bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of clustered categorical data—application in dental health
Authors: Das Kalyan , Chattopadhyay Asis Kumar
Published: August 2004

Quite often in medical studies multiple discrete indicators are used to measure some characters that are defined only conceptually and are difficult to measure directly. Studies of this type exhibit categorical responses of dependent nature. Analysis of such categorical data appears to be extremely difficult (intractable) particularly in the presence of risk (causal) factors. In the present article, our purpose is to develop a latent mixture regression model for analysing such multivariate categorical data. Such a mixture model accommodates correlated and overdispersed data through the incorporation of random effects. Unfortunately, a full likelihood analysis is often hampered by the need for numerical integration. Two different procedures have been considered here. Both involve intensive computations. Numerical investigation has been carried out on the basis of a survey data covering 220 individuals from medical colleges in and around Calcutta (India). The purpose of the study is to compare tooth cleaning efficiency of brushes manufactured by different companies. Copyright © 2004 John Wiley & Sons, Ltd.
Estimating vaccine efficacy from household data observed over time
Authors: Davis Xiaohong M. , Haber Michael
Published: August 2004

Estimation of vaccine efficacy has traditionally focused on the reduction in susceptibility to infection, or the vaccine efficacy for susceptibility (VES). However, a vaccine, such as a prophylactic HIV vaccine, may also lower the infectiousness of a vaccinated person who became infected. The relative reduction in infectiousness due to vaccination is the vaccine efficacy for infectiousness (VEI). Estimation of VEI is challenging because it requires information on exposure to infection, and gathering this type of information is often expensive and difficult, or even impossible. Household studies are expected to provide more information on who is exposed to whom. In a previous paper, we developed a method for estimating VES and VEI from a household study where only the final outbreak data are available. However, the resulting estimates were quite unstable. In this work, we develop a survival model for the estimation of VES and VEI from household data where the time of infection is known for every study participant. Using stochastic simulations, we show that the proposed method significantly reduces the bias and mean square error in the estimation of both VES and VEI as compared to the method based on final outbreak data. We also show that when time‐to‐event data are available, a household study produces more robust estimators than a same‐size study of unrelated individuals. In addition, we investigate the bias in estimating VES and VEI due to misclassification of infection status when only illness data, rather than true infection data, are available. Copyright © 2004 John Wiley & Sons, Ltd.
Imputation for incomplete high‐dimensional multivariate normal data using a common factor model
Authors: Song Juwon , Belin Thomas R.
Published: August 2004

It is common in applied research to have large numbers of variables measured on a modest number of cases. Even with low rates of missingness on individual variables, such data sets can have a large number of incomplete cases. Here we present a new method for handling missing continuously scaled items in multivariate data, based on extracting common factors to reduce the number of covariance parameters to be estimated in a multivariate normal model. The technique is compared in several simulation settings to available‐case analysis and to a multivariate normal model with a ridge prior. The method is also illustrated on a study with over 100 variables evaluating an emergency room intervention for adolescents who attempted suicide. Copyright © 2004 John Wiley & Sons, Ltd.
Cross calibration in longitudinal studies
Authors: Ambrosius Walter T. , Hui Siu L.
Published: August 2004

In a long‐running longitudinal study using complex machinery to obtain measurements, it is sometimes necessary to replace the machine. This can result in lack of continuity in the measurements that can overwhelm any treatment effect or time trend. We propose a Bayesian procedure implemented using Markov chain Monte Carlo to calibrate the measurements on the old machine utilizing both person‐specific and population information. The goal is to convert the previous measurements to values that can be treated as though they were made on the new machine. This methodology is applied to a bone mineral density study where the first densitometer uses gadolinium as the energy source (Lunar DP‐3) and the second uses X‐rays (Hologic QDR‐1000W). Finally, simulation results are presented to show the superiority of the proposed method over existing methods of cross calibration. Copyright © 2004 John Wiley & Sons, Ltd.
Power analyses for longitudinal trials and other clustered designs
Authors: Tu X. M. , Kowalski J. , Zhang J. , Lynch K. G. , Crits‐Christoph P.
Published: August 2004

Existing methods for power and sample size estimation for longitudinal and other clustered study designs have limited applications. In this paper, we review and extend existing approaches to improve these limitations. In particular, we focus on power analysis for the two most popular approaches for clustered data analysis, the generalized estimating equations and the linear mixed‐effects models. By basing the derivation of the power function on the asymptotic distribution of the model estimates, the proposed approach provides estimates of power that are consistent with the methods of inference for data analysis. The proposed methodology is illustrated with numerous examples that are motivated by real study designs. Copyright © 2004 John Wiley & Sons, Ltd.
A statistical model for high‐resolution mapping of quantitative trait loci determining HIV dynamics
Authors: Wang Zuoheng , Wu Rongling
Published: August 2004

