Whatever works best for you! Some of our clients write most of their own blogs but need us to help them out from time to time, others prefer that we keep a consistent flow on their blog and they write their own as time allows.
If you lead them to it. You can tag the blogs to the corresponding service, or post them on social media for people to see them. Most patients will just skim them, but if it's something interesting they may spend more time on them. And even if the patients aren't reading the more service related blogs, search engines sure are.