topic Re: DIfference between survival rates and quantities in Statistical Procedures

DIfference between survival rates and quantities

jonatan_velarde — Thu, 22 Apr 2021 14:09:04 GMT

data new;

input day live death;

cards;

Day_0 37 0
Day_6 36 1
Day_12 21 16
Day_18 8 29
Day_24 2 35

;

SO, in this case i want to estimate the survival rate between days and find statistical differences between them, and estimate, in the same way, in wich day occured the major mortality. THs objective here is to obtain a table like this:

Day	Total	Survival
Day_0	37	100.00%
Day_6	36	97.30%
Day_12	21	56.76%
Day_18	8	21.62%
Day_24	2	5.41%

Re: DIfference between survival rates and quantities

sbxkoenk — Sat, 24 Apr 2021 12:14:36 GMT

Hello,

Producing the table shown is easy of course, but I have no idea on how to detect 'statistical differences between them'. The fact that this question was/is still un-answered makes me think your question is not entirely clear and/or your data are not suitable for this test.

Here's the program to produce the table:

data new;
input day $ live death;
cards;
Day_0  37  0
Day_6  36  1
Day_12 21 16
Day_18  8 29
Day_24  2 35
;
run;

proc means data=new /*nway*/ MAX noprint;
 var live;
 output out=MaxLive(drop=_TYPE_ _FREQ_) max=MaxLive;
run;

data want(drop=MaxLive);
 if _N_=1 then set MaxLive;
 set new;
 Total=live+death;
 Survival=live/MaxLive;
 format Survival percent7.2;
run;

proc print; run;
/* end of program */

Cheers,

Koen

Re: DIfference between survival rates and quantities

jonatan_velarde — Sat, 24 Apr 2021 13:04:56 GMT

Thanks for your answer.

i would like to know if 100% ofs survival is statisticallydifferent than
the other percentages in next days:

SAS Output

Survival1

100%

97.3%

56.8%

21.6%

5.41%

if 100% is different than 97,3% and if 100% is different than 56,8% ans so
on

Re: DIfference between survival rates and quantities

sbxkoenk — Sat, 24 Apr 2021 13:55:59 GMT

Hello,

I see.

I do not know the answer.

I have little experience with survival models.

I know it's 'easy' to compare survival rates and survival curves across groups (with PROC LIFETEST f.e.), but how to compare survival rates at different time points within one group (within one curve), that I don't know (or do not know it by heart in any case).

I know how to compare proportions but that is not really applicable here (and for sure not with the data you present).

But thanks to my intervention, your question is again at the top of the list and so I hope experts on survival analysis will chime in and help you out. 😆

Cheers,

Koen

Re: DIfference between survival rates and quantities

jonatan_velarde — Sat, 24 Apr 2021 14:03:56 GMT

Thanks for the answeer dude, this group is really awesome to solve some
puzzles.

Even i work in SAS 10 years ago, i learned everythin by my self, and
continue to learn

Thanks one more time