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PubMedDate not supplied

Social and school factors in predicting cannabis use among Ontario high school students.

This paper explores the influence of social factors and school factors on cannabis use among Ontario high school students. The data are derived from a survey of students conducted by the Addiction Research Foundation in 1987. Multiple classification analysis was used to examine the relationship between the two groups of factors and cannabis use. Results of the analysis indicate that social factors are more highly predictive of cannabis use than are school factors. A theoretical framework specifying the influence of social and school factors on cannabis use needs to be developed and tested in order to understand this relationship more clearly.

Adolescent↗
PubMedDate not supplied

Nonvoluntary sexual activity among adolescents.

Data from the 1987 round of the National Survey of Children indicate that seven percent of Americans aged 18-22 have experienced at least one episode of nonvoluntary sexual intercourse. Women were more likely than men to report having had such an experience, with just under half of all nonvoluntary experiences among women occurring before the age of 14. Multiple classification analysis reveals that white women who had lived apart from their parents before age 16, those who had been brought up in poverty, those who had had a physical, emotional or mental limitation when they were young, those whose parents had been heavy drinkers, those whose parents had used illegal drugs and those whose parents had smoked cigarettes when they themselves were teenagers were at significantly greater risk for experiencing sexual abuse. Six percent of young white women with no risk factors, nine percent of those with one, 26 percent of those with two, and 68 percent of those with three or more had been sexually abused before or during adolescence.

Adolescent↗
PubMed1987

Self-care under war conditions. The case of Beirut, Lebanon.

This article attempts to explain the choice of treatment plan made by individuals as a result of a perceived health problem in a war-afflicted population. The prevalence of self-care in Beirut was measured and the characteristics of individuals who choose self-care versus other responses to an illness determined. The study population consisted of all individuals who experienced an ailment during the 2-week period prior to the interview (N = 1,392). Using certain sociodemographic, economic, and need factors as the independent variables and the use of home remedies as the dependent variable, a series of t-tests and Multiple Classification Analysis were performed separately on two age groups. Overall, Beirut residents were found to use home remedies rather extensively. Among individuals younger than 18 years, the type of household, religion, intake of medicine on a regular basis, and the type of ailment were significant predictors of the use of self-care. In the older age group, however, only the last two need variables were significantly related to the use of home remedies.

Adolescent↗
PubMed1984

Self-care. Substitute, supplement, or stimulus for formal medical care services?

This article examines the relationship between selected self-care practices during an episode of illness and the use of formal medical care. Stimulated by conflicting evidence and assertions, the general question addressed is: "Is self-care a substitute, a supplement, or a stimulus for use of formal medical care services?" Multiple Classification Analysis was used in a secondary data analysis of a 1976 nationwide study on access to medical care. The results suggest that self-care users may visit the physician less often and stay fewer days in the hospital, and thus they are expected to have lower expenditures for hospital and physician services. Therefore, the self-care activities examined appear to be substitutes for, rather than supplements or stimuli to, health services utilization. The results must be viewed with some caution due to limitations in the data. However, the results also argue for a greater research emphasis on self-care.

Adolescent↗
PubMed1982

[Internal migration and mental disorders: new evidence for an old hypothesis].

The relationships between migration and mental illness have been perhaps the most important research topic of Social Psychiatry. Studies on this issue conducted in Latin America have in general reached the conclusion that migration, and the experience of modernization related to it, is a major risk factor of emotional disturbance. This hypothesis was tested with data from a survey based on a representative sample of 1549 adults living in a low-income neighborhood in Bahia, Brazil. The survey employed the QMPA, a 43-item symptom scale which was developed and tested especially for studies in that sociocultural setting; it showed high sensitivity (.93) and specificity (.72) and adequate overall misclassification rate (.12). Seven trained interviewers applied a family questionnaire (20 items on demographic and socioeconomic information) and the QMPA to all the families (493) in the sample. Multiple classification analysis and covariance analysis were used to control for the effect of potential confounding factors. Crude analyses showed a statistically significant association between migration status and poor mental health. However, taking into account the combined effect of age, marital status and education as confounders resulted in non-significant levels for the association under study. Sex and economic position, despite being themselves related to emotional disturbances, did not appear as confounders or interaction terms in these analyses. The results on rural-urban origin did not provide any evidence in support to the modernization hypothesis.

