heijmans Bastiaan T. , Lakenberg Nico , Suchiman H. Eka D. , Snieder Harold , de Knijff Peter , Frants Rune R. , van Ommen Gert Jan B. , Kluft Cornelis , Vogler George P. , Slagboom P. Eline , Boomsma Dorret I. 
Published: March 2004

AbstractCombined association and linkage analysis is a powerful tool for pinpointing functional quantitative traits (QTLs) responsible for regions of significant linkage identified in genome‐wide scans. We applied this technique to apoE plasma levels and the APOEε2/ε3/ε4 polymorphism in two Dutch twin cohorts of different age ranges. Across chromosome 19, short tandem repeats and the APOEε2/ε3/ε4 polymorphism were genotyped in adolescent (aged 13–22 years) and adult (aged 34–62 years) Dutch twins. In both samples, evidence for indicative linkage with plasma apoE levels was found (maximum LOD score (MLS)=0.8, MLS=2.5, respectively) at 19q13.32. These linkage regions included the APOE locus. As expected, the APOEε2/ε3/ε4 polymorphism was strongly associated with apoE plasma levels in both samples. An extension of the between/within families association test developed by Fulker et al. ([1999] Am. J. Hum. Genet. 64:259–267) showed that these associations were not due to population stratification. The combined association and linkage analyses revealed that the association of the APOEε2/ε3/ε4 polymorphism with apoE plasma levels completely explained the linkage in the adolescent twins and partly in the adult twins. © 2004 Wiley‐Liss, Inc.
Consanguinity and endogamy in Northern Tunisia and its impact on non‐syndromic deafness
Authors: Ben Arab Saida , Masmoudi Saber , Beltaief Najeh , Hachicha Slah , Ayadi Hammadi 
Published: March 2004

AbstractDeafness is an important health problem in the Tunisian population, especially in isolates where the prevalence ranges from 2 to 8%. To evaluate the effect of inbred unions on deafness, a study was conducted on 5,020 individuals (160 are deaf) between 2000 and 2002 in the North of Tunisia. The coefficient of inbreeding for all individuals and the levels of inbreeding in ten districts were computed. The higher levels were obtained in the rural districts. Our study revealed that geographic isolation, social traditions, and parental involvement in mode selection all contribute to increase consanguinity in these regions. The mean inbreeding seems to be similar to those estimated in highly inbred isolates in the world. The relative risk of the 35delG mutation, the single most frequent allele for non‐syndromic recessive deafness in Tunisia, was estimated from the observed inbreeding coefficient and found to be 10.76 (SD 7.74) for first‐cousin marriages, which are the most common form of consanguineous marriage encountered. Our knowledge of the risk rate of deafness and our understanding of consanguinity is required for the prevention of genetic deafness in the Tunisian population. © 2004 Wiley‐Liss, Inc.
The estimation of sibling genetic risk parameters revisited
Authors: Zou Guohua , Zhao Hongyu 
Published: March 2004

AbstractThis report points out that some sibling genetic risk parameters can be regarded as the ratios of the characteristic values in the ascertainment subpopulation. Based on this observation, we reconsider Olson and Cordell's ([2000] Genet. Epidemiol. 18:217–235) and Cordell and Olson's ([2000] Genet. Epidemiol. 18:307–321) estimators, and re‐derive these estimators. Furthermore, we provide the closed‐form variance estimators. Simulation results suggest that our proposed estimators perform very well, and single ascertainment may be better than complete ascertainment for estimating these genetic parameters. © 2004 Wiley‐Liss, Inc.
Sodium valproate in aggressive behaviour in dementia: a twelve‐week open label follow‐up study
Authors: Sival Rob C. , Duivenvoorden Hugo J. , Jansen Paul A. F. , Haffmans P. M. Judith , Duursma Sijmen A. , Eikelenboom Piet 
Published: March 2004