Are there specific genes that control the pathogenesis of HIV infection? This question, which is of fundamental importance in designing personalized strategies of gene therapy to control HIV infection, can be examined by genetic mapping approaches. In this article, we present a new statistical model for unravelling the genetic mechanisms for the dynamic change of HIV that causes AIDS by marker‐based linkage disequilibrium (LD) analyses. This new model is the extension of our functional mapping theory to integrate viral load trajectories within a genetic mapping framework. Earlier studies of HIV dynamics have led to various mathematical functions for modelling the kinetic curves of plasma virions and CD4 lymphocytes in HIV patients. Through incorporating these functions into the LD‐based mapping procedure, we can identify and map individual quantitative trait loci (or QTL) responsible for viral pathogenesis. We derive a closed‐form solution for estimating QTL allele frequency and marker‐QTL linkage disequilibrium in the context of EM algorithm and implement the simplex algorithm to estimate the mathematical parameters describing the curve shapes of HIV pathogenesis. We performed different simulation scenarios based on currently used clinical designs in AIDS/HIV research to illustrate the utility and power of our model for genetic mapping of HIV dynamics. The implications of our model for genetic and genomic research into AIDS pathogenesis are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Two‐stage adaptive strategy for superiority and non‐inferiority hypotheses in active controlled clinical trials
Authors: Shih Weichung J. , Quan Hui , Li Gang
Published: August 2004

In active controlled trials without a placebo arm, there are usually two study objectives: to test a superiority hypothesis that the experimental treatment is more effective than the active control therapy, and to test a non‐inferiority hypothesis that the experimental treatment is therapeutically no worse than the active control within a defined margin. For a two‐stage adaptive design, it is not necessary to give a fixed sample size calculation at the planning stage of the study when treatment effect information is often insufficient. Instead, decision and estimation of the design specifications can be made more reliably after the first stage when interim results are available. We propose the use of conditional power approach to determine the sample size and critical values for testing the superiority and non‐inferiority hypotheses for the second stage based on the observed result of the first stage. The proposed adaptive procedure preserves the overall type I error rate for both superiority and non‐inferiority, and has the flexibility of early termination of the study (for futility or efficacy) or extending the study by appropriate sample size. Copyright © 2004 John Wiley & Sons, Ltd.
Improved confidence intervals for a binomial parameter following a group sequential phase II clinical trial
Authors: Chang Myron N.
Published: August 2004

Group sequential procedures are widely employed in phase II clinical trials. It is often desirable to provide an interval estimate of the true response rate upon termination of a group sequential phase II clinical trial. The confidence intervals proposed by Jennison and Turnbull (Technometrics 1983; 25: 49–58) are conservative. Utilization of auxiliary statistics based on the overall disease status is proposed to reduce the discreteness of the underlying distribution. Confidence intervals generated by the proposed methods have confidence coefficients closer to the nominal level and have shorter average lengths than JT. Copyright © 2004 John Wiley & Sons, Ltd.
Regression analysis of multiple source and multiple informant data from complex survey samples
Authors: Horton Nicholas J. , Fitzmaurice Garrett M.
Published: August 2004

In this tutorial, we describe regression‐based methods for analysing multiple source data arising from complex sample survey designs. We use the term ‘multiple‐source’ data to encompass all cases where data are simultaneously obtained from multiple informants, or raters (e.g. self‐reports, family members, health care providers, administrators) or via different/parallel instruments, indicators or methods (e.g. symptom rating scales, standardized diagnostic interviews, or clinical diagnoses). We review regression models for analysing multiple source risk factors or multiple source outcomes and show that they can be considered special cases of generalized linear models, albeit with correlated outcomes. We show how these methods can be extended to handle the common survey features of stratification, clustering, and sampling weights. We describe how to fit regression models with multiple source reports derived from complex sample surveys using general purpose statistical software. Finally, the methods are illustrated using data from two studies: the Stirling County Study and the Eastern Connecticut Child Survey. Copyright © 2004 John Wiley & Sons, Ltd.
Modelling infectious disease transmission with complex exposure pattern and sparse outcome data
Authors: Reilly Marie , Salim Agus , Lawlor Emer , Smith Owen , Temperley Ian , Pawitan Yudi
Published: August 2004

We present a regression modelling framework to analyse infectious disease transmission during a time period where extensive exposure data are available, but where the outcome data are sparse. A latent variable model is used for each exposure time, allowing a straight‐forward accumulation of risk for a collection of exposures for which outcome data are available. We describe an analysis of HIV infection from blood products among a cohort of haemophiliacs in Ireland between 1980 and 1985. The analysis provides estimates of the time pattern and batch effects; we show how analytical complexity such as smoothly varying coefficients or random coefficient models can be accommodated by the model. Finally, we discuss other problems where the model is applicable. Copyright © 2004 John Wiley & Sons, Ltd.
Multiple comparisons with a control in families with both one‐sided and two‐sided hypotheses
Authors: Cheung Siu Hung , Kwong Koon Shing , Chan Wai Sum , Leung Shun Piu
Published: August 2004

