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PubMed2006

Double burden of iron deficiency in infancy and low socioeconomic status: a longitudinal analysis of cognitive test scores to age 19 years.

OBJECTIVE: To assess change in cognitive functioning after iron deficiency in infancy, depending on socioeconomic status (SES; middle vs low). DESIGN: Longitudinal study. SETTING: Urban community in Costa Rica (infancy phase [July 26, 1983, through February 28, 1985] through 19-year follow-up [March 19, 2000, through November 4, 2002]). PARTICIPANTS: A total of 185 individuals enrolled at 12 to 23 months of age (no preterm or low-birth-weight infants or infants with acute or chronic health problems). The participants were assessed in infancy and at 5, 11 to 14, 15 to 18, and 19 years of age. A total of 97% were evaluated at 5 or 11 to 14 years and 78% at 15 to 18 or 19 years. Individuals who had chronic iron deficiency in infancy (iron deficiency with hemoglobin concentrations < or =10.0 g/dL or, with higher hemoglobin concentrations, not fully corrected within 3 months of iron therapy) were compared with those who had good iron status as infants (hemoglobin concentrations > or =12.0 g/dL and normal iron measures before and/or after therapy). MAIN OUTCOME MEASURES: Cognitive change over time (composite of standardized scores at each age). RESULTS: For middle-SES participants, scores averaged 101.2 in the group with chronic iron deficiency vs 109.3 in the group with good iron status in infancy and remained 8 to 9 points lower through 19 years (95% confidence interval [CI], -10.1 to -6.2). For low-SES participants, the gap widened from 10 points (93.1 vs 102.8; 95% CI for difference, -12.8 to -6.6) to 25 points (70.4 vs 95.3; 95% CI for difference, 20.6 to 29.4). CONCLUSIONS: The group with chronic iron deficiency in infancy did not catch up to the group with good iron status in cognitive scores over time. There was a widening gap for those in low-SES families. The results suggest the value of preventing iron deficiency in infancy.

Adolescent↗
PubMed1980

Organizational effects on mentally retarded adults: a longitudinal analysis.

Normalization has gained wide acceptance as a goal that residential institutations for the mentally retarded should strive to achieve, but many organizations have been shown to have difficulty achieving the goal. Theories developed from the organizational contingency perspective suggest that organizations with bureaucratic structures will have particular difficulty accomplishing the nonroutine tasks associated with normalization. Our major purpose was to test the usefulness of such theories for the evaluation of mental retardation facilities by ascertaining whether a less bureaucratic organization for the mentally retarded would achieve greater success than a more bureaucratic organization. The closing of a large public hospital and the subsequent transfer of most of its residents to two new facilities (one of which was more bureaucratic than the other) allowed us to examine bureaucracy's effect on treatment. As predicated, the analysis showed that the less bureaucratic organization produced a greater average positive change in behavior than did the more bureaucratic organization. A number of clinical and demographic characteristics of the residents which could have influenced the observed changes in behavioral level were identified and controlled. They were not found to explain the differences between facilties. Other factors, which could not be controlled in this study, provide suggestions for future research.

Analysis of Variance↗
PubMedDate not supplied

Chronicity of pain associated with spinal cord injury: A longitudinal analysis.

This study determined the stability of self-reported clinical pain characteristics and pain-induced interference with sleep and daily activities in people with spinal cord injury. The study followed up a previous survey that identified clinical pain patterns (i.e., neuropathic pain below the level of injury; upper-limb pain in tetraplegia; and severe, persistent pain). A confirmatory factor analysis (CFA) of the present study's data confirmed the previously observed pain patterns. The CFA also confirmed positive correlations between the surveys on individual pain characteristics (i.e., number of pain locations [r = 0.63, p < 0.001], number of descriptors [r = 0.61, p < 0.001], pain intensity [r = 0.68, p < 0.001], and temporal aspects [r = 0.47, p < 0.001]). Despite an overall stable clinical picture of pain, "aching" pain (p < 0.001) and sleep interference caused by pain (p < 0.001) significantly increased over time.

Adult↗
PubMed1996

Cessation and persistence of wife assault: a longitudinal analysis.

Patterns of wife assault, rates of cessation, and the effect of cessation on psychological aggression were evaluated in a three-year longitudinal study of 772 couples. More than one-third of the men who had been violent in the year prior to the initial survey ceased or interrupted their violence and showed significant reductions in their psychological aggression during the course of the study. Implications for the conceptualization and further study of wife assault are discussed.

