One thing to do is to try it. :)
The other thing to do is to think about the number of 'cells' in the
analysis. You need to ensure that every combination of predictor and
outcome has a few (say 5-10) people in it (that is you want at least 5
people with risk factor 1 in each of your three outcome groups, and
five people without risk factor 1 in each of your three outcome
groups). I think you're going to be pushing that. I would do them
one risk factor at a time, using either chi-square tests or
multinomial logistic regression - they're the same.
Jeremy
On 12 October 2010 10:01, Fleur-Michelle Coiffait
<[log in to unmask]> wrote:
> Thanks to all who have responded to my query.
>
> Just wondering if you had any idea how large the sample would need to be to use multiple predictors in a multinomial logistic regression? My sample is 90.
>
> Many thanks,
> _________________
> Fleur-Michelle Coiffait
> Trainee Clinical Psychologist
> University of Edinburgh & NHS Lothian
>
> On 12 Oct 2010, at 17:50, Jeremy Miles wrote:
>
>> Hi Fleur-Michelle,
>>
>> If you just wanted to run one risk-factor predictor at a time, then
>> the chi-square test will be exactly the same as a multinomial logistic
>> regression. (Note, that's the chi-square test you find buried under
>> crosstabs in the SPSS menus, not the chi-square test that you find in
>> non-parametric tests, which is different).
>>
>> If you have multiple predictors, then you need to use multinomial
>> logistic regression. But you'll need a large sample, and you'll get a
>> LOT of parameter estimates out, which will take some interpreting.
>>
>> If you have a large enough sample, I'd consider doing a principal
>> components analysis first, to reduce the number of predictors.
>>
>> Jeremy
>>
>> On 12 October 2010 06:58, Fleur-Michelle Coiffait
>> <[log in to unmask]> wrote:
>>> Hi all
>>>
>>> I am analysing some data derived from routine information collected via a screening form, which has twelve 'risk factors' on it that get ticked if present (e.g. substance misuse, domestic abuse, etc). I am trying to look at whether the presence of any of these risk factors is related to three 'outcome' categories (no further service involvement, service X involvement, or social work involvement). I had initially thought about doing a Chi square analysis, but came across multinomial logistic regression and wondered if this might be more appropriate? Or are neither of these suitable analyses for this kind of data?
>>>
>>> I realise this may be a really silly question, but any advice/clarification would be much appreciated.
>>>
>>> Many thanks,
>>> Fleur-Michelle
>>> _________________
>>> Fleur-Michelle Coiffait
>>> Trainee Clinical Psychologist
>>> University of Edinburgh & NHS Lothian
>>>
>>>
>>>
>>>
>>>
>>> --
>>> The University of Edinburgh is a charitable body, registered in
>>> Scotland, with registration number SC005336.
>>>
>>
>>
>>
>> --
>> Jeremy Miles
>> Psychology Research Methods Wiki: www.researchmethodsinpsychology.com
>>
>
>
>
>
>
>
>
> --
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
>
>
--
Jeremy Miles
Psychology Research Methods Wiki: www.researchmethodsinpsychology.com
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