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Regression Analysis (regression + analysis)
Kinds of Regression Analysis Terms modified by Regression Analysis Selected AbstractsHIGHWAY INFRASTRUCTURE INVESTMENT AND COUNTY EMPLOYMENT GROWTH: A DYNAMIC PANEL REGRESSION ANALYSIS,JOURNAL OF REGIONAL SCIENCE, Issue 2 2009Piyapong Jiwattanakulpaisarn ABSTRACT This paper uses recent advances in dynamic panel econometrics to examine the impact of highway infrastructure on aggregate county-level employment using data for all 100 North Carolina counties from 1985 through 1997. Results are compared to models that do not take endogeneity of highway investment and dynamics of employment adjustment into account. Fully specified dynamic models are found to give insignificant results compared to these other models. Thus, when these issues are properly modeled, the results show that improvements in highways have no discernible impact on employment. [source] PREDICTING IATROGENIC GALL BLADDER PERFORATION DURING LAPAROSCOPIC CHOLECYSTECTOMY: A MULTIVARIATE LOGISTIC REGRESSION ANALYSIS OF RISK FACTORSANZ JOURNAL OF SURGERY, Issue 3 2006Kamran Mohiuddin Background: Seventeen independent risk factors were examined using multivariate logistic regression analysis to develop a profile of patients most likely at risk from iatrogenic gall bladder perforation (IGBP) during laparoscopic cholecystectomy. Methods: Since 1989, a prospectively maintained database on 856 (women, 659; men, 197) consecutive laparoscopic cholecystectomies by a single surgeon (R. J. F.) was analysed. The mean age was 48 years (range, 17,94 years). The mean operating time was 88 min (range, 25,375 min) and the mean postoperative stay was 1 day (range, 1,24 days). There were 311 (women, 214; men, 97) IGBP. Seventeen independent variables, which included sex, race, history of biliary colic, dyspepsia, history of acute cholecystitis, acute pancreatitis and jaundice, previous abdominal surgery, previous upper abdominal surgery, medical illness, use of intraoperative laser or electrodiathermy, performance of intraoperative cholangiogram, positive intraoperative cholangiogram, intraoperative common bile duct exploration, presence of a grossly inflamed gall bladder as seen by the surgeon intraoperatively and success of the operation, were analysed using multivariate logistic regression for predicting IGBP. Results: Multivariate logistic regression analysis against all 17 predictors was significant (,2 = 94.5, d.f. = 17, P = 0.0001), and the variables male sex, history of acute cholecystitis, use of laser and presence of a grossly inflamed gall bladder as seen by the surgeon intraoperatively were individually significant (P < 0.05) by the Wald ,2 -test. Conclusion: Laparoscopic cholecystectomy, using laser, in a male patient with a history of acute cholecystitis or during an acute attack of cholecystitis is associated with a significantly higher incidence of IGBP. [source] DETECTING INFLUENTIAL OBSERVATIONS IN SLICED INVERSE REGRESSION ANALYSISAUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS, Issue 3 2006Luke A. Prendergast Summary The detection of influential observations on the estimation of the dimension reduction subspace returned by Sliced Inverse Regression (SIR) is considered. Although there are many measures to detect influential observations in related methods such as multiple linear regression, there has been little development in this area with respect to dimension reduction. One particular influence measure for a version of SIR is examined and it is shown, via simulation and example, how this may be used to detect influential observations in practice. [source] Short-term travel speed prediction models in car navigation systemsJOURNAL OF ADVANCED TRANSPORTATION, Issue 2 2006Seungjae Lee The objective of this study is the development of the short-term prediction models to predict average spot speeds of the subject location in the short-term periods of 5, 10 and 15 minutes respectively. In this study, field data were used to see the comparison of the predictability of Regression Analysis, ARIMA, Kalman Filtering and Neural Network models. These field data were collected from image processing detectors at the urban expressway for 17 hours including both peak and non-peak hours. Most of the results were reliable, but the results of models using Kalman Filtering and Neural Networks are more accurate and realistic than those of the others. [source] Artificial neural networks model for the prediction of steady state phenol biodegradation in a pulsed plate bioreactorJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2008K Vidya Shetty Abstract BACKGROUND: A recent innovation in fixed film bioreactors is the pulsed plate bioreactor (PPBR) with immobilized cells. The successful development of a theoretical model for this reactor relies on the knowledge of several parameters, which may vary with the process conditions. It may also be a time-consuming and costly task because of their nonlinear nature. Artificial neural networks (ANN) offer the potential of a generic approach to the modeling of nonlinear systems. RESULTS: A feedforward ANN based model for the prediction of steady