The analysis of randomised controlled trial data with more than one follow-up measurement. A comparison between different approaches.

When more than one follow-up measurement is analysed in a randomized controlled trial, there is no consensus how to analyse the overall intervention effect in a proper way. Mostly, longitudinal analysis of covariance is used, because with this method a correction is made for possible regression to the mean. However, in this paper it is shown that this method (mostly) leads to an overestimation of the intervention effect. A possible solution is the use of autoregression, although this does not seem to be the best solution, because it leads to an overcorrection. Due to these flaws, in this paper a new approach is introduced in which a correction for the baseline value is made for the first follow-up, but no correction is made for the remaining follow-up measurements

Predicting transitions in the use of informal and professional care by older adults

To prepare the care system for a rising population of older people, it is important to understand what factors predict the use of care. This paper reports a study of transitions in the use of informal and professional care using Andersen-Newman models of the predictive predisposing, enabling and need factors. The study has drawn on Longitudinal Ageing Study Amsterdam (LASA) data on the use of care and the contextual factors. The data were collected at three-yearly intervals from a random, sex- and age-stratified, population-based sample of adults aged 55-85 years. In summary, the findings for those who initially did not receive care were that almost one-third received some kind of care three years later, most of which was provided by informal care-givers. Need factors were important predictors of most transitions in care, and predisposing and enabling factors, such as age, partner status and income, also played a role. On the relationship between informal and professional care, evidence was found for both 'compensatory processes', i.e. informal care substitutes for professional care, and 'bridging processes', i.e. informal care facilitates professional care. In view of the increasing discrepancy between the demand for professional care and its supply, the significant impact of predisposing and enabling factors offers opportunities for intervention. © 2005 Cambridge University Press

The relationship between body composition and physical fitness in 14 year old adolescents residing within the Tlokwe local municipality, South Africa: The PAHL study

<p>Abstract</p> <p>Background</p> <p>Little is known about the relationship between body composition and physical fitness in 14 year-old high school adolescents of South Africa. Baseline data from a longitudinal study on physical activity and health (PAHLS) may provide valuable information for future studies, hence to inform public health policy makers. The objectives of this study are to determine the prevalence of underweight, normal weight and overweight among adolescents aged 14 years in the Tlokwe Local Municipality of the North West Province of South Africa, and to assess the association between physical fitness and body composition separately for boys and girls, adjusted for race and locality.</p> <p>Methods</p> <p>Body weight, height and triceps, and subscapular skinfolds of 256 adolescents (100 boys and 156 girls) aged 14 years were measured, and percentage body fat and body mass index (BMI) were calculated. BMI was used to determine underweight, normal weight and overweight based on the standard criterion. Physical fitness was assessed by standing broad jump, bent arm hang and sit-ups according to the EUROFIT fitness standard procedures. Multinomial logistic regression analyses stratified for gender and adjusted for race (black or white), and the locality (urban or township) of the schools were used to analyze the data.</p> <p>Results</p> <p>In the total group 35.9% were underweight and 13.7% overweight. Boys were more underweight (44%) than girls (30.7%). The prevalence of overweight was 8% in boys and 17.3% in girls. BMI was strongly (p = 0.01) related with percentage body fat. Strong and significant positive associations between physical fitness and BMI for the underweight girls with high physical fitness scores (OR, 10.69 [95%CI: 2.81-40.73], and overweight girls with high physical fitness scores (OR, 0.11 [95%CI: 0.03-0.50]) were found. Non-significant weaker positive relationship between physical fitness and BMI for the underweight boys with high physical fitness scores (OR, 1.80 [95%CI: 0.63-5.09]), and the overweight boys with high physical fitness scores (OR, 0.18 [95%CI: 0.02-1.78]) were found.</p> <p>Conclusion</p> <p>Both underweight and overweight among boys and girls in Tlokwe Local Municipality exist, and their effects on physical fitness performances were also noticed. As such, strategic physical activity, interventions or follow-up studies recognizing this relationship particularly in the overweight adolescents are needed. In addition, authorities in health and education departments dealing with adolescents should make use of this evidence base information in policies development.</p

Self-management abilities and frailty are important for healthy aging among community-dwelling older people; A cross-sectional study

