u/Ammo991

I’m having a hard time interpreting the result of my quadratic term on my linear regression model.

My exposure is a continuous variable ranging from 3-9 and my exposure is also a continuous ranging from 0-4.

After i added a quadratic term i got a significant result with a very low increase in the R2=0.004. Also the curvature starts at 8.9 so its very close to the max of 9 on my exposure.

Does this null my linear model? Or is it okay to use it?

I also ran a ordinal logistic regression model where i collapsed my outcome into categories and got a similar coefficient to the linear model. Just to double check

Statisticians of reddit where are you :)