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Results for “longitudinal data”

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PubMed1987

[Inpatient final weight data and long-term prognosis of anorexia nervosa].

In a study of 36 patients with anorexia nervosa (age at onset: 14.5 +/- 1.9 years), an attempt was made to predict longterm outcome (follow-up interval: 7.8 +/- 3.77 years) from weight changes during inpatient treatment (duration of treatment: 156 +/- 76 days). Several statistical methods appropriate for use with longitudinal data were applied. The long-term course could be predicted correctly for 96% of the patients with a good or intermediate outcome (prognostic criteria of Morgan and Russel) and for 89% of those with a poor outcome. The most important factors predictive of a good outcome were relatively long time to stabilization of weight (greater than 47 days), a stabilized weight of at least 64% of ideal weight, low age at onset (less than 13 years) and a high variability in weight during inpatient treatment as compared with patients who had a poor prognosis.

Adult↗

PubMed2004

Change in object naming ability during adulthood.

Using longitudinal data on the Boston Naming Test ( Kaplan, Goodglass, & Weintraub, 1983) collected over 20 years from healthy individuals aged 30 to 94, we examined change in lexical retrieval with age, gender, education, and their interactions. We compared results between random-effects longitudinal and traditional cross-sectional models. Random-effects modeling revealed significant linear and quadratic change in lexical retrieval with age; it also showed a Gender x Education interaction, indicating poorest performance for women with less education. Cross-sectional analyses produced greater estimates of change with age than did longitudinal analyses.

Adult↗

PubMed1998

Macro-to-micro links in the relation between income inequality and mortality.

A growing literature points to links between income inequality and mortality. Any examination of the link should distinguish, both theoretically and empirically, between shifts in inequality that result from changes in the bottom and top of the income distribution. When state-level data from the U.S. censuses of 1980 and 1990 were used to measure differences in mortality, the results indicated that inequality measures reflecting depth of poverty show stronger correlations with mortality than do inequality measures reflecting heights of affluence. In addition, longitudinal data from the Panel Study of Income Dynamics were used to related state-level inequality measures to individual-level data on mortality. This comparison revealed significant associations between degree of income inequality in state of residence and individual risk of death only for nonelderly individuals with middle-class incomes in 1990.

Health Status Indicators↗

PubMed2006

The impact of alcohol-specific rules, parental norms about early drinking and parental alcohol use on adolescents' drinking behavior.

BACKGROUND: The present study explores the role of having rules about alcohol, parental norms about early alcohol use, and parental alcohol use in the development of adolescents' drinking behavior. It is assumed that parental norms and alcohol use affect the rules parents have about alcohol, which in turn prevents alcohol use by adolescent children. METHODS: Longitudinal data collected from 416 families consisting of both parents and two adolescents (aged 13 to 16 years) were used for the analyses. RESULTS: Results of structural equation modeling show that having clear rules decreases the likelihood of drinking in adolescence. However, longitudinally alcohol-specific rules have only an indirect effect on adolescents' alcohol use, namely through earlier drinking. Analyses focusing on explaining the onset of drinking revealed that having strict rules was related to the postponement of drinking initiation of older and younger adolescents. Further, parental norms about adolescents' early drinking and parental alcohol use were associated with having alcohol-specific rules. Parental norms were also related to adolescents' alcohol use. CONCLUSIONS: The current study is one of the first using a full family design to provide insight into the role of alcohol-specific rules on adolescents' drinking. It was shown that having strict rules is related to postponement of drinking, and that having alcohol-specific rules depends on other factors, thus underlining the complexity of the influence of parenting on the development of adolescents' alcohol use.

Adolescent↗

PubMed2002

Changes in maximal aerobic capacity with age in endurance-trained women: 7-yr follow-up.

