Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Longitudinal analysis”

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 235 records · Page 13Linked to original sources
PubMed1991

A longitudinal analysis of young children's cohesion and noun specification in narratives.

The early production of nine cohesive devices during narration about personal experience was examined in an 18-month longitudinal study of 10 children between approximately age 2;0 and 3;6. The specification of noun phrases and types of noun errors were also explored. The number of cohesive ties increased with both age and MLU, due to increased pronominal reference and conjunctions (while clausal and verbal ellipsis decreased). Specific cohesive devices also were acquired at different MLU levels. Most noun phrases were non-problematic and errors declined with increasing age and MLU; specifically, noun omissions declined. However, when new nouns were introduced, approximately one out of five were ambiguous throughout the study. Thus, children's narratives become more comprehensible with age as cohesive links increase, and noun errors decrease, but at 3;6 children are still having difficulty properly managing the introduction of novel nouns.

Child Language↗
PubMedDate not supplied

A longitudinal analysis of the growth of limb segments in adolescence.

The growth of upper and lower-limb segments of 96 adolescent boys and girls from the Royal Hospital School Longitudinal Study was analysed. Preece-Baines Model 1 curves were fitted to the longitudinal data to obtain, for each measurement, age at peak velocity and the magnitude of this velocity. Mean-constant peak velocities were between 1-0 and 2-5 cm/yr in all segments. They were in all cases greater than the values obtained from fitting the P-B curve to the cross-sectional means at successive ages. Boys had greater peak velocities than girls in all measurements (sex ratio 1-1 to 1-4). On average distal segments preceded more proximal segments in the ages at which peak velocity occurred. Considerable individual differences, however, occurred in the order for the upper limb segments. These differences seemed to be related to the individual's tempo of growth; late developers had a significantly different order to early developers.

Adolescent↗
PubMed2004

Longitudinal analysis of lymphocyte ratios and HIV-1 intracellular DNA levels in children.

The associations between human immunodeficiency virus type 1 (HIV-1) intracellular DNA and immunological markers were analyzed longitudinally for children with sustained, undetectable RNA levels while receiving highly active antiretroviral therapy (HAART) for >2 years. When DNA levels reached a plateau at week 104 of therapy, in contrast to findings for adults, there was no correlation between the CD4(+) : CD8(+) ratio and DNA levels (r=-0.02; P=.95), and naive CD4(+)CD45RA(+) lymphocytes predominated. These data suggest that the increased proportion of naive lymphocytes found in children are less susceptible to HIV-1 infection than are the memory lymphocytes that dominate immune reconstitution in adults.

Adolescent↗
PubMed2001

Longitudinal analysis of subjective quality of life in schizophrenia: anxiety as the best symptom predictor.

We examined the relationships among changes in anxiety, depression, core symptoms of schizophrenia, and subjective quality of life (QL) longitudinally. Fifty-three stabilized outpatients diagnosed with schizophrenia or schizoaffective disorder were assessed for QL and symptoms every 3 months for a period of 1 year. Using mixed effects models, we found that changes in anxiety, as rated on the Brief Psychiatric Rating Scale, were inversely associated with general life satisfaction and satisfaction with many specific domains. These relationships were stronger than the relationships of QL and any other core symptoms of schizophrenia, including depression. Anxiety was also related to some positive and negative symptoms. These findings support the notion that more precise analysis of general psychopathology, and anxiety in particular, is important in clarifying the factors involved in QL in schizophrenia. We explain our findings in the context of current theories of affect and suggest implications for the treatment of schizophrenia.

Adult↗
PubMed1991

A longitudinal analysis of household and nonhousehold living arrangements in later life.

Most explanatory models of living arrangements in later life link the decision process surrounding choice of living arrangement to personal resources such as income and health. Applications of these models, however, are based for the most part on cross-sectional rather than longitudinal data. In this paper we examine living arrangements in later life among the nonmarried population aged 55 and over, using data from the Survey of Income and Program Participation. We observe individuals as they change living arrangements, die, or become institutionalized. Our results suggest that economic resources dominate the decision-making process in transitions across different household arrangements, whereas health is most important in explaining institutionalization.

Age Factors↗
PubMedDate not supplied

[Age differences versus aging--a cross-sectional and longitudinal analysis on the development of memory in advanced age].

This study examines the development of episodic memory in later adulthood and old age in a combined cross-sectional and longitudinal design. 124 normal aging subjects, aged 50-87 years, representing four age groups (M1 = 53.65 years, M2 = 60.60 years, M3 = 68.44 years, M4 = 75.83 years) participated in a cross-sectional study. Seven years later a retest was done in which 70% of the original sample again participated. Significant differences between the cross-sectional and the longitudinal results were found, with the latter showing the more severe decline in memory performances. Moreover, the age decline occurred earlier in the longitudinal study. Cohort differences account for these differences between the cross-sectional and longitudinal findings, favoring subjects of earlier-born cohorts.

Aged↗
PubMed2004

[Predictors and mechanisms of tinnitus distress - a longitudinal analysis].

BACKGROUND: The available cross-sectional and retrospective evidence does not provide a clear answer to the question whether the multiple psychological problems and disturbances found in patients with chronic decompensated tinnitus are cause or consequence of the tinnitus. The present research took a longitudinal approach to examine this question. METHOD: Psychopathological symptoms, personality, socio-demographical variables and otological features were assessed in 48 patients which had suffered from tinnitus for a period of no longer than 4 weeks. Six months after first assessment 92 % of the original sample (n = 44) were re-examined. 34 of these patients displayed chronic tinnitus. Univariate and multiple regression analyses were conducted in order to identify variables at first assessment which predicted tinnitus distress at second assessment for the 34 patients with chronic tinnitus. RESULTS: Tinnitus attributed sleep disturbance, anxiousness, and life satisfaction, each assessed at first investigation, independently predicted tinnitus distress at second assessment six months later. These three variables together predicted 56 % of the variance of tinnitus distress at second assessment. CONCLUSIONS: Our results support the model that the symptom tinnitus may develop on the basis of an enhanced psychophysiological tension and become a condensational core of preexisting psychological distress as a facilitatory process. Our results suggest that early psychotherapeutic interventions in patients at risk may prevent decompensation.

