Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Structural Equation Modeling”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

Genetic influences on childhood hyperactivity: contrast effects imply parental rating bias, not sibling interaction.

BACKGROUND: Previous twin studies of hyperactivity have supported a 'contrast effect', whereby the more hyperactive the rating of one twin, the less the rating of the other. It has not been clear whether contrast effects occur in the twins' behaviour or in the ratings made of their behaviour but the implications for hyperactivity are different under the two models. METHOD: We use hyperactivity ratings from mothers and teachers for 1644 twin pairs in the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) to explore the origin of contrast effects, making use of independent teacher reports in a proportion of twins. Models were fitted separately for the two informants and jointly to ratings combined through a latent variable, using structural equation modelling. RESULTS: Models for maternal data confirm the contrast effect previously reported. Teacher ratings show a different form of bias, with both twin confusion and correlated errors representing alternative but not mutually exclusive explanations of the data. Latent variable modelling of the joint responses allowed comparison of a model in which the contrast effect was placed on maternal ratings, representing bias, versus one in which the contrast occurred in the underlying 'true' phenotype. The fit of the former model was significantly better. CONCLUSIONS: Support is provided for the notion of contrast effects as a form of rater bias in maternal hyperactivity ratings. Different bias in teacher reports highlight that no one report can be considered a gold standard. The extent to which such biases may distort information for other data sources such as sib-pair studies of concordance/discordance is discussed.

Adolescent↗

The role of personality, coping style and social support in health-related quality of life in HIV infection.

OBJECTIVE: To determine the role of health status, personality and coping style, on self-report health-related quality of life (QoL). METHODS: Participants were HIV seropositive individuals at all disease stages from three samples (a) gay/bisexual men from the UK, (b) injecting drug users from the UK, (c) injecting drug users from Italy. All participants completed questionnaires evaluating QoL, personality, coping style and social support. Explicit models of the relationships between the measured variables based on a review of the literature were tested using structural equation modelling. RESULTS: Health status was modestly associated with the physical but not the psychological aspects of QoL (beta = 0.44). Neuroticism was strongly associated with psychological QoL (beta = -0.73) but only weakly with physical QoL (beta = -0.21). The samples did not differ in either the pattern or the magnitude of these relationships. Mediating factors such as coping style, social support and other personality variables had only a weak influence on the role of Neuroticism. CONCLUSIONS: Neuroticism had a strong influence on health-related QoL that was independent of health status. Neuroticism was more strongly associated with the psychological aspects of QoL than health status. Coping styles and the other psychological variables assessed had only a weak mediating influence on this relationship.

Adaptation, Psychological↗

Rater bias in the EASI temperament scales: a twin study.

Under trait theory, ratings may be modeled as a function of the temperament of the child and the bias of the rater. Two linear structural equation models are described, one for mutual self- and partner ratings, and one for multiple ratings of related individuals. Application of the first model to EASI temperament data collected from spouses rating each other shows moderate agreement between raters and little rating bias. Spouse pairs agree moderately when rating their twin children, but there is significantly rater bias, with greater bias for monozygotic than for dizygotic twins. MLE's of heritability are approximately .5 for all temperament scales with no common environmental variance. Results are discussed with reference to trait validity, the person-situation debate, halo effects, and stereotyping. Questionnaire development using ratings on family members permits increased rater agreement and reduced rater bias.

Adult↗

Self-reported physical health among aged adults.

A multiple indicator structural equation model is proposed to delineate the various aspects of self-reported physical health. In particular, it specifies structural linkages among five measures of health including chronic illness, number of sick days, physical self-maintenance, instrumental activities of daily living, and subjective rating of one's own health. The proposed model is evaluated by using data from the 1968 National Senior Citizens Survey. The results support the predictions derived from the proposed model and are consistently replicated across four randomly divided subsamples.

Aged↗

Coping efficacy and psychological problems of children of divorce.

