topic Type 3 Analysis of Effect in Logistic Regression in Statistical Procedures

Type 3 Analysis of Effect in Logistic Regression

MLAC — Mon, 11 Nov 2019 03:30:48 GMT

In Logistic Regression, the Type 3 Analysis tests are performed to test the statistical significance of each input. What exactly is the statistical test?

Re: Type 3 Analysis of Effect in Logistic Regression

Ksharp — Mon, 11 Nov 2019 12:54:55 GMT

I don't understand your question. Do you mean pick up the most significant variables ?

proc logistic data=sashelp.class;
model sex=age weight height/selection=stepwise;
run;

Re: Type 3 Analysis of Effect in Logistic Regression

PaigeMiller — Mon, 11 Nov 2019 13:08:28 GMT

@MLAC wrote:

In Logistic Regression, the Type 3 Analysis tests are performed to test the statistical significance of each input. What exactly is the statistical test?

https://documentation.sas.com/?docsetId=statug&docsetTarget=statug_introglmest_sect015.htm&docsetVersion=14.3&locale=en

In layman's terms, Type III tests are what you would use if there is no particular ordering of the predictor variables, each is considered to be entered into the model last, to see if it adds any predictive value. (I think) PROC LOGISTIC only uses Type III anyway, the other types of tests are for PROC GLM and similar procedures, and it is called Type III in PROC LOGISTIC just to keep the naming consistent with other modeling procedures. (A case where you would have a definite ordering is a polynomial model, where linear term is entered first, and quadratic term is entered second, and so on, in which case you would use Type II test; but you don't mention anything like this, so Type III is appropriate)

Re: Type 3 Analysis of Effect in Logistic Regression

MLAC — Mon, 11 Nov 2019 14:23:43 GMT

Is the type lll test Chi-Square Association test on each input?

Re: Type 3 Analysis of Effect in Logistic Regression

PaigeMiller — Tue, 12 Nov 2019 13:41:37 GMT

The specific output table you want says "Type 3" (or maybe "Type III") in the header above the table.

Re: Type 3 Analysis of Effect in Logistic Regression

StatDave — Tue, 12 Nov 2019 20:17:26 GMT

If you are asking what type of test the Type3 tests are, they are Wald chi-square tests if done by PROC LOGISTIC. If they are done by PROC GENMOD, they are likelihood ratio chi-square tests by default unless the WALD option is specified in the MODEL statement. But if the REPEATED statement is used in PROC GENMOD, then they are score chi-square statistics by default (again, WALD option makes them Wald chi-squares).

Re: Type 3 Analysis of Effect in Logistic Regression

MLAC — Wed, 13 Nov 2019 05:44:16 GMT

Thanks. I was wondering if it is Wald Chi-Square test. Thanks for the confirmation.