state percentage degradation of phenol in a PPBR by immobilized cells of Nocardia hydrocarbonoxydans (NCIM 2386) during continuous biodegradation has been developed to correlate the steady state percentage degradation with the flow rate, influent phenol concentration and vibrational velocity (amplitude × frequency). The model used two hidden layers and 53 parameters (weights and biases). The network model was then compared with a Multiple Regression Analysis (MRA) model, derived from the same training data. Further these two models were used to predict the percentage degradation of phenol for blind test data. CONCLUSIONS: The performance of the ANN model was superior to that of the MRA model and was found to be an efficient data-driven tool to predict the performance of a PPBR for phenol biodegradation. Copyright © 2008 Society of Chemical Industry [source] A Tobit Regression Analysis of the Covariation Between Middle School Students' Perceived School Climate and Behavioral ProblemsJOURNAL OF RESEARCH ON ADOLESCENCE, Issue 2 2010Ming-Te Wang This study uses an ecological framework to examine how adolescents' perceptions of school climate in 6th grade covary with the probability and frequency of their engagement in problem behaviors in 7th and 8th grades. Tobit analysis was used to address the issue of having a highly skewed outcome variable with many zeros and yet account for censoring. The 677 participating students from 8 schools were followed from 6th through 8th grade. The proportions of students reporting a positive school climate perception decreased over the middle school years for both genders, while the level of problem behavior engagement increased. The findings suggested that students who perceived higher levels of school discipline and order or more positive student,teacher relationships were associated with lower probability and frequency of subsequent behavioral problems. [source] The Impact of Trade Liberalisation on Economic Growth: Evidence from a Quantile Regression AnalysisKYKLOS INTERNATIONAL REVIEW OF SOCIAL SCIENCES, Issue 4 2008Neil Foster SUMMARY Individual country experience with trade liberalisation has been mixed. This paper examines the relationship between liberalisation and growth for a sample of 75 liberalising countries. To consider the importance of heterogeneity in the growth response to liberalisation this paper employs quantile regression methods which allow the coefficient on liberalisation to vary across the conditional growth distribution. The results suggest that countries experiencing the lowest rates of growth benefit most from liberalisation. The results also suggest that while such countries benefit most in the long-run they are the most likely to suffer from short-run negative effects of liberalisation. [source] Under Performers and Over Achievers: A Quantile Regression Analysis of GrowthTHE ECONOMIC RECORD, Issue 248 2004Raul A. Barreto Numerous papers have searched for empirical linkages between long run economic growth and a myriad of economic, socio-political and environmental factors. Most of these studies use ordinary least-squares regression or panel regression analysis on a sample of countries and therefore consider the behaviour of growth around the mean of the conditional distribution. We extend the literature by using quantile regression to analyse long-term growth at a variety of points in the conditional distribution. By using this approach, we identify the determinants of growth for under performing countries relative to those for over achieving countries. [source] Sex Differences in Outcomes of Sinus Surgery,THE LARYNGOSCOPE, Issue 7 2006Sabrina Mendolia-Loffredo MS Abstract Purpose: Sex has been demonstrated to affect outcome in many diseases. Our current aim is to investigate the relationship between sex and outcomes of endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis (CRS). Methods: Forty-four males and 73 females undergoing ESS for CRS with a mean follow-up of 1.4 years were evaluated prospectively. Computed tomography (CT), endoscopy, and quality of life (QOL) assessment was performed. Univariate analyses were performed to evaluate whether sex was predictive of outcome. Multiple logistic regression analysis was performed to evaluate sex association with patient factors predictive of outcome. Results: Although no sex differences in CT and endoscopy were observed (CT, P = .107 and endoscopy, P > .1), females consistently scored worse than males on disease-specific QOL pre- and postoperatively. Importantly, there was no effect of sex on improvement/change scores for the QOL instruments. Predictive Models and Multiple Logistic Regression Analysis: Sex was not found to be predictive of QOL or endoscopic outcome. Female sex was, however, associated with acetylsalicylic acid (ASA) intolerance and depression, both factors that have been associated with poorer outcome. Conclusion: Despite similarities in objective disease measures, females report significantly worse QOL scores pre- and postoperatively. Postoperative improvement did not differ by sex, nor was sex predictive of postoperative outcome. Sex differences in QOL reflect sex differences in ASA intolerance and