Almost one-fifth of older Australians who contested their Support at Home funding allocation determined by an algorithm had a higher level of support or higher priority allocated once a human reviewed the decision.

The department of health and ageing would not provide the most current data on how many people have contested their funding allocation under the integrated assessment tool (IAT), introduced in November, which is used across aged care to determine eligibility and classification for services, including Support at Home.

It provided data up to 31 March only, which shows there were 757 requests for a review of a Support at Home funding allocation. Of those, 141 led to a change in outcome more favourable for the older person, resulting in eligibility for more services, a different classification or higher classification level, or a higher priority category.

A further 177 cases had no change, 304 were closed, and 135 are still in progress.

The IAT involves an assessor asking an older person questions about their physical, social and personal circumstances to determine how much government-funded home support they are eligible to receive.

An algorithm then uses this data to allocate a level of support. The algorithmic decision is unable to be overridden by the assessor if they believe the older person has been allocated a lower level of support than is needed. It is a system that has left many people without adequate care, potentially forcing them into aged care homes sooner.

It prompted the commonwealth ombudsman to launch an investigation in April into the tool, which has been described by assessors and older people as “cruel” and “inhumane”. That investigation is ongoing.

The Greens senator Penny Allman-Payne is one of several politicians who has been calling for the government to reinstate human oversight to the tool. She said the department’s data does not show the complete picture of how many people are being left without adequate support, since many people do not know how to contest a decision.

“We know the integrated assessment tool is under-assessing older people far in excess of what the applications for reassessments would suggest,” she said.

“Many would not be applying for reassessment, and many reassessments are unsuccessful due to the fact that the tool did not make a mistake, it was working as designed when it denied them adequate care. The way the tool is set up makes it systematically incapable of accurately determining need for those with cognitive issues, mental health conditions, and frailty.”

‘Complex and stressful’

Mark Aitken is nurse who has worked in aged care, and in February he blew the whistle on the lack of human oversight in home support decisions.

He has since established Mascotte Aged Care Solutions, which provides independent guidance and advocacy for older adults and their families navigating the aged care system.

Aitken said he has been supporting people to challenge their Support at Home funding allocations but said “many older people don’t have the luxury of time”.

“Why is the system, that states in the Aged Care Act that it is supposed to be person-centred, putting older people through these complex and stressful appeal processes?” he said.

Aitken said the government needs to explain how decisions are reviewed and what criteria is used, and what the data on the number of closed cases means.

“How many people waiting for a decision were admitted to hospital or respite or permanent care while waiting for a decision and hoping to get a higher level support at home package to remain living at home?” he said.

The shadow health and aged care minister, Anne Ruston, told Guardian Australia that the number of review requests had “exploded” since the government “put their faceless algorithm in charge of deciding who gets care, and who gets left behind”.

“Requests for reviews have grown six-fold, even as older Australians and their families report the process has resulted in them fighting with a computer in a system that’s become impossible to navigate,” she said.

“Too many older Australians are dying while waiting for assessments, for their packages to be approved, or for their assessments to be reviewed.

“The Senate has passed a bill to fix the mess of the integrated assessment tool, but Labor is refusing to debate it in the House of Representatives. Australians are right to feel let down.”

Do you know more? melissa.davey@theguardian.com