Analysis of Variance↗
PubMed1982

Attitudes and opinions on health and medical care - a case study of the rural population of the Eastern Townships (Quebec).

This paper presents the relationship between concepts of attitude, perception of the availability of health care, scepticism toward medical care, scepticism toward medical practitioners, dependence resulting from illness and certain socioeconomic and demographic variables. The authors used the multiple classification analysis (M.C.A.) technique to put into operation these relationships. The findings show that age and income are, respectively, the best indicators of the perceptions of the availability of medical care and of the dependence resulting from illness. These findings corroborate the most recent research concerning the use of psychosocial factors to explain accessibility to medical care. The data used in this study come from an investigation during the summer of 1978 which involved 215 rural families from the Eastern Townships (Quebec).

Adolescent↗
PubMed1993

[Functional capacity of the elderly: measurement by the TMIG Index of Competence].

The functional capacity of the elderly was assessed in a national representative sample of elderly community residents. A stratified multistage random sampling yielded, 2,240 eligible persons, and 80.8% of them (n = 1,810) were successfully interviewed. The respondents ranged in age from 65 to 96 years, and the average age was 72.5 years; 43.2% of them were men, and the remaining 56.8% were women. The TMIG Index of Competence, a standardized multidimensional 13-item index of competence, was used for measuring the functional capacity. The total score of the index (maximum 13 points) showed a negatively skewed leptokurtic distribution: 69.6% of the respondents scored 11 points or greater while the mean was 10.8 points. A multiple classification analysis of the total score utilizing age, gender, educational attainment, and size of community as independent variables showed significant effects of age and educational attainment; the score significantly decreased with age, and the highly educated elderly showed higher score than those with lower educational attainment. The results of this study show that the majority of the elderly living in the community are well in functional capacity though the capacity tends to decline with age. The distribution of total scores observed in this study can be considered as a national standard of distribution of functional capacity measured by the TMIG Index Competence.

Activities of Daily Living↗
PubMed1977

Wife's employment and cumulative family size in the United States, 1970 and 1960.

Using a multiple classification analysis of the data from the 1 percent public-use samples of the 1960 and 1970 censuses of population, it is found that the negative relationship between wives' employment and their cumulative family size is stronger among whites than nonwhites and is strongest among women married less than 10 years, with 12 or more years of schooling, and who have no relatives living with them. Moreover, although there are many similarities in the pattern of the employment status/fertility relationship between the 1960 and 1970 data, the relationship is weaker in 1970 than in 1960.

Adolescent↗
PubMed1990

Use of multiple dipole analysis for the classification of benign rolandic epilepsy.

The clinical literature has suggested that while the clinical features and presentation of benign rolandic epilepsy in children (BREC) are known, the neuronal mechanism of the epileptic focus is poorly understood. Classification of clinical subtypes is usually made by determining whether there are supplementary clinical signs of brain damage, in which case the epilepsy is classified as non-benign or "atypical". Studies of EEG findings in BREC have suggested that the source of the epilepsy is in the Rolandic fissure. We investigated dipole source modelling in 24 children, comparing the results of one and two dipole models. The results indicate that atypical BREC patients have a more complex distribution of dipoles and that single dipole fits may be more predictive of typical BREC than multiple dipole fits. The implications of these results are discussed.

Brain Mapping↗
PubMed2005

CAGER: classification analysis of gene expression regulation using multiple information sources.

