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 289 records · Page 16Linked to original sources
PubMedDate not supplied

Determinants of exercise among children. II. A longitudinal analysis.

BACKGROUND: Research has demonstrated that physical activity serves an important preventive function against the development of cardiovascular disease. The recognition that U.S. children are often sedentary, coupled with the observation that physical activity habits tend to persist into adulthood, has prompted the investigation of exercise determinants consistent with social learning theory. The purposes of the present study were to identify social learning variables relevant to children's exercise and to explore the longitudinal predictive value of the determinants. METHODS: Data were collected from 111 families (N = 54 girls, N = 57 boys) who were interviewed in both Phase 1 (fifth and sixth grades) and Phase 2 (eight and ninth grades) of this study. Data from mothers (N = 111) were collected during both phases; data from 80 fathers were collected at Phase 2 only. RESULTS: The results of simultaneous stepwise regression analyses indicated that child's enjoyment of physical activity was the only consistent predictor of physical activity during Phase 1. At Phase 2, child's exercise knowledge, mother's physical activity, and child's and mother's friend modeling/support emerged as predictors for girls. For boys, child's self-efficacy for physical activity, exercise knowledge, parental modeling, and interest in sports media were important. Longitudinally, mother's self-efficacy, barriers to exercise, enjoyment of physical activity, and child's self-efficacy for physical activity were important for girls. Only child's exercise knowledge predicted boys' physical activity. The addition of information from fathers nearly doubled the explanatory power of the predictors for both genders. CONCLUSIONS: Socialization in the family unit exerts a tremendous influence on health-related behaviors such as exercise. The relative importance of determinants seems to differ for girls and boys and the pattern of these determinants appears to change over time.

Adult↗
PubMed2005

Do occupation and work conditions really matter? A longitudinal analysis of psychological distress experiences among Canadian workers.

This study analyses the relationship between occupation, work conditions and the experience of psychological distress within a model encompassing the stress promoted by constraints-resources embedded in macrosocial structures (occupational structure), structures of daily life (workplace, family, social networks outside the workplace) and agent personality (demography, physical health, psychological traits, life habits, stressful childhood events). Longitudinal data were derived from Statistics Canada's National Population Health Survey and comprised 6,359 workers nested in 471 occupations, followed four times between 1994-1995 and 2000-2001. Discrete time survival multilevel regressions were conducted on first and repeated episodes of psychological distress. Results showed that 42.9 per cent of workers had reported one episode of psychological distress and 18.7 per cent had done so more than once. Data supported the model and challenged the results of previous studies. The individual's position in the occupational structure plays a limited role when the structures of daily life and agent personality are accounted for. In the workplace, job insecurity and social support are important determinants, but greater decision authority increases the risk of psychological distress. Workplace constraints-resources are not moderated either by the other structures of daily life or by agent personality.

Adult↗
PubMedDate not supplied

Longitudinal analysis of serum KL-6 levels in patients with systemic sclerosis: association with the activity of pulmonary fibrosis.

OBJECTIVE: To determine whether changes in serum KL-6 levels reflect the activity of pulmonary fibrosis (PF) in patients with systemic sclerosis (SSc). METHODS: KL-6 levels were determined by ELISA in 39 SSc patients. In a retrospective longitudinal study, 250 serum samples were analyzed during a follow-up period of 0.3-6.1 years. RESULTS: KL-6 levels at the first visit were higher in patients with SSc, especially with PF, compared with healthy controls. In the longitudinal study, KL-6 levels in 4 patients with anti-topo I Abs increased rapidly, parallel to the progression of PF. Four patients with inactive PF exhibited elevated, but stable levels of KL-6 during the follow-up. The 31 patients with almost normal KL-6 levels during the follow-up exhibited no deterioration or new onset of PF. CONCLUSION: Rapidly increased serum KL-6 levels during disease course were associated with new onset or deterioration of PF.

Adult↗
PubMed1988

Longitudinal analysis of infantile growth in children with celiac disease.