__Abstract__ Background: This study aimed to identify the relationships of self-management abilities and frailty to perceived poor health among community-dwelling older people in the Netherlands while controlling for important individual characteristics such as education, age, marital status, and gender. Methods. The cross-sectional study sample consisted of 869/2212 (39% response rate) independently living older adults (aged ≥70 years) in 92 neighborhoods of Rotterdam. In the questionnaires we assessed self-rated health, frailty using the Tilburg Frailty Indicator (TFI) and self-management abilities with the short version of the Self-Management Ability Scale (SMAS-S). We first used descriptive analysis to identify those in poor and good health. Differences between groups were established using chi-squared and t-tests. Relationships between individual characteristics, frailty, self-management abilities and poor health were investigated with correlation analyses. Multilevel logistic regression analyses were than performed to investigate the relationships of self-management abilities and frailty to health while controlling for age, gender, education, and marital status. The results of the multilevel regression analyses are reported as odd ratios. Results: Respondents in poor health were older than those in good health (78.8 vs. 77.2; p ≤.001). A significantly larger proportion of older people in poor health were poorly educated (38.4% vs. 19.0%; p ≤.001) and fewer were married (33.6% vs. 46.3%; p ≤.001). Furthermore, older people in poor health reported significantly lower self-management abilities (3.5 vs. 4.1; p ≤.001) and higher levels of frailty (6.9 vs. 3.3; p ≤.001). Correlation analyses showed significant relationships between frailty, self-management abilities and poor health. Multilevel analyses showed that, after controlling for background characteristics, self-management abilities were negatively associated with poor health (p ≤.05) and a positive relationship was found between frailty and poor health (p ≤.05) among older people in the community. Conclusions: Self-management abilities and frailty are important for healthy aging among community-dwelling older people in the Netherlands. Pa

Prevention of hip fractures by external hip protectors - A randomized controlled trial

Context: Several randomized controlled trials have been performed to examine the effectiveness of external hip protectors in reducing the incidence of hip fractures, but the results are controversial. Objective: To examine the effectiveness of hip protectors in reducing the incidence of hip fractures in an elderly high-risk population. Design, Setting, and Participants: Randomized controlled trial of elderly persons aged 70 years or older, who have low bone density, and are at high risk for falls. Participants lived in apartment houses for the elderly, homes for the elderly, and nursing homes in Amsterdam and surrounding areas in the Netherlands. They were enrolled in the study between March 1999 and March 2001; the mean follow-up was 69.6 weeks. Of the 830 persons who were screened, 561 persons were enrolled. Intervention: External hip protector. Both groups received written information on bone health and risk factors for falls. Main Outcome Measure: Time to first hip fracture. Survival analysis was used to include all participants for the time they participated. Results: In the intervention group, 18 hip fractures occurred vs 20 in the control group. Four hip fractures in the intervention group occurred while an individual was wearing a hip protector. At least 4 hip fractures in the intervention group occurred late at night or early in the morning. Both in univariate analysis (log-rank P=.86) and in multivariate analysis (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.55-2.03), no statistically significant difference between the intervention group and control group was found with regard to time to first hip fracture. In addition, the per protocol analysis in compliant participants did not show a statistically significant difference between the groups (HR, 0.77; 95% CI, 0.25-2.38). Conclusion: The hip protector studied was not effective in preventing hip fractures

Longitudinal relationships between lifestyle and cardiovascular and bone health status indicators in males and females between 13 and 27 years of age: a review of findings from the Amsterdam Growth and Health Longitudinal Study

UNLABELLED: The Amsterdam Growth and Health Longitudinal Study is longitudinal co-hort study on 181 males and females initially aged 13 years, with follow-up measurements at ages 14, 15, 16, 21 and 27 years. METHODS: Anthropometrical, biological and lifestyle parameters, and age 27 also bone mineral density (BMD) of the lumbar spine (L2-L4), were measured repeatedly. Adolescent dietary intake and physical activity was related to adult cardiovascular and bone health status indicators by MLR; longitudinal relationships between physical activity and dietary intake, and cardiovascular health status indicators were assessed hy GEE-analysis. RESULTS: Adolescent physical activity was not related to most of the indicators of adult cardiovascular health status, with the exception of a positive relationship with the waist-to-hip in females; in males 'energetic' adolescent physical activity contributed significantly to adult BMD; both in males and females, when taking the entire longitudinal period into account, peak strain physical activity was a relatively more important predictor of adult BMD than 'energetic' physical activity; calcium intake during adolescence was not a significant predictor of bone health status measured at age 27, both in males and females; a consistent significant positive longitudinal relationship was found between physical activity and serum HDL-cholesterol and significant negative longitudinal relationships were found with the subscapular skinfold and with body fat mass; a positive longitudinal relationship was found between serum total cholesterol (TC) and cholesterol intake, saturated fat (SFA) intake and the Keys-score; a negative longitudinal relationship was found between TC and polyunsaturated fit and total energy intake; for HDL a positive longitudinal relationship was found with SFA intake; low tracking was found for physical (in-) activity and dietary intake variables

Predicting improvement in gait after stroke: a longitudinal prospective study

0.001). CONCLUSIONS: Improvement in standing balance control is more important than improvement in leg strength or synergism to achieve improvement in walking ability, whereas reduction in visuospatial inattention is independently related to improvement of gait. Finally, time itself is an independent covariate that is negatively associated with change on FAC, suggesting that most pronounced improvements occur earlier after strok