SEARCH · PubMed Health

Results for “Structural equation modeling”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 397 records · Page 22Linked to original sources

PubMedDate not supplied

A mediational model for the impact of exposure to community violence on early child behavior problems.

This study examined how maternal distress mediates the link between exposure to community violence (CV) and the development of early child behavior problems. Research was conducted among 160 children, 3,0 to 5,11 in age, who resided in high-crime neighborhoods. Using structural equation modeling, latent variables were constructed to identify model components: maternal socioeconomic status (SES) and public assistance status, exposure to CV (maternal perceptions of local violence, social disorder, and fear of crime; and frequency of child cowitnessing violent events), family aggression (partner aggression toward mother and partner aggression toward child), maternal distress (global distress and posttraumatic stress disorder symptoms), and early child behavior problems (internalizing and externalizing). Bivariate correlations indicated that CV, maternal distress, and early child behavior problems were significantly intercorrelated. A series of structural equation models was specified to estimate the direct and indirect effect of CV on early child behavior problems. A direct model indicated a significant path from CV to early child behavior problems, after controlling for maternal SES and family aggression. The direct CV-early child behavior problems path diminished, however, when maternal distress was included in the model, after controlling for maternal SES and family aggression. Results are consistent with a mediation model of the impact of maternal distress symptoms on the link between CV and early child behavior problems.

Black or African American↗

PubMed2000

Factors influencing the relation between extraversion and pleasant affect.

Factors that influence the relation between extraversion and pleasant affect were examined in 6 studies. In Studies 1 through 5, the authors used structural equation modeling techniques to test whether different extraversion and pleasant affect scales and the use of multiple methods of assessment influenced the strength of the relation. In Study 6, the authors conducted a meta-analysis of previous literature to calculate an average effect size and to assess the influence of moderator variables. Results from both the structural equation models and the meta-analysis showed that with only a few exceptions, the use of different extraversion and affect scales resulted in moderate to strong correlations. The use of "on-line" methods of mood assessment (moment reports or daily-diary reports) resulted in lower and more homogeneous correlations than did the use of global, retrospective measures of mood.

Adult↗

PubMed2007

Physiological correlates of age-related decline in vibrotactile sensitivity.

The purpose of this study was to describe age-related changes in vibrotactile sensitivity in participants of the Baltimore Longitudinal Study of Aging and to identify factors that are associated with impairment in vibrotactile sensitivity independent of age. Participants (n=523, age: 26-95 years) underwent measurements of vibration perception threshold (VPT, 100Hz) under the 2nd metatarsal head, glucose tolerance, serum inflammatory markers, nerve conduction parameters, movement time and cognition. Univariate and multivariate regression analyses were performed to identify factors that predicted VPT independent of age. Structural equation modeling was used to describe relationships between these variables. VPT was progressively higher with older age. Adjusting for age and height, VPT was similar in men and women and the slope of age-related decline was similar in the two genders. Age, height, peroneal nerve conduction velocity and peroneal nerve amplitude were independent predictors of VPT. Structural equation model demonstrated a direct relationship between peripheral nerve function and VPT. Height and circulating inflammatory markers may influence age-related decline in vibrotactile sensitivity through their negative impacts on peripheral nerve function.

Adult↗

PubMed2003

The effects of state counterindustry media campaigns on beliefs, attitudes, and smoking status among teens and young adults.

OBJECTIVES: This study sought to identify the pathways through which state-funded counterindustry media campaigns influence beliefs and attitudes regarding tobacco industry practices and smoking status. METHODS: A national random-digit-dial telephone survey of 6875 youths 12 to 24 years old was conducted in Winter 1999-2000. Exploratory and confirmatory factor analysis investigated the structure underlying beliefs and attitudes toward the tobacco industry. Structural equation modeling tested whether the data were consistent with a theoretically based causal model of campaign effects from exposure to an aggressive counterindustry campaign, mediated by beliefs about tobacco industry practices and attitudes toward the tobacco industry, to smoking status. RESULTS: Exploratory and confirmatory factor analysis indicated that two dimensions underlie perceptions of the tobacco industry: beliefs about tobacco industry practices and attitudes toward the industry. Structural equation models provided strong support for the hypothesized model: youth living in states with aggressive counterindustry media campaigns had more negative beliefs about tobacco industry practices, which led to negative attitudes toward the industry and less progression along a continuum of smoking intentions and behavior. CONCLUSIONS: Media campaigns using counterindustry messages show promise in reducing smoking behavior among teens and young adults by changing beliefs about industry practices.