depression, both more prevalent in females. [source] Circadian and Gender Effects on Repolarization in Healthy Adults: A Study Using Harmonic Regression AnalysisANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2010Kenneth A. Mayuga M.D. Background: Sudden cardiac death and myocardial infarction have a circadian variation with a peak incidence in the early morning hours. Increased dispersion of repolarization facilitates the development of conduction delay necessary to induce sustained arrhythmia. Both QT-dispersion and T-wave peak to T-wave end (TpTe) have been proposed as markers of dispersion of myocardial repolarization. Methods: Forty healthy adults (20 women), age 35,67 years old, with normal EKGs, echocardiograms, stress tests, and tilt-table tests were analyzed during a 27-hour hospital stay. EKGs were done at eight different time points. QT-intervals, QT-dispersion, and TpTe were measured at each time point. Harmonic regression was used to model circadian periodicity, P < 0.05 was considered significant. Results: The composite QT-interval was longer in women than in men (416 ± 17 msec vs 411 ± 20 msec, respectively, P = 0.006). The QT-dispersion among all leads was greater in men than women (37 ± 13 msec vs 30 ± 11 msec, respectively, P < 0.0001); a similar difference was found in the precordial leads. Harmonic regression showed that QT-dispersion had a significant circadian variation, primarily in men. In men, the maximum QT-dispersion occurred at 6 AM (45 ± 15 msec). TpTe also had a significant circadian variation that was not affected by gender in the majority of leads. Conclusions: A circadian variation exists in the dispersion of myocardial repolarization, as measured by both TpTe and QT-dispersion. Men and women have a different circadian variation pattern. Further studies regarding the mechanisms and clinical implications are needed. Ann Noninvasive Electrocardiol 2010;15(1):3,10 [source] Regression Analysis with a Misclassified Covariate from a Current Status Observation SchemeBIOMETRICS, Issue 2 2010Leilei Zeng Summary Naive use of misclassified covariates leads to inconsistent estimators of covariate effects in regression models. A variety of methods have been proposed to address this problem including likelihood, pseudo-likelihood, estimating equation methods, and Bayesian methods, with all of these methods typically requiring either internal or external validation samples or replication studies. We consider a problem arising from a series of orthopedic studies in which interest lies in examining the effect of a short-term serological response and other covariates on the risk of developing a longer term thrombotic condition called deep vein thrombosis. The serological response is an indicator of whether the patient developed antibodies following exposure to an antithrombotic drug, but the seroconversion status of patients is only available at the time of a blood sample taken upon the discharge from hospital. The seroconversion time is therefore subject to a current status observation scheme, or Case I interval censoring, and subjects tested before seroconversion are misclassified as nonseroconverters. We develop a likelihood-based approach for fitting regression models that accounts for misclassification of the seroconversion status due to early testing using parametric and nonparametric estimates of the seroconversion time distribution. The method is shown to reduce the bias resulting from naive analyses in simulation studies and an application to the data from the orthopedic studies provides further illustration. [source] Marginal Mark Regression Analysis of Recurrent Marked Point Process DataBIOMETRICS, Issue 2 2009Benjamin French Summary Longitudinal studies typically collect information on the timing of key clinical events and on specific characteristics that describe those events. Random variables that measure qualitative or quantitative aspects associated with the occurrence of an event are known as marks. Recurrent marked point process data consist of possibly recurrent events, with the mark (and possibly exposure) measured if and only if an event occurs. Analysis choices depend on which aspect of the data is of primary scientific interest. First, factors that influence the occurrence or timing of the event may be characterized using recurrent event analysis methods. Second, if there is more than one event per subject, then the association between exposure and the mark may be quantified using repeated measures regression methods. We detail assumptions required of any time-dependent exposure process and the event time process to ensure that linear or generalized linear mixed models and generalized estimating equations provide valid estimates. We provide theoretical and empirical evidence that if these conditions are not satisfied, then an independence estimating equation should be used for consistent estimation of association. We conclude with the recommendation that analysts carefully explore both the exposure and event time processes prior to implementing a repeated measures analysis of recurrent marked point process data. [source] Functional Regression Analysis of Fluorescence CurvesBIOMETRICS, Issue 