Im trying to compare the mean scale score for participants enrolled in a program to the same scale score for people who did not enroll in the program, while controlling for baseline differences in a set of confounders. Ive tried a couple of regressions and anova in SPSS with enrollment as the dependent variable and I don't think any of the results I'm getting make a lot of sense. Which analyses should I use for this kind of test in SPSS?