Rubin's variance estimator is well\nknown to be biased compared to the reference based imputation estimator's true\nrepeated sampling variance. Somewhat surprisingly given the increasingly\npopularity of these methods, there has been relatively little debate in the\nliterature as to whether Rubin's ...
However, the reference-based imputation methods were not formally justified. We present a causal model which makes an explicit assumption in a potential outcomes framework about the maintained causal effect of treatment after discontinuation. We show that the "jump to reference", "copy reference" ...
Reference-based controlled imputations have become a popular tool to assess the sensitivity of primary analysis inference to different post-dropout assumptions and to yield an alternative effectiveness estimand of treatment effect. As the imputation and analysis models are uncongenial in this setting, ...
Reference Based Multiple Imputation (rbmi) Overviewrbmi is a R package for imputation of missing data in clinical trials with continuous multivariate normal longitudinal outcomes. It supports imputation under a missing at random (MAR) assumption, reference-based imputation methods, and delta ...
Intent-to-Treat Analysis for Longitudinal Studies with Drop-Outs We propose a method that involves multiple imputation of the missing values following drop-out based on an ''as treated'' model, using actual dose ... R Little,L Yau - 《Biometrics》 被引量: 900发表: 1996年 STATISTICAL ...
Reference‐based imputation has two advantages: (a) it avoids the user specifying numerous parameters describing the distribution of patients' postwithdrawal data and (b) it is, to a good approximation, information anchored, so that the proportion of information lost due to missing data under the...
(1-phi)*beta + bsvalue*gamma); * MNAR; * no imputation needed for subjects with events or for completers; if status=1 or (status=0 and time=followup) then do; time3 = time; status3 = status; end; else do; * impute censored event time; * locate the time interval that contains...
(2021). Rapid genotype imputation from sequence with reference panels. Nature Genetics. https://doi.org/10.1038/s41588-021-00877-0 廉价的基因分型方法对现代基因组学至关重要。作者开发了QUILT工具,对低覆盖率的全基因组测序数据执行二倍体基因型填充。通过利用吉布斯采样,QUILT首先将读段划分为母本集和...
In summary, the ChinaMAP reference panel was constructed for accurate and comprehensive imputation based on the large, high-coverage WGS dataset. The population-specific ChinaMAP reference panel exhibited significant superiorities in the well-imputed number, imputation accuracy, precision and sensitivity ...
Accuracy assessment of a simulated imputation based on the GA100K-SG10K panel Imputation on the masked OA whole genome sequencing data (consisting of 256,439 variants) was performed using the GA100K-SG10K and 1KGP reference panel, respectively. After filtering the imputed data with INFO score ≥...