Adolescent↗

PubMed2006

Social perception as a mediator of the influence of early visual processing on functional status in schizophrenia.

OBJECTIVE: The potential of social cognition as a mediator of relations between neurocognition and functional status in schizophrenia has been suggested by correlational studies that link neurocognition to social cognition or link social cognition to functional status. The authors used structural equation modeling to test more directly whether one aspect of social cognition (social perception) mediates relations between basic visual perception and functional status in patients with schizophrenia. METHOD: Seventy-five outpatients with schizophrenia were administered measures of early visual processing (computerized visual masking procedures), social perception (Half Profile of Nonverbal Sensitivity), and functional status (Role Functioning Scale). RESULTS: Structural equation modeling supported social perception as a mediator of relations between early visual processing and functional status in schizophrenia. The mediation model indicated that early visual processing is linked to functional status through social perception, thereby supporting a significant indirect relationship. The direct relationship between early visual processing and functional status was significant in a model that did not include social perception but was not significant in the mediation model that included social perception. CONCLUSIONS: Social cognition appears to be a key determinant of functional status in schizophrenia. Using a very basic measure of visual perception, the present study found that social perception mediates the influence of early visual processing on functional status in schizophrenia.

Ambulatory Care↗

PubMed2000

Adolescent and young adult antisocial behavior and adult alcohol use disorders: a fourteen-year prospective follow-up in a national survey.

OBJECTIVE: Data from the National Longitudinal Survey of Youth (NLSY) are used to examine the association between antisocial behaviors (ASB) reported in youth (15-22 years old) and alcohol use disorders (AUD) 14 years later in a large (N = 7,326) representative national sample. METHOD: Structural equation modeling generalized to dichotomous outcomes was used to assess the associations between latent variables of ASB with latent variables of AUD and background variables. RESULTS: Exploratory factor analysis of 17 ASB items yielded three factors having clear interpretations with the literature-property offenses, person offenses and illicit substance involvement. When examined in the context of the multivariate structural equation model, several independent associations between ASB and AUD symptoms and covariates were found. Although there were significant and independent effects for each ASB factor on each of the alcohol use disorder factors, the strength of the association was strongest for the effects of early illicit substance involvement on alcohol abuse and dependence. CONCLUSIONS: Both illicit substance involvement and delinquency other than illicit substance involvement reported in 1980 were associated with alcohol use disorders 14 years later.

Adolescent↗

PubMed2000

Service use patterns of youth with, and at high risk for, HIV: a care typology.

This paper uses confirmatory structural equation models to develop and test a theoretical model for understanding the service utilization history of 4679 youth who received services from 10 national HIV/AIDS demonstration models of youth-appropriate and youth-attractive services funded by the Special Projects of National Significance (SPNS) Program, HIV/AIDS Bureau, Health Resources and Services Administration. Although the projects differ from one another in the areas of emphasis in their service models, each is targeted to youth at high risk for HIV, or those youth who have already contracted HIV. Collectively, the projects represent a comprehensive adolescent HIV service model. This paper examines the characteristics of the services provided to young people ranging from outreach to intensive participation in medical treatment. Major typologies of service utilization are derived empirically through exploratory factor and cluster analysis methods. Confirmatory structural equation modeling methods are used to refine the exploratory results using a derivation and replication strategy and methods of statistical estimation appropriate for non-normally distributed service utilization indicators. The model hypothesizes that youth enter the service system through a general construct of connectedness to a comprehensive service model and through service-specific methods, primarily of outreach or emergency services. Estimates are made of the degree to which a comprehensive service model drives the services as opposed to specific service entry points.