Comparing several treatments with a control is a common objective of clinical studies. However, existing procedures mainly deal with particular families of inferences in which all hypotheses are either one‐ or two‐sided. In this article, we seek to develop a procedure which copes with a more general testing environment in which the family of inferences is composed of a mixture of one‐ and two‐sided hypotheses. The proposed procedure provides a more flexible and powerful tool than the existing method. The superiority of this method is also substantiated by a simulation study of average power. Selected critical values are tabulated for the implementation of the proposed procedure. Finally, we provide an illustrative example with sample data extracted from a medical experiment. Copyright © 2004 John Wiley & Sons, Ltd.
A cost‐related approach for evaluating drug development programs
Authors: Yan Eric C. , Chen Ling
Published: August 2004

Most pharmaceutical statisticians make a contribution to drug development at the study level by designing and analysing clinical studies. There is less involvement at the drug project level, especially when it comes to making a strategic decision for a drug development program. Motivated by the assessment of drug safety, this paper presents a new decision rule on whether or not to continue developing a new drug based on a cost function. The cost function takes into account both type I and type II errors in a decision making problem. It also incorporates both the cost and benefit from a drug development program. This cost–benefit approach enables company senior management to evaluate a drug program objectively and make decisions in a quantitative and rational manner. The probabilities of making correct decisions are illustrated by using a real data example. Copyright © 2004 John Wiley & Sons, Ltd.
Improving Cox survival analysis with a neural‐Bayesian approach
Authors: Bakker Bart , Heskes Tom , Neijt Jan , Kappen Bert
Published: August 2004

In this article we show that traditional Cox survival analysis can be improved upon when supplemented with sensible priors and analysed within a neural Bayesian framework. We demonstrate that the Bayesian method gives more reliable predictions, in particular for relatively small data sets.

The obtained posterior (the probability distribution of network parameters given the data) which in itself is intractable, can be made accessible by several approximations. We review approximations by Hybrid Markov Chain Monte Carlo sampling, a variational method and the Laplace approximation. We argue that although each Bayesian approach circumvents the shortcomings of the original Cox analysis, and therefore yields better predictive results, in practice the use of variational methods or Laplace is preferable. Since Cox survival analysis is infamous for its poor results with (too) many inputs, we use the Bayesian posterior to estimatep‐values on the inputs and to formulate an algorithm for backward elimination. We show that after removal of irrelevant inputs Bayesian methods still achieve significantly better results than classical Cox. Copyright © 2004 John Wiley & Sons, Ltd.
Correction. O. C. Ukoumunne, A comparison of confidence interval methods for the intraclass correlation coefficient in cluster randomized trials Statistics in Medicine 2002; 21: 3757–3774.
Authors: Ukoumunne Obioha C.
Published: August 2004

The original article to which this correction refers was published in Statistics in Medicine 2002; 21: 3757–3774.
Multiple imputation for body mass index: lessons from the Australian Longitudinal Study on Women's Health
Authors: Mishra Gita D. , Dobson Annette J.
Published: August 2004

In large epidemiological studies missing data can be a problem, especially if information is sought on a sensitive topic or when a composite measure is calculated from several variables each affected by missing values. Multiple imputation is the method of choice for ‘filling in’ missing data based on associations among variables. Using an example about body mass index from the Australian Longitudinal Study on Women's Health, we identify a subset of variables that are particularly useful for imputing values for the target variables. Then we illustrate two uses of multiple imputation. The first is to examine and correct for bias when data are not missing completely at random. The second is to impute missing values for an important covariate; in this case omission from the imputation process of variables to be used in the analysis may introduce bias. We conclude with several recommendations for handling issues of missing data. Copyright © 2004 John Wiley & Sons, Ltd.
Biomechanical efficiency is decreased in heart failure during low‐level steady state and maximal ramp exercise
Authors: Levy Wayne C. , Maichel Barbara A. , Steele Natalie P. , Leclerc Kenneth M. , Stratton John R.
Published: August 2004

Background:

Previous studies of biomechanical efficiency (external work/energy input – Watt/O2 consumed) in heart failure (HF) using cardiopulmonary exercise testing (CPET) and magnetic resonance spectroscopy (MRS) have had discordant results with increased efficiency by CPET and decreased efficiency by MRS.

Aims:

Compare biomechanical efficiency of HF subjects and normal controls during steady state (SS=35 W for 6 min) and ramp cycle ergometer exercise. The hypothesis was that HF subjects would have impaired biomechanical efficiency that correlated with HF symptoms.

Methods:

Biomechanical efficiency used the actual Vo2 during exercise and recovery. Gross (Vo2 above zero), Net (Vo2 above the resting Vo2) and Work (Vo2 above the unloaded pedaling Vo2) efficiencies were calculated.

Results:

HF subjects had an 18% higher Vo2 during SS exercise (P=0.029). Biomechanical efficiency was reduced during SS exercise (gross −15%, P=0.019, net −15%, P=0.062, and work −35%, P=0.002). Gross Efficiency during SS exercise had the strongest correlation with HF symptoms (r=0.55). During ramp exercise gross (−26%), net (−10%) and work (−8%) biomechanical efficiency were all reduced (all P<0.05). The slope of the Vo2/Watt relationship during ramp exercise had the best correlation with HF symptoms (r=0.46).