2 2009Christian Ritz Summary Fluorescence curves are useful for monitoring changes in photosynthesis activity. Various summary measures have been used to quantify differences among fluorescence curves corresponding to different treatments, but these approaches may forfeit valuable information. As each individual fluorescence curve is a functional observation, it is natural to consider a functional regression model. The proposed model consists of a nonparametric component capturing the general form of the curves and a semiparametric component describing the differences among treatments and allowing comparisons of treatments. Several graphical model-checking approaches are introduced. Both approximate, asymptotic confidence intervals as well as simulation-based confidence intervals are available. Analysis of data from a crop experiment using the proposed model shows that the salient features in the fluorescence curves are captured adequately. The proposed functional regression model is useful for analysis of high throughput fluorescence curve data from regular monitoring or screening of plant growth. [source] Joint Regression Analysis of Correlated Data Using Gaussian CopulasBIOMETRICS, Issue 1 2009Peter X.-K. Summary This article concerns a new joint modeling approach for correlated data analysis. Utilizing Gaussian copulas, we present a unified and flexible machinery to integrate separate one-dimensional generalized linear models (GLMs) into a joint regression analysis of continuous, discrete, and mixed correlated outcomes. This essentially leads to a multivariate analogue of the univariate GLM theory and hence an efficiency gain in the estimation of regression coefficients. The availability of joint probability models enables us to develop a full maximum likelihood inference. Numerical illustrations are focused on regression models for discrete correlated data, including multidimensional logistic regression models and a joint model for mixed normal and binary outcomes. In the simulation studies, the proposed copula-based joint model is compared to the popular generalized estimating equations, which is a moment-based estimating equation method to join univariate GLMs. Two real-world data examples are used in the illustration. [source] Haplotype-Based Regression Analysis and Inference of Case,Control Studies with Unphased Genotypes and Measurement Errors in Environmental ExposuresBIOMETRICS, Issue 3 2008Iryna Lobach Summary It is widely believed that risks of many complex diseases are determined by genetic susceptibilities, environmental exposures, and their interaction. Chatterjee and Carroll (2005, Biometrika92, 399,418) developed an efficient retrospective maximum-likelihood method for analysis of case,control studies that exploits an assumption of gene,environment independence and leaves the distribution of the environmental covariates to be completely nonparametric. Spinka, Carroll, and Chatterjee (2005, Genetic Epidemiology29, 108,127) extended this approach to studies where certain types of genetic information, such as haplotype phases, may be missing on some subjects. We further extend this approach to situations when some of the environmental exposures are measured with error. Using a polychotomous logistic regression model, we allow disease status to have K+ 1 levels. We propose use of a pseudolikelihood and a related EM algorithm for parameter estimation. We prove consistency and derive the resulting asymptotic covariance matrix of parameter estimates when the variance of the measurement error is known and when it is estimated using replications. Inferences with measurement error corrections are complicated by the fact that the Wald test often behaves poorly in the presence of large amounts of measurement error. The likelihood-ratio (LR) techniques are known to be a good alternative. However, the LR tests are not technically correct in this setting because the likelihood function is based on an incorrect model, i.e., a prospective model in a retrospective sampling scheme. We corrected standard asymptotic results to account for the fact that the LR test is based on a likelihood-type function. The performance of the proposed method is illustrated using simulation studies emphasizing the case when genetic information is in the form of haplotypes and missing data arises from haplotype-phase ambiguity. An application of our method is illustrated using a population-based case,control study of the association between calcium intake and the risk of colorectal adenoma. [source] Regression Analysis of Doubly Censored Failure Time Data Using the Additive Hazards ModelBIOMETRICS, Issue 3 2004Liuquan Sun Summary Doubly censored failure time data arise when the survival time of interest is the elapsed time between two related events and observations on occurrences of both events could be censored. Regression analysis of doubly censored data has recently attracted considerable attention and for this a few methods have been proposed (Kim et al., 1993, Biometrics49, 13,22; Sun et al., 1999, Biometrics55, 909,914; Pan, 2001, Biometrics57, 1245,1250). However, all of the methods are based on the proportional hazards model and it is well known