On the basis of cross-sectional data, we previously reported that the absolute, but not the relative (%), rate of decline in maximal oxygen consumption (VO(2 max)) with age is greater in endurance-trained compared with healthy sedentary women. We tested this hypothesis by using a longitudinal approach. Eight sedentary (63 +/- 2 yr at follow-up) and 16 endurance-trained (57 +/- 2) women were reevaluated after a mean follow-up period of 7 yr. At baseline, VO(2 max) was ~70% higher in endurance-trained women (48.1 +/- 1.7 vs. 28.1 +/- 0.8 ml. kg(-1). min(-1). yr(-1)). At follow-up, body mass, fat-free mass, maximal respiratory exchange ratio, and maximal rating of perceived exertion were not different from baseline in either group. The absolute rate of decline in VO(2 max) was twice as great (P < 0.01) in the endurance-trained (-0.84 +/- 0.15 ml. kg(-1). min(-1). yr(-1)) vs. sedentary (-0.40 +/- 0.12 ml. kg(-1). min(-1). yr(-1)) group, but the relative rates of decline were not different (-1.8 +/- 0.3 vs. -1.5 +/- 0.4% per year). Differences in rates of decline in VO(2 max) were not related to changes in body mass or maximal heart rate. However, among endurance-trained women, the relative rate of decline in VO(2 max) was positively related to reductions in training volume (r = 0.63). Consistent with this, the age-related reduction in VO(2 max) in a subgroup of endurance-trained women who maintained or increased training volume was not different from that of sedentary women. These longitudinal data indicate that the greater decrease in maximal aerobic capacity with advancing age observed in middle-aged and older endurance-trained women in general compared with their sedentary peers is due to declines in habitual exercise in some endurance-trained women. Endurance-trained women who maintain or increase training volume demonstrated age-associated declines in maximal aerobic capacity not different from healthy sedentary women.

Female↗

PubMed1993

Collecting data to evaluate the effect of health policies on vulnerable populations.

Public health policies often have disproportionate effects on the poor and other vulnerable groups. Standard survey techniques are often difficult to apply to these vulnerable populations, and many data bases systematically omit such individuals. The purpose of this paper is to review our experience in collecting primary survey data from public hospital, mentally ill, HIV-infected, and non-English-speaking patients. Important issues in conducting research on these populations include proper selection of subjects and comparison groups and difficulties involved in recruitment and enrollment of subjects. Maintaining longitudinal data on these populations is difficult and often requires tracking, secondary contacts, home visits and community outreach, and the use of organizations, institutions, and networks. Investigators must also pay careful attention to ethical issues involved in conducting research on vulnerable populations.

Data Collection↗

PubMed1992

The chronic disease data bank model: a conceptual framework for the computer-based medical record.

The principles underlying the chronic disease data bank model are straight-forward: (1) the purpose of medical care is to improve patient outcomes; (2) patient outcomes in contemporary developed societies are overwhelmingly linked to chronic illnesses and degenerative processes and will become increasingly so; (3) such outcomes have multiple determinants including the psychological and social, as well as the biologic; (4) outcome antecedents (risk factors) may precede clinical illness by years or decades; and (5) these complex characteristics require for their study (a) computer aid and (b) longitudinal data. The chronic disease data bank provides an important resource, available to many investigators, for examination of the complex set of clinical and policy questions arising with long-term illness and addressing the questions of lifetime health. The chronic disease data bank consecutively enrolls eligible subjects, follows them for life, and amasses time-oriented, multidisciplinary data including clinical findings, medical history, demographics, treatments, resource utilization and disease outcomes, and assessing both the quality of life and its duration. Analyses are longitudinal and time-series in type, examining changes in trends and tempo of the disease, and are focused upon long-term outcomes. Outcomes are regularly and carefully assessed, and include the outcome dimensions of death, disability, discomfort, iatrogenic toxicity, and dollar cost. Specific studies address the description of the disease from biologic, demographic, economic, and social viewpoints, identify the factors associated with good and bad outcomes, and assess the effects of treatment, both good and ill. The clinical and policy goals are focused upon delaying transitions from more benign disease states to more serious ones, thus improving both longevity and the quality of life. The time is appropriate to consider generalization of the chronic disease data bank model to the usual clinical care situation, with large rewards in improvement of the quality of care. The traditional medical record lacks systematic documentation of end results and of important covariates related to health risks. As such, it cannot readily be used to assess the ultimate quality of care and to establish a feedback loop to change behaviors and thereby improve outcomes. It is weak where the chronic disease data bank is strong. The technology is transferable.

