ordered effect modification

[tim bradshaw]

Hi there
I want to know if an effect size differs in an ordered way with each category of another variable.
For example:

clear
input float(strata exposure outcome)
1 1 0
1 1 0
1 1 0
1 1 0
1 1 1
1 2 0
1 2 0
1 2 0
1 2 1
1 2 1
2 1 0
2 1 0
2 1 0
2 1 0
2 1 1
2 2 0
2 2 0
2 2 1
2 2 1
2 2 1
3 1 0
3 1 0
3 1 0
3 1 0
3 1 1
3 2 0
3 2 1
3 2 1
3 2 1
3 2 1
end

expand 20

logistic outcome i.exposure##i.strata

lincom 2.exposure + 2.exposure#1.strata, or
lincom 2.exposure + 2.exposure#2.strata, or
lincom 2.exposure + 2.exposure#3.strata, or

The effect size gets stronger with each level of strata, but is there a way to test for this ordered heterogeneity?

Hope that makes sense.

Any advice gratefully received! Thanks