that the proportional hazards model may not fit failure time data well sometimes. This article investigates regression analysis of such data using the additive hazards model and an estimating equation approach is proposed for inference about regression parameters of interest. The proposed method can be easily implemented and the properties of the proposed estimates of regression parameters are established. The method is applied to a set of doubly censored data from an AIDS cohort study. [source] The Impact of Board Independence and CEO Duality on Firm Performance: A Quantile Regression Analysis for Indonesia, Malaysia, South Korea and ThailandBRITISH JOURNAL OF MANAGEMENT, Issue 3 2010Dendi Ramdani We study the effect of board independence and CEO duality on firm performance for a sample of stock-listed enterprises from Indonesia, Malaysia, South Korea and Thailand, applying quantile regression. Quantile regression is more powerful than classical linear regression since quantile regression can produce estimates for all conditional quantiles of the distribution of a response variable, whereas classical linear regression only estimates the conditional mean effects of a response variable. Moreover, quantile regression is better able to handle violations of the basic assumptions in classical linear regression. Our empirical evidence shows that the effect of board independence and CEO duality on firm performance is different across the conditional quantiles of the distribution of firm performance, something classical linear regression would leave unidentified. This finding suggests that estimating the quantile effect of a response variable can well be more insightful than estimating only the mean effect of the response variable. Additionally, we find a negative moderating effect of board size on the positive relationship between CEO duality and firm performance. [source] A Censored Quantile Regression Analysis of Vegetable Demand: The Effects of Changes in Prices and Total ExpenditureCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 4 2006Geir Wæhler Gustavsen Many diseases are linked to dietary behavior. One major diet-related risk factor is a low consumption of vegetables. The consumption may be increased through public policies. The effects on vegetable purchases of either removing the value added tax on vegetables or a general income support are investigated. Adverse health effects are most serious in households consuming low quantities of vegetables. Therefore, the effects on high- and low-consuming households are estimated by using quantile regressions (QRs). Since many households did not purchase any vegetable during each survey period, censored as well as ordinary QRs are used. Our results suggest that the effects of the policy variables differ in different parts of the conditional distribution of vegetable purchases. None of the proposed policy options is likely to substantially increase vegetable purchases among low-consuming households. Bon nombre de maladies découlent des habitudes alimentaires. La faible consommation de légumes constitue un important facteur de risque liéà l'alimentation. Cette consommation pourrait être accrue par l'instauration de politiques gouvernementales. Nous avons examiné les effets de l'abolition de la taxe sur la valeur ajoutée ou d'un soutien du revenu sur les achats de légumes. Les effets néfastes sur la santé sont plus graves chez les ménages qui consomment de faibles quantités de légumes. Nous avons donc estimé les effets chez les ménages à forte et à faible consommation de légumes à l'aide de régressions par quantile. Comme de nombreux ménages n'ont pas acheté de légumes au cours des périodes sondées, nous avons utilisé des régressions par quantile censurées et des régressions par quantile ordinaires. Nos résultats ont indiqué que les effets des variables concernant les politiques diffèrent dans différentes parties de la distribution conditionnelle des achats de légumes. Aucune des options politiques proposées ne semble susceptible d'accroître substantiellement les achats de légumes chez les ménages qui en consomment peu. [source] Factors predicting arrest for homeless persons receiving integrated residential treatment for co-occurring disordersCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 5 2009Blake Barrett Background,Homeless individuals are at increased risk for health and criminal justice problems. Aims,The aim of this study was to examine risk factors affecting arrest rates in a cohort of homeless people with co-occurring psychiatric and substance-abuse disorders. Methods,Baseline data were collected from 96 homeless individuals residing in a residential treatment facility for people with co-occurring disorders. Arrest data were obtained for 2 years following treatment intake. Regression analyses were employed to examine interactions between study variables. Results,One third of the sample was arrested during the 2-year follow-up period, principally for drug offences. People referred to treatment directly from the criminal justice system were four times more likely to re-offend than those referred from other sources. Participants' perceived need for mental-health services