survival analysis generating failure variable and associated date

[Helen Hougen]

I am new to statalist and have read through the rules as well as several related posts, but know I will probably do something wrong, so all constructive feedback is welcome! Thanks in advance.

Hello, I would like to generate a progression variable and the associated progression/failure date in a survival analysis for bladder cancer.

Below are several key variables for generating recurrence:

• grade (levels 1,2)
• tstage (levels 1 through 6)
• radcx_reas – reason for cystectomy (levels 1-6)
• mstage (levels 1,2,3)
• ut – upper tract recurrence (levels 0,1)

I have my data in long form, where each variable has an event name 1-10, and patients can have anywhere between 2 to 10 events/surgeries. Progression is defined as outcome relative to event 1 (initial diagnosis). Each event is associated with a "days" variable which is the number of days since event 1.

Below are the failure criteria:

Variable name: grade, levels 1, 2:
- grade = 1 and event = 1 AND grade = 2 and event = 2 through 10.
- Written out long ways: grade = 1 and event = 1 AND grade = 2 and event = 2 or grade = 2 and event = 3

Variable name: tstage, levels 1, 2,3,4,5,6 (for PUNLMP, Tis, Ta, T1, T2, T3+ respectively):
- tstage=2 and event=1 AND tstage= 4,5, or 6 and event = 2 through 10
- tstage=3 and event=1 AND tstage= 4,5, or 6 and event = 2 through 10
- tstage=4 and event=1 AND tstage= 5 or 6 and event = 2 through 10

Variable name: radcx_reas, levels 1-6
- radcx_reas==1-6 at events 2 through 10

Variable name: mstage, levels 1,2,3
- mstage=2 and event 2-10

Variable name: ut, levels 0, 1
-ut=1 and event 2-10

I then need to generate the earliest failure date for each patient (record_id) using the “days” variable associated with that event.

I tried to reference this post but have hard time understanding how to emulate the code as I am still a stata amateur.

Thank you in advance. Happy to clarify any points.

* Example generated by -dataex-. For more info, type help dataex
clear
input int record_id byte event int days byte(grade tstage radcx_reas mstage ut)
 1 1    0 2 3 1 1 .
 1 2 3535 2 3 1 1 0
 1 3 4242 2 3 1 1 0
 1 4 4596 2 5 1 1 0
 2 1    0 2 3 . 1 0
 2 2  364 2 3 . 1 0
 3 1    0 2 3 . 1 0
 3 2 1604 . . . . .
 4 1    0 2 3 . 1 0
 5 1    0 2 3 . 1 .
 5 2  185 2 3 . 1 .
 5 3  322 2 3 . 1 .
 5 4  485 2 3 . 1 0
 5 5  602 2 3 . 1 .
 6 1    0 1 3 . 1 0
 6 2 1178 2 3 . 1 .
 6 3 1549 2 3 . 1 .
 6 4 2085 . . . . .
 6 5 2380 2 3 . 1 0
 6 6 2739 2 3 . 1 .
 6 7 2841 . . . . .
 7 1    0 1 3 . 1 .
 7 2  999 2 3 . 1 .
 7 3 1553 2 3 . 1 0
 7 4 2014 2 3 . 1 0
 7 5 2156 1 3 . 1 .
 8 1    0 2 3 . 1 0
 8 2 1769 2 4 . 1 0
 8 3 2746 2 3 . 1 0
 8 4 2805 1 2 . 1 .
 8 5 3023 . . . . .
 9 1    0 2 4 . 1 0
10 1    0 1 3 . 1 .
11 1    0 2 3 . 1 0
11 3  206 1 3 . 1 0
11 4 1883 2 3 . 1 .
12 1    0 2 3 . 1 0
13 1    0 2 4 . 1 0
13 2  686 2 2 . 1 .
15 1    0 2 3 . 1 0
15 3  239 . . . . .
15 4  827 . . . . 0
17 1    0 2 4 . 1 .
17 2 2044 2 4 . 1 1
17 3 2169 2 3 . 1 .
18 1    0 1 4 . 1 0
18 2   58 2 3 . 1 .
21 1    0 2 4 . 1 0
21 2  202 2 . . 1 .
21 3 1530 1 3 . 1 0
22 1    0 2 2 2 1 .
22 2  568 2 3 2 1 .
22 3  703 2 4 2 3 .
23 1    0 2 3 . 1 .
23 2   49 1 3 . 1 0
23 3  168 2 3 . 1 .
23 4  714 . . . . 0
27 1    0 2 3 . 1 .
27 3  172 1 . . 1 .
27 4  439 1 3 . 1 0
27 5 1797 . . . . .
29 1    0 2 4 . 3 .
29 2  139 2 4 . 1 .
29 3  183 . . . . .
29 4  351 2 3 . 3 .
29 5  443 2 3 . 1 0
29 6  499 . . . 3 0
29 7  524 . . . . .
29 8  818 . . . . 0
30 1    0 2 2 . 1 0
30 2  168 2 4 . 1 0
30 3  205 1 2 . 1 .
30 4 1129 2 5 . 2 .
31 1    0 . 2 . 1 0
31 2  677 2 6 . 1 0
36 1    0 2 3 2 1 0
36 2  637 2 4 2 1 0
37 1    0 2 3 . 1 0
37 2  718 2 3 . 1 .
37 3 1030 2 3 . 1 .
38 1    0 2 3 . 1 .
38 2 1235 1 3 . 1 0
38 3 1483 2 4 . 1 0
38 4 1586 2 4 . 1 .
38 5 1768 2 3 . 1 .
38 6 2131 2 4 . 1 .
39 1    0 2 3 . 1 .
39 2 4998 . . . . .
39 3 4784 . . . . .
39 4 5016 2 3 . 1 0
39 5 5060 2 4 . 1 .
40 1    0 2 3 . 1 0
40 3  176 2 4 . 1 .
42 1    0 1 3 . 1 .
42 2 1354 . 2 . 1 0
42 3 1916 . 2 . 1 .
42 4 2285 . . . 3 .
44 1    0 1 3 . 1 .
44 2 1121 2 3 . 1 .
45 1    0 2 3 . 1 0
end
label values grade grade1_v2_v10_92650b_
label def grade1_v2_v10_92650b_ 1 "LG", modify
label def grade1_v2_v10_92650b_ 2 "HG", modify
label values tstage stage1_v2_v10_504c29_
label def stage1_v2_v10_504c29_ 2 "cTis", modify
label def stage1_v2_v10_504c29_ 3 "cTa", modify
label def stage1_v2_v10_504c29_ 4 "cT1", modify
label def stage1_v2_v10_504c29_ 5 "cT2", modify
label def stage1_v2_v10_504c29_ 6 "cT3 or higher", modify
label values radcx_reas radcx_reas_
label def radcx_reas_ 1 "Progression after intravesical therapy", modify
label def radcx_reas_ 2 "Persistence/Recurrence after intravesical therapy", modify
label values mstage metastases_v2_v10_90cc44_
label def metastases_v2_v10_90cc44_ 1 "M0", modify
label def metastases_v2_v10_90cc44_ 2 "M1", modify
label def metastases_v2_v10_90cc44_ 3 "MX", modify
label values ut ut_dx_v2_v10_d8ec7f_
label def ut_dx_v2_v10_d8ec7f_ 0 "No", modify
label def ut_dx_v2_v10_d8ec7f_ 1 "Yes", modify