search for: accruals

I have been trying to create code to calculate the power for an adaptive design with a survival endpoint according to the method of Schafer and Muller ('Modification of the sample size and the schedule of interim analyses in survival trials based on interim inspections,' Stats in Med, 2001). This design allows for the sample size to be increased (if necessary) based on an interim look at

A few months ago, I posted a query regarding code for a sample size estimate for a one arm survival trial. Below is some code I created to calculate such an estimate - perhaps it may be of some use. #cox.pow computes sample size for a one arm survival trial. med.0 is the null median #survival, med.a is the alternative median survival, a.time is the accrual time, and #f.time is the follow up

useR's, I am trying to do a power calculation for a survival analysis using a logrank test and I need some help properly doing this in R. Here is the information that I know: - I have 2 groups, namely HG and LG - Retrospective analysis with subjects gathered from archival data over 20 years. No new recruitment of subjects and no estimated time to target accrual and accrual rate. - Survival

Hi, I am trying to calculate the descretionary accruals using the bootstrapping technique with the R program, but I keep getting an error message. Previously, after typing in the command on the front sreen, R would return the output without any problems. I am now using a different dataset, and am getting the following error: Error in solve.d...

Hi everyone, I was wondering whether extension of the current spower function for Hmisc were existing? My current focus is to calculate sample size based on the log-rank test with more than 2 groups (with/without trend) Taking into account the loss of follow up and the accrual processes. A SPSS library (ART) is existing but can't find anything in R Any information is welcome ! Many

I would like to do some power estimations for a log-rank two sample test and cpower seems to fit the bill. I am getting confused though by the man page and what the arguments actually mean. I am also not sure whether cpower takes into account censoring or not. Could anyone provide a simple example of how I would get the power for a set control/non-control clinical trial where censoring occurs at

I think we all know that the readability of steps isn''t great right now, and in fact there''s a very recent thread that discusses just that. It was that recent thread that prompted me to explore this a bit. The basic idea is that you define step matchers, which have a regex, and then you match step names against that regex. Kind of tough for me to explain so I''ll just

On Oct 17, 2018, at 3:28 PM, Mark Rousell <mark.rousell at signal100.com> wrote: > > On 17/10/2018 20:03, Warren Young wrote: >> On Oct 17, 2018, at 10:03 AM, Mark Rousell <mark.rousell at signal100.com> wrote: >>> launchd is not being forced on them as systemd is in practice >> Try doing without launchd on macOS. > > If launchd was on Linux and it

On 10/17/18 7:55 PM, Warren Young wrote: > On Oct 17, 2018, at 3:28 PM, Mark Rousell <mark.rousell at signal100.com> wrote: >> >> On 17/10/2018 20:03, Warren Young wrote: >>> On Oct 17, 2018, at 10:03 AM, Mark Rousell <mark.rousell at signal100.com> wrote: >>>> launchd is not being forced on them as systemd is in practice >>> Try doing

On Oct 17, 2018, at 10:03 AM, Mark Rousell <mark.rousell at signal100.com> wrote: > > launchd is not being forced on them as systemd is in practice Try doing without launchd on macOS. If you think that?s irrelevant, count the number of MacBooks at the next FreeBSD conference you attend. For an init system to gain sufficient momentum, it must be the default, with no easy way to