Paul Visintainer wrote:
Is there an approach to analyzing the trend in odds ratios across the
ordered levels of a 3rd variable? For example,
Suppose I have the risk of obesity in high school students by gender
over three different grades:
Grade OR
10 1.5
11 1.9
12 2.2
There is a test of homogeneity to determine whether these ORs differ
across grade strata. Is there a test to determine whether the pattern
is linear across strata?
--------------------------------------------------------------------------------
Are you looking for something other than -tabodds-?
Joseph Coveney
. webuse bdesop
. tabodds case alcohol [fweight = freq], or
---------------------------------------------------------------------------
alcohol | Odds Ratio chi2 P>chi2 [95% Conf. Interval]
-------------+-------------------------------------------------------------
0-39 | 1.000000 . . . .
40-79 | 3.565271 32.70 0.0000 2.237981 5.679744
80-119 | 7.802616 75.03 0.0000 4.497054 13.537932
120+ | 27.225705 160.41 0.0000 12.507808 59.262107
---------------------------------------------------------------------------
Test of homogeneity (equal odds): chi2(3) = 158.79
Pr>chi2 = 0.0000
Score test for trend of odds: chi2(1) = 152.97
Pr>chi2 = 0.0000
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