BookmarkSubscribeRSS Feed
Ashwini_uci
Obsidian | Level 7

Hi,

In the following text, I am trying to understand the red colored text?

Any help/suggestions what it really means and how to actaully do that?

Multivariable logistic regression was used to adjust for

  1. confounding. Factors in Table
    I
    as well as AIDS, liver disease, peptic ulcer disease, obesity, alcohol or drug abuse, andpsychiatric disorders were included in an initial logistic regression model. Age, sex, race, and renal function were forced into the model, and backward stepwise logistic regression was used to generate the final model. Terms whose removal did not alter the effect estimate for dialysis status by  >10% were removed in order of significance.

Thanks,

Ashwini

2 REPLIES 2
Reeza
Super User

My interpretation:

Fit a model with the dialysis and age, sex, race, renal function.  The remaining variables are added all at once.  Each one is removed one at a time with the highest p value first, if the dialysis status had not changed by more than 10% from the previous or original model (I'm not sure what the 10% would be in comparison to).

SteveDenham
Jade | Level 19

And mine:  They fit the full model.  Then they fit reduced models, deleting one predictor at a time.  They made a list of the "deleted models" where the predicted value of dialysis status was changed less than 10%, ordered by the significance of the independent variables that happened to be deleted.  The model with the least significant deleted independent variable from this list was then selected.  Iterate this process until the deletion resuts in a change in dialysis status of 10% or more.

I just don't see why they used significance to remove an independent variable.  Why not choose the variable that had the least effect on the predicted value (i.e., smallest effect size in some context)?

Steve Denham

sas-innovate-2024.png

Join us for SAS Innovate April 16-19 at the Aria in Las Vegas. Bring the team and save big with our group pricing for a limited time only.

Pre-conference courses and tutorials are filling up fast and are always a sellout. Register today to reserve your seat.

 

Register now!

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 2 replies
  • 1215 views
  • 6 likes
  • 3 in conversation