AbstractIntroductionShort‐term randomised clinical trials on valproate in distinct types of disturbed behaviour in dementia showed no effects on agressive behaviour.ObjectivesTo assess the course of disturbed behaviour during medium term treatment with sodium valproate for aggressive behaviour.DesignAn open label observational 12‐week follow‐up study consecutive to a preceding randomised control trial; assessments at 4‐week interval.SettingA psychogeriatric medium‐stay ward at a psychiatric teaching hospital and psychogeriatric nursing home wards.ParticipantsPatients who completed a preceding randomised placebo controlled clinical trial on sodium valproate in aggressive behaviour in dementia were included.InterventionThe starting dose of sodium valproate was 2×6 ml of a 40 mg/ml suspension (daily defined dose of 480 mg). The patient's regular physicians managed all treatment decisions, including decisions on dosage and plasma level measurements of sodium valproate and decisions regarding discontinuation. Co‐medication was allowed and any change in prescription was recorded.MeasurementsThe Social Dysfunction and Aggression Scale‐9 (SDAS‐9), the Behaviour Observation scales for Intramural Psychogeriatrics (in Dutch: Gedragsobservatieschaal voor Intramurale Psychogeriatrie (GIP) and the Clinical Global Impression of aggressive behaviour (CGI) were performed at the last week of each 4‐week interval.ResultsData of 39 patients (F=24 and M=15) were analysed. At week 12 compared to week 0 mean sodium valproate prescriptions were higher; aggressive behaviour as measured by the SDAS‐9 improved. Non‐social behaviour, apathetic behaviour, disoriented behaviour and distorted memory improved, but rebellious behaviour increased as measured by the GIP. Seven patients died during this study.Limitations of the studyOpen label observational design; absence of placebo/reference prescription; no systematic measurements of sodium valproate plasma levels and the allowance of psychotropic co‐medication.ConclusionLow dose sodium valproate may be effective reducing a broad range of types of disturbed behaviours in aggressive demented patients. The high death rate underlines the fragility of demented patients with aggressive behaviour. Copyright © 2004 John Wiley & Sons, Ltd.
Conceptualization of mild cognitive impairment: a review
Authors: Davis Heather S. , Rockwood Kenneth 
Published: March 2004

AbstractBackgroundSeveral factors have prompted renewed interest in the concept of declines in cognitive function that occur in association with aging, in particular the area between normal cognition and dementia. We review the changing conceptualization of what has come to be known as mild cognitive impairment (MCI) in an effort to identify recent developments and highlight areas of controversy.MethodsStandard MEDLINE search for relevant English‐language publications on mild cognitive impairment and its associated terms, supplemented by hand searches of pertinent reference lists.ResultsMany conditions cause cognitive impairment which does not meet current criteria for dementia. Within this heterogenous group, termed ‘Cognitive Impairment, No Dementia’ (CIND), there are disorders associated with an increased risk of progression to dementia. Still, the conceptualization of these latter disorders remains in flux, with variability around assumptions about aging, the relationship between impairment and disease, and how concomitant functional impairment is classified. Amongst patients with MCI, especially its amnestic form, many will progress to Alzheimer's disease (AD). In contrast with clinic‐based studies, where progression is more uniform, population‐based studies suggest that the MCI classification is unstable in that context. In addition to Amnestic Mild Cognitive Impairment (AMCI), other syndromes exist and can progress to dementia. For example, an identifiable group with vascular cognitive impairment without dementia shows a higher risk of progression to vascular dementia, Alzheimer's disease and mixed dementia.ConclusionsRecent attempts to profile patients at an increased risk of dementia suggest that this can be done in skilled hands, especially in people whose symptoms prompt them to seek medical attention. Whether these people actually have early AD remains to be determined. The more narrowly defined MCI profiles need to be understood in a population context of CIND. Copyright © 2004 John Wiley & Sons, Ltd.
Correlations between cognitive, behavioural and psychological findings and levels of vitamin B12 and folate in patients with dementia
Authors: Engelborghs Sebastiaan , Vloeberghs Ellen , Maertens Karen , Mariën Peter , Somers Nore , Symons Anoek , Clement Frederik , Ketels Veerle , Saerens Jos , Goeman Johan , Pickut Barbara A. , Vandevivere Johan , De Deyn Peter P. 
Published: March 2004

