Search results for "statistical [methods]"
showing 10 items of 1664 documents
Removing Batch Effects from Longitudinal Gene Expression - Quantile Normalization Plus ComBat as Best Approach for Microarray Transcriptome Data
2016
International audience; Technical variation plays an important role in microarray-based gene expression studies, and batch effects explain a large proportion of this noise. It is therefore mandatory to eliminate technical variation while maintaining biological variability. Several strategies have been proposed for the removal of batch effects, although they have not been evaluated in large-scale longitudinal gene expression data. In this study, we aimed at identifying a suitable method for batch effect removal in a large study of microarray-based longitudinal gene expression. Monocytic gene expression was measured in 1092 participants of the Gutenberg Health Study at baseline and 5-year fol…
Association of Common Polymorphisms in the Nicotinic Acetylcholine Receptor Alpha4 Subunit Gene with an Electrophysiological Endophenotype in a Large…
2016
PLoS one 11(4), e0152984 (2016). doi:10.1371/journal.pone.0152984
Genome-Wide Association Study for Incident Myocardial Infarction and Coronary Heart Disease in Prospective Cohort Studies: The CHARGE Consortium
2016
Background Data are limited on genome-wide association studies (GWAS) for incident coronary heart disease (CHD). Moreover, it is not known whether genetic variants identified to date also associate with risk of CHD in a prospective setting. Methods We performed a two-stage GWAS analysis of incident myocardial infarction (MI) and CHD in a total of 64,297 individuals (including 3898 MI cases, 5465 CHD cases). SNPs that passed an arbitrary threshold of 5×10−6 in Stage I were taken to Stage II for further discovery. Furthermore, in an analysis of prognosis, we studied whether known SNPs from former GWAS were associated with total mortality in individuals who experienced MI during follow-up. Res…
Fruit and vegetable consumption in Europe according to gender, educational attainment and regional affiliation—A cross-sectional study in 21 European…
2020
Objective The purpose of the present study was to examine fruit and vegetable consumption according to gender, educational attainment and regional affiliation in Europe. Design Cross-sectional study. Setting 21 European countries. Participants 37 672 adults participating in the 7th round of the European Social Survey. Main outcome measures Fruit and vegetable consumption was measured using two single frequency questions. Responses were dichotomized into low (<once a day) and high (≥once a day) consumption. The association between consumption of fruit and vegetables and gender, educational level, regional affiliation was examined using logistic regression analyses. Results Overall, females s…
Differential models of twin correlations in skew for body-mass index (BMI)
2018
Background Body Mass Index (BMI), like most human phenotypes, is substantially heritable. However, BMI is not normally distributed; the skew appears to be structural, and increases as a function of age. Moreover, twin correlations for BMI commonly violate the assumptions of the most common variety of the classical twin model, with the MZ twin correlation greater than twice the DZ correlation. This study aimed to decompose twin correlations for BMI using more general skew-t distributions. Methods Same sex MZ and DZ twin pairs (N = 7,086) from the community-based Washington State Twin Registry were included. We used latent profile analysis (LPA) to decompose twin correlations for BMI into mul…
Epigenetic outlier profiles in depression: A genome-wide DNA methylation analysis of monozygotic twins
2018
Recent discoveries highlight the importance of stochastic epigenetic changes, as indexed by epigenetic outlier DNA methylation signatures, as a valuable tool to understand aberrant cell function and subsequent human pathology. There is evidence of such changes in different complex disorders as diverse as cancer, obesity and, to a lesser extent, depression. The current study was aimed at identifying outlying DNA methylation signatures of depressive psychopathology. Here, genome-wide DNA methylation levels were measured (by means of Illumina Infinium HumanMethylation450 Beadchip) in peripheral blood of thirty-four monozygotic twins informative for depressive psychopathology (lifetime DSM-IV d…
Gait asymmetry, ankle spasticity, and depression as independent predictors of falls in ambulatory stroke patients
2017
Background Falls are the leading cause of injury in stroke patients. However, the cause of a fall is complicated, and several types of risk factors are involved. Therefore, a comprehensive model to predict falls with high sensitivity and specificity is needed. Methods This study was a prospective study of 112 inpatients in a rehabilitation ward with follow-up interviews in patients’ homes. Evaluations were performed 1 month after stroke and included the following factors: (1) status of cognition, depression, fear of fall and limb spasticity; (2) functional assessments [walking velocity and the Functional Independence Measure (FIM)]; and (3) objective, computerized gait and balance analyses.…
Prevalence and severity of eating disorders: A comparison of DSM-IV and DSM-5 among German adolescents.
2016
Objective Changes in the DSM-5 eating disorders criteria sought to increase the clarity of the diagnostic categories and to decrease the preponderance of nonspecified eating disorders. The first objective of this study was to analyze how these revisions affect threshold and EDNOS/OSFED eating disorder diagnoses in terms of prevalence, sex ratios, and diagnostic distribution in a student sample. Second, we aimed to compare the impairment levels of participants with a threshold, an EDNOS/OSFED and no diagnosis using both DSM-IV and DSM-5. Method A sample of 1654 7th and 8th grade students completed self-report questionnaires to determine diagnoses and impairment levels in the context of an ea…
Statistical power of disease cluster and clustering tests for rare diseases: A simulation study of point sources
2012
Abstract Two recent epidemiological studies on clustering of childhood leukemia showed different results on the statistical power of disease cluster and clustering tests, possibly an effect of spatial data aggregation. Eight different leukemia cluster scenarios were simulated using individual addresses of all 1,009,332 children living in Denmark in 2006. For each scenario, a number of point sources were defined with an increased risk ratio at centroid, decreasing linearly to 1.0 at the edge; aggregation levels were administrative units of Danish municipalities and squares of 5, 12.5 and 25 km 2 . Six statistical methods were compared. Generally, statistical power decreased with increasing s…
Menarcheal age and socio-economic factors in Poland
2005
Menarcheal age is the most important measure of sexual maturation in girls and a sensitive indicator of environmental conditions during childhood.The study analysed the association between age at menarche and socio-economic characteristics (urbanization, population size, education of parents and number of children in the family).Questionnaire data were collected from 3271 female schoolchildren born between 1981 and 1984, living in three provinces of southern Poland. Menarcheal age was estimated by the recall method and based on the date of menarche given by the study participants. ANCOVA and multiple regression analyses were applied to test statistical significance of differences between gr…