The latest Ministry of Health's Annual Data Explorer found about one in seven adults - or 15 per cent - reported not visiting a GP due to cost, and this figure had not changed significantly since 2011.
"It's not only the fees that can be a barrier, but also transport costs to get there. Even with free doctors' visits for children under 13, if there's no car, no petrol and no bus money, it's near impossible for some whānau," Bell said.
He said children from the most disadvantaged communities were twice as likely to end up in hospital for medical conditions - and three times more likely to be hospitalised for respiratory conditions compared to those from the most advantaged communities.
The Salvation Army relies heavily on public donations to provide essential services to 120,000 people each year. The organisation is pleading for those more fortunate to dig deep and donate to its Winter Appeal launching today.
"We provide emergency help and services for long-term transformational change to disadvantaged communities, but we can't do it alone – we need public support," Bell said.
"Our work will not let up in the coming months as people continue to struggle with keeping the house warm and food on the table.
"We humbly ask people to give generously to our Winter Appeal so we can continue to fight poverty in New Zealand.
The Salvation Army Winter Appeal runs from today until the end of the month and people can donate by visiting www.salvationarmy.org.nz/winter