Hi, I'm a bit confused on about the event time column in the pheno csv. The metadata table says "Time from baseline to the heart failure", a negative value in the column indicates hf occurred before the baseline, and that in the event column, a 1 indicates a heart failure occurred after the baseline. But why does the event_time column have varying amounts of time even when the event has 0 for a value? What does this time value indicate or what am I misunderstanding about the data?
Created by Natalie Perez perez Hi @perez,
I want to clarify Ece's points. Point 2 and 3 are correct.
For point 1,4 the real data situations:
1. If the event is 0 --> PrevalentHFAIL can be 1,0,or NAs; event time varied depending on the patients status. The time could indicates 2 possibilities: 1. the length of the study (i.e patients did not experience Heart Failure until the study is over); 2. if it shorter than study period, it means that patients withdraw from the study. Therefore, you observed varying amounts of event time, when the event has 0 for value.
4. correct for the synthetic data. Please see the [this discussion](https://www.synapse.org/#!Synapse:syn27130803/discussion/threadId=9722) that Ece pointed out. However, in real dataset all patients with PrevalentHFAIL 1 always have event==0, with negative event_time. Normally, in our survival analysis we removed all patients with PrevalentHFAIL==1, we provided this value just in case participants comes out with novel idea to use the information.
Best regards,
Pande Hello @perez,
I will try to explain a bit.
Since the data is simulated, there might be some confusions, however in the real data we have those 4 scenarios below only:
1. if the event is 0 -> event time is NA & PrevalentHFAIL is NA
2. If the event is 0 -> event time is a negative number representing the time of heart failure before the study was conducted and PrevalentHFAIL is 1
3. If the event is 1 -> event time is a positive number representing the time of heart failure and PrevalentHFAIL is 0/NA
4. If the event is 1 -> event time is a negative number representing the time of heart failure before the study was conducted and PrevalentHFAIL is 1
"But why does the event_time column have varying amounts of time even when the event has 0 for a value? " Regarding this please see the previous issue: https://www.synapse.org/#!Synapse:syn27130803/discussion/threadId=9722
Hope it is clear now.
Cheers, ece
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