reduced risk of arrest while their perception of medical needs increased this risk. Conclusions,The relationship between referral from a criminal justice source and re-arrest after admission to the treatment facility is unsurprising, and consistent with previous literature, but the suggestion of an independently increased risk in the presence of perceived physical health-care needs is worthy of further study. The lower risk of arrest for people who perceive that they have psychological needs is encouraging. Copyright © 2009 John Wiley & Sons, Ltd. [source] Prevalence and correlates of traumatic brain injury among delinquent youthsCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 4 2008Brian E. Perron Background,Delinquent youth frequently exhibit high-risk behaviours that can result in serious injury. However, little is known about traumatic brain injuries (TBIs) and their correlates in this population. Aims,To examine the period prevalence and correlates of TBIs in delinquent youths. Method,Interviews were conducted with 720 (97.3%) residents of 27 Missouri Division of Youth Services rehabilitation facilities between March 1 and May 31, 2003. Participants [mean age (Mage) = 15.5, standard deviation (SD) = 1.2, 87% male] completed measures assessing TBI, substance use, psychiatric symptoms, and antisocial traits/behaviours. TBI was defined as ever having sustained a head injury causing unconsciousness for more than 20 minutes. Results,Nearly one-in-five youths (18.3%) reported a lifetime TBI. Youths with TBIs were significantly more likely than youths without to be male, have received a psychiatric diagnosis, report an earlier onset of criminal behaviour/substance use and more lifetime substance use problems and past-year criminal acts, evidence psychiatric symptoms, report lifetime suicidality, be impulsive, fearless, and external in locus of control and criminally victimized in the year preceding incarceration. Male gender and frequency of own criminal victimization were important predictors of TBI in multivariate analyses. Regression analyses adjusted for demographic factors, indicated that youths with TBIs were at significantly elevated risk for current depressive/anxious symptoms, antisocial behaviour, and substance abuse problems. Conclusions,TBI is common among delinquent youth and associated with wide ranging psychiatric dysfunction; however, the causal role of TBIs in the pathogenesis of co-morbid conditions remains unclear. Copyright © 2008 John Wiley & Sons, Ltd. [source] IN AND OUT OF HARM'S WAY: VIOLENT VICTIMIZATION AND THE SOCIAL CAPITAL OF FICTIVE STREET FAMILIES,CRIMINOLOGY, Issue 4 2002BILL McCARTHY Homeless youth establish a variety of relationships with people they meet on the street. These associations generate different levels of the intangible resources of trust, commitment, and reciprocity that contribute to a person's social capital. We argue that the relationships homeless youth describe as "street families" resemble the fictive kin common among people who have limited resources, and that these relationships are a greater source of social capital than are other associations. Social capital may improve access to many valued outcomes, including protections. Regression analyses of violent victimization support our argument, demonstrating that fictive street families keep youth out of harm's way more than do other street associations. [source] The role of autonomy,connectedness in depression and anxietyDEPRESSION AND ANXIETY, Issue 5 2006Marrie H.J. Bekker Ph.D. Abstract The relationship between autonomy,connectedness, and depression and anxiety was investigated in 94 primary mental health care patients and 95 psychology students. All participants completed the Autonomy,Connectedness Scale,30 (ACS-30), the Beck Depression Inventory (BDI), and the Symptom Checklist,90 (SCL-90). Results indicated that the primary mental health care group compared with the control group scored lower in Self-Awareness and Capacity for Managing New Situations, and higher in Sensitivity to Others. Women compared with men had higher levels of self-reported Sensitivity to Others. Regression analyses showed that both (low) Self-Awareness and (high) Sensitivity to Others predicted depression, as well as anxiety; also, (low) educational level had predictive value. These results indicate that low autonomy,connectedness might be a risk factor for depression and anxiety. Depression and Anxiety 23:274,280, 2006. © 2006 Wiley-Liss, Inc. [source] Association between familial suicidal behavior and frequency of attempts among depressed suicide attemptersACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2009D. Lizardi Objective:, Only a few studies have examined whether a family history of suicide influences the severity of suicidal acts and the results have been inconsistent. The current study aimed to examine whether a family history of suicidal acts predicts severity of suicide attempts. Method:, 190 suicide attempters aged 18,75 years with a lifetime history of major depression were assessed for first-degree family history of suicidality and severity of suicide attempts (number and lethality of prior suicide attempts and age at first