Statistical tests used in this research paper?

[Genecks]

Hello, all.

 

I'm reading through a recent research paper entitled: Association Between Urinary Bisphenol A Concentration and Obesity Prevalence in Children and Adolescents

 

The article is from the Journal of the American Medical Association. (Attached)

 

Page 2, the last paragraph is of importance, as is the information going to page 6 with table 3.

I know it seems like a lot. The most important thing to me is understanding what kinds of statistical tests are being used, how, and how the p-values and prevalence values are being calculated.

 

I'm having a major problem understanding how the authors computed their data and performed statistical tests on the data. I suspect my background in statistics just isn't enough when looking at this kind of thing. My only other option would jump on a stats package and brute force it, hopefully on something like Stata 12, and try to get the same values back that the authors got by trying various tests until I get the right ones.

 

I know the following about it:

1. It's listing variables and running tests against them to control them and see if they're related to other variables, particular the variable(s) of interest, which are "overweight" and "obese."

2. It's giving a P-value based off some kind of chi-square value. I can't say this is really a chi-square test, but I'm thinking it's some kind of multiple regression test. I'm still not sure.

3. It's found that the levels of the independent variable, which is BPA concentration, are against variables, which some may be confounding or not.

4. I think table 2 is a z-test, but I'm not sure about that.

5. I know it's multivariate, but I can't figure out much beyond that.

 

I've spent a lot of time trying to figure this out, so I figured I would ask others about this.

Edited September 21, 2012 by hypervalent_iodine
Attachment removed.

[hypervalent_iodine]

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Moderator Note

Genecks,

The article you attached to your OP is not available free to the public. As such, attaching it for download here violates copyright laws and I need to remove it.

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