Efficacy Time to event

CathyVI — Thu, 13 Jan 2022 16:53:34 GMT

Hello,

Am new to this topic so I will appreciate any feedback.

I am to analyze the efficacy endpoint that include the occurrence of an infection between the last vaccination and the subsequent 168 days (2 month) and separately for the subsequent 532 (5 month) days if efficacy is shown for the initial follow-up period. The number censored are small, say < 10%, so I think the resulting bias is likely to be small and can be ignored (Please let me know any other thoughts).

Question1: I have these following dates but am not sure which ones I’ll use to calculate my survival time.

SubjectReferenceStartDate SubjectReferenceEndDate DateofFirstStudyTreatment DateofLastStudyTreatment DateofEndofParticipation.

Question 2: What will my variables be for the TIME statement ?

For example:

proc lifetest data= notable;

time survtime*censor(0);

strata treat;

run;

I have created this artificial data with variable of interest to help demonstrate my idea

subjectID $ Age ArmCode $ SubjectReferenceStartDate SubjectReferenceEndDate DateofFirstStudyTreatment DateofLastStudyTreatment DateofEndofParticipation Result $ VisitName $

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Negative Day 10, Dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Negative Month 1, Post-dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Positive Month 2, Post-dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Negative Month 3, Post-dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Negative Month 4, Post-dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Positive Month 5, Post-dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Positive Month 6, Post-dose 3

AB123 30 Drug 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Positive Month 7, Post-dose 3

CD456 35 Placebo 2015-03-01 2017-12-01 2015-03-01 2015-06-27 2017-12-01 Negative Day 10, Dose 3

Re: Efficacy Time to event

sbxkoenk — Thu, 13 Jan 2022 19:21:56 GMT

Hello,

I have moved your post to the "statistical procedures" board (as it is a question on survival | time-to-event analysis).

Higher probability to get a proper answer here.

Koen

Re: Efficacy Time to event

SteveDenham — Tue, 18 Jan 2022 15:39:04 GMT

I am confused by the day to month correspondence you present (2 months = 168 days, 5 months = 532 days). It is unlikely to affect your analysis, but I think interpretation of results might be difficult as it looks like the two cohorts are not commensurate.

SteveDenham

topic Re: Efficacy Time to event in Statistical Procedures

Efficacy Time to event

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Re: Efficacy Time to event