18 research outputs found
Characterizing the skull base in craniofacial microsomia using principal component analysis
The aim of this study was to compare the anatomical differences in the skull base between the affected and non-affected side in patients with craniofacial microsomia (CFM), and to compare the affected and non-affected sides with measurements from a normal population. Three-dimensional computed tomography scans of 13 patients with unilateral CFM and 19 normal patients (age range 7–12 years) were marked manually with reliable homologous landmarks. Principal component analysis (PCA), as part of a point distribution model (PDM), was used to analyse the variability within the normal and preoperative CFM patient groups. Through analysis of the differences in the principal components calculated for the two groups, a model was created to describe the differences between CFM patients and normal age-matched controls. The PDMs were also used to describe the shape changes in the skull base between the cohorts and validated this model. Using thin-plate splines as a means of interpolation, videos were created to visualize the transformation from CFM skull to normal skull, and to display the variability in shape changes within the groups themselves. In CFM cases, the skull base showed significant asymmetry. Anatomical areas around the glenoid fossa and mastoid process showed the most asymmetry and restriction of growth, suggesting a pathology involving the first and second pharyngeal arches
The equity impact of community women's groups to reduce neonatal mortality: a meta-analysis of four cluster randomized trials
Background: Socioeconomic inequalities in neonatal mortality are substantial in many developing countries. Little is known about how to address this problem. Trials in Asia and Africa have shown strong impacts on neonatal mortality of a participatory learning and action intervention with women's groups. Whether this intervention also reduces mortality inequalities remains unknown. We describe the equity impact of this women's groups intervention on the neonatal mortality rate (NMR) across socioeconomic strata. Methods: We conducted a meta-analysis of all four participatory women's group interventions that were shown to be highly effective in cluster randomized trials in India, Nepal, Bangladesh and Malawi. We estimated intervention effects on NMR and health behaviours for lower and higher socioeconomic strata using random effects logistic regression analysis. Differences in effect between strata were tested. Results: Analysis of 69120 live births and 2505 neonatal deaths shows that the intervention strongly reduced the NMR in lower (50-63% reduction depending on the measure of socioeconomic position used) and higher (35-44%) socioeconomic strata. The intervention did not show evidence of 'elite-capture': among the most marginalized populations, the NMR in intervention areas was 63% lower [95% confidence interval (CI) 48-74%] than in control areas, compared with 35% (95% CI: 15-50%) lower among the less marginalized in the last trial year ( P -value for difference between most/less marginalized: 0.009). The intervention strongly improved home care practices, with no systematic socioeconomic differences in effect. Conclusions: Participatory women's groups with high population coverage benefit the survival chances of newborns from all socioeconomic strata, and perhaps especially those born into the most deprived households
Individual differences in the use of the response scale determine valuations of hypothetical health states: an empirical study
Background. The effects of socio-demographic characteristics of the respondent, including age, on valuation scores of hypothetical health states remain inconclusive. Therefore, we analyzed data from a study designed to discriminate between the effects of respondents' age and time preference on valuations of health states to gain insight in the contribution of individual response patterns to the variance in valuation scores. Methods. A total of 212 respondents from three age g
Age and sex distribution of the prevalence of Barrett's esophagus found in a primary referral endoscopy center
BACKGROUND: Both the demographics underlying the sex ratio in the prevalence of Barrett's esophagus (BE) and the status of BE without intestinal metaplasia (IM) are unclear. AIMS: To establish the demographics of histologically proven BE, IM+ and IM-, over a 15-yr period from a primary referral, endoscopy unit. PATIENTS: For all BE patients aged 20-89 yr, identified between 1982 and 1996, IM+ or IM-, AND METHODS: prevalences were calculated per 100 first endoscopies. RESULTS: A total of 492 cases of BE, 320 (248 IM+) in males, 175 (127 IM+) in females were identified in 21,899 first endoscopies (10,939 males, 10,960 females). Between ages 20 and 59 yr in males and 20-79 in females, IM+, IM- and all BE prevalences rose by +/- 7.36% for each additional year of age (p = 0.92) with, however, a 20-yr age shift between the sexes, resulting in a male:female OR 4.15 95% Cl 2.99-5.77. A declining rate of increase in over 59 males resulted in an overall male:female OR 2.14, 95% Cl 1.77-2.58. Over the age of 79 yr, BE prevalences/100 first endoscopies fell from a maximum of 5.1 in males and 3.65 in females to 3.38 and 2.53, respectively. CONCLUSION: The 4:1 sex ratio and 20-yr age shift between males and females in the prevalence of BE, both IM+ and IM-, found in younger age groups, was the main cause of the overall BE 2:1 sex ratio. The very similar demographics of IM- and IM+ BE suggest they may be two consecutive stages in the same metaplastic process
Morphometry of human ovaries in normal and growth-restricted fetuses
According to the fetal origins hypothesis, normal growth and development of abdominal organs is disturbed by intra-uterine growth restriction, leading to diseases later in life. The aims of this study were to investigate the effect of growth restriction on the ovaries of human fetuses and to investigate the dynamics of follicular growth in normal fetuses. We selected 21 normal female fetuses (controls) and seven severely intra-uterine growth-restricted female fetuses (IUGR cases) from all autopsy records over a 10-year period. Ovarian volume was calculated and from histological sections the volume-percentage of follicles in the ovarian cortex, the maximum diameters of individual follicles and the distribution of the follicle classes and oogonia were determined. The volume of the ovaries increased significantly from 0.10 to 0.36 cm(3) in the second half of gestation. The mean volume-percentage of ovarian follicles and the mean follicle diameter significantly increased with 0.48% and 0.52 mum per week, respectively. Class B/C (intermediary) follicles (72%) were predominantly present. Class B (primordial) follicles decreased from over 20% to less than 10% and class C (primary) increased from 6 to 19%. Class A (oogonia) were frequently present before 30 gestational weeks, but were rare after that age. For all studied parameters we did not find differences between IUGR cases and controls. Intra-uterine growth restriction does not seem to disturb ovarian development in the human fetus. In the second half of gestation the follicle pool increases by the growth of individual follicles, the transition of follicle to larger classes, and probably by increasing follicle numbers. As most follicles at term were class B/C and C, follicles up to class C are probably part of the resting stock. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved
The shape of the relationship between income and self-assessed health: an international study
BACKGROUND: The relationship between income and health is usually thought to be curvilinear, but previous studies have yielded inconsistent results. We therefore examined the shape of the relationship between household equivalent income and self-assessed health in seven European countries. METHODS: Data were obtained from nationally representative health, level of living, or similar surveys in Belgium, Denmark, England, Finland, France, The Netherlands, and Norway and applied to men and women aged 25 years and older in the 1990s. Smooth nonparametric curves were fitted to the data, as well as a spline regression function with three linear pieces connected by two knots. RESULTS: A higher household equivalent income is associated with better self-assessed health among men and women in all countries, particularly in the middle-income range. In the higher income ranges, the relationship is generally curvilinear and characterized by less improvement in self-assessed health per unit of rising income. In the lowest income ranges, the relationship is found to be curvilinear in four countries (Belgium, Finland, The Netherlands, and Norway), where the usual deterioration of health associated with lower incomes levels off or even reverses into an improvement. CONCLUSIONS: Further research is necessary to investigate the background of differences between countries in the shape of the relationship between income and self-assessed health, and should focus on both methodological and substantive explanations. Assuming causality, the results of our study lend some support to the notion of decreasing marginal health returns of a unit increase in income at the higher income range