Chronic Disease↗

PubMed2001

Homozygous and heterozygous CCR5-Delta32 genotypes are associated with resistance to HIV infection.

OBJECTIVE: To investigate evidence for resistance to HIV-1 infection associated with the heterozygous genotype CCR5-+/Delta32 and with the homozygous genotype CCR5-Delta32/Delta32, which results in a nonfunctional CCR5 receptor. DESIGN: Cohort study of initially HIV-seronegative high-risk individuals from eight different cities. Enrollment data were analyzed to investigate the association of demographic factors and risk behaviors with CCR5 genotypes on the assumption that increased genotype prevalence among persons with histories of longer or more intensive exposure to HIV would indicate HIV resistance associated with that genotype. Longitudinal data were analyzed to investigate the association of HIV seroincidence with CCR5 genotypes. The cohort of 2996 individuals included 1892 men who have sex with men (MSM), 474 male injection drug users (IDUs), 347 women at heterosexual risk, and 283 female IDUs. MEASUREMENTS: CCR5 genotype, HIV serostatus, demographic factors, and risk behaviors during the 6 months before enrollment, followed by measurement of HIV seroincidence during the subsequent 18 months (for men) and 24 months (for women). RESULTS: Forty (1.3%) subjects were homozygous CCR5-Delta32/Delta32 and 387 (12.9%) were heterozygous CCR5-+/Delta32. All but 1 CCR5-Delta32/Delta32 individuals and 51 CCR5-+/Delta32 individuals were Caucasian. Among 1531 Caucasian MSM, CCR5-+/Delta32 individuals were present more frequently (22.3%) among those reporting unprotected receptive anal intercourse than among those not reporting this risk (15.9%) (p =.002), suggesting a selective advantage of the heterozygous genotype. CCR5-+/Delta32 individuals also had a significantly reduced relative risk of HIV seroconversion adjusted for unprotected receptive anal intercourse compared with CCR5-/+ individuals (relative risk = 0.30, 95% confidence interval [CI]: 0.08-0.97). CCR5-Delta32/Delta32 prevalence among Caucasian MSM was significantly associated with age among subjects recruited from high HIV seroprevalence cities (New York City and San Francisco) (odds ratio [OR] for each decade increase in age = 2.57, CI: 1.56-4.21) but not among those recruited from lower HIV prevalence sites (Boston, Chicago, Philadelphia, Seattle, and Providence/Pawtucket, Rhode Island) (OR = 1.20, CI: 0.75-1.89). CONCLUSIONS: Cross-sectional and longitudinal analyses indicated that among high-risk HIV seronegative MSM, CCR5-+/Delta32 and CCR5-Delta32/Delta32 are associated with protection against HIV infection. These findings imply that strategies aimed at reducing susceptibility to HIV infection by blocking CCR5 receptor sites need not seek blockage of all receptor sites to achieve an imperfect but substantial degree of protection.

Adolescent↗

PubMed2005

Hospitalization and death associated with potentially inappropriate medication prescriptions among elderly nursing home residents.

BACKGROUND: This study examines the association of potentially inappropriate medication prescribing (PIRx) with hospitalization and death among elderly long-stay nursing home residents. METHODS: We defined PIRx using the combined version of the Beers criteria. Data were from the 1996 Medical Expenditure Panel Survey Nursing Home Component. The study sample included 3372 residents, 65 years and older, who had nursing home stays of 3 consecutive months or longer in 1996. We performed multivariate logistic regression analyses of longitudinal data using generalized estimating equations. RESULTS: Residents who received any PIRx had greater odds (odds ratio [OR], 1.27; P = .002) of being hospitalized in the following month than those receiving no PIRx. Residents with PIRx exposure for 2 consecutive months were at increased risk (OR, 1.27; P = .004) of hospitalization, as were those receiving PIRx in the second month only (OR, 1.80; P = .001), compared with those receiving no PIRx. Residents who received PIRx were at greater risk of death (OR, 1.28; P = .01) that month or the next. Residents with intermittent PIRx exposures were at greater odds of death (OR, 1.89; P<.001), compared with those with no PIRx exposure. CONCLUSIONS: The association of PIRx with subsequent adverse outcomes (hospitalization and death) provides new evidence of the importance of improving prescribing practices in the nursing home setting.

