“Although students must have written parental permission to be treated at Portland’s school-based health centers, state law allows them to seek confidential health care and to decide whether to inform their parents about the services they receive, Belanger said. “
It seems the second part of this statement says that children can go get this “advice” and tell the “health center” that they don’t want their parents to know. The first part of the sentence is meaningless in light of the second part.
No, the students have to have parental permission to use the school health center at all. Once they have that permission, they have access to the whole range of services provided, without their parents having to be informed of any details.