Adolescent↗
PubMed1991

[Longitudinal analysis of a four-year follow up of pulmonary function development in children with a past history of asthma].

In order to longitudinally study the pulmonary function development of children with a history of asthma, we measured the flow-volume curves of 441 fourth-grade children in seven primary schools randomly selected from the Kashima district in Ibaraki prefecture in 1980, and again in 1982 and 1984. Levels and slopes of pulmonary function indices for individual children were calculated in 325 children who performed acceptable forced expiratory maneuvers at all of the three surveys. In FVC and FEV1, no significant difference of levels and slopes was observed between children with asthmatic history and control children. However, the level and slope of V25 of children with asthmatic history were significantly lower than those of control children (0.5 l/sec for the level, 0.08 l/sec for the slope) even when only those who did not suffer from wheezing attack during the follow-up period were concerned. These results suggested that the functional change of peripheral airways in children with asthmatic history did not recover within a couple of years even when they were in remission. Moreover, the functional differences between those two groups of children might become larger in early adolescence.

Asthma↗
PubMed2003

Longitudinal analysis of head growth in low-birth-weight children according to their chronological and gestational age.

Head growth in 283 LBW (< 2500 g) children was longitudinally analyzed from birth till the 24th month of life. The studied children were divided into three groups: AGA preterms (181 children), SGA preterms (32 children) and S-f-D newborns (70 children). The data for chronological age and corrected for gestational age were statistically analyzed by analysis of variance and Duncan's test. Means of head circumference were plotted against percentile charts for boys and girls respectively. Considering the chronological and corrected age, a different course of head growth in preterms was observed. According to chronological age, the head circumference in AGA and SGA preterms reached in the second year of life a higher percentile position than at birth. After correction of the data to gestational age the mean values of head circumference in two groups of preterms were placed at a lower percentile position than at the time of birth. The group of S-f-D newborns presented the highest velocity of head growth: in the 2nd year of life the mean head circumference in this group reached a higher growth level than at birth.

Age Factors↗
PubMed1990

Growth patterns of low birth weight preterm infants: a longitudinal analysis of a large, varied sample.

To obtain growth data on a large sample of low birth weight preterm infants, we monitored 608 infants longitudinally in an eight-site collaborative program. Ninety-nine infants weighed less than or equal to 1250 gm at birth, 289 between 1250 and 2000 gm, and 220 infants between 2000 and 2500 gm. Thirty-four percent were white, 52% black, and 14% Hispanic. Weight, height, and head circumference were measured at birth and at 40 weeks and 4, 8, and 12 months of gestation-corrected age on at least 553 infants each time. Descriptive statistics for all growth variables and a body mass index (kilograms per square meter), plotted by sex and birth weight group, demonstrated growth patterns lower than published standards for term infants of the same age and sex. These patterns of growth differed by birth weight group. No catch-up growth was noted by the 12-month examination (gestation-corrected age) for any birth weight group. We conclude that low birth weight preterm infants have different patterns of growth than term infants during the first year of life, even with plotting corrected for gestational age.

Birth Weight↗
PubMed2002

Copenhagen City Heart Study: longitudinal analysis of ventilatory capacity in diabetic and nondiabetic adults.

The natural history of lung function in diabetes is unknown due to the lack of longitudinal observations. The decline of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) was studied over 15 yrs in the 17,506 adult participants of The Copenhagen City Heart Study, which included 266 individuals with diabetes. Multiple linear regression and a mixed-effects model were used, taking into account correlation between repeated measurements and adjusting for relevant confounders. In both sexes, FEV1 and FVC were consistently lower in diabetic individuals, compared with healthy individuals, with an average reduction of approximately 8% of the predicted value. Longitudinal analyses showed that the decline of FEV1 and FVC in diabetic individuals was similar to that observed in nondiabetic subjects. It was concluded that although diabetic subjects have, on average, a lower forced expiratory volume in one second and forced vital capacity than individuals without diabetes, this deficit seems not to be progressive in the long term. These observations may be of importance with regard to diabetes treatment with inhaled pulmonary insulin, which is likely to become available within a few years.

Adult↗
PubMed1977

Longitudinal analysis of growth of the soft palate and nasopharynx from six months to six years.

