I have a long format data set with a repeated by year ordinal dependent variable Y (0=mild, 1=moderate, 2=severe), the repeated factor year (0=2014, 1=2016) and centre (1, 2, 3, 4). I would like to test the marginal homogeneity in the variable centre. What I’m doing is:
use dataset_long, clear
xtset id year
ologit Y i.centre##year b4.i.centre
Obtaining (cut points omitted)
Y Coef. Std. Err. z P>z [95% Conf. Interval]
centre
1 -.1290855 .3169848 -0.41 0.684 -.7503643 .4921933
2 -.5908961 .2714226 -2.18 0.029 -1.122875 -.0589175
3 -.1446371 .3012552 -0.48 0.631 -.7350864 .4458122
1.year -.760835 .2815766 -2.70 0.007 -1.312715 -.2089551
centre#year
1 1 | 1.094596 .4460686 2.45 0.014 .2203171 1.968874
2 1 | .8680099 .3843708 2.26 0.024 .1146569 1.621363
3 1 | 1.053251 .4283335 2.46 0.014 .2137328 1.892769
Could someone tell me if this code is correct? If so, I would appreciate if you may indicate me some reference for interpreting centre#year.
Thank you very much.
use dataset_long, clear
xtset id year
ologit Y i.centre##year b4.i.centre
Obtaining (cut points omitted)
Y Coef. Std. Err. z P>z [95% Conf. Interval]
centre
1 -.1290855 .3169848 -0.41 0.684 -.7503643 .4921933
2 -.5908961 .2714226 -2.18 0.029 -1.122875 -.0589175
3 -.1446371 .3012552 -0.48 0.631 -.7350864 .4458122
1.year -.760835 .2815766 -2.70 0.007 -1.312715 -.2089551
centre#year
1 1 | 1.094596 .4460686 2.45 0.014 .2203171 1.968874
2 1 | .8680099 .3843708 2.26 0.024 .1146569 1.621363
3 1 | 1.053251 .4283335 2.46 0.014 .2137328 1.892769
Could someone tell me if this code is correct? If so, I would appreciate if you may indicate me some reference for interpreting centre#year.
Thank you very much.
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