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Questions related from David Zurakowski
In medical and surgical research the hazard function is often used to estimate risk of an event across time. However the assumption of constant hazard is often not met and is not ideal when...
05 May 2017 2,602 3 View
Applying the Cox model for censored survival data is common in medical research but usually researchers do not report adequacy of the model unless pressed by reviewers. Residual plots can be...
02 February 2017 8,100 5 View
Dear RG Members, When using meta-analysis based on a fixed effects model in which the summary statistic is an odds ratio for a binary outcome, how does one calculate statistical power for...
06 June 2016 2,448 4 View
Almost always in clinical research the log-rank test (Mantel-Haenszel test) is employed to compare the equality of two survival curves. Is there a good way to decide whether other tests may be...
05 May 2016 3,845 3 View
When estimating EC50 for a single drug, does one need all of the raw data at each drug concentration or simply the average response at each concentration? How does one decide what model or...
03 March 2016 7,612 9 View
When applying logistic regression to identify predictors of an outcome, it is not clear whether the Wald test or likelihood ratio test is preferred for evaluating the significance of candidate...
08 August 2015 7,533 11 View
In 1998 we published an article showing a new simple statistical method for determining endpoint titer in immunoassays. Please see abstract below. Can anyone can suggest a useful method when no...
06 June 2015 9,989 0 View
Several statistical tests have been proposed for comparing survival distributions or Kaplan-Meier curves between two or more groups. It seems that 99% of the time in clinical research the log-rank...
01 January 1970 1,098 4 View