Conclusions:

HF subjects have an increased O2 cost/Watt during SS and ramp exercise that correlates with HF symptoms of fatigue and breathlessness. Methods to improve biomechanical efficiency in HF subjects by exercise training or medications may improve the symptoms and the impaired exercise capacity associated with HF.
Is plasma N‐BNP a good indicator of the functional reserve of failing hearts? The FRESH‐BNP study
Authors: Williams Simon G. , Ng Leong L. , O'Brien Russell J. , Taylor Steve , Wright D. Jay , Tan Lip‐Bun
Published: August 2004

Aims:

Whether plasma N‐terminal brain natriuretic peptide (N‐BNP) is useful in the diagnosis of heart failure (HF) depends traditionally on whether it is as good as the putative ‘gold‐standard’, left ventricular ejection fraction (LVEF), in indicating cardiac dysfunction. However, since HF is primarily an impairment of function of the cardiac pump, we explored the relationship between N‐BNP and direct and indirect indicators of cardiac pump dysfunction.

Methods and Results:

Eighty‐six HF patients (mean age 56 years) with a range of LVEF's (mean 36.9±15.2%, range 15–66%) and 10 age‐matched healthy controls were recruited into the study and had resting N‐BNP measured. Cardiopulmonary exercise testing was performed to assess peak oxygen consumption (Vo2). A subgroup of 23 subjects underwent further exercise haemodynamic assessment to evaluate peak cardiac power output (CPO). The CHF group had significantly higher N‐BNP (median [interquartile range]) levels (299 [705] fmol/ml) than the control group (7 [51] fmol/ml, P<0.005). Significant correlations between N‐BNP and peak Vo2, and N‐BNP and peak CPO were observed (R≥0.5, P<0.005). Although significant correlation was observed between N‐BNP and LVEF (R=0.34, P=0.01), the correlations between LVEF and peak Vo2 or peak CPO (all R<0.3, P>0.3) were not significant. Multivariate analysis identified plasma N‐BNP and NYHA class, but not LVEF, as independent predictors of peak Vo2.

Conclusions:

We have found that N‐BNP was surprisingly good as a simple indicator of cardiac pump dysfunction. Since heart failure is an inadequacy of function, these results strongly support the notion that N‐BNP is a useful blood test in estimating the extent of cardiac pump dysfunction and helpful in establishing positive diagnosis of heart failure.
Non‐compliance in patients with heart failure; how can we manage it?
Authors: van der Wal Martje H.L. , Jaarsma Tiny , van Veldhuisen Dirk J.
Published: August 2004

Background:

Because of the improvement of the pharmacological and non‐pharmacological treatment in heart failure (HF) patients, the HF related therapeutic regimen is becoming more complicated. Non‐compliance with this regimen can result in worsening HF symptoms, sometimes leading to hospitalisation.

Aims:

The aims of this systematic literature review are (1) to describe the consequences of non‐compliance in HF patients; (2) to summarise the degree of compliance in the various aspects of the therapeutic regimen; and (3) to review interventions that are recommended to improve compliance in HF patients.

Methods:

A literature search of the MEDLINE and CINAHL database from 1988 to June 2003 was performed. Studies on compliance with life style recommendations according to the HF Guidelines of the European Society of Cardiology and the American Heart Association/American College of Cardiology were included.

Conclusion:

Non‐compliance with medication and other lifestyle recommendations is a major problem in patients with HF. Evidence based interventions to improve compliance in patients with HF are scarce. Interventions that can increase compliance and prevent HF related readmissions in order to improve the quality of life of patients with HF need to be developed and tested.
Serum levels of different tumour markers in patients with chronic heart failure
Authors: Faggiano Pompilio , D'Aloia Antonio , Brentana Loretta , Bignotti Tommaso , Fiorina Claudia , Vizzardi Enrico , Cas Livio Dei
Published: August 2004

Background:

serum levels of carbohydratic antigen 125 (CA 125), a tumour marker related to ovarian cancer, are increased in patients with heart failure (CHF). To our knowledge there are no data concerning the levels of other tumour markers in CHF.

Methods:

we measured serum levels of Alpha‐Fetoprotein (AFP), Carcinoembrionic antigen (CEA), CA 19.9, CA 15.3 and CA 125, in 191 pts (86 males, mean age 67±10 years) with mild to severe CHF due to left ventricular systolic dysfunction.

Results:

Only CA‐125 was increased in CHF patients: mean values were significantly higher (P<0.05) in NYHA classes III (60±22 UI/ml) and IV (192±115 UI/ml) compared to NYHA class I‐II patients (16±11). Mean values of the other tumor markers were within the normal range. AFP was above the upper normal limit in 2/191 patients (1%), CEA in 5/191 (2.6%), CA 19.9 in 0, CA 15.3 in 2/191 (1%) and CA 125 in 126/191 patients (66%). In 30 NYHA IV patients, tumour markers were repeated after 5–20 days of aggressive medical treatment, when a clinical improvement (reduction of at least 1 NYHA class) was reached: mean serum levels of CA 125 decreased from 107±85 to 19±8 U/ml (P<0.05); no changes in other tumour markers were observed.