Three models of the relations of coping efficacy, coping, and psychological problems of children of divorce were investigated. A structural equation model using cross-sectional data of 356 nine- to twelve-year-old children of divorce yielded results that supported coping efficacy as a mediator of the relations between both active coping and avoiding coping and psychological problems. In a prospective longitudinal model with a subsample of 162 of these children, support was found for Time 2 coping efficacy as a mediator of the relations between Time 1 active coping and Time 2 internalizing of problems. Individual growth curve models over four waves also found support for coping efficacy as a mediator of the relations between active coping and psychological problems. No support was found for alternative models of coping as a mediator of the relations between efficacy and symptoms or for coping efficacy as a moderator of the relations between coping and symptoms.

Adaptation, Psychological↗

A measurement model for the Type A Self-Rating Inventory.

Compared to other questionnaire measures of Type A behavior, the Type A Self-Rating Inventory (TASRI) possesses particularly strong face validity. This study sought to develop a formal measurement model for the TASRI using a sample of 352 male and 479 female undergraduate psychology students. Assessed via structural equation modeling, an oblique two-factor (Hard-Driving, Extroverted) model explained over 90% of the common variance in responses to a subset of 13 of the original 28 TASRI items for men, women, and the pooled data. As hypothesized, relative to women, men had a greater mean score on the Hard-Driving factor and a lower mean score on the Extroverted factor. However, the magnitude of these gender differences is small. When reconceptualized in the context of work on the Big Five factor model, the Hard-Driving and Extroverted factors were found to reflect related elements of positive sociability and negative power, respectively.

Adolescent↗

Quality-of-life assessment in comparative therapeutic trials and causal structure considerations in peripheral occlusive arterial disease.

When considering the use of quality of life as a primary end-point in phase III to IV comparative trials, the trial designer generally faces some unresolved questions. These include: How does one explain that some dimensions [quality-of-life (QOL) instruments usually have more than 1 dimension] are directly influenced by the studied treatments whereas others are not? How can one interpret conflicting results between conventional clinical measurements and QOL measurements, when the relationships between conventional clinical measurement and quality of life are not known? In this paper, we consider the use of Structural Equation Modelling (SEM) as a methodological alternative to answer these problems. As an example, we analyse the internal causal structure of the Claudication Scale (CLAU-S), a specific QOL 5-dimensional instrument for peripheral occlusive arterial disease. In applying SEM to different studies and different types of calculation, we suggest that CLAU-S is based on a stable, simple and comprehensive QOL model, is compatible with the general International Classification of Impairments, Disabilities and Handicaps (ICIDH) classification, is coherent and complementary with clinical data measurements and, using differences in a prospective study, considerably improves specificity. We suggest that SEM can help in QOL scale validation, in providing a unified scheme of the inter-relationships between internal dimensions and with external variables, in particular, clinical measurements.

Arterial Occlusive Diseases↗

Empowerment and staff nurse decision involvement in nursing work environments: testing Kanter's theory of structural power in organizations.

Work redesign initiatives have transformed approaches to patient care that will require increased control of nurses over both the content and context of their practice. A secondary analysis of two studies linking perceived work empowerment with two aspects of staff nurse decisional involvement using Kanter's (1977, 1993) theory of structural power in organizations is described. In these studies, the pattern of relationships among variables in Kanter's theory and two different facets of work decisional involvement (control over the content and context of nursing practice) were examined using structural equation modeling techniques. Consistent with theoretical expectations, perceptions of formal and informal power significantly influenced perceived access to work empowerment structures. Informal power was found to mediate the relationship between formal power and access to work empowerment structures. Formal and informal power and access to empowerment structures, in combination, were found to be significant predictors of the extent of involvement in decisions related to the content and context of nursing practice, respectively. The results provide empirical support for propositions derived from Kanter's theory of work empowerment, and provide potential guidance for theory-based management practices to enhance nurses' involvement in professional and organizational decision making.

Adult↗

The role of availability as a moderator of family fruit and vegetable consumption.

