A new study has identified a blood test that could reduce the number of antibiotics patients receive in hospital.
Research at a Paris hospital looked at levels of the hormone procalcitonin, which shows doctors how the body is responding to antibiotics.
The number of days patients in intensive care were administered the drugs after having had the blood test fell by a quarter, or from two weeks to 11 days, according to a study published in The Lancet medical journal.
Scientists said cutting the amount of antibiotics that are prescribed unnecessarily is a good cost-saving mechanism and could also be of benefit by reducing the rate of people building up a resistance to the drugs.
During the study, 311 patients had the blood test and had their prescription adjusted, and slightly more, 319, were treated as normal.
There was also no difference in mortality rates or recurring infections, the study found.