Adolescent↗

PubMed2005

Bitter taste markers explain variability in vegetable sweetness, bitterness, and intake.

Intake of vegetables falls short of recommendations to lower risk of chronic diseases. Most research addresses bitterness as a sensory deterrent to consuming vegetables. We examined bitter and sweet sensations from vegetables as mediators of vegetable preference and intake as well as how these tastes vary with markers of genetic variation in taste (3.2 mM 6-n-propylthiouracil bitterness) and taste pathology (1.0 mM quinine bitterness, chorda tympani nerve relative to whole mouth). Seventy-one females and 39 males (18-60 years) reported prototypical tastes from and preference for Brussels sprouts, kale and asparagus as well as servings of vegetables consumed, excluding salad and potatoes. Intensity and hedonic ratings were made with the general Labeled Magnitude Scale. Data were analyzed with multiple linear regression and structural equation modeling. Vegetable sweetness and bitterness were independent predictors of more or less preference for sampled vegetables and vegetable intake, respectively. Those who taste PROP as most bitter also tasted the vegetables as most bitter and least sweet. The spatial pattern of quinine bitterness, suggestive of insult to chorda tympani taste fibers, was associated with less bitterness and sweetness from vegetables. Via structural equation modeling, PROP best explained variability in vegetable preference and intake via vegetable bitterness whereas the quinine marker explained variability in vegetable preference and intake via vegetable bitterness and sweetness. In summary, bitterness and sweetness of sampled vegetables varied by taste genetic and taste function markers, which explained differences in preference for vegetables tasted in the laboratory as well as overall vegetable intake outside the laboratory.

Adolescent↗

PubMedDate not supplied

Model testing for reliability and validity of the Outcome Expectations for Exercise Scale.

BACKGROUND: Development of a reliable and valid measure of outcome expectations for exercise appropriate for older adults will help establish the relationship between outcome expectations and exercise. Once established, this measure can be used to facilitate the development of interventions to strengthen outcome expectations and improve adherence to regular exercise in older adults. OBJECTIVES: Building on initial psychometrics of the Outcome Expectation for Exercise (OEE) Scale, the purpose of the current study was to use structural equation modeling to provide additional support for the reliability and validity of this measure. METHODS: The OEE scale is a 9-item measure specifically focusing on the perceived consequences of exercise for older adults. The OEE scale was given to 191 residents in a continuing care retirement community. The mean age of the participants was 85 +/- 6.1 and the majority were female (76%), White (99%), and unmarried (76%). Using structural equation modeling, reliability was based on R2 values, and validity was based on a confirmatory factor analysis and path coefficients. RESULTS: There was continued evidence for reliability of the OEE based on R2 values ranging from .42 to .77, and validity with path coefficients ranging from .69 to .87, and evidence of model fit (X2 of 69, df = 27, p < .05, NFI = .98, RMSEA = .07). CONCLUSION: The evidence of reliability and validity of this measure has important implications for clinical work and research. The OEE scale can be used to identify older adults who have low outcome expectations for exercise, and interventions can then be implemented to strengthen these expectations and thereby improve exercise behavior.

Aged↗

PubMed1991

Statistical issues in the study of temporal data: daily experiences.

This article reviews statistical issues that arise in temporal data, particularly with respect to daily experience data. Issues related to nonindependence of observations, the nature of data structures, and claims of causality are considered. Through the analysis of data from a single subject, we illustrate concomitant time-series analysis, a general method of examining relationships between two or more series having 50 or more observations. We also discuss detection of and remedies for the problems of trend, cycles, and serial dependency that frequently plague temporal data, and present methods of combining the results of concomitant time series across subjects. Issues that arise in pooling cross-sectional and time-series data and statistical models for addressing these issues are considered for the case in which there are appreciably fewer than 50 observations and a moderate number of subjects. We discuss the possibility of using structural equation modeling to analyze data structures in which there are a large number (e.g., 200) of subjects, but relatively few time points, emphasizing the different causal status of synchronous and lagged effects and the types of models that can be specified for longitudinal data structures. Our conclusion highlights some of the issues raised by temporal data for statistical models, notably the important roles of substantive theory, the question being addressed, the properties of the data, and the assumptions underlying each technique in determining the optimal approach to statistical analysis.

