topic Re: significant linear trend in proportion of males: some of same people found in different years in Statistical Procedures

significant linear trend in proportion of males: some of same people found in different years

mjkop56 — Sat, 18 Sep 2021 17:35:49 GMT

I am trying to determine if there is a significant linear trend over time in the proportion of males. This post is very helpful, and the suggestion to use a logistic regression with gender as the outcome and year as the predictor:

https://communities.sas.com/t5/Statistical-Procedures/Test-for-significant-difference-in-proportion-of-Males-from-2005/td-p/119299

I have some of the same people who are found in different years (but not in the same year). Can I use the same set up, or does the logit model need to be modified?

Re: significant linear trend in proportion of males: some of same people found in different years

sbxkoenk — Sat, 18 Sep 2021 18:26:59 GMT

Hello,

See the answers of @PGStats and @SteveDenham in this post :

Testing Trend in Proportion Over Time
Posted 06-25-2020 04:42 PM
https://communities.sas.com/t5/Statistical-Procedures/Testing-Trend-in-Proportion-Over-Time/td-p/665159

Test your errors for autocorrelation if you use a regression modelling approach!!

Koen

Re: significant linear trend in proportion of males: some of same people found in different years

mjkop56 — Sat, 18 Sep 2021 19:20:49 GMT

Thanks, I'm trying to figure our how to test for autocorrelation with a logistic regression.

I have individual level data, for example, and the outcome (gender) does not change within a person.

ID year gender

1 2005 M

1 2006 M

1 2007 M

2 2005 F

3 2006 M

3 2007 M

3 2008 M

Could a model with cluster robust standard errors fix the issue (with same person in multiple yrs), or does one need to go to a random intercept or random coefficient model?

Re: significant linear trend in proportion of males: some of same people found in different years

sbxkoenk — Sat, 18 Sep 2021 20:25:22 GMT

Hello,

You could consider fitting a GEE model in PROC GENMOD and using TYPE=AR or MDEP(1) to examine the estimated correlation between adjacent observations.

GEEs = Generalized Estimating Equations

GEEs should cope with having data that are correlated in clusters.

Generalized Estimating Equations

https://support.sas.com/rnd/app/stat/topics/gee/gee.pdf

Cheers,

Koen

Re: significant linear trend in proportion of males: some of same people found in different years

mjkop56 — Sat, 18 Sep 2021 22:51:10 GMT

I will try that. Many thanks, Koen!