st: Fw: Negative binomial regression and Incident rate ratio(IRR)

 From Muhammad Riaz <[email protected]> To [email protected] Subject st: Fw: Negative binomial regression and Incident rate ratio(IRR) Date Wed, 2 Sep 2009 04:41:38 -0700 (PDT)

```Hi,
I am resending this query if somebody could help with, I sent it yesterday but did not get any response.

Adding further my query given below, my dependent variable is count (0-9) based on certain scale, i mean the dependent variable measure counts of 9 items for each individual,  these counts are given in the table as:

d_cap       |
|      Freq.     Percent        Cum.
------------+-----------------------------------
0 |        449       38.71       38.71
1 |        214       18.45       57.16
2 |        163       14.05       71.21
3 |        112        9.66       80.86
4 |         89        7.67       88.53
5 |         56        4.83       93.36
6 |         41        3.53       96.90
7 |         18        1.55       98.45
8 |         12        1.03       99.48
9 |          6        0.52      100.00
------------+-----------------------------------
Total |      1,160      100.00

Can we fit a regression model with negative binomial distribution?
How can we compute the Incident rate ratio?

--- On Tue, 9/1/09, Muhammad Riaz <[email protected]> wrote:

> From: Muhammad Riaz <[email protected]>
> Subject: Negative binomial regression and Incident rate ratio(IRR)
> To: [email protected]
> Date: Tuesday, September 1, 2009, 3:22 PM
> Dear All,
> I am trying to fit a model for count data using Negative
> binomial regression, it gives incident rate ratios for the
> variables in the model, one of the options for this type of
> model is specifying the offset variable while fitting the
> model in stata using glm. This offset should be the person
> years (if i am correct). however I do not have data on this
> variable. My question is:
>
> Is it correct to fit the model without an offset and would
> the Incident rate ratio be still correct to report If I do
> not specify the offset variable in the model?
>
> I will really appreciate any help.
>
> Thank you,
>
> M Riaz
>
>
>
>
>

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