Statistical analyses and sample size calculations
Sample size and power calculations
... These calculations are only as good as their assumptions; in particular, one would generally not know the true value of p before doing the ...power analyses can be useful in giving a sense of the ...
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Key Vocabulary: Sample size calculations
... 2. Significance: the likelihood that the measured effect did not occur by chance. Statistical tests are performed to determine whether one group (e.g. the experimental group) is different from another group (e.g. ...
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Sample size calculations for skewed distributions
... Considering robustness at the analysis stage, the t test performs well under certain large departures from nor- mality [36]. Nevertheless, it is liable to break down when ‘skew is severe or when population variances and ...
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Practical guide to sample size calculations: an introduction
... Because of the practical nature of conducting a clinical trial, it is recom- mended to set the power as high as possible, preferably at least 90%. When designing a trial, it is necessary to estimate the population ...
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Statistics review 4: Sample size calculations
... the size of the effect to be ...large sample and vice versa, and careful consideration should be given to the choice of ...the size of the effect will be based on clinical ...lated sample ...
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2 Precision-based sample size calculations
... the sample size — there is no point in carrying out a study that is too small, only to come up with results that are inconclusive, since you will then need to carry out another study to confirm or refute ...
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Practical guide to sample size calculations: superiority trials
... Abstract A sample size justification is a vital part of any investigation. However, estimating the number of participants required to give meaningful results is not always as straightforward. A number of ...
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Novel Statistical Approaches to Assessing the Risk of QT Prolongation and Sample Size Calculations in 'thorough QT/QTc studies'
... the sample size that achieves a specific value for this lower bound for power can be determined using standard ...the sample size and power and therefore should be taken into ...
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A multivariate approach to sample size calculations for thorough QT studies
... hence sample size cal- culations play a very important role in ensuring a small but adequately powered thorough QT ...and sample size ...smaller sample size for fixed ...
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Power and Sample Size Calculations for Interval-Censored Survival Analysis
... calculations varying the number of visits from 1 to 24 (size of failure intervals). See Table 3. In particular, the first line of Table 3 corresponds to a current status study design (one assessment time). ...
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Sample size calculations and normalization methods for RNA-seq data.
... two sample size methods based on a two-sided Wald’s test are presented under a wide range of settings including the imbalanced design and unequal read depth, which is applicable in many ...explicit ...
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Sample size calculations for model validation in linear regression analysis
... and sample size ...and sample size procedure for the joint test of inter- cept and slope coefficients with specific recognition of the stochastic features of predictor ...and sample ...
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STATISTICAL PATTERNS OF TRAFFIC DATA AND SAMPLE SIZE ESTIMATION
... Naturally, traffic engineers and field practitioners find the sample size calculation process cumbersome. In the past, attempts have been made to simplify this process and even render it a one-step ...
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Practical guide to sample size calculations: non-inferiority and equivalence trials
... A sample size justification is a vital part of any trial ...suitable sample size ...conducting sample size calculations for non-inferiority and equivalence trials are ...
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Sample size calculations for the design of cluster randomized trials: A summary of methodology.
... parallel statistical developments concerned with the design and analysis of these trials have been ...trial size is determined and the associated results are ...cluster size and the effect ...
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Sample size calculations for cluster randomised trials, with a focus on ordinal outcomes.
... in sample size ...on sample size methods for ordinal outcomes in circumstances where the assumptions underlying the use of the design effect may not be appropriate, for example under extensive ...
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Sample size calculations in pediatric clinical trials conducted in an ICU: a systematic review
... When a sample size calculation is performed, the value of the NP used corresponds to its assumed population value. Therefore, misspecification can be shown on a per trial basis in terms of ...
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Sample size calculations for stepped wedge and cluster randomised trials: a unified approach
... Design effects are presented for the SW-CRT design with 5 and 10 steps. These results demonstrate how effi- ciency and comparability of the different designs depends crucially on the ICC and the sample size ...
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Bayesian average error based approach to sample size calculations for hypothesis testing
... classic statistical framework, sample size calculations for a hypothesis test of interest are made to adequately maintain pre-specified Type-I and Type-II error ...and sample ...
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Sample size calculations for controlling the distribution of false discovery proportion in microarray experiments
... including sample size calculations as well as to the analysis of microarray ...for sample size calculation to detect differen- tial genes are to control the expectation of FDP, that is ...
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