Conclusions:

Of the tumour markers evaluated, only CA 125 seems to be related to the presence and severity of CHF and shows significant changes in response to medical therapy. The biologic and clinical relevance of this observation needs to be defined.
Heart failure after myocardial infarction: clinical presentation and survival
Authors: Hellermann Jens P. , Jacobsen Steven J. , Redfield Margaret M. , Reeder Guy S. , Weston Susan A. , Roger Véronique L.
Published: August 2004

Objectives:

To characterize the presentation and outcome of patients with heart failure (HF) after myocardial infarction (MI) according to left ventricular ejection fraction (LVEF) and test the hypothesis that the outcome of HF did not change over time.

Background:

Little is known about the presentation and outcome of HF post‐MI and how these may have changed over time.

Methods:

Using the Rochester Epidemiology Project, all residents of Olmsted County, Minnesota who experienced an incident MI between 1979 and 1998 were identified; MI and HF were validated using standardized criteria. Subjects were followed through their community medical record.

Results:

Between 1979 and 1998, 1915 patients with incident MI and no prior history of HF were identified. Of these, 791(41%) experienced new onset HF as defined by Framingham criteria during 6.6±5.0 years of follow‐up. Forty‐seven percent were men, mean age was 73±12 years. Forty‐four percent had impaired LVEF, 18% preserved LVEF and 38% had no LVEF measurement within 60 days after the HF event. Median survival after HF onset was 4 years and at 5 years after HF onset, only 45% were alive. Older age, male sex, comorbidity, hypertension and no LVEF assessment were associated with increased risk of death, however, patients with impaired LVEF had the worst outcome. Over time, survival did not improve (HR for year: 1.00; 95% CI 0.99, 1.02; P=0.919) even after adjustment for baseline characteristics.

Conclusion:

In this geographically defined cohort of patients with MI, new onset HF after the MI was frequent. When measured, LVEF was most frequently reduced, consistent with systolic heart failure. Mortality was high and did not decline over time and death was independently associated with male sex, older age, hypertension and comorbidity. It also differed according to LVEF, which was inconsistently ascertained in this setting, potentially representing practice opportunities.
Tomato TERF1 modulates ethylene response and enhances osmotic stress tolerance by activating expression of downstream genes
Authors: Huang Zejun , Zhang Zhijin , Zhang Xiuling , Zhang Hongbo , Huang Dafang , Huang Rongfeng
Published: August 2004

The interaction between ethylene and osmotic stress pathways modulates the expression of the genes relating to stress adaptation; however, the mechanism is not well understood. In this paper, we report a novel ethylene responsive factor, tomato ethylene responsive factor 1 (TERF1), that integrates ethylene and osmotic stress pathways. Biochemical analysis indicated that TERF1 binds to the GCC box (an element responsive to ethylene) and to the dehydration responsive element, which is responsive to the osmoticum. Expression of TERF1 was induced by ethylene and NaCl treatment. Under normal growth conditions, overexpression of TERF1 in tobacco activated the expression of GCC box‐containing pathogen related genes and also caused the typical ethylene triple response. Further investigation indicated that transgenic TERF1 tobacco exhibited salt tolerance, suggesting that TERF1 might function as a linker between the ethylene and osmotic stress pathways.
Working memory and aging: A cross-sectional and longitudinal
analysis using a self-ordered pointing task
Authors: CHAYTOR NAOMI , SCHMITTER-EDGECOMBE MAUREEN
Published: August 2004

Age-related declines in working memory performance have been
associated with deficits in inhibition, strategy use, processing speed,
and monitoring. In the current study, cross-sectional and longitudinal
methodologies were used to investigate the relative contribution of
these components to age-related changes in working memory. In
Experiment 1, a sample of 140 younger and 140 older adults completed an
abstract design version of the Self-Ordered Pointing Task modeled after
Shimamura and Jurica (1994). Experiment 1
revealed that only processing speed and monitoring explained age
differences in SOPT performance. Participants in Experiment 2 were 53
older adults who returned 4 years after the initial testing and 53
young adults. A task that assessed the ability to generate and monitor
an internal series of responses as compared to an externally imposed
series of responses was also administered. Experiment 2 replicated the
key findings from Experiment 1 and provided some further evidence for
age-related internal monitoring difficulties. Furthermore, the
exploratory longitudinal analysis revealed that older age and lower
intellectual abilities tended to be associated with poorer performance
on the SOPT at Time 2. (JINS, 2004, 10,
489–503.)
Performance discrepancies on the California Verbal Learning
Test–Children's Version (CVLT–C) in children with
traumatic brain injury
Authors: DONDERS JACOBUS , MINNEMA MICHAEL T.
Published: August 2004