The public health objective to improve the diet of Americans includes increasing the consumption of fruits and vegetables (F&V). The availability of F&V in the home has been suggested but not confirmed as one environmental factor that influences the types and quantities of F&V eaten by family members. Using a model of parental and child influences on a child's intake of F&V, the authors investigated F&V availability as a moderating variable for the relationships between the model constructs and how the relationships might change with varying levels of F&V availability. Path analysis and multigroup structural equation modeling were the analytic tools. Results indicated that homes with more F&V available had a richer and generally stronger set of motivating factors for parent and child F&V consumption than homes with low F&V availability. Findings have implications for parental involvement in interventions to enhance the diet of fourth-grade children.

Adult↗

Older adults and financial bequests.

Using data from Aging and Health Dynamics (AHEAD), this research investigated a model predicting an older adult's assessment regarding the chances (from 0 to 100) of leaving a financial bequest. Structural equation modeling analyses revealed three significant predictors of a high assessment (i.e., older age, high sense of control, and high socioeconomic status) and three predictors of a low assessment (i.e., race, physical health problems, and assessment of the chances of medical expenses depleting savings). Whites had higher financial bequests assessments than non-Whites. Physical health problems and the depleting savings assessment exerted negative effects on the financial bequest assessment. Marital status and negative psychological functioning exerted indirect effects through sense of control and through the depleting savings assessment.

Activities of Daily Living↗

Flashbulb memories and the underlying mechanisms of their formation: toward an emotional-integrative model.

Flashbulb memories (FBMs) are detailed recollections of the context in which people first heard about important events. The present study investigates three models of the formation and maintenance of FBM. Two models have previously been proposed in the literature (Brown & Kulik, 1977; Conway et al., 1994). A third model of FBM that integrates theories of FBM and recent developments in the field of emotions is proposed. The present study compares these three competing models by investigating the FBMs that Belgian citizens developed upon learning of the unexpected death of their king Baudouin. Structural equation modeling revealed that, as compared to the two previously proposed models, the third model, which takes into account emotional processes, better explains FBM.

Adolescent↗

Well-being of haemophilia patients: a model for direct and indirect effects of medical parameters on the physical and psychosocial functioning.

This study outlines the development and evaluation of a structural equation model for establishing the consequences of haemophilia. The hereditary disorder is characterized by a high tendency to haemorrhages, with recurrent bleeding into the joints causing irreversible joint damage. The model is, in general, an attempt to answer the following questions: what is the effect of haemophilia on the well-being (i.e. satisfaction, health, somatic complaints and self-esteem) of patients and what is the additional or mediating role of other individual characteristics in this pathway? Disease severity, joint impairment and disability are defined as antecedents of well-being and the mediating roles of appraisal (i.e. the personal evaluation of the disease), health beliefs (i.e. locus of control), psychological characteristics (i.e. anxiety, anger, depression and optimism) and social support are investigated. Psychological variables turned out to be the strongest determinants of well-being and partly mediated the detrimental effect of disability on well-being. The role of appraisal remained somewhat unclear, as no significant relationship was established between this personal evaluation of haemophilia and well-being. Nevertheless, appraisal very well reflected the level of disability. An internal locus of control and favourable psychological characteristics appeared to reduce the perceived seriousness of haemophilia. No evidence was found for social support to act as a mediator between disability and well-being. The perception of support did show moderately strong associations with psychological characteristics (i.e. anxiety and depression) and satisfaction ratings. The study merits further research on quantifying the relationships between clinical parameters and psychosocial outcomes in patients with a chronic disease.

Adult↗

Logistic regression analysis of twin data: estimation of parameters of the multifactorial liability-threshold model.

We extend the DeFries-Fulker regression model for the analysis of quantitative twin data to cover binary traits and genetic dominance. In the proposed logistic regression model, the cotwin's trait status, C, is the response variable, while the proband's trait status, P, is a predictor variable coded as k (affected) and 0 (unaffected). Additive genetic effects are modeled by the predictor variable PR, which equals P for monozygotic (MZ) and P/2 for dizygotic (DZ) twins; and dominant genetic effects, by PD, which equals P for MZ and P/4 for DZ twins. By setting an appropriate scale for P (i.e., the value of k), the regression coefficients of P, PR, and PD are estimates of the proportion of variance in liability due to common family environment, additive genetic effects, and dominant genetic effects, respectively, for a multifactorial liability-threshold model. This model was applied to data on lifetime depression from the Virginia Twin Registry and produced results similar to those from structural equation modeling.