AbstractBackgroundAssociations between low levels of folate and vitamin B12 and cognitive impairment in patients with dementia have been reported. Some studies revealed correlations between low levels of vitamin B12 and behavioural and psychological signs and symptoms of dementia (BPSD) in Alzheimer's disease (AD) patients. Given the lack of studies in frontotemporal dementia (FTD) and on folate and given the methodological shortcomings of former publications, we set up a prospective study.MethodsAt inclusion, AD (n=152) and FTD (n=28) patients underwent a neuropsychological examination. Behaviour was assessed using a battery of behavioural assessment scales. Determination of serum vitamin B12 and red cell folate levels were performed within a time frame of two weeks of inclusion.ResultsIn both patient groups, significantly negative correlations between levels of serum vitamin B12 and red cell folate and the degree of cognitive deterioration were found. No correlations with BPSD were found in the AD patient group. In FTD patients, levels of vitamin B12 were negatively correlated with both hallucinations (p=0.022) and diurnal rhythm disturbances (p=0.036).ConclusionsThe observed negative correlations between levels of vitamin B12 and folate and cognitive impairment in both AD and FTD patients, raise the possibility of a non‐specific etiological role. Although levels of vitamin B12 and folate did not correlate with BPSD in AD patients, negative correlations between serum vitamin B12 levels and BPSD in FTD patients were revealed. Decreased serum vitamin B12 levels may predispose FTD patients to develop hallucinations and diurnal rhythm disturbances. Copyright © 2004 John Wiley & Sons, Ltd.
Coping with post‐traumatic stress: young, middle‐aged and elderly comparisons
Authors: Chung Man Cheung , Werrett Julie , Easthope Yvette , Farmer Steven 
Published: March 2004

AbstractObjectivesDebate persists about whether people of different ages react similarly to traumatic events, and whether elderly people are more vulnerable to such events, or better able to cope with them. The first aim of this paper was to shed light on this debate by comparing the post‐traumatic responses of young, middle‐aged and elderly community residents who had been exposed to technological disasters. The second aim was to differentiate between these three age groups in terms of coping strategies.MethodsOne hundred and forty‐eight community residents, who were exposed to two technological disasters, participated in the study. They were assessed using the Impact of Event Scale (IES), the General Health Questionnaire (GHQ‐28) and the Ways of Coping Checklists (WOC).ResultsThe results showed that in terms of IES, GHQ and WOC scores, no significant differences were found across the three age groups. However, main effects were found according to type of disaster and intensity of exposure to disaster. One significant interaction effect was that residents exposed to the aircraft crash used significantly more confrontive coping than those exposed to the train collision, in all three age groups. Correlation coefficients results showed that for all three age groups, on the whole, the more they experienced intrusive thoughts and avoidance behaviour, the more they experienced general health problems.ConclusionsFollowing exposure to technological disasters, young, middle‐aged and elderly community residents could display similar post‐traumatic responses and employ similar coping strategies, which contradicts the vulnerability hypothesis and the inoculation hypothesis. Copyright © 2004 John Wiley & Sons, Ltd.
Agitated behaviours among the institutionalized elderly with dementia: validation of the Korean version of the Cohen‐Mansfield Agitation Inventory
Authors: Suh Guk‐Hee 
Published: March 2004