Adaptation, Psychological↗

PubMed1995

It takes two to replicate: a mediational model for the impact of parents' stress on adolescent adjustment.

In this study of parental stress and adolescent adjustment, experiences of negative life events during the recent past were used to generate a measure of acute stress. In addition, multiple indicators based on reports from various informants were used to estimate latent constructs for parental depression, discipline practices, and adolescent adjustment. Employing 2 independent samples of families from 2 different regions of the country (rural Iowa and a medium-sized city in Oregon), structural equation models were used to test the hypothesis that in intact families acute stress experienced by parents is linked to boys' adjustment (average age equaled 11.8 years in the Oregon sample, 12.7 years in the Iowa sample) through 2 different causal mechanisms. The findings showed that parental stress was related to adjustment through stress-related parental depression that is, in turn, correlated with disrupted discipline practices. Poor discipline appears to provide the direct link with developmental outcomes. The structural equation model (SEM) used to test the proposed mediational process was consistent with the data for mothers and boys from both the Oregon and the Iowa samples. The similarity in results was less clear for fathers and boys. Implications of these results for future replication studies are discussed.

Adaptation, Psychological↗

PubMed2003

Treatment process components and heroin use outcome among methadone patients.

The study proposes and tests an integrative and directional (structural equations) model to explain how pre-treatment motivation, frequency and content of counselling services, programme perceptions, and methadone dose are related to 1 and 6 months heroin use outcomes among opiate addicts receiving outpatient methadone treatment. Data were collected as part of the National Treatment Outcome Research Study (NTORS). The sample comprised 262 patients who were admitted to, and retained in methadone treatment programmes at 6 months. Structural equation models showed several relationships between treatment process variables and heroin use outcomes at 1 and 6 months follow-up. Programme perceptions and methadone dose were related to reduced heroin use at 1 month; early engagement with treatment services was related to reduced heroin use at 6 months. Pre-treatment motivation and engagement with treatment services were indirectly related to reduced heroin use at 1 month through their association with programme perceptions. Short-term (1 month) heroin use was strongly related to heroin outcome at 6 months. In addition to direct effects, treatment factors may have important indirect effects upon subsequent outcomes through their influence upon short-term outcomes.

Adult↗

PubMed2004

Does perceived behavioural control mediate the relationship between power beliefs and intention?

OBJECTIVES: In order to determine whether the relationship between power beliefs (Sigma(p)) and health-related behavioural intentions is mediated by perceived behavioural control (PBC) we used structural equation modelling of eight cross-sectional data sets. METHOD: Eight studies that examined health-related behaviours and employed representative samples totalling N = 4663 participants were analysed. All studies involved power belief items derived from pilot testing and employed standard multi-item measures of power beliefs, PBC and intention that were highly reliable. RESULTS: Confirmatory factor analysis confirmed the discriminant validity of power beliefs, PBC and intention. Structural equation modelling of relevant paths indicated that PBC only partially mediated the relationship between power beliefs and intention (Z(Sobel) = 5.15, p < .001; Z(Baron&Kenny) = 5.16, p < .001). Power beliefs had a significant direct relationship with intention even after PBC had been taken into account. CONCLUSION: The findings undermine Ajzen's contention that PBC mediates the power beliefs-intention relationship and suggests that it is important to employ measures of power beliefs in addition to measures of PBC in order to enhance the prediction of intentions to perform health-risking, or health-promoting, behaviours.

Adolescent↗

PubMed2005

The effects of multisystemic therapy on diabetes stress among adolescents with chronically poorly controlled type 1 diabetes: findings from a randomized, controlled trial.