Adult↗

Physician utilization of computers in medical practice: policy implications based on a structural model.

The development of policies regarding computer-based medical technology is hampered by a lack of knowledge about the process by which such applications are adopted and utilized by physicians. This study was designed to test a model of the process by which physicians change their practice behavior by utilizing a computer-based hospital information system (HIS). A structural model was developed, estimated, and tested using data from 270 members of the medical staff of a 1160 bed, private teaching hospital. The overall model consists of a measurement model which assumes that the observed variables are generated by a smaller number of unobserved variables or factors; and a structural equation model that relates exogenous and endogenous variables. The model indicates that consultation with other physicians on a hospital service leads to greater exposure to potential computer applications resulting in less concern about the potential impact of computers on medical practice. Physicians who are more knowledgeable about computers are far more likely to tailor the system to their individual practice by developing their own personal order sets for use on the HIS. All of these factors result in increased use of the HIS by physicians. A number of policy implications related to the introduction of new computer-based technology into medical practice settings are discussed.

Attitude to Computers↗

Reassurance seeking, stress generation, and depressive symptoms: an integrative model.

The purpose of this study was to examine a mechanism through which interpersonal vulnerability factors may be linked with depressive symptoms by integrating a stress-generation model with an interpersonal theory of depression. The proposed conceptual framework was tested with 267 college students in a prospective structural equation model with 3 assessments over a 5-week period. Results supported all hypotheses. Initial depressive symptoms and initial reassurance seeking style were positively associated, and initial depressive symptoms were positively related to the occurrence of subsequent minor social stressors. Finally, a reassurance-seeking style was positively related to outcome depressive symptoms indirectly through minor social stressors. As predicted, stress generation operated as a mediating mechanism linking an initial reassurance-seeking style to subsequent depressive symptoms.

Adaptation, Psychological↗

Reasoned action and social reaction: willingness and intention as independent predictors of health risk.

Three studies are described that assess elements of a new model of adolescent health-risk behavior, the prototype/willingness (P/W) model (F. X. Gibbons & M. Gerrard, 1995, 1997). The 1st analysis examined whether a central element of the prototype model, behavioral willingness, adds significantly to behavioral expectation in predicting adolescents' smoking behavior. The 2nd set of analyses used structural-equation-modeling procedures to provide the 1st test of the complete model in predicting college students' pregnancy-risk behavior. Finally, the 3rd study used confirmatory factor analysis to assess the independence of elements of the model from similar elements in other health behavior models. Results of the 3 studies provided support for the prototype model and, in particular, for 2 of its primary contentions: (a) that much adolescent health-risk behavior is not planned and (b) that willingness and intention are related but independent constructs, each of which can be an antecedent to risk behavior.

Adolescent↗

Modeling caregiver adaptation over time: the longitudinal impact of behavior problems.

Although cross-sectional research has established the link between care demands and various indicators of caregiver adaptation, few studies have examined the impact of care recipients' problematic behavior over time. The present analysis determines the importance of behavior problems when predicting rates of change in subjective stressors (role overload and role captivity) and depression. Using 4-wave longitudinal data (N = 137) on dementia caregivers, the authors fit individual growth curve models for care demands (i.e., behavior problems, activities of daily living dependencies, and cognitive impairment), subjective stressors, and depression. Subsequent structural equation models found that increases in behavior problems were most likely to predict increases in role overload. The findings emphasize the deleterious long-term impact of behavior problems on individuals' emotional adaptation to caregiving.

Activities of Daily Living↗

Path model analyzed with ordinary least squares multiple regression versus LISREL.

The data of a specified path model using the variables of voice, perceived organizational support, being heard, and procedural justice were subjected to the two separate structural equation modeling analytic techniques--that of ordinary least squares regression and LISREL. A comparison of the results and differences between the analyses is discussed, with the LISREL approach being stronger from both theoretical and statistical perspectives.

Data Interpretation, Statistical↗