AbstractObjectivesTo analyze the factor structure, the criterion validity, the internal consistency, inter–rater reliability and test–retest reliability of the Korean version of Cohen‐Mansfield Agitation Inventory, to provide data on the frequency and distribution of agitated behaviours, and to compare patterns of agitated behaviours among the institutionalized elderly with Alzheimer's disease (AD) or Vascular dementia (VaD).MethodsThe Korean version of the Cohen‐Mansfield Agitation Inventory (CMAI‐K) was administered to a total of 257 elderly with AD or VaD in a nursing home in Seoul, Korea. Three kinds of reliability and criterion validity were tested. Factor analysis using principal component analysis with the varimax rotation was performed. To identify different patterns of agitated behaviours, multiple logistic regression analysis was used.ResultsThis study demonstrated satisfactory reliability and validity for the CMAI‐K as an instrument measuring agitation in Korean dementia sufferers in nursing homes. Eighty‐three percent of the subjects manifested one or more agitated behaviours at least once a week. Factor analysis yielded four subtypes of agitation: physically aggressive behaviours, physically nonaggressive behaviours, verbally agitated behaviours, and hiding/hoarding behaviours.ConclusionThese results indicate that the CMAI‐K is a reliable and valid instrument to measure agitated behaviours in Korean elderly with AD or VaD. These results validate and expand previous research on the agitation in dementia, and guide in the development of interventions. Copyright © 2004 John Wiley & Sons, Ltd.
Profile of mental disorders among the elderly United Arab Emirates population: sociodemographic correlates
Authors: Ghubash Rafia , El‐Rufaie Omer , Zoubeidi Taoufik , Al‐Shboul Qasim M. , Sabri Sufyan M. 
Published: March 2004

AbstractObjectivesTo investigate the prevalence, nature and sociodemographic correlates of mental disorders among the elderly United Arab Emirates (UAE) population.Study subjects and sampleUAE nationals aged 60 years or more, were recruited from within a random sample of households representing the UAE national population, irrespective of the age of individuals in each household.Research Instruments(i) Geriatric Mental State Interview (GMS‐A3): an Arabic version, using the AGECAT for analysis; (ii) A short questionnaire for relevant sociodemographic data.ProcedurePurposely trained, Arabic speaking interviewers visited the targeted sample households to interview study subjects at their homes.ResultsThe total number of screened subjects was 610: 166 (27.2%) in Al‐Ain; 286 (46.9%) in Dubai and 158 (25.9%) in Ras Al‐Khaimah. There were 347 (56.9%) male subjects and 263 (43.1%) female subjects. The mean age of the interviewed subjects was 68.6 (SD 8.3). The commonest diagnostic entities at the AGECAT syndrome case level were depression (20.2%), anxiety (5.6%), hypochondriasis (4.4%) and organic, mostly cognitive impairment with or without dementia (3.6%). Organic syndrome caseness, as an independent entity, showed significant correlation only to older age, while the rest of the mental disorders showed significant correlation with female gender, insufficient income and being single, separated, divorced or widowed.ConclusionThe GMS‐AGECAT package proved to be a useful tool for psychiatric assessment among the elderly in this Arabian culture. The prevalence rates of mental disorders among the elderly UAE population were, more or less, within the same range reported by other comparable worldwide studies. Copyright © 2004 John Wiley & Sons, Ltd.
Emotional reactions of lay persons to someone with Alzheimer's disease
Authors: Werner Perla , Davidson Michael 
Published: March 2004

AbstractBackgroundInformation about the nature of public reactions to people with Alzheimer's disease (AD) can help reduce stigmatization associated with the disease.ObjectiveThe aim of this study was to examine emotional reactions to persons with AD, and its correlates.MethodsA total of 150 Jewish Israeli adults (mean age=59.9) were interviewed face‐to‐face regarding their emotional reactions to people with AD using a vignette methodology.ResultsOnly a third of the participants gave the correct label. The person described in the vignette elicited more positive than negative emotions. Gender and perceived threat were the most important factors associated with emotional reactions.ConclusionsFindings suggest the need to expand the efforts to increase the recognition of AD by lay persons, and to address the negative emotions of several risk groups, such as male adults and those with greater concern about developing the disease. Copyright © 2004 John Wiley & Sons, Ltd.
Stated and actual altruistic willingness to pay for insecticide‐treated nets in Nigeria: validity of open‐ended and binary with follow‐up questions
Authors: Onwujekwe Obinna , Uzochukwu Benjamin 
Published: March 2004