One hundred sixty-seven children with traumatic brain injury (TBI),
selected from an 8-year series of consecutive referrals to a Midwestern
rehabilitation hospital, completed the California Verbal Learning
Test–Children's Version (CVLT–C) and the Wechsler
Intelligence Scale for Children–Third Edition (WISC–III)
within 1 year after injury. A large proactive interference (PI) effect,
defined as performance on the second list that was at least 1.5
standard deviations below that on the 1st one, was statistically
significantly more common in this clinical sample (21%) than in the
CVLT–C standardization sample (11%). Other performance
discrepancies, including retroactive interference, rapid forgetting,
and retrieval problems, occurred at approximately the same rate in the
clinical and standardization samples. Children with anterior cerebral
lesions were about 3 times less likely to have a large PI effect than
children without such lesions, but the former group performed worse on
the first CVLT–C list. The impact of pediatric TBI on a wide
range of CVLT–C quantitative variables was mediated by speed of
information processing, as assessed by the WISC–III Processing
Speed factor index. It is concluded that failure to release from PI is
somewhat common, although certainly not universal, in children with
TBI. Unlike with adults, anterior cerebral lesions are not associated
selectively with an increased risk for PI after pediatric TBI but
rather with a reduced efficiency of allocation of cognitive resources.
Deficits in speed of information processing appear to be primarily
responsible for the learning deficits on the CVLT–C after
pediatric TBI. (JINS, 2004, 10, 482–488.)
Effect of age on forward and backward span tasks
Authors: HESTER ROBERT L. , KINSELLA GLYNDA J. , ONG BEN
Published: August 2004

The central executive component of working memory has been argued to play an important role in the performance of span tasks, particularly backward span. Age-related decline in central executive function has also been reported, and yet there have been inconsistent findings to indicate that with increasing age, the discrepancy between forward and backward span increases. A secondary analysis of the Wechsler Memory Scale–Third Edition standardization sample (N= 1030) was performed to investigate this relationship. It was hypothesized on the basis of past research indicating an age-related decline in central executive performance, that backward digit and spatial span performance would decrease at a greater rate than forward span performance. However, the results indicated that the rate of age-related performance decline was equivalent for both measures. It is proposed that both forward and backward span tasks recruit central executive resources for successful task performance. (JINS, 2004,10, 475–481.)
Increasing the reliability of ipsative interpretations in neuropsychology: A comparison of reliable components analysis and other factor analytic methods
Authors: FRAZIER THOMAS W. , YOUNGSTROM ERIC A. , CHELUNE GORDON J. , NAUGLE RICHARD I. , LINEWEAVER TARA T.
Published: August 2004

Ipsative approaches to neuropsychological assessment typically involve interpreting difference scores between individual test scores. The utility of these methods is limited by the reliability of neuropsychological difference scores and the number of comparisons between scores. The present study evaluated the utility of difference scores using factor analytic methods, including reliable components analysis (RCA), equally weighted composites and individual neuropsychological measures. Data from 1,364 individuals referred for neuropsychological assessment were factor analyzed and the resulting solutions were used to compute composite scores. Reliabilities and confidence intervals were derived for each method. Results indicated that RCA outperformed other factor analytic methods, but produced a slightly different factor structure. Difference scores derived using orthogonal solutions were slightly more reliable than oblique methods, and both were more reliable than those from equally weighted composites and individual measures. Confidence intervals for difference scores were considerably smaller for factor methods relative to those for individual test comparisons, due to the greater reliability of factor based difference scores and the smaller number of comparisons required. These findings suggest that difference scores derived from orthogonal factor solutions, particularly RCA solutions, may improve reliability for clinical assessment purposes. (JINS, 2004,10, 578–589.)
Hippocampal volume and retention in Alzheimer's disease
Authors: KRAMER JOEL H. , SCHUFF NORBERT , REED BRUCE R. , MUNGAS DAN , DU AN-TAO , ROSEN HOWARD J. , JAGUST WILLIAM J. , MILLER BRUCE L. , WEINER MICHAEL W. , CHUI HELENA C.
Published: August 2004

This study tested the hypothesis that the hippocampus has a
relatively specific role in retaining information over delays.
Thirty-seven subjects with probable Alzheimer's disease were
evaluated with a verbal memory task and structural MRI. Cortical gray
matter but not hippocampal volume predicted immediate free recall. In
contrast, hippocampal volume was the best predictor of how well
information was retained over a delay, even after controlling for
levels of immediate recall. Results suggest that the role of the
hippocampus is relatively specific to the consolidation of new
memories. (JINS, 2004, 10, 639–643.)
Performance of illiterate and literate nondemented elderly subjects in two tests of long-term memory
Authors: NITRINI RICARDO , CARAMELLI PAULO , HERRERA EMÍLIO , PORTO CLÁUDIA SELLITTO , CHARCHAT-FICHMAN HELENICE , CARTHERY MARIA TERESA , TAKADA LEONEL TADAO , LIMA EDSON PEREIRA
Published: August 2004

Cognitive evaluation in developing countries is a difficult undertaking due to low levels of schooling and particularly the illiteracy still frequent in the elderly. This study was part of the epidemiologic evaluation of dementia in Catanduva, Brazil, and had the objective of comparing the performance of illiterate and literate nondemented elderly individuals in 2 tests of long-term memory—the delayed recall of a word list from the CERAD and the delayed recall of common objects presented as simple drawings from the Brief Cognitive Screening Battery (BCSB). Fifty-one elderly subjects (23 illiterates) were evaluated, and the performance of the illiterates and literates differed in the CERAD memory test, but not in the BCSB memory test. This test may be more suitable for the assessment of long-term memory in populations with a high frequency of illiterates, and therefore might prove to be a useful screening tool for the diagnosis of dementia. (JINS, 2004,10, 634–638.)
Relationship of affect recognition with psychopathology and cognitive performance in schizophrenia
Authors: BOZIKAS VASILIS P. , KOSMIDIS MARY H. , ANEZOULAKI DIMITRA , GIANNAKOU MARIA , KARAVATOS ATHANASIOS
Published: August 2004

