First, note that the title "question" is not informative.
You have two questions. On the second, there is an FAQ
FAQ . . . . . . . . . . . . . . . . . . . . . . . Replacing missing values
2/03 How can I replace missing values with previous or
following nonmissing values?
http://www.stata.com/support/faqs/data/missing.html
. search missing
points to this.
On the first, I am no survival expert,
but absent a view of all your data your question looks very
difficult to answer. But you can at a minimum compare the results on
non-missing data and on data including imputations to see
what difference it makes.
Nick
[email protected]
Scott Cunningham
> I am estimating a hazard, but I am missing data for certain time-
> variant covariates when t is very small. Seeing data will help me
> explain this.
>
> +--------------------------------+
> | sr _st _d _t _t0 |
> |--------------------------------|
> 1. | . 1 0 1 0 |
> 2. | . 1 0 2 1 |
> 3. | . 1 0 3 2 |
> 4. | . 1 0 4 3 |
> 5. | . 1 0 5 4 |
> |--------------------------------|
> 6. | . 1 0 6 5 |
> 7. | . 1 0 7 6 |
> 8. | . 1 0 8 7 |
> 9. | . 1 0 9 8 |
> 10. | .9738716 1 0 10 9 |
> |--------------------------------|
> 11. | 1.081043 1 0 11 10 |
> 12. | 1.21261 1 0 12 11 |
> 13. | 1.125889 1 1 13 12 |
> 14. | . 1 0 1 0 |
> 15. | . 1 0 2 1 |
> |--------------------------------|
> 16. | . 1 0 3 2 |
> 17. | . 1 0 4 3 |
> 18. | . 1 0 5 4 |
> 19. | . 1 0 6 5 |
> 20. | . 1 0 7 6 |
> |--------------------------------|
> 21. | . 1 0 8 7 |
> 22. | . 1 0 9 8 |
> 23. | .9738716 1 0 10 9 |
> 24. | 1.081043 1 0 11 10 |
> 25. | 1.21261 1 0 12 11 |
> |--------------------------------|
> 26. | 1.125889 1 0 13 12 |
> 27. | 1.080463 1 0 14 13 |
> 28. | .9527455 1 1 15 14 |
>
>
> Notice that for all values of t=0 to t=9, I am missing data for sr.
> My first question is when I -streg-, what effect does this
> have on my
> estimation? None of my respondents complete their respective spells
> prior to t=10. Secondly, assume I wanted to fill in those missing
> values with the same value as t=10. How would I do this?
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