More than one-quarter of residents affected by bushfires in NSW at the start of the year were not fully insured, new research shows.

The Bushfire Co-operative Research Centre study draws on interviews with people near Coonabarabran, Yass and Shoalhaven.

The fires in January were the worst in the region for more than a decade, with 1.4 million hectares burned, 62 homes destroyed and 50,000 head of livestock lost.

About 73% of residents considered themselves fully insured, with the remainder either underinsured or uninsured.

Fully insured residents were the least likely (23%) to stay and defend their properties, with 45% of underinsured and 38% of uninsured saying they would do so.

Most respondents (52%) felt their properties and familie