OBJECTIVE: The goal of this study was to determine whether multisystemic therapy (MST), an intensive, home-based psychotherapy, could decrease diabetes-related stress among adolescents with chronically poorly controlled type 1 diabetes. Stress was also evaluated as a mediator of the effect of MST on adherence and metabolic control. METHODS: A randomized, controlled trial was conducted with 127 adolescents with type 1 diabetes mellitus and chronically poor metabolic control (hemoglobin A1c levels of > or =8% at study enrollment and for the past 1 year) who received their diabetes care in a children's hospital located in a major Midwestern city. Participants assigned randomly to MST received treatment for approximately 6 months. Data were collected at baseline and at a 7-month posttest (ie, treatment termination). Changes in diabetes-related stress, as measured with a self-report questionnaire, were assessed. Structural equation models were used to test the degree to which changes in stress levels mediated the ability of the MST intervention to improve adherence and metabolic control. RESULTS: In intent-to-treat analyses, participation in MST was associated with significant reductions in diabetes-related stress. Tests for moderation found no significant effects of age, gender, or ethnicity, which suggests that the intervention was equally effective in reducing diabetes stress for all participants. However, structural equation modeling did not provide support for diabetes stress as the mechanism through which MST improved health outcomes. Rather, the final model suggested that MST improved metabolic control through increased regimen adherence. CONCLUSIONS: Intensive, home-based psychotherapy reduces diabetes-related stress among adolescents with chronically poorly controlled type 1 diabetes. Such stress reductions are important for the psychological wellbeing of a subset of youths with diabetes who are at high risk for future health complications.

Adolescent↗

PubMed2003

The effects of preparatory sensory information on ICU patients.

Preparatory sensory information (PSI) has been found to have significant effects in reducing distress, tension, restlessness, negative moods, and anxiety, and also in reducing length of postoperative hospitalization during various threatening medical events, but no evidence has demonstrated the effect of PSI on a patient during ICU hospitalization. On the basis of Lazarus' theory, a structural equation model was developed to examine the role of the nursing intervention, PSI, as a significant factor influencing patients' processes of cognitive appraisals and coping, adaptational responses, and patient care outcomes during ICU hospitalization. The analytical model examined the net effect of PSI on outcomes, controlling for the effects of mastery, interpersonal trust, social support, socioeconomic status, severity of illness, age, and gender. A quasi-experiment was executed in four large acute care hospitals. Data were collected from 41 subjects in the control group and from 42 in the treatment group receiving PSI before ICU admission. Structural equation modeling was employed to test the proposed analytic model. The initial tests of model fit indicate that the original model did not fit the data well with GFI = 0.85, AGFI = 0.76, RMSEA = 0.059, p_close = 0.28, and critical N = 78. A revised model was developed, and the fit indices suggested an adequate fit with GFI = 0.90, AGFI = 0.84, RMSEA = 0.00, p_close = 0.89, and critical N = 109. These findings provide empirical support for Lazarus' theory on stress, appraisal, and coping. The findings also verify the beneficial effects of the nursing intervention of PSI on ICU patients.

APACHE↗

PubMed2003

Impaired thalamocortical connectivity in humans during general-anesthetic-induced unconsciousness.

Whereas converging lines of evidence suggest that anesthetic-induced unconsciousness may result from disruption of functional interactions within neural networks involving the thalamus and cerebral cortex, the effects anesthetics have on human thalamocortical connectivity remain unexamined with current neuroimaging techniques. To address this issue we retrospectively analyzed positron emission tomography data from 11 volunteers scanned for regional cerebral glucose utilization (rCMRglu) when awake and again during isoflurane- (n = 6) or halothane- (n = 5) induced unconsciousness using statistical parametric mapping (SPM99) and structural equation modeling. A main effect analysis, contrasting awake and unconscious metabolic activity, localized a discrete region of the left va/vl thalamus whose relative rCMRglu activity was significantly suppressed (P < 0.05, corrected) during the unconscious state. To identify brain regions whose functional connectivity with this region of the thalamus was impaired during the unconscious state, a psychophysiological interaction analysis was performed. This analysis revealed effects predominantly in topographically related areas of the primary motor and supplementary motor association cortices. Structural equation modeling of a neuroanatomical network encompassing these empirically identified regions revealed significant state-related changes in effective connectivity (chi(2)diff (6)-15.88; P < 0.05) which primarily involved impairment of thalamocortical and corticocortical projections during the unconscious state. These findings support the hypothesis that a mechanistic component underlying general-anesthetic-induced unconsciousness involves disruption of functional interactions within thalamocortical neural networks.