BACKGROUND: Many classification approaches have been applied to analyzing transcriptional regulation of gene expressions. These methods build models that can explain a gene's expression level from the regulatory elements (features) on its promoter sequence. Different types of features, such as experimentally verified binding motifs, motifs discovered by computer programs, or transcription factor binding data measured with Chromatin Immunoprecipitation (ChIP) assays, have been used towards this goal. Each type of features has been shown successful in modeling gene transcriptional regulation under certain conditions. However, no comparison has been made to evaluate the relative merit of these features. Furthermore, most publicly available classification tools were not designed specifically for modeling transcriptional regulation, and do not allow the user to combine different types of features. RESULTS: In this study, we use a specific classification method, decision trees, to model transcriptional regulation in yeast with features based on predefined motifs, automatically identified motifs, ChlP-chip data, or their combinations. We compare the accuracies and stability of these models, and analyze their capabilities in identifying functionally related genes. Furthermore, we design and implement a user-friendly web server called CAGER (Classification Analysis of Gene Expression Regulation) that integrates several software components for automated analysis of transcriptional regulation using decision trees. Finally, we use CAGER to study the transcriptional regulation of Arabidopsis genes in response to abscisic acid, and report some interesting new results. CONCLUSION: Models built with ChlP-chip data suffer from low accuracies when the condition under which gene expressions are measured is significantly different from the condition under which the ChIP experiment is conducted. Models built with automatically identified motifs can sometimes discover new features, but their modeling accuracies may have been over-estimated in previous studies. Furthermore, models built with automatically identified motifs are not stable with respect to noises. A combination of ChlP-chip data and predefined motifs can substantially improve modeling accuracies, and is effective in identifying true regulons. The CAGER web server, which is freely available at http://cic.cs.wustl.edu/CAGER/, allows the user to select combinations of different feature types for building decision trees, and interact with the models graphically. We believe that it will be a useful tool to facilitate the discovery of gene transcriptional regulatory networks.

Algorithms↗
PubMed1984

[A demographic analysis of multiple contingencies].

Using the multidimensional model developed by Andrei Rogers, the authors formulate a method for analyzing the interaction between and the multiplicity of certain behavior patterns such as migration. "The present article attempts to present a conceptual approach which extends classical demographic analysis to multiple phenomena or which adapts the analysis of mobility to demographic methods." (summary in ENG, SPA)

Behavior↗
PubMed1997

Classification by multiple-resolution statistical analysis with application to automated recognition of marine mammal sounds.

A multiple-resolution statistical pattern recognition technique for classification by supervised learning is developed and then applied to automated recognition of marine mammal sounds. The data to be classified may be either unprocessed or transformed, e.g., time series or time-frequency distributions of acoustic transients. Training data consist of samples previously grouped by a human expert into labeled sets; these sets are presumed to be associated with different "classes." The labeled sets are then characterized by occupancy statistics associated with a multiple-resolution, binary partition of the (unreduced) sample space. Classification of a new sample is performed by calculating a posteriori probabilities of membership of the new sample in each class, computed by Bayesian inference from the occupancy statistics of the associated labeled set. These a posteriori probabilities are calculated by a recursive algorithm that progresses from coarse to fine resolution in the sample space. The algorithm is implemented in a simple, highly efficient computer program. Automated classification of both time series and time-frequency distributions of marine-mammal vocalizations is demonstrated using a small number of labeled samples (approximately ten samples per class).

Algorithms↗
PubMedDate not supplied

Multiple classification and receiver operating characteristic (ROC) analysis.

The receiver operating characteristic (ROC) curve was applied to observer performances in a multiple-alternative decision task. It was shown that the probability of correct classification, a performance criterion often maximized in multiple-classification procedures, corresponds to the area under an appropriately constructed ROC curve. Degrees of confidence in the observer's judgment of 0, 1, ..., 10 were used for both classification and ROC rating. To demonstrate the validity of the method, 1,190 photofluorograms were examined by experienced staff radiologists to identify four cardiovascular conditions distinguishable on the basis of images of structural elements of the contours of the heart and great vessels. The classification matrices for three radiologists who achieved high, medium, and low performance ratings in this experiment are reported. The ROC curves are symmetric, with their points located around the off-diagonal. Differences between the overall probability of correct classification and the ROC curve index calculated from the same evaluator's data were very small, 0.004 to 0.011.

Cardiovascular Diseases↗