PubMed Health⌕ Search

Biomedical subjects

I C Siegler

Publications and source records attributed to I C Siegler.

At least 73 records · Page 4Linked to original sources
PubMed1982

Cross-sectional and longitudinal patterns of three Wechsler Memory Scale Subtests.

This study evaluated cross-sectional and longitudinal age relationships, after age 60, for three subtests of the Wechsler Memory Scale: logical memory, associate learning, and visual reproduction. Cross-sectional regression analyses indicated that age, sex, race, and education accounted for approximately 20 to 35% of the variance in test scores, with education the strongest predictor. Longitudinally, consistent linear declines were found only for hard associates and visual reproduction. Visual reproduction was related more consistently and strongly to age than the two verbal subtests. The effects of selective attrition from the study were discussed.

Aged↗
PubMed1981

Separating age, cohort, and time of measurement: analysis of variance or multiple regression.

This paper empirically compares the relative advantages of analysis of variance (ANOVA) and multiple regression (MR) approaches to the separation of age, cohort, and time of measurement effects in sequential research designs. The comparison utilizes four synthetic data sets, designed to have specific characteristics. The results support Adam's recent claim that standard ANOVA procedures, as described by Schaie, do not permit the development of accurate decision rules for age-period-cohort analysis. A modified dummy variable regression procedure developed by Mason, et al. is demonstrated to permit accurate attribution of variance among age, cohort, and time of measurement effects in the developmental model.

Age Factors↗
PubMed1979

A long-term longitudinal study of intellectual ability of older adults: the matter of selective subject attrition.

Two hundred and forty-six subjects aged 60 to 94 were tested with the WAIS at test session 1, the start of a longitudinal study which lasted approximately 20 years. The subject attrition from the first session to the last (session No. 11) was progressive and selective, leaving mainly the intellectually superior ones in the study. Two facts appeared particularly important: One, little intellectual decline was seen in these superior subjects until very late in life. Two, analyses based on such superior subjects without reference to the larger body of subject populations can lead to spurious generalizations about aging in general. Age decline in intellectual ability seen in more representative populations may not be apparent when analyzing data of select samples.

Aged↗
PubMed1979

Stress and adaptation in later life.

The effects of five major life events, and of three types of resources, on the physical and social-psychological adaptation of 375 participants in a longitudinal study were examined. As expected, medical events had the most impact on physical adaptation, but they had surprisingly little impact on social-psychological adaptation. Retirement had the most negative social-psychological effects, but had little effect on physical adaptation. The other three events had even less effects, although multiple events tended to cumulate in impact. Better physical resources helped only physical adaptation, and better psychological and social resources mainly helped satisfaction. It appears that most of these potential stressors have less serious long-term outcomes than the crisis orientation would suggest.

Adaptation, Physiological↗
PubMed1978

Cautiousness and verbal learning in adulthood.

Twenty-two young (age 17-21)and 22 old (age 60-74) men and women participated in an investigation designed to determine the extent to which age differences in omission errors and performance in a serial learning task are accounted for by cautiousness. Age differences were found on the measures of cautiousness, and verbal learning, with young adults making more correct responses and proportionately fewer omission errors on the learning task and taking greater risks on the risk-taking tasks. The results indicated that cautiousness measures accounted for age differences in omission errors but not in performance.

Adolescent↗
PubMed1976

Learning to live in a therapeutic community: a study of elderly inpatients.

Fifty-two elderly mental patients in a state hospital were transferred to a new milieu ward. In order to evaluate patient success in the unit, three outcome categories were defined nine months after the unit opened: discharge to the community, adjustment to the setting, and return to the previous ward. Despite the unit's emphasis on performance criteria for success, staff evaluations of the patients' personality rather than the patients' achievement of the behavioural criteria, accounted for success in the setting.

Achievement↗
PubMed1975

The terminal drop hypothesis: fact or artifact?

Findings from eight longitudinal investigations were reviewed in order to evaluate the terminal drop hypothesis. The concept of terminal drop was seen to be more useful when partitioned into its component parts: the relationship between the level of cognitive performance with survival and with distance from death, and the relationship between changes in cognitive performance and death. Health status and age at death emerged as important intervening variables in understanding the terminal drop concept.

Age Factors↗
PubMedDate not supplied

Cigarette smoking in veteran women: the impact of job strain.

To evaluate the health effects of role overload, the relationship between multiple role (i.e., worker, spouse, caretaker) strain and current cigarette smoking was examined. A cross-sectional survey of women veterans, aged 36-85 years, was performed measuring home and job strain and health behaviors. Of the 275 women who rated both their work and home strains, 25% (n = 69) currently smoke cigarettes. Higher work strain, but not higher home strain, was associated with smoking adjusting for age, education, income, weight, and marital status. A stressful work environment may trigger persistent smoking and should be addressed during smoking cessation counseling.

Adult↗
PubMedDate not supplied

Markov Network Analysis: suggestions for innovations in covariance structure analysis.

Studies of aging offer special methodological challenges to the researcher in that he must often examine the change of multiple correlated variables over time. We present a set of procedures that are specifically designed to model change in such multivariate situations. These procedures, which we will call Markov Network Analysis, are directly applicable to modeling change from longitudinal or serial data. In such cases, the parameters of the model have dynamic interpretations, e.g., as coefficients in positive or negative feedback loops. In cross-sectional data, one cannot directly estimate the dynamic coefficients but the model does show how certain dynamic interpretations can be made. Statistically, maximum likelihood estimation procedures are developed and presented. In the development of the statistical model, it is shown how the bias of sequential hypothesis testing, a frequent occurrence in the estimation of complex covariance structure models, may be reduced.