The aim of the present study was to describe linear growth of infants with celiac disease, using the "ICP-growth model". Supine length during the first three years of life was studied longitudinally in 63 infants with diagnosed celiac disease. "Undisturbed" linear growth was seen during the first six postnatal months followed by reduced growth during the second half of the first year. After 1.5 years of age a pattern of catch-up growth was observed, leading to an average attained length at 3 years of age similar to that of the controls. According to the "ICP-growth model", normal linear growth can mathematically be represented during the first 3 years of life by an Infancy component with the addition of a Childhood component, the latter acting from the second half of the first postnatal year. The onset of the Childhood component (assumed to represent the age at which growth hormone begins to influence linear growth significantly) was delayed by about an average of 3 months, which is in agreement with the observed reduction in gain during the second half of the first year of life. Children suffering from celiac disease and with "late" onset of the Childhood component were shorter at 1, 2 and 3 years of age than those with "normal" onset. The results of this investigation show that ICP-based growth charts are helpful in detecting and monitoring growth for children with celiac disease, and indicate a possible mechanism whereby malabsorption (and perhaps secondary malnutrition) leads to reduced growth velocity.

Age Factors↗
PubMed1997

Longitudinal analysis of pulmonary function decline in patients with cystic fibrosis.

BACKGROUND: Chronic progressive lung disease is the most prominent cause of morbidity and death in patients with cystic fibrosis (CF), but severity of lung disease and rate of lung function decline are widely variable. Accurate estimates of decline have been difficult to define and compare because the timing of measurements and duration of follow-up differ in various patient groups. PATIENTS: Three hundred sixty-six patients with CF, born from 1960 to 1974, were selected from a CF database birth cohort if they had two or more measurements of pulmonary function, at least one of which was performed before the age of 10 years. METHODS: Mixed model regression analysis provided estimates of the average rate of decline of spirometry measurements in subgroups on the basis of survival age, sex, pancreatic status, and genotype. RESULTS: Patients who died before the age of 15 years had significantly poorer pulmonary function when first tested and a more rapid decline in pulmonary function thereafter than patients who survived beyond the age of 15 years. In the latter, functional levels at the age of 5 years were normal, but average rates of decline were significantly related to survival age. Female patients had significantly steeper decline than male patients, and those with pancreatic insufficiency had much steeper decline than those with pancreatic sufficiency. In the subset of 197 who survived to 1990 and were subsequently genotyped, rate of decline was greater in those homozygous for the delta F508 mutation, compared with those who were heterozygous for delta F508 or those, who had two other mutations. DISCUSSION: All but the most severely affected patients, who died before age 15, appear to have had normal pulmonary function when first tested in early childhood. Pancreatic sufficiency, male gender, and some non-delta F508 mutations are associated with a slower rate of pulmonary function decline. Mixed model analysis is a valuable tool for describing and comparing pulmonary function decline in groups of patients with CF.

Adolescent↗
PubMed2006

Physical activity and strength of the femoral neck during the adolescent growth spurt: a longitudinal analysis.

Loading of the femoral neck (FN) is dominated by bending and compressive stresses. We hypothesize that adaptation of the FN to physical activity would be manifested in the cross-sectional area (CSA) and section modulus (Z) of bone, indices of axial and bending strength, respectively. We investigated the influence of physical activity on bone strength during adolescence using 7 years of longitudinal data from 109 boys and 121 girls from the Saskatchewan Paediatric Bone and Mineral Accrual Study (PBMAS). Physical activity data (PAC-Q physical activity inventory) and anthropometric measurements were taken every 6 months and DXA bone scans were measured annually (Hologic QDR2000, array mode). We applied hip structural analysis to derive strength and geometric indices of the femoral neck using DXA scans. To control for maturation, we determined a biological maturity age defined as years from age at peak height velocity (APHV). To account for the repeated measures within individual nature of longitudinal data, multilevel random effects regression analyses were used to analyze the data. When biological maturity age and body size (height and weight) were controlled, in both boys and girls, physical activity was a significant positive independent predictor of CSA and Z of the narrow region of the femoral neck (P < 0.05). There was no independent effect of physical activity on the subperiosteal width of the femoral neck. When leg length and leg lean mass were introduced into the random effects models to control for size and muscle mass of the leg (instead of height and weight), all significant effects of physical activity disappeared. Even among adolescents engaged in normal levels of physical activity, the statistically significant relationship between physical activity and indices of bone strength demonstrate that modifiable lifestyle factors like exercise play an important role in optimizing bone strength during the growing years. Physical activity differences were explained by the interdependence between activity and lean mass considerations. Physical activity is important for optimal development of bone strength.