The purpose of the present study was to explore the relationship between emotion perception and both psychopathology and cognitive functioning in a group of Greek patients with schizophrenia. Thirty-five patients with schizophrenia were assessed with computerized tests of emotion perception, using visual faces (Kinney's Affect Matching Test, KAMT), prosody (Affective Prosody Test, APT), and visual everyday scenarios (Fantie's Cartoon Test, FCT), as well as a facial recognition test (Kinney's Identity Matching Test, KIMT). The patients were also evaluated with the symptoms dimensions derived from the PANSS (positive, negative, cognitive, depression, and excitement) and a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and visual scanning/psychomotor speed. The three emotion perception and face recognition tests correlated significantly with each other. The KAMT was significantly related to the cognitive symptoms dimension of the PANSS and executive functions. The FCT was significantly related to level of education and attention. Finally, the APT was significantly related to the cognitive symptoms dimension, executive functions, and attention. Our findings regarding the significant relationships of affect perception, both facial and vocal, as well as in everyday scenarios, with several cognitive abilities support the notion that deficits in decoding affective information in schizophrenia could be attributed to impairment in more basic neurocognitive domains. (JINS, 2004,10, 549–558.)
Cognitive flexibility in anorexia nervosa and bulimia nervosa
Authors: TCHANTURIA KATE , ANDERLUH MARIJA BRECELJ , MORRIS ROBIN G. , RABE-HESKETH SOPHIA , COLLIER DAVID A. , SANCHEZ PATRICIA , TREASURE JANET L.
Published: August 2004

The aim of this study was to determine if there are differences in
cognitive flexibility in anorexia nervosa and bulimia nervosa.
Fifty-three patients with an eating disorder (34 with anorexia nervosa
and 19 with bulimia nervosa) and 35 healthy controls participated in
the study. A battery of neuropsychological tests for cognitive
flexibility was used, including Trail Making B, the Brixton Test,
Verbal Fluency, the Haptic Illusion Test, a cognitive shifting task
(CatBat) and a picture set test. Using exploratory factor analysis,
four factors were obtained: 1: Simple Alternation; 2: Mental
Flexibility; 3: Perseveration; and 4: Perceptual Shift. Patients with
anorexia nervosa had abnormal scores on Factors 1 and 4. Patients with
bulimia nervosa showed a different pattern, with significant
impairments in Factors 2 and 4. These findings suggest that
differential neuropsychological disturbance in the domain of mental
flexibility/rigidity may underlie the spectrum of eating disorders.
(JINS, 2004, 10, 513–520.)
Risk taking during decision-making in normal volunteers changes
with age
Authors: DEAKIN JULIA , AITKEN MICHAEL , ROBBINS TREVOR , SAHAKIAN BARBARA J.
Published: August 2004

Risk taking in a large cohort of adults (N = 177; ages
17–73) decreased with age, demonstrated by performance on a
computer based gambling task, which has previously been shown to be
sensitive to certain pharmacological manipulations including tryptophan
depletion, lesions of the orbitofrontal cortex and neuropsychiatric
disorders such as mania. Aging was also associated with longer
deliberation times, poorer decision making, reduced risk taking, but no
significant change in delay aversion. Subjects with a higher
(NART-estimated) IQ were faster to make decisions and showed a greater
modulation of risk-taking. Both sexes showed similar patterns of
decision making, although male participants exhibited a greater
modulation of risk-taking in response to the probability of winning.
The Decision-Gamble task provides a variety of behavioral measures,
corresponding to different aspects of impulsivity. Factor analysis of
these measures suggested that two independent traits underlies
performance on the task in normal individuals: one associated with risk
tolerance, and a second associated with delay aversion. Age was related
to decreases in the risk tolerance factor, but unrelated to the delay
aversion; neither factor was significantly related to verbal IQ. This
study thus provides support for the concept that impulsivity can be
fractionated into 2 or more components. (JINS, 2004,
10, 590–598.)
Bimanual coordination in alcohol-exposed children: Role of the corpus callosum
Authors: ROEBUCK-SPENCER TRESA M. , MATTSON SARAH N. , MARION SARAH DEBOARD , BROWN WARREN S. , RILEY EDWARD P.
Published: August 2004