Age Factors↗
PubMedDate not supplied

Life goals, satisfaction, and self-rated health: preliminary findings.

Several recent studies have suggested that a better understanding of health and psychological well-being in later life requires insights into the life goals and motivations of research participants. However, goal importance has not been examined separately from goal achievement. This distinction is important for a more fine-grained analysis of how goals may relate to adaptive outcomes among older adults. Data from surviving respondents of the Duke Second Longitudinal Study were analyzed in order to replicate and extend results from previous studies. Interestingly, a differential pattern of predictors was found for health and satisfaction. The rated importance of goals accounted for a significant portion of the variance in health, but was not predictive of satisfaction, whereas rated achievement of goals was predictive of health and satisfaction. Results are discussed in relation to theories of motivation in later life.

Aged↗
PubMedDate not supplied

Age and gender differences in the content scales of the Minnesota Multiphasic Personality Inventory.

We examined time of measurement, gender, and age differences on the nine content scales of the Minnesota Multiphasic Personality Inventory using data collected by three separate studies during the 1950s, 1960s and 1980s. No evidence was found for differences in the content scales due to time of measurement that also could not have been explained by demographic differences. Differences due to gender were found on only one of the nine scales, Masculinity-Femininity, and age differences were found on the Neuroticism, Extraversion, and Agreeableness scales. Younger men and women had significantly higher scores on the Neuroticism and Extraversion scales, and these differences were consistent in both magnitude and direction across sample and gender. Our results suggest that it is likely that openness reaches its lifetime stable level by the time typical adolescents enter college, because we found no significant age differences in intellectual interests. Neuroticism, extraversion, and agreeableness on the other hand, are likely to show instability throughout, and probably after, adolescence and early adulthood, because we found significant age differences in the content dimensions associated with these factors in separate analyses of three samples.

Adolescent↗
PubMedDate not supplied

Approaches to the nonparametric analysis of limited longitudinal data sets.

The traditional goals of longitudinal studies are many: consideration of stability and change; description of patterns of development and behavior; and understanding of the processes involved in disease, including disease onset, recovery, response to treatment, natural history of the aging process, and identification of factors that predict age-related outcomes. Researchers in aging seek to unravel the impact and interaction of physical and psychological processes on human development, health, and disease. From the point of view of statistical analysis, the critical aspect of data obtained from longitudinal studies is the inherent correlational structure of multiple measurements made on a single subject or other experimental unit, which must be appropriately treated in the analysis of the data. We discuss a series of nonparametric approaches that are both analytically accessible and particularly well suited to the analysis of sparse or otherwise limited longitudinal data.

Humans↗
PubMedDate not supplied

Premorbid personality predicts level of rated personality change in patients with Alzheimer disease.

Multiple studies of individuals with Alzheimer disease have substantiated significant levels of informant-rated change in several domains and facets of the Neuroticism-Extraversion-Openness Personality Inventory, including increases in Neuroticism and decreases in Extraversion and Conscientiousness relative to premorbid personality traits. Decline in Openness was cited in some reports, and replicable changes were identified in several facets. Current and premorbid personality of 50 patients with Alzheimer disease were rated by informants using the Neuroticism-Extraversion-Openness Personality Inventory. Multiple regression analysis was used to assess possible relationships of levels of reported change with covariates, including premorbid rating, education, duration of dementia, age, gender, and Mini-Mental State Examination score. Premorbid rating was the only significant predictor of reported change for Neuroticism, Extraversion, Conscientiousness, and the facets Anxiety (N1), Assertiveness (E3), and Activity (E4). Rated change in Depression was also found to be related to duration of dementia, change in Vulnerability was influenced by gender, and reported change in both Openness and Ideas showed a relationship to level of education.

Aged↗
PubMedDate not supplied

Suspiciousness, health, and mortality: a follow-up study of 500 older adults.

Scores on Factor L of the 16 PF, a measure of suspiciousness that is closely related to the Cook and Medley hostility scale, predicted survival in a sample of 500 older men and women during a follow-up of approximately 15 years. Those individuals with scores indicating higher levels of suspiciousness had greater mortality risk. This association remained significant after controlling for age, sex, physician's ratings of functional health, smoking, cholesterol, and alcohol intake. In addition, Factor L was associated with physician's ratings of health at the initiation of follow-up. These findings add to the weight of evidence that implicates a set of negative interpersonal attitudes in the domain of hostility, anger, cynicism, and mistrust as a prospective marker of individuals at risk for adverse health outcomes.

Aged↗
PubMedDate not supplied

A caution on the use of the MMPI K-correction in research on psychosomatic medicine.

The MMPI K scale is widely used to screen for invalid responses and to adjust substantive scale scores for defensiveness. In a normal volunteer sample, correlations of MMPI clinical scales and the Cook-Medley Hostility (HO) scale with self-reports and peer ratings on the NEO Personality Inventory (NEO-PI) were decreased rather than increased by K-correction. Similarly, in a medical sample, structured interview-based ratings of Potential for Hostility were better predicted by uncorrected HO scores than by K-corrected HO scores. Finally, in a prospective study of mortality among lawyers, uncorrected HO scores were a significant predictor of all-cause mortality; K-corrected scores were not. The data suggest that, under some circumstances, the K scale may measure substantive traits rather than defensiveness, and should be used and interpreted with caution. Its use is probably contraindicated for most research on psychiatrically normal subjects.

Adult↗