Part 2: Why not just use regression? · Module 4
"Can't I just run a regression?"
Why We Need Something Different
It is a fair question, and one every analyst should ask. Logistic regression is an excellent, well-tested tool, and if your question is "which single factor moves the outcome most, holding the others constant," you should reach for it, not CNA. The two methods are not rivals so much as instruments tuned to different questions.
The catch is that regression, by design, estimates the average independent contribution of each factor. It answers "how much does supervision matter on its own?" But immunization coverage rarely fails because of one factor acting on its own. It fails when a broken cold chain meets missing supervision in the same place, at the same time. That is a question about combinations , and it is a different question than the one regression is built to answer.
What You Will Be Able to Do
- Explain, in plain language, the question regression is built to answer.
- Explain why that question misses how immunization programs actually work.
- Say when CNA is the better tool, and when it is not.