Search results for "Sample Size"
showing 10 items of 219 documents
Health literacy of pregnant women and duration of breastfeeding maintenance: a feasibility study
2020
Research the association between health literacy (HL) and exclusive breastfeeding at 4-months postpartum.Despite the benefits of breastfeeding (BF), its rates are low worldwide. Among the reasons for abandonment is the level of maternal education. Maternal education has been associated with HL, but evidence between HL and BF maintenance is limited.A cross-sectional study.The sample compromised 229 nursing mothers recruited from January 2018 to the end of December 2018 at Spain by systematic sampling method. Women were interviewed postpartum on parameters associated with the start and continuation of BF up to 4 months postpartum. Multivariate logistic regression models to explain exposure va…
The effects of computer-based mindfulness training on Self-control and Mindfulness within Ambulatorily assessed network Systems across Health-related…
2016
Background Self-control is an important ability in everyday life, showing associations with health-related outcomes. The aim of the Self-control and Mindfulness within Ambulatorily assessed network Systems across Health-related domains (SMASH) study is twofold: first, the effectiveness of a computer-based mindfulness training will be evaluated in a randomized controlled trial. Second, the SMASH study implements a novel network approach in order to investigate complex temporal interdependencies of self-control networks across several domains. Methods The SMASH study is a two-armed, 6-week, non-blinded randomized controlled trial that combines seven weekly laboratory meetings and 40 days of e…
Effects of Interrater Reliability of Psychopathologic Assessment on Power and Sample Size Calculations in Clinical Trials
2002
Although rater training is increasingly used to improve the quality of the investigated outcome parameters, the reliability of assessments is not perfect. Thus, empirical reliability estimates should be used instead of theoretically assumed perfect reliability. Implications of the reliability of psychiatric assessments for sample size and power calculations in clinical trials are presented. The theoretical basis of sample size and power calculations using empirical reliability scores is delineated. Examples from contemporary research on schizophrenia and depression are used to illustrate several implications for study design and interpretation of results. The tremendous impact of the lack o…
Vascular endothelial growth factor polymorphisms as effect modifiers of oral squamous cell carcinoma risk: A systematic review and meta-analysis.
2014
Smoking is one of the main risk factors for the development of oral squamous cell carcinoma (OSCC). Smoking may affect single-nucleotide polymorphism (SNP)-dependent vascular endothelial growth factor (VEGF)-induced angiogenic activity. Therefore, we systematically reviewed the published VEGF-SNP genotype data of OSCC patients and healthy individuals and performed a meta-analysis comparing the VEGF-SNP genotypes of smoking and non-smoking patients in association with OSCC incidence. Prospective and retrospective studies on the clinical comparison of OSCC patients with different VEGF-SNP genotypes were reviewed. The meta-analysis re-pooled studies of smoking and non-smoking OSCC patients wit…
Anterior teeth root inclination prediction derived from digital models: A comparative study of plaster study casts and CBCT images
2018
Background To assess the accuracy of digital models generated using commercially available software to predict anterior teeth root inclination characteristics and compare the results to relevant data obtained from CBCT images. Material and Methods Following sample size calculation and after application of inclusion and exclusion criteria, pre-treatment maxillary and mandibular plaster models and the corresponding CBCT scans of 31 patients attending a private orthodontic clinic were selected. The subjects were 10 males and 21 females with age range 12 to 40 years. Plaster models were scanned using the high resolution mode of an Ortho Insight 3D scanner and CBCT scans were taken using a Kodak…
Manipulating the alpha level cannot cure significance testing
2018
We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple in…
Correlation between neonatal outcomes of twins depends on the outcome : Secondary analysis of twelve randomised controlled trials
2018
ObjectiveTo estimate the magnitude of the correlation between neonatal outcomes of twins and demonstrate how this information can be used in the design of randomised controlled trials (RCTs) in women with twin pregnancies.DesignSecondary analysis of data from 12 RCTs.SettingObstetric care in multiple countries, 2004-2012.Population or sample4504 twin pairs born to women who participated in RCTs to assess treatments given during pregnancy.MethodsIntraclass correlation coefficients (ICCs) were estimated using log-binomial and linear models.Main outcome measuresPerinatal death, respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular haemorrhage, necrotising enterocolitis, s…
Facetten der Körperbildstörung: eine differenzielle Analyse des TEK-KJ (Test zur Erfassung der Körperbildstörung bei Kindern und Jugendlichen) zur di…
2018
Zusammenfassung. Zur Erfassung der haptisch-perzeptiven Komponente der Körperbildstörung – einem Kernkriterium der Essstörungen Anorexia nervosa und Bulimia nervosa – stehen nur sehr wenige gut evaluierte Verfahren zur Verfügung. In der vorliegenden Arbeit werden differenzielle Analysen zum Test zur Erfassung der Körperbildstörung bei Kindern und Jugendlichen (TEK-KJ) anhand einer großen Kinder- und Jugendlichenstichprobe dargestellt und zum ersten Mal Daten für männliche Kinder und Jugendliche ausgewertet. Dies beinhaltet die Prüfung der konvergenten Validität im Vergleich zur Contour Drawing Rating Scale (CDRS) und die Analyse von Unterschieden zwischen Kindern und Jugendlichen verschied…
Estimators and confidence intervals of f2 using bootstrap methodology for the comparison of dissolution profiles
2021
Abstract Background and objectives: The most widely used method to compare dissolution profiles is the similarity factor f 2 . When this method is not applicable, the confidence interval of f 2 using bootstrap methodology has been recommended instead. As neither details of the estimator nor the types of confidence intervals are described in the guidelines, the suitability of five estimators and fourteen types of confidence intervals were investigated in this study by simulation. Methods: One million individual dissolution profiles were simulated for the reference and test populations with predefined target population f 2 values, where random samples of different sizes were drawn without rep…
Comparison of Procedures to estimate Steady Flow Rate in Field Measurement of Saturated Hydraulic Conductivity by the Guelph Permeameter Method
1999
Abstract Different procedures for estimating steady flow rate during field application of the Guelph permeameter method were compared in terms of field-saturated hydraulic conductivity K fs and equilibration time t s estimates. The steady flow rate was evaluated by the slope of the linear portion of the cumulative drop in water level in the permeameter reservoir versus time plot (reference procedure) and by approximate procedures that use the first three or four consecutive values of the rate of fall of the water level equal or differing by less than a given percentage. The influence of the selected time interval between two successive readings ( Δt =2 or 10 min) at the permeameter was also…