Anesthesia, General↗

PubMedDate not supplied

Cocaine exposure and developmental outcome from birth to 6 months.

The theoretical framework for many of the early studies of prenatal cocaine exposure has been rooted in the basic concepts of teratology/developmental toxicology. Few have published longitudinal analyses of the complex interplay between the relative effects of prenatal cocaine exposure and perinatal and environmental factors on development. The purpose of this paper was to use structural equation modeling to describe the direct and indirect effects of prenatal drug exposure on developmental outcome from birth to age 6 months. Key variables considered for study include prenatal drug exposure, perinatal medical characteristics, maternal/caregiver/family characteristics, the home environment, and neurobehavioral outcomes. We prospectively enrolled 154 predominantly crack-using women. A priori exclusion criteria included: <18 years old, major illnesses diagnosed prior to pregnancy, chronic use of legal drugs, and any use of illicit drugs other than cocaine and marijuana. From the pool of noncocaine users, 154 subjects were matched to users on pregnancy risk, parity, race, and socioeconomic status. At the end of each trimester, experienced staff conducted private interviews prompting memory of amount and timing of past drug use. Urine specimens were collected at two unanticipated times; positive screens were confirmed by gas chromatography/mass spectroscopy. Measures analyzed include medical (birth) and developmental (birth, 1 month, 6 months) assessments, all performed by blinded evaluators, as well as caregiver characteristics and environmental factors (birth, 1 month). A series of four theoretical models was tested, one for each time point (birth, 1 month, 6 months) and a longitudinal model spanning birth to 6 months. Key findings include direct effects of prenatal cocaine exposure on development at birth in the birth model and on development at birth and 6 months in the longitudinal model. In addition, indirect effects of prenatal cocaine exposure were identified on development at birth, 1 month, and 6 months, mediated through the prenatal use of alcohol and tobacco and the birth head circumference. Implications of these and other findings, including the advantages and limitations of structural equation modeling, are discussed.

Child Development↗

PubMed1996

Origins of comorbidity between conduct and affective disorders.

OBJECTIVE: This analysis used methods of structural equation modeling to assess the extent to which comorbidity between conduct and affective disorders could be explained by (1) common or correlated causal factors that influenced both outcomes or (2) reciprocal causation between these conditions. METHOD: Data were obtained during the course of a 16-year longitudinal study of a birth cohort of New Zealand children. The data analyzed comprised measures of conduct and affective disorders at ages 15 and 16 years and data on a series of antecedent childhood factors. RESULTS: Structural equation modeling suggested that a substantial component of the comorbidity between conduct and affective disorders arose because the risk factors associated with the development of conduct disorders in teenagers overlapped and were correlated with the risk factors for adolescent affective disorders; of the shared variance between conduct disorder and affective disorders, more than two thirds was explained by common risk factors. These conclusions were replicated using diagnostically scored measures and methods of categorical data analysis. Model extensions suggested an absence of direct causal pathways between conduct and affective disorders. CONCLUSIONS: A substantial amount of the correlation and comorbidity between conduct and affective disorders arises because the risk factors and life pathways that predispose adolescents to one outcome are also associated with the risk factors and life pathways that predispose adolescents to the other outcome. Nonetheless, even after control for common causal factors, there was evidence of some unexplained comorbidity between conduct and affective disorders.

Adolescent↗