Between the ages of six months and six years, longitudinal lateral headfilms were taken on 54 patients with palatal clefts or with unilateral and bilateral clefts of the lip and palate. They were measured and were compared to data on both normals and subjects with clefts of the lip only. The objectives of the study were: 1. To sutdy the effects of palatal surgery on the growth of the soft palate. 2. To compare the growth of the soft palate and nasopharynx among the patients with various types of clefts and normals. 3. To study the growth acceleration or so-called catch-up growth after palatal surgery at various ages. (Anterior palatal surgery at 14 months +/- 2 months. Posterior palatal surgery at 16 months +/- 2 months.) 4. To evaluate the relationship between velopharyngeal growth in cleft groups and voice quality.

Child↗
PubMed1977

Self-esteem in young men: a longitudinal analysis of the impact of educational and occupational attainment.

This paper analyzes relationships among self-esteem, educational attainment, and occupational status. Data from a nationwide longitudinal study of more than 1600 young men show a substantial increase in self-esteem between 19TT (when respondents were beginning tenth grade) and 1974. Reliability and construct validity data for the self-esteem measure are reported. As expected, both educational attainment and occupational status are correlated with self-esteem. Contrary to expectations, educational attainment as of 1974 is more strongly correlated with tenth grade self-esteem than with 1974 self-esteem. A path analysis led to these conclusions: (a) Self-esteem during high school has little or no direct causal impact on later educational and occupational attainment; self-esteem and attainment are correlated primarily because of shared prior causes including family background, ability, and scholastic performance. (b) Occupational status has a direct positive impact on self-esteem. (c) Post high school educational attainment has no direct impact on self-esteem and only a trivial indirect impact via occupational status. Additional findings indicate that factors associated with educational success become less central to the self-evaluations of young men during late high school and the years thereafter.

Achievement↗
PubMed1991

Women's physical activity and pregnancy outcome: a longitudinal analysis from the Philippines.

We assessed the effects of physical activity on pregnancy outcome in 2741 Filipino women identified during pregnancy as part of a two-year longitudinal study. Specific elements of physical activity hypothesized to be relevant to pregnancy outcome were posture, energy expenditure, and physical stress. Variables were developed for nine household and 48 formal and informal economic activities. Analyses were stratified by whether the woman performed formal waged work outside of the home, income-related activity at home, or was economically inactive. Results show that traditional definitions of physical activity and work based on participation in the formal labour force ignore a sizeable amount of home economic production, as well as the physical demands of housework. We saw no difference in risk of low birthweight or preterm delivery in economically active compared to economically inactive women. However, we found that increased amounts of standing activity affected pregnancy outcome in certain groups of women. Accurate assessment of the effects of physical activity during pregnancy must examine specific components of the activity, rather than relying on formal employment as a proxy for exposure.

Adult↗
PubMed1994

Longitudinal analysis of the effects of smoking onset and cessation on pulmonary function.

We examined the effects of smoking onset and cessation on FEV1 in participants in the Tucson Epidemiological Study of Airways Obstructive Disease 18 yr of age or older who reported a change in smoking habits during 17 yr of follow-up. Subjects were classified as "new quitters" (n = 288) and "new starters" (n = 45) at each survey on the basis of questionnaire responses concerning current smoking habits. The pulmonary function data were analyzed using a mixed longitudinal or random effects model (REM). We compared FEV1 before and after changing smoking habits in the same subjects while adjusting for important covariables such as height, pack-years, and respiratory symptoms and diseases. The results for smoking cessation showed a beneficial effect related to quitting that was largest for younger subjects and decreased linearly with age. For women, quitting resulted in an improvement in FEV1 of 4.3% at 20 yr of age which decreased to 2.5% by 80 yr of age. Men had an improvement of only 1.2% at 20 yr of age and no improvement at 80 yr of age. After excluding subjects with low initial function (FEV1/FVC in the lowest quartile) and those with only a single observation after quitting, men (n = 70) showed a significantly higher FEV1 improvement of 4% at 20 yr of age that decreased linearly to zero by age 80 yr. In contrast, women in this subgroup (n = 89) had nearly the same degree of improvement at all ages. The onset results showed mean FEV1 values after starting smoking that were higher at the younger ages (< 23 yr) and that decreased more rapidly with age, compared with nonsmoking mean estimates, in both sexes.

Adult↗
PubMedDate not supplied

Longitudinal analysis of growth in children with idiopathic short stature.

