Sydney researchers have developed a test that can determine if terminally ill and elderly patients will die within 30 days of being admitted to a hospital.

The Criteria for Screening and Triaging to Appropriate alternative care or CriSTAL test, developed by the University of New South Wales researcher Magnolia Cardona-Morrel, studies 29 indicators of health, including age, frailty, illness, mental impairment, past emergency admissions and heart rate, and thereafter determines a percentage estimate of the chance of death within one month.

According to researchers, CriSTAL is designed to reduce unnecessary invasive ineffective treatments and allow the elderly to spend their last few days with their loved ones.

Dr. Cardona-Morrel said the test will allow doctors to have a "transparent conversation" with terminally ill patients and seek their preference on whether or not they would like to receive life-saving treatments.

"The test is easy to administer and the [answers] are readily available in the patient's clinical records and it can be completed in five or 10 minutes," said Dr. Cardona-Morrel, reported The Sydney Morning Herald.

"Doctors are keeping people alive because they can. Hospitals are full of elderly people living longer because technology allows it. A lot of them would like to die at home.

"When a patient is diagnosed with a terminal illness their first question is always 'Doctor, how long do I have left?' Doctors see their role as to protect their patients so they don't like to give them sad or bad news."

The test, which was first presented at a medical conference in the US, is being hailed by medical professionals across the world.

"I had lots of nurses and doctors standing there saying 'We have been waiting for a tool like this for years, when can we start using it?' To me that is an indication there is a need out there," said Dr. Cardona-Morrel.

The test is already being implemented across various Irish and US hospitals, said Dr. Cardona-Morrel.