attempt). Results:, Regression analyses indicate that a positive family history of suicidal behaviors predicts a greater number of suicide attempts. Reasons for living predict number and lethality of prior attempts. Conclusion:, It is critical to assess for family history of suicidal behavior when treating depressed suicide attempters as it may serve as an indicator of the risk of repeat suicide attempt and as a guide for treatment. [source] Auditory and speech processing and reading development in Chinese school children: behavioural and ERP evidenceDYSLEXIA, Issue 4 2005Xiangzhi Meng Abstract By measuring behavioural performance and event-related potentials (ERPs) this study investigated the extent to which Chinese school children's reading development is influenced by their skills in auditory, speech, and temporal processing. In Experiment 1, 102 normal school children's performance in pure tone temporal order judgment, tone frequency discrimination, temporal interval discrimination and composite tone pattern discrimination was measured. Results showed that children's auditory processing skills correlated significantly with their reading fluency, phonological awareness, word naming latency, and the number of Chinese characters learned. Regression analyses found that tone temporal order judgment, temporal interval discrimination and composite tone pattern discrimination could account for 32% of variance in phonological awareness. Controlling for the effect of phonological awareness, auditory processing measures still contributed significantly to variance in reading fluency and character naming. In Experiment 2, mismatch negativities (MMN) in event-related brain potentials were recorded from dyslexic children and the matched normal children, while these children listened passively to Chinese syllables and auditory stimuli composed of pure tones. The two groups of children did not differ in MMN to stimuli deviated in pure tone frequency and Chinese lexical tones. But dyslexic children showed smaller MMN to stimuli deviated in initial consonants or vowels of Chinese syllables and to stimuli deviated in temporal information of composite tone patterns. These results suggested that Chinese dyslexic children have deficits in auditory temporal processing as well as in linguistic processing and that auditory and temporal processing is possibly as important to reading development of children in a logographic writing system as in an alphabetic system. Copyright © 2005 John Wiley & Sons, Ltd. [source] On the relationship between dynamic visual and auditory processing and literacy skills; results from a large primary-school studyDYSLEXIA, Issue 4 2002Joel B. Talcott Abstract Three hundred and fifty randomly selected primary school children completed a psychometric and psychophysical test battery to ascertain relationships between reading ability and sensitivity to dynamic visual and auditory stimuli. The first analysis examined whether sensitivity to visual coherent motion and auditory frequency resolution differed between groups of children with different literacy and cognitive skills. For both tasks, a main effect of literacy group was found in the absence of a main effect for intelligence or an interaction between these factors. To assess the potential confounding effects of attention, a second analysis of the frequency discrimination data was conducted with performance on catch trials entered as a covariate. Significant effects for both the covariate and literacy skill was found, but again there was no main effect of intelligence, nor was there an interaction between intelligence and literacy skill. Regression analyses were conducted to determine the magnitude of the relationship between sensory and literacy skills in the entire sample. Both visual motion sensitivity and auditory sensitivity to frequency differences were robust predictors of children's literacy skills and their orthographic and phonological skills. Copyright © 2002 John Wiley & Sons, Ltd. [source] A Person-Organization Fit Model of Owner-Managers' Cognitive Style and Organizational DemandsENTREPRENEURSHIP THEORY AND PRACTICE, Issue 1 2007Keith H. Brigham Based on survey responses from 159 owner-managers in small high-technology firms, we examined the association among specific individual characteristics, firm characteristics, and the individual outcomes of satisfaction and intentions to exit. Regression analyses indicated higher satisfaction and lower intentions to exit for owner-managers whose dominant decision-making style complemented the levels of formalization and structure in their firms. In addition, we found that both satisfaction and intentions to exit were significantly associated with actual turnover over a 5-year period. The theoretical and practical implications of these findings are discussed. [source] Hostility, drinking pattern and mortalityADDICTION, Issue 1 2008Stephen H. Boyle ABSTRACT Aims This study examined the association of hostility to drinking pattern and whether this association mediated the relation of hostility to mortality. Participants and design Subjects were 3326 current drinkers from the Vietnam Experience Study cohort who were followed for