[R] cumulative incidence plot vs survival plot

[David Winsemius]

On Jun 27, 2011, at 5:04 PM, array chip wrote:

> Hi David,
>
> Thanks for responding, and plain text ...(didn't realized I was in  
> rich text).
>
> The endpoint is disease recurrence, I was producing a regular KM  
> plot of
> recurrence-free probability. Then someone recommend using cumulative  
> incidence
> is preferred because death was censored in the dataset. I did a  
> little googling,
> I found CI was used often in the context of competing risk. I am  
> totally new to
> competing risk and trying to understand what competing risk means  
> and why CI is
> preferred than KM survival in this context. If you could share your  
> thoughts
> helping me to understand, greatly appreciated.
>
> Searched archive, found people talking about cmprsk package for  
> estimating and
> plotting CI. would that be the same as the code you suggested:  
> plot(time,
> cumsum(dead))
>

I do not think it would. I think this morning's post from Dr Geskus is  
on point here. You should read his 2011 'Biometrics' paper.

-- 
David.

> Thanks very much!
>
> John
>
>
>
>
> ________________________________
> From: David Winsemius <dwinsemius at comcast.net>
> To: array chip <arrayprofile at yahoo.com>
> Cc: r-help at r-project.org
> Sent: Mon, June 27, 2011 1:45:35 PM
> Subject: Re: [R] cumulative incidence plot vs survival plot
>
>
> On Jun 27, 2011, at 4:31 PM, array chip wrote:
>
>> Hi, I am wondering if anyone can explain to me if cumulative  
>> incidence (CI) is
>> just "1 minus kaplan-Meier survival"?
>
> First tell us what you think CI is defined as. I suspect it is not  
> the same. The
>
> KM estimator is cumulative product of (alive-n(dead))/alive so is  
> the product of
>
> interval survival probabilities. I doubt that your definition of CI  
> has a
> similar denominator.
>
>
>> Under what circumstance, you should use
>> cumulative incidence vs KM survival? If the relationship is just CI =
>> 1-survival, then what difference it makes to use one vs. the other?
>>
>> And in R how I can draw a cumulative incidence plot.
>
> plot(time, cumsum(dead)) ...?
>
>> I know I can make a
>> Kaplan-Meier survival plot using plot(survfit()), for example:
>>
>> fit<-survfit(Surv(time,status)~group,data=data)
>> plot(fit, col=1:2)
>>
>> How to draw CI plot then?
>
> As above. Specify what you are seeking.
>
> There is a well-defined relationship between S(t) and the cumulative  
> hazard.
> Maybe you should do a little study of those terms in texts regarding  
> survival
> analysis.
>
>> Thanks very much!
>>
>> John
>>    [[alternative HTML version deleted]]
>
> Isn't it time you learned to post in plain text?
>
> --
> David Winsemius, MD
> West Hartford, CT

David Winsemius, MD
West Hartford, CT