The corpus callosum (CC) is one of several brain structures affected in children prenatally exposed to alcohol. This structure plays a major role in coordinating motor activity from opposite sides of the body, and deficits in bimanual coordination have been documented in individuals with agenesis of or damage to the CC, particularly when the task is performed without visual feedback. The Bimanual Coordination Test was used to assess speed and accuracy on a task where both hands must coordinate to guide a cursor through angled pathways providing measures of interhemispheric interaction or the ability of the two hemispheres to coordinate activityviathe corpus callosum. Twenty-one children with fetal alcohol spectrum disorders (FASD) and 17 non-exposed control children (CON), matched closely in age, sex, and ethnicity were tested. For trials with visual feedback (WV), children with FASD were slower than CON children but were equally accurate. Although statistically significant group differences were not observed on most trials completed without visual feedback (WOV), accuracy of the FASD group on WOV trials was highly variable. Group differences in accuracy on WOV angles approached significance after accounting for performance on the WV angles, and children with FASD were significantly less accurate on an individual angle believed to be particularly sensitive to interhemispheric interaction. These results indicate that children with FASD are slower than CON children but equally accurate on basic visuomotor tasks. However, as task complexity and reliance on interhemispheric interaction increases, children with FASD demonstrate variable and inaccurate performance. Preliminary analyses suggest that inaccurate performance on the bimanual coordination task, and presumably impaired callosal functioning, may be related to the attention and problem solving impairments commonly reported in children with FASD. (JINS, 2004,10, 536–548.)
African American acculturation and neuropsychological test performance following traumatic brain injury
Authors: KENNEPOHL STEPHAN , SHORE DOUGLAS , NABORS NINA , HANKS ROBIN
Published: August 2004

The present study examined the influence of African American acculturation on the performance of neuropsychological tests following traumatic brain injury (TBI). Seventy one participants already enrolled in a larger-scale study assessing the impact of TBI (i.e., the South Eastern Michigan Traumatic Brain Injury Model Systems project) completed a self-report measure of African American acculturation (African American Acculturation Scale–Short Form; Landrine & Klonoff, 1995) in addition to a standardized battery of neuropsychological tests. Hierarchical regression analyses were conducted to evaluate the relationship between level of acculturation and test performance after controlling for injury-related (initial Glasgow Coma Scale score, time since injury) and demographic variables (age, sex, years of education, and socioeconomic status). Lower levels of acculturation were associated with significantly poorer performances on the Galveston Orientation & Amnesia Test, MAE Tokens test, WAIS–R Block Design, Rey Auditory Verbal Learning Test, and Symbol Digit Modalities Test. Decreased levels of acculturation were also significantly related to lower scores on a composite indicator of overall neuropsychological test performance. In addition, the examiner's ethnicity (Black or White) was related with scores on a few of the tests (i.e., Block Design, Trail Making Test), but was not significantly associated with the overall neuropsychological test performance. Overall, these findings suggest that differences in cultural experience may be an important factor in the neuropsychological assessment of African Americans following TBI, and provide additional support for the hypothesis that cultural factors may partially account for the differences among ethnic/cultural groups on neuropsychological tests. (JINS, 2004,10, 566–577.)
Verbal fluency deficits in Parkinson's disease: A meta-analysis
Authors: HENRY JULIE D. , CRAWFORD JOHN R.
Published: August 2004

A meta-analysis of 68 studies with a total of 4644 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of Parkinson's disease (PD) relative to healthy controls. Both phonemic and semantic fluency were moderately impaired but neither deficit qualified as a differential deficit relative to verbal intelligence or psychomotor speed. However, PD patients were significantly more impaired on semantic relative to phonemic fluency (rs = .37vs..33, respectively), and confrontation naming, a test of semantic memory that imposes only minimal demands upon cognitive speed and effortful retrieval, was associated with a deficit that was of a comparable magnitude to the deficits upon each of these types of fluency. Thus, the disorder appears to be associated with particular problems with semantic memory. Tests that impose heavy demands upon switching may also be disproportionately affected. Demented and non-demented PD patients differ quantitatively but not qualitatively in terms of the relative prominence of deficits on tests of phonemic and semantic fluency. However, patients with dementia of the Alzheimer's type and demented PD patients can be differentiated from one another by the relative magnitude of deficits upon these two measures. (JINS, 2004,10, 608–622.)
Memory and attention performance in psychiatric patients: Lack of correspondence between clinician-rated and patient-rated functioning with neuropsychological test results
Authors: MORITZ STEFFEN , FERAHLI SABINE , NABER DIETER
Published: August 2004

In the present study, the correspondence between clinician-assessed and self-reported neurocognitive performance was contrasted with scores obtained from psychometric neuropsychological tests in 148 psychiatric in-patients. Results revealed that self-reported cognitive functioning was strongly associated with depressive symptomatology but was only poorly related to psychometric neurocognitive performance, particularly in schizophrenia. Afterillness denialwas controlled for, the overall association between subjective and objective test performance was slightly increased but still failed to reach significance in six out of eight analyses. In approximately 20% to 40% of all cases, clinicians judged memory performance to be normal despite substantial impairment revealed by neuropsychological test results (attention parameters: 7–51%). Since (ecological) validity and reliability have been demonstrated for many neurocognitive paradigms, the present results question the validity of non-psychometric neurocognitive assessment and call for a complementation of clinical judgment with neurocognitive assessment. Reasons for decreased sensitivity of self-reported and clinician-assessed neurocognitive functioning are discussed. (JINS, 2004,10, 623–633.)