Hi Ioanna
Intention to treat analysis usually refers to the treatment that a
patient received, for dealing with non-compliance. That is, if the
person did not attend the parenting program, but they were randomized
to receive it, you still analyze them as in the parenting program
group. (Or if they were not supposed to attend, but did).
This is different to missing data.
For a regular ITT, you should include all cases for whom you have
data, regardless of whether they attended.
J
2010/1/6 Ioanna Vrouva <[log in to unmask]>:
> Dear All,
> I would be grateful for your advice concerning the following.
> I am working on an outcome analysis (with outcome data-CBCL scores-
> available at intake and end of treatment) regarding a parenting program.
> It has been impossible to obtain data from parents who dropped out (around
> 25 %). Moreover, another 15% have not provided data at either intake or
> follow-up, although they completed the intervention.
> I had previously based the outcome analysis on only those who had data
> available at both intake and completion. However, the Editor has asked me
> to present an intention to treat analysis (ITTA).
> My questions
> 1. Should I include all cases for this analysis? (regardless of whether
> they completed the treatment, and whether they provided data at both
> intake and the second time point?)
> 2. When performing an ITTA with missing data, which is the best way to
> impute the missing data (CBCL scores)? The average? Or?
> Any guidance/reading suggestions would be hugely appreciated
> Many thanks and happy New Year
> Ioanna
>
--
Jeremy Miles
Psychology Research Methods Wiki: www.researchmethodsinpsychology.com
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