AbstractObjectives: To determine whether the binary with follow‐up (BWFU) or open‐ended (OPED) contingent valuation question format would yield better valid estimates of altruistic willingness to pay (WTP) and examine the feasibility of using intra‐community altruistic contributions to procure insecticide‐treated nets (ITNs) for the poor in Nigeria.Methods: Structured questionnaires were used to elicit stated altruistic WTP from a random sub‐sample of respondents that had either the OPED or BWFU used to elicit WTP in Southeast Nigeria. One month after the survey the respondents were asked to redeem their WTP pledges. Construct validity was determined using econometric analyses, while phi correlation coefficient was used to determine criterion validity.Findings: More than 57% of the respondents were hypothetically willing to pay for altruism in both BWFU and OPED groups. Altruistic WTP was positively related to respondents' WTP for own nets (p<0.01) and nets for other household members (p<0.05) in both groups. A total of 27.0% and 33.1% of the respondents with positive hypothetical WTP in the BWFU and OPED actually contributed. Phi correlation coefficient was 0.23 (95%CI 0.20–0.29) in BWFU and 0.49 (95%CI 0.44–0.54) in OPED. The money realised was used to buy some ITNs, which were presented to poor people selected by community leaders.Conclusion: The OPED elicited better valid estimates of altruistic WTP than BWFU. The potential for more capable people to contribute for the poor in ITNs programmes actually exist and malaria control programmes should explore altruistic contributions as a means to increase net coverage. Copyright © 2004 John Wiley & Sons, Ltd.
Why cost‐effectiveness should trump (clinical) effectiveness: the ethical economics of the South West quadrant
Authors: Dowie Jack 
Published: March 2004

AbstractIn many health decision making situations there is a requirement that the effectiveness of interventions, usually their ‘clinical’ effectiveness, be established, as well as their cost‐effectiveness. Often indeed this is effectively a prior requirement for their cost‐effectiveness being investigated. If, however, one accepts the ethical argument for using a threshold incremental cost‐effectiveness ratio (ICER) for interventions that are more effective but more costly (i.e. fall in the NE quadrant of the cost‐effectiveness plane), one should apply the same decision rule in the SW quadrant, where the intervention is less effective but less costly. This implication is present in most standard treatments of cost‐effectiveness analysis, including recent stochastic versions, and had gone relatively unquestioned within the discipline until the recent suggestion that the ICER threshold might be ‘kinked’. A kinked threshold would, O'Brien et al. argue, better reflect the asymmetrical individual preferences found in empirical studies of consumer's willingness to pay and willingness to accept and justify different decision rules in the NE and SW quadrants. We reject the validity of such asymmetric preferences in the context of public health care decisions and consider and counter the two main ‘ethical’ objections that probably underlie the asymmetry in this case – the objection to ‘taking away’ and the objection to being required to undergo treatment that is less effective than no treatment at all. Copyright © 2004 John Wiley & Sons, Ltd.
Co‐payments for prescription drugs and the demand for doctor visits – Evidence from a natural experiment
Authors: Winkelmann Rainer 
Published: March 2004

AbstractThe German health care reform of 1997 provides a natural experiment for evaluating the price sensitivity of demand for physicians' services. As a part of the reform, co‐payments for prescription drugs were increased step up to 200%. However, certain groups of people were exempted from the increase, providing a natural control group against which the changed demand for physicians' services of the treated, those subject to increased co‐payments, can be assessed. The differences‐in‐differences estimates indicate that increased co‐payments reduced the number of doctor visits by about 10% on an average. Copyright © 2004 John Wiley & Sons, Ltd.
The wage effects of obesity: a longitudinal study
Authors: Baum Charles L. , Ford William F. 
Published: March 2004

AbstractWe use National Longitudinal Survey of Youth (NLSY) data to examine the effects of obesity on wages by gender. Sample means indicate that both men and women experience a persistent obesity wage penalty over the first two decades of their careers. We then control for a standard set of socioeconomic and familial variables but find that standard covariates do not explain why obese workers experience persistent wage penalties. This suggests that other variables – including job discrimination, health‐related factors and/or obese workers' behavior patterns – may be the channels through which obesity adversely affects wages. The study closes with a discussion of the public policy implications suggested by these findings. Copyright © 2004 John Wiley & Sons, Ltd.