Family of people with dementia are being urged to get their loved ones a locator device, as soon as they find out they have the disease.

Nearly one in four of our missing person searches involves people with cognitive impairments.

Alzheimer's New Zealand chief executive Catherine Hall told Kate Hawkesby that locator devices, like WanderSearch, can be very useful.

She says it has a long battery life and is linked to LandSAR and police.

"There are a lot of devices out in the market which are starting to carry this GPS technology."

Hall says those who find out they have Alzheimer's should start planning early by getting a locator device.