Aged↗

PubMed2004

Social relationships and allostatic load in Taiwanese elderly and near elderly.

Despite the increasing evidence linking aspects of the social environment to a range of health outcomes, important questions remain concerning the precise mechanisms or pathways through which social circumstances exert their influence. Biological pathways are one important area of current research interest. Using data from the Social Environment and Biomarkers of Aging Study (SEBAS) in Taiwan, we examined relationships between social environment characteristics and an index of cumulative biological dysregulation ("allostatic load," AL) in near elderly (NE) (aged 54-70) and elderly Taiwanese (aged 71+). Longitudinal data on levels of social integration and extent of social support were used to predict cumulative AL at the final survey year. Linear regression analyses revealed that among the NE, presence of a spouse between 1996 and 2000 was associated with lower AL in 2000 among men, but not women. Among the elderly, ties with close friends and/or neighbors were found to be significantly related to lower AL for both men and women. Perceived qualities of these social relationships did not show consistent associations with AL. This relatively modest set of significant relationships stands in contrast to somewhat stronger patterns of findings from studies in Western societies. Cross-cultural differences between Western societies and an East Asian society such as Taiwan raise the intriguing possibility that contextual, normative influences on social experience affect the patterns of association between features of these social worlds and the physiological substrates of health.

Aged↗

PubMed1997

Are premarital prevention programs reaching couples at risk for marital dysfunction?

In 2 studies, newlyweds reported whether they had participated in premarital counseling and provided data on known risk factors for marital dysfunction. Couples who participated in premarital programs were not at greater risk for marital difficulties, and in some cases participating husbands were at lower risk for marital difficulties compared with husbands who did not participate. Longitudinal data indicated that couples who participated in premarital programs did not have better marital outcomes than couples who did not participate. The present article also addresses the need to develop procedures that will increase at-risk couples' participation in premarital programs and to improve the effectiveness of these programs in community settings.

Adult↗

PubMed2005

Using data augmentation to obtain standard errors and conduct hypothesis tests in latent class and latent transition analysis.

Latent class analysis (LCA) provides a means of identifying a mixture of subgroups in a population measured by multiple categorical indicators. Latent transition analysis (LTA) is a type of LCA that facilitates addressing research questions concerning stage-sequential change over time in longitudinal data. Both approaches have been used with increasing frequency in the social sciences. The objective of this article is to illustrate data augmentation (DA), a Markov chain Monte Carlo procedure that can be used to obtain parameter estimates and standard errors for LCA and LTA models. By use of DA it is possible to construct hypothesis tests concerning not only standard model parameters but also combinations of parameters, affording tremendous flexibility. DA is demonstrated with an example involving tests of ethnic differences, gender differences, and an Ethnicity x Gender interaction in the development of adolescent problem behavior.

Humans↗

PubMed1997

Predicting problem drinking: a test of an interactive social learning model.

This study tested a social learning model and explored the direct and interactive relationships between personality and environment in predicting problem alcohol use. We used longitudinal data from a nonclinical sample of males and females first tested in adolescence and followed into young adulthood. Hierarchial regression analyses were used to test main effects and interaction models. The cross-sectional data supported an interactive social learning model. Both personality and environment variables significantly predicted problem drinking. Two interactions between heavy drinking peer groups and personality variables were significant. Contrary to our hypothesis, the direction of the interaction was negative. In contrast, the longitudinal analyses did not provide strong support for our interactive model. Personality variables were significant predictors longitudinally, but in only one analysis did an environment variable significantly predict problem drinking. Furthermore, none of the interactions was significant predictors over time. Overall, the findings suggest that social learning models based on the interaction of personality and environmental influences may be more appropriate for predicting concurrent, as opposed to future problems, and that future research should include person-environment interactions. In addition, cultural tolerance of heavy drinking may be an important determinant of the role of psychological vulnerability in the development of problem drinking.