Adaptation, Psychological↗
PubMedDate not supplied

[Longitudinal analysis of change in sports performance of women between ages 30 and 75: a comparison between peak and leisure sports participation].

The paper considers motor development in women aged 30 to 75 years. The present research examines performance changes in several track and field disciplines comparing senior master athletes and competitors on a mass sport level. The change itself and its acceleration is expressed by the linear and the coefficients of quadratic polynomials fitted to the original and the z-transformed data. Correlation-, regression- and cluster analysis as well as Manova were conducted with the coefficients and the original data from 585 and 224 repeated measurement series. Significant differences were found for the original data and the change parameters: 1) Between the two groups considered longitudinally and cross-sectionally, 2) within both groups concerning several disciplines and age groups considered longitudinally and cross-sectionally. Further research will be conducted with additional methods to support the present findings. The most important issue will be to investigate the interaction between the observed pattern and external variables concerning training effort, lifestyle, state of health, life events and personality traits gathered from the group at the mass sport level.

Adult↗
PubMed2005

Longitudinal analysis of metalloproteinases, tissue inhibitors of metalloproteinases and clinical parameters in gingival crevicular fluid from periodontitis-affected patients.

BACKGROUND: The aim of this work was to improve the assessment of the periodontal disease status through measurements of extracellular matrix metalloproteinases (MMPs) and their tissular inhibitors (TIMPs) in the gingival crevicular fluid from patients diagnosed with chronic periodontitis. METHODS: Gingival crevicular fluid samples from patients (n = 13) were taken from 60 sites initially, and from 51 and 41 sites, respectively, 3 and 6 months after scaling and root planing. Gingival crevicular fluid samples were also taken from healthy subjects (n = 11, 24 sites). The presence of MMP-9 and MMP-8 was assessed by zymography and immunowestern blotting, respectively. The actual MMP activity (gelatinase and collagenase) was measured using the fluorogenic substrate assay. TIMP-1 and -2 levels were measured by immunodot blot. RESULTS: The fluorogenic substrate assay determinations showed higher MMP activity in sites with probing depth > or = 4 mm, with significant reduction post-treatment. Gelatinase activity followed by zymography consisted mainly of MMP-9. A different pattern of MMP-8 in control and patient sites was found. Controls only showed species of a partially active form (69 kDa), whereas patient sites showed a high frequency of the active form (56 kDa), and in some cases the latent form (85 kDa) was also observed. The active form reduced its frequency in sites with probing depth > or = 4 mm. TIMP-1 and -2 levels in patients were significantly lower than in controls, and after treatment the recovery of TIMP-1 level similar to control was observed. CONCLUSION: Significant correlations between the severity of the periodontal disease and the actual MMP activity, the active form of MMP-8 and the low level of both TIMP-1 and TIMP-2 were found.

Adult↗
PubMed1999

Predominant expression of Fas (CD95) ligand in metastatic melanoma revealed by longitudinal analysis.

The expression of Fas ligand has recently been proposed as a novel tumor escape mechanism for melanoma. To establish the characteristics of Fas ligand expression during the course of melanoma progression we performed a longitudinal study analyzing primary tumors as well as subsequently evolving metastases. In primary melanoma Fas ligand was expressed in two of 20 lesions; this expression was weak and restricted to few parts of the tumors. The Fas ligand positive primary melanomas were rather thick, i.e., 8.5 and 3.8 mm, versus a median of 2.4 mm of the remaining tumors. In contrast, for metastatic melanoma Fas ligand expression was present in six of 11 cases investigated. The metastases of primary tumors displaying Fas ligand maintained its expression. As Fas ligand positive melanoma cells are capable of inducing apoptosis in susceptible cells, e.g., Fas positive tumor infiltrating lymphocytes, we tested for the presence of apoptotic cells in situ by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. This analysis revealed that apoptotic cells were present within the Fas ligand positive tumors. The number of apoptotic cells, however, never exceeded 5% of the total cells. Thus, Fas ligand mediated apoptosis does not seem to be a major immune escape mechanism for melanoma but its expression correlates with the stage of melanoma.

Adult↗
PubMed2003

Marital status changes and body weight changes: a US longitudinal analysis.

The role of spouse is associated with better health. The dynamics of spousal roles can be represented by marital trajectories that may remain stable or may change by entry into marriage, dissolution of marriage, or death of a spouse. Body weight is an important health-related characteristic that has been found to have mixed relationships with marital status. This analysis examined changes in marital status and body weight in 9043 adults in the US National Health and Nutrition Epidemiological Follow-up Survey (NHEFS), a longitudinal national study that interviewed and measured adults in a baseline assessment and reassessed them again in a follow-up approximately 10 years later. Men's and women's weights were differently associated with marital changes. Women who were unmarried at baseline and married at follow-up had greater weight change than those who were married at both times. Analysis of weight loss and weight gain separately revealed that sociodemographic variables, including marital change, were more predictive of variation in weight loss than weight gain. Unmarried women who married gained more weight than women married at both times. Men who remained divorced/separated and men who became widowed lost more weight than men married at both baseline and follow-up. These findings suggest that changes in social roles, such as entering or leaving marriage, influence physical characteristics such as body weight.

Adolescent↗