The aged care algorithm deciding support for older Australians

The last time 96-year-old Audrey Staniland was assessed for in-home aged care funding was with a human clinician more than a decade ago.

When her daughter applied for a reassessment late last year — hoping Audrey would receive a higher level of care — she knew a clinician would assess her, but would not make the final decision.

Instead, a "classification algorithm" would be deciding the outcome — with the clinician unable to change it.

The algorithm was introduced in November and has been mired in controversy ever since.

The government has resisted calls from the opposition and crossbenchers to hand over documents about its design.

Australia's pre-eminent expert on health care algorithms, Kathy Eagar, has unpacked the algorithm's opaque workings and is adamant about what should happen next.

"It can only be fixed by ditching the whole algorithm and starting again, if you think that it's better to have an algorithm [rather] than an expert clinical assessor determine what a person needs," she said.

Using Professor Eagar's expert analysis, evidence revealed by bureaucrats at Senate estimates, and documents obtained under FOI, a Four Corners investigation can reveal the fullest picture yet of the secretive algorithm affecting the lives of tens of thousands of older Australians and their families.

It was January 20 when a clinical assessor came to Audrey's Perth home of 43 years.

She brought a laptop containing an electronic questionnaire known as the Integrated Assessment Tool.

"I was very worried about a computer making a decision on a human being [rather than] the person in the room [who] could see mum's condition," Audrey's daughter Jan Helgeland said.

Jan had arranged for Audrey to have a reassessment because her provider had increased its hourly rate for services like personal care and social support from $90 to $115, meaning Audrey had to cut back on care.

Jan was hoping her mother would be approved for a new, higher level of funding to restore the hours of care she had lost.

"I think what she's missing out on most of all is having someone in the house here with her," Jan said.