Adolescent↗
PubMed2004

Monocyte activation and disease activity in multiple sclerosis. A longitudinal analysis of serum MRP8/14 levels.

In active multiple sclerosis (MS) lesions macrophages expressing myeloid related protein (MRP) 8/14 are present. The aim of this study was to determine whether serum levels of MRP8/14 complexes are related to disease activity in MS. In a longitudinal study of 16 relapsing remitting (RR) MS patients that underwent monthly gadolinium diethylentriaminepenta acid (Gd-DTPA) magnetic resonance imaging (MRI), the relation between serum MRP8/14 levels and disease activity was investigated. Patients were participating in a monoclonal antibody study targeting a specific T cell population (Vbeta5.2/5.3+ T-cells). In time, within patients large variations in serum MRP8/14 levels were observed. Serum MRP8/14 levels were not related to changes in clinical disease activity or increase in Gd-DTPA lesion enhancement. Neither did comparison of active (>1 relapse in follow-up period) with inactive (0-1 relapse) MS patients reveal any differences in MRP8/14 levels. Therefore, we conclude that although MRP8/14 expression is a good histopathological marker for monocyte activation, serum levels of these proteins do not correlate with disease activity in RR MS.

Adult↗
PubMed1998

Association between Der p 1 concentration and peak expiratory flow rate in children with wheeze: a longitudinal analysis.

BACKGROUND: House dust mite (HDM) allergen exposure has been well documented as an environmental cause of airway hyperresponsiveness (AHR) and asthma symptoms. The relationship between asthma morbidity and exposure to low concentrations of HDM allergen suggests that there may be no safe exposure threshold to HDM allergen. OBJECTIVE: We aimed to investigate the associations between Der p 1 in bedding and lung function in 30 children with a history of wheezing in a longitudinal study. METHODS: After a cross-sectional study of school children, which included histamine challenge for AHR and skin testing for dust mite atopy, we made repeated measurements of HDM allergens in children with a history of wheeze over a 12-month period. These children also kept a daily asthma diary in which they recorded their peak expiratory flow rates (PEFRs). We used a repeated measures model to determine the association between PEFR and HDM allergen concentration. RESULTS: There was a significant association between PEFRs and HDM allergen concentration (beta-coefficient = -14.17, P = .0024) in children with HDM atopy. An association was not found in children without HDM atopy. CONCLUSIONS: These findings support the hypothesis that HDM allergens have an adverse effect on the lung function of children with wheeze and highlight the importance of maintaining low dust mite allergen levels throughout the year in the home environment of children sensitized to HDMs.

Allergens↗
PubMed1986

A longitudinal analysis of the effects of different patterns of employment and unemployment on school-leavers.

Large samples of young employed and unemployed respondents in metropolitan Adelaide, South Australia, completed questionnaires on two occasions one year apart. A wide range of variables was assessed that included measures of aspects of the self-concept, Protestant Ethic values, desired work values, stress symptoms, life satisfaction, unemployment disappointment, job need, employment value, external control and attributions for youth unemployment. There was little evidence from longitudinal analyses of change scores that a shift from employment to unemployment or the reverse transition had significant effects on psychological well-being, but unemployment attributions were affected. The shift from employment to unemployment led to less internal and more external causal attributions for youth unemployment; the reverse transition had the opposite effects. Cross-sectional comparisons of findings from the employed and unemployed samples replicated previous results that were consistent with the conclusion that many of the obtained differences were present when respondents were still at school. Variables assumed to reflect employment importance did not have moderating effects on psychological well-being when employed and unemployed groups were compared in either longitudinal or cross-sectional analyses but they were involved in significant associations with other measures. Results suggested the need for more empirical and conceptual analysis of the concepts of psychological well-being and employment importance.