In this study the growth curves of 229 children (145 boys, 84 girls ) with idiopathic short stature (ISS) were analysed in three ways: (1) we compared the results of longitudinal modelling by means of Karlberg's ICP model with those of a cross-sectional analysis; (2) we studied to what extent an individual changes his/her height standard deviation score (SDS) position during childhood; and (3) we constructed height velocity curves for children with ISS using Cole's LMS method, and compared these with the British references. During childhood the difference between the average longitudinal and the cross-sectional height curves was less than 1 cm and the spread was almost identical. The average change in height SDS during childhood was not different from zero, indicating that in general growth of children with ISS was well canalized. The individual change in height SDS position during childhood was within 0.6 SDS for a follow-up of 1 year, increasing to 1.9 SDS for a follow-up of 7 years. During childhood mean height velocity was about 1 cm/year lower than that of the British reference. With respect to the pubertal growth spurt the maximum height velocity took place 1 year later, and was 0.6 cm/year lower than the British reference in boys as well as girls. We conclude that spontaneous growth of children with ISS adequately described by a cross-sectional curve.

Body Height↗
PubMed2005

Arthritis instantaneously causes collagen type I and type II degradation in patients with early rheumatoid arthritis: a longitudinal analysis.

BACKGROUND: Markers of collagen type I (CTX-1) and type II (CTX-II) degradation, reflecting bone and cartilage breakdown, appear to predict long term radiographic progression in chronic persistent arthritis. OBJECTIVE: To analyse longitudinally whether changes in arthritis severity are linked to immediate changes in the level of CTX-I and CTX-II degradation. METHODS: CTX-I and CTX-II were measured in urine samples from 105 patients with early rheumatoid arthritis who had participated in the COBRA trial at baseline and at 3, 6, 9, and 12 months after the start of treatment. The course of the biomarkers over time was compared with the course of ESR, swollen and tender joint counts, and 28 joint disease activity score (DAS28), measured at the same time points, with adjustment for rheumatoid factor, treatment, and baseline radiographic damage, by generalised estimating equations (GEE) with first order autoregression. RESULTS: GEE showed that CTX-I was longitudinally associated with DAS28, but not with ESR, swollen joint count, or tender joint count. CTX-II, however, was longitudinally associated with ESR, swollen joint count and DAS28, but not with tender joint count. The longitudinal association implies that an increase in the extent of arthritis is immediately followed by an increase in collagen type II degradation, and to a lesser extent collagen type I degradation. CONCLUSIONS: Cartilage degradation as measured by CTX-II and to a lesser extent bone degradation as measured by CTX-I closely follows indices of arthritis. Clinically perceptible arthritis is responsible for immediate damage, which will become visible on plain x rays only much later.

Adult↗
PubMed1997

Genetic influences on changes in body mass index: a longitudinal analysis of women twins.

Numerous studies have demonstrated genetic influences on body fat, but there also may be genetic effects on its intraindividual variation over time. This study examined changes in body mass index (BMI) using longitudinal data from two examinations of the Kaiser Permanente Women Twins Study, performed a decade apart. The analysis included 630 women, 185 monozygotic and 130 dizygotic twin pairs, with average ages of 41 years and 51 years at the two examinations, respectively. Age-adjusted heritability estimates for the change in BMI over the decade ranged from 0.57 to 0.86 (all p < or = 0.001) using three different statistical analysis approaches, indicating that at least half and possibly as much as 85%+, of the variance in the change in BMI is attributable to genetic influences under a polygenic model. These estimates remained statistically significant after adjusting for environmental factors (ranging from 0.57 to 0.78) and with additional adjustment for BMI at baseline (ranging from 0.41 to 0.79), although dizygotic intraclass correlations were low after these adjustments. Thus, in addition to known environmental and behavioral influences, these results provide evidence for genetic influences on changes in BMI over a decade in women.

Adolescent↗
PubMed2006

Addiction treatment history, medical services utilization, and cost: a longitudinal analysis of problem drinkers.

Few studies have examined the long-term patterns of health services utilization and cost for alcohol use disorders. This paper used data from baseline, 3-year, and 5-year follow-up interviews to compare utilization and cost of medical care services for problem drinkers who received chemical dependence treatment and those who did not. The analysis examined overnight hospital stays, emergency room visits, and medical office visits. The unadjusted analysis indicates that in the year immediately preceding each follow-up period, a significantly higher percentage of the chemical dependency treatment group stayed overnight at a hospital or used ER services. In terms of medical office visits, a significantly lower percentage of the treatment sample had office visits at the 5-year follow-up, but otherwise no significant differences existed. Most of the significant differences between the two groups vanished when we controlled for covariates. Researchers, policy makers, and clinicians could benefit from such information to develop alternative delivery models, formulate research initiatives, and determine areas for potential intervention and improvement.

Costs and Cost Analysis↗