[R] survival analysis

[Paul Pynsent]

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
>>>> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._. 
>>>> _.
>>>> _._._._._
>>>
>>>
>>> -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
>>> .-.-.-.-.-
>>> 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
>>> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._ 
>>> ._
>>> ._._._._
>>>
>>
>> -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 
>> .-.-.-.-.-
>> 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
>> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._. 
>> _._._._._
>
>
> -- 
> 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
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._