I am estimating an age-period-cohort (APC) model to isolate cohort trends in diabetes (0=does not have diabetes, 1=has diabetes) by using a mixed model framework specifying cohort at level 1 and period and age at level 2 such that they are not linear combinations. This method I am using is based on Yang Y, Land KC. Age-Period-Cohort Analysis: New Models, Methods, and Empirical Applications. New York: Chapman and Hall/CRC; 2013.
Code:
meqrlogit diabe i.cohort || _all:R.period || agecat:, var or
Here's an example of what I want to produce (I am interested in the first two graphs): Array
Source: https://conservancy.umn.edu/bitstrea...=1&isAllowed=y
In searching the forum, I have found a dearth of threads that address APC models, and the ones that do exist have not addressed creating these type of graphs.
From what I have gathered from the forum and Google searching, I believe I need the following pieces:
Code:
// predict fixed part predict pfx, xb // predict random effects predict v0*, reffects // predict standard errors predict v0se*, reses // Period Probability gen probPeriod = 1 /(1+exp(-1*(pfx + v01))) *95% CI gen probPrL = probPeriod-1.96*v0se1 gen probPrU = probPeriod+1.96*v0se1 // Age Probability gen probAge = 1 /(1+exp(-1*(pfx + v02))) *95% CI gen probArL = probAge-1.96*v0se2 gen probArU = probAge+1.96*v0se2
Code:
preserve collapse (mean) probP = probPeriod (semean) probPs = probPeriod, by(period) gen probPrL = probP-1.96*probPs gen probPrU = probP+1.96*probPs twoway (connected probP period, mcolor(black) lcolor(black)) /// (connected probPrL period, mcolor(black) lcolor(black) lpattern(dash)) /// (connected probPrU period, mcolor(black) lcolor(black) lpattern(dash)), /// ytitle(Predicted probability with 95% confidence band) xtitle(Period) xlabel(#3) legend(off) restore
I have also been wondering if it is a possibility to use the margins & marginsplot commands to get what I want.
I appreciate you all for reading this and look forward to anyone that may be able to help me learn how to do this.
EDIT: I forgot to include that I am using Stata version 16.
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