"What is it that we want to see? When do we get that platform of change and what does that mean and what does it look like?"
She said they had seen from free healthcare in the UK that "their free universal policy doesn't equate with health and wellness".
"You can't just put a policy on the table and say 'this is going to create health and wellness'," she told the Chronicle.
"Just because a service is free doesn't mean you have the right people coming in and accessing the service earlier."
Heading to a GP might not be a "top priority" for teenagers, she said, and it was important to look at the policy from a "system-wide approach".
Mrs MacDonald said she would be keen to involve Wanganui youth in discussions about what was needed to get them into primary care.