vital status. Setting United States. Measurements Hostility was measured by an abbreviated version of the Cook,Medley Hostility Scale (ACM). The alcohol variables were total monthly intake of alcohol, drinking frequency, drinks per drinking day and drinking , 5 drinks on at least one occasion in the past month (i.e. heavy episodic drinking). Findings Regression analyses showed associations between the ACM and total monthly intake of alcohol (P < 0.0001), drinks per drinking day (P < 0.0001) and heavy episodic drinking (P < 0.0001), but not with frequency of drinking days. Hostility, drinks per drinking day, heavy episodic drinking and total monthly alcohol intake were also associated with all-cause mortality (all Ps < 0.0001). Further analyses showed that drinking pattern, particularly drinks per drinking day, may account partially for the relation of hostility to mortality. Conclusions High hostility is associated with elevated mortality and a deleterious drinking pattern characterized by relatively high intake per drinking occasion. Drinking pattern could help explain the relationships between hostility and health. [source] The importance of dental beliefs for the outcome of dental-fear treatmentEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2003Kajsa Henning Abrahamsson This study investigated the importance of dental beliefs and the predictive value of the Dental Belief Survey (DBS) in dental-fear treatment. The sample comprised 117 adult patients seeking treatment at a dental-fear clinic. Pretreatment data were collected during a screening procedure, including two visits to the dentist. Outcome measurements were completed after treatment. The dentist rated successful/unsuccessful treatment outcome. Patients unsuccessful in treatment (n = 48) reported more initial negative dental beliefs, while patients successful in treatment (n = 69) showed a larger decrease in negative beliefs between the first and second visit to the dentist. However, these differences were small. There was a significant difference between the groups at visit two. Thus, patients unsuccessful in treatment reported more negative beliefs about how dentists communicate. Regression analyses showed that improved dental beliefs during the first two visits to the dentist predicted dental-fear reduction, while longer avoidance time, female gender, low engagement in treatment, and depressed mood increased the risk of unsuccessful treatment outcome. Our results suggest that the DBS provides valuable information, and that patients' subjective perceptions about how dentists communicate are important for treatment outcome. However, initial dental beliefs were not found to predict clinical treatment outcome. [source] Personality, expectations, and response strategies in multiple-choice question examinations, in university students: a test of Gray's hypothesesEUROPEAN JOURNAL OF PERSONALITY, Issue 1 2004César Ávila The relation between personality and type of error made in multiple-choice examinations when correction for guessing is applied was investigated across two studies. Our general hypothesis was that disinhibited subjects (those scoring high on the Sensitivity to Reward (SR) scale and/or low on the Sensitivity to Punishment (SP) scale) would make more incorrect responses and fewer omission errors (blanks) than inhibited subjects (those with high SP and/or low SR scores). The meta-analyses of 19 examinations in study 1 confirmed our hypotheses for SP, SR, and extraversion. Regression analyses on effect sizes revealed that SP differences were obtained in examinations with low marks, whereas SR differences were obtained in examinations with more responses and fewer questions. Study 2 showed that a low-mark expectation increased omissions in high-SP subjects, whereas a high-mark expectation increased incorrect responses in high-SR subjects. These results suggest two different mechanisms mediating inhibition/disinhibition: one associated with aversive motivation, and the other with appetitive motivation. Copyright © 2003 John Wiley & Sons, Ltd. [source] Unconditional respect for persons and the prediction of intergroup action tendenciesEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 5 2009Mansur Lalljee Unconditional respect for persons is an orientation that rests on the assumption that all people have intrinsic worth and deserve respect simply by their being human. This paper reports three cross-sectional studies concerning unconditional respect in intergroup relations in three very different contexts. In all three studies, unconditional respect was positively related to positive action tendencies, and negatively related to negative action tendencies, toward other groups. Regression analyses showed that respect was a significant predictor of negative action tendencies even when attitude to the other group, social dominance orientation, empathy, and the quality and quantity of intergroup contact were statistically controlled. Moderation analyses showed that respect was particularly important under conditions of high threat. The implications of unconditional respect for intergroup relations are discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||||||||