The number of older Australians seeking help from the lasting effects of childhood sex abuse has risen, research shows.

There has been a spike in the number of older Australians seeking professional help because of childhood sex abuse, new research shows.

The research released by Adults Surviving Child Abuse (ASCA) on Monday to coincide with Blue Knot Day - a national day to raise awareness about the five million Australian adults who survived childhood abuse.

The research, based on an analysis of 5000 calls to ASCA's 1300 professional support line, reveals abuse survivors aged between 40-69 are still the most common age group to seek support for past abuse.

There has, however, been a 10 per cent increase in the 50-59-year-old age group looking for help compared to last year.

The data shows 19 per cent of callers in the 60-69-year-old age group, and six per cent in the 70-79 age bracket called the helpline for the first time.

The Royal Commission into Institutional Responses to Child Sexual Abuse interim report shows it takes on average 22 years for people to disclose abuse, but ASCA's latest data reveals it often takes longer.

Cathy Kezelman, president of ASCA, told AAP many of the older callers had never told anyone about their abuse and reported how it had affected their whole life.

"You just need to look at the impacts on people's lives... to begin to appreciate the lifetime burden of which many survivors speak," she said.

The data shows more than half (52 per cent) of the callers reported impacts on relationships with their immediate family, 37 per cent reported impacts on their partner, 17 per cent on their parenting abilities, and 23 per cent on extended family.

Seventy three per cent of callers reported multiple impacts.

ASCA says this could be an underestimate given the majority of callers make only one call to the line.

Dr Kezelman said the need for a national redress scheme was "urgent".

She urged the Turnbull government to show leadership, and to work with the states and territories to commit to a national redress scheme before it was too late.

The commission has made its final recommendations on redress and favours a national scheme, run by the federal government and paid for by the institutions where children were abused.

The commission modelled a scheme for 65,000 abuse survivors that would cost $4.3 billion.

It is understood attorneys-general will discuss the recommendations at the upcoming Council of Australian Governments meeting.

Dr Kezelman says the current data validated the findings from ASCA's Economic Report, released in early 2015, which conservatively estimated the cost of failing to provide the right pathways for recovery for Australian adult survivors of childhood trauma would be $9.8 billion annually.

"As a community we need to bring hope and very real possibilities for recovery," she said.

This year, ASCA's official Blue Knot Day opening event will be held at 6am on Monday at Sydney's Government House. It marks the start of a week of events across the country to support sex abuse survivors.