survival analysis
Frank, You are quite right of course, the line: rounded.fu <-ceiling(fuperiod) does the trick. As to why, this is what the J Bone Jnt Surg expect, although I agree that there is a loss of precision. Any way thank you again.
On Thursday, November 21, 2002, at 03:32 pm, Frank E Harrell Jr wrote:
I'm not clear on why the actuarial method is still used, as it loses resolution by rounding follow-up times to the nearest month/year/week instead of using all the precision in the data. Anyway if you rounding the follow-up times and used Kaplan-Meier, wouldn't you get actuarial estimates? Frank Harrell On Thu, 21 Nov 2002 13:54:00 +0000 Paul Pynsent <p.b.pynsent at bham.ac.uk> wrote:
Jun, Thank you for this information. It is half of what I wanted as there are no confidence limits calculated. Survfit in the survival package gives very useful alternatives for calculating the confidence limits including adjustments to the lower limits, for data that is heavily censored (see Dorey and Korn as referenced in the survfit documentation). On the other hand, unfortunately survfit does not offer an actuarial method. It looks as though I am going to have to write my own code for this. On Wednesday, November 20, 2002, at 03:19 pm, Jun Yan wrote:
I am not sure if this is what you want. The function lifetab in package KMsurv creates a cohort life table as described in Klein and Moeschberger (1997), Survival Analysis.
library(KMsurv) ?lifetab
Jun On Wed, 20 Nov 2002, Paul Pynsent wrote:
Has anybody written an actuarial (life) survival procedure, this does not appear to be an option in the survival package? This approach is common in orthopaedic surgery to demonstrate the survival of prostheses. I need to apply the "modified" lower conf.int because of the censoring over time. I want a life table which I can then easily plot. Many thanks -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- .- .-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._. _. _._._._._
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-- Frank E Harrell Jr Prof. of Biostatistics & Statistics Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences U. Virginia School of Medicine http://hesweb1.med.virginia.edu/biostat
Dr. P. B. Pynsent, Research and Teaching Centre, Royal orthopaedic Hospital, Birmingham, B31 2AP, U.K. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._