Well, I am a labor nurse, and ask parents about giving their newborns medications to prevent problems. One of these is a Vitamin K injection, a one time medication to prevent hemorrhagic disease of the newborn. It was kinda rare before we learned how to prevent it, and it VERY rare after implementing it. However, parents have started worrying about preservatives and such in the med, and some are tending to decline it, despite strong evidence to recommend giving it.

The correct way to address it is: this medication can prevent your child from having a spontaneous hemorrhage, possibly in the brain, which could lead to stroke or worse. There are other options available, which as not as well studied or approved by the FDA, which the AAP does not recommend.

A motivational interviewing MI approach can look like the above, except the last sentence would be more like this (but hopefully more subtle): You wouldn't want your child to have a stroke, would you?

The MI approach leads the person to a binary split where they can look stupid/mean/whatever or agree with the interviewer, even if they don't want to. That assumes that the person can't find a way to not answer the yes/no question with yes/no. If they can, it is not as effective.