Adolescent↗

PubMed1975

A longitudinal study of total body potassium in normal children.

Most investigators studying changes in body composition during growth agree to the desirability of having longitudinal data. A group of 110 boys and 126 girls, studied annually for 4-5 years with 880 measurements of total body K in a 2pi liquid scintillation whole body counter, had total body K vs. height and total body K vs. weight data that fit previously described regression lines.

Adolescent↗

PubMed1998

Bayesian optimal design in population models for haematologic data.

We introduce a population model to design optimal apheresis schedules to collect blood stem cells from cancer patients. Blood stem cells are collected prior to the patient undergoing high-dose chemoradiotherapy and are returned after this treatment to enable reconstitution of the white blood cell components. Maximizing the number of cells collected in as few apheresis as possible is desirable. We use a longitudinal data model with random effects to describe profiles of individual patients. A hierarchical prior model introduces common mean profiles for patients undergoing different treatments. We find the optimal apheresis schedule for a new patient by minimizing an expected loss over the posterior predictive distribution of the patient's predicted CD34 profile. We implement estimation of the model and solution of the optimal design problem by a simulation approach, which allows us to accommodate arbitrary shapes for the profiles and realistic loss functions that include relative penalties for the number of scheduled stem cell collections and for collecting fewer than a specified target quantity of total collected stem cells.

Antigens, CD34↗

PubMedDate not supplied

Achievement of reproductive intentions in Sri Lanka, 1982-1985: a longitudinal study.

The achievement or reproductive intentions of Sri Lankan women was examined by using longitudinal data for the period 1982-85. Aggregate consistency between reproductive intentions and behavior was almost perfect, but at the individual level there were inconsistencies. Among those who wanted to have no more children, 23 per cent reported a birth in the intersurvey period of 3 years and 2 months, while failures to have a wanted birth stood at 36 per cent. There was a clear declining trend in the former type of inconsistencies in Sri Lanka, but the latter type has increased, possibly due to a continuing decline in family size ideals or due to deferred childbearing. Even though inconsistencies existed, expressed fertility intentions in 1982 significantly influenced the fertility outcome. The study also has a methodological focus on whether to include sterilized women when fertility intentions and behavior are examined longitudinally, but no specific problems were found with their inclusion. Results indicate that, apart from the intention variable, age, marital duration, family size, and education of husband and wife variables all influenced fertility in the follow-up period.

Adolescent↗

PubMed1999

Personal or environmental causes of happiness: a longitudinal analysis.

The author analyzed an integrative model of happiness, which incorporated personal factors (demographics, extraversion, neuroticism, and locus of control) and environmental factors (life events and social support), using a longitudinal data set. A secondary purpose was to clarify the relationship between overall happiness and life satisfaction. Using systematic random sampling, 581 residents of Kaohsiung, Taiwan, completed structured questionnaires at Time 1; among them, 105 returned valid questionnaires 2.5 years later, at Time 2. Longitudinal analysis indicated moderate stability of the subjective well-being (SWB) measures. More importantly, when both the baseline SWB levels and personality traits were statistically controlled, social support still predicted overall happiness, and positive life events predicted life satisfaction. Furthermore, there was a consistently strong bidirectional relationship between overall happiness and life satisfaction.

Adolescent↗

PubMed1999

Goal striving, need satisfaction, and longitudinal well-being: the self-concordance model.

An integrative model of the conative process, which has important ramifications for psychological need satisfaction and hence for individuals' well-being, is presented. The self-concordance of goals (i.e., their consistency with the person's developing interests and core values) plays a dual role in the model. First, those pursuing self-concordant goals put more sustained effort into achieving those goals and thus are more likely to attain them. Second, those who attain self-concordant goals reap greater well-being benefits from their attainment. Attainment-to-well-being effects are mediated by need satisfaction, i.e., daily activity-based experiences of autonomy, competence, and relatedness that accumulate during the period of striving. The model is shown to provide a satisfactory fit to 3 longitudinal data sets and to be independent of the effects of self-efficacy, implementation intentions, avoidance framing, and life skills.

Female↗