Adolescent↗
PubMed2005

Longitudinal analysis of heart rate variability in chronic hypertensive pregnancy.

In the US, it is currently estimated that 3% of pregnant women have chronic hypertension, or more than 100,000 pregnant women each year. The aim of our study was to investigate the adaptation of autonomic control during pregnancy based on heart rate variability analysis and to determine whether chronic hypertension during pregnancy has an impact on this adaptation. Sixteen pregnant women with chronic hypertension (CH group; mean age, 30 years; range, 25-33 years) and 35 healthy pregnant women serving as controls (CON group; mean age, 28 years; range, 24-30 years) were recruited for this longitudinal study. Beginning at the 20th week of pregnancy, the women were monitored every 4th week until delivery. For the analysis of heart rate variability, Portapres signals (200 Hz) were recorded for 30 min under resting conditions. Women in the CH group had significantly elevated blood pressure compared to controls (CON, 111 mmHg [105-132]; CH, 140 mmHg [132-148]; p<0.001). An increased heart rate was found in both groups during the second half of pregnancy. Consequently, decreased heart rate variability was observed, but was more pronounced in the CON group. There was a shift in the frequency bands indicated by an elevation of the low-to-high frequency ratio (LF/HF) in both groups due to a decrease in HF, and thus a significant increase in LFn (LF power in normalized units). However, VLF (power of very low frequency range) increased exclusively in the CON pregnancies. Our data showed no significant difference in heart rate variability between the subjects of the CH and CON groups. Longitudinal variations were detectable in normal pregnancies and also, albeit to a lesser degree, in chronic hypertensive pregnant women. Thus, our data indicate that patients with long-term hypertension are still able to respond to the physiological changes occurring during pregnancy.

Adult↗
PubMed2002

Preservation of cognitive function with antihypertensive medications: a longitudinal analysis of a community-based sample of African Americans.

BACKGROUND: Results of previous studies of white older adults suggest that antihypertensive medications preserve cognition. We assessed the long-term effect of antihypertensive medications on cognitive function in a community sample of African American older adults. METHODS: We conducted longitudinal surveys and clinical assessment of cognitive function in a random sample of 2212 community-dwelling African Americans 65 years and older. We identified 1900 participants without evidence of cognitive impairment at baseline, 1617 of whom had subsequent follow-up information, and 946 of whom had blood pressure measurements. Cognitive function was measured at baseline and at 2 and 5 years by means of scores on the Community Screening Instrument for Dementia and neuropsychological and clinical assessment for dementia and cognitive impairment. Prescription and nonprescription medication use was derived from in-home inspection of medications and participant and informant reports. RESULTS: Of 1900 participants, 288 (15.2%) developed incident cognitive impairment. Using logistic regression to control for the effects of age, sex, education, baseline cognitive scores, and hypertension and angina or myocardial infarction, we found that antihypertensive medications reduced the odds of incident cognitive impairment by 38% (odds ratio, 0.62; 95% confidence interval, 0.45-0.84). Corresponding analysis using blood pressure measurements on the subset of participants was inconclusive. CONCLUSION: Antihypertensive medication use is associated with preservation of cognitive function in older African American adults.

Black or African American↗
PubMed1991

Predicting vulnerability to hopelessness. A longitudinal analysis.

The role of loneliness, irrational beliefs, and deficient reasons for living in predicting vulnerability to hopelessness under conditions of negative life stress was examined. Subjects (N = 178) completed the UCLA Loneliness Scale. Rational Beliefs Inventory, and the Reasons for Living Inventory at the beginning of the semester. Then, at midterm, measures of negative life stress, depression, and hopelessness were obtained from the same subjects. It was hypothesized that the vulnerability factors would interact with negative life stress to predict hopelessness, independent of depressed mood. The results of multiple regression analyses supported this hypothesis. Implications for research, prevention, and treatment are noted.

Adaptation, Psychological↗