We made him famous, we imputed all this power to him, and he took advantage of it, putting him in the same category as people like JFK, Bill Clinton, John Edwards, John Ensign, and Mark Sanford – people whom we actually did invest with real power, who then acted duplicitously not just with their wives, but with we who empowered them.
all the investigated methods can boost signals with imputed genotypes, and the power of association improves under medium and high levels of LD, with the magnitude of power increase depending on the strength of LD; 2) the power increases with increasing MAF of untyped causal SNPs under medium LD level; 3).
For GWAS, it has also been suggested to include the uncertainty of imputed genotypes to improve power [ 28- 31].
To minimize possible bias associated with excluding individuals with missing data while maintaining power, we imputed data for missing chemical exposures stemming from insufficient urine for quantification and relevant covariates (10%%) using data for the entire cohort and Markov Chain Monte Carlo methods, under an assumption of 'missing at random' [ 32, 33].
Our analysis of multiply imputed data confirmed that the power of multiple imputation lies in obtaining smaller standard errors and narrower confidence intervals in addition to allowing one to work with the entire dataset.
Approaches include omitting the cases with missing data, which is an inefficient use of the data, reducing precision and power; imputing the missing values, which must be done with care 8; and fitting a more sophisticated model where the baseline and post-treatment measurements are modelled 'jointly', which allows participants with partial missing data to be included.
Here, using a 2 × 3 chi-square test, we describe a relationship between genotype-imputation error rates and the sample-size inflation required for achieving statistical power at an imputed marker equal to that obtained if genotypes at the marker were known with certainty.
In this situation, selection candidates can be genotyped for a small panel (e.g. <1,000 SNP) and 60k genotypes imputed to improve the predictive power.
To improve the study's power, we also imputed a total of 158 SNPs across the IL18 locus using data from an SLE genome-wide association study and performed association testing.
For the remaining 76 890 antennas, 66 790 (87%) had complete data, 5081 (7%) had missing data on tilt, beam widths, or frequency (replaced by company specific medians), and 5019 (7%) had missing data on height or effective isotropic radiated power, which we imputed from a regression model calibrated using antennas with complete data.
