This systematic review by Ma et al was published in the Cochrane Library in December 2016. The text below is the plain language summary with the full text available via this link.
Review question To find out whether using the hormone progesterone to treat people who have had an injury to the head that caused brain damage (traumatic brain injury (TBI)) is helpful and safe, if given within 24 hours of the injury.
Background TBI is one of the main causes of death and disability in people with injuries. Damage to the brain can start at the time of the injury, but can continue for days after the injury too. Progesterone is a hormone that some doctors think could be used as a potential medicine for reducing brain damage if given shortly after TBI. However, as there is uncertainty about the effectiveness of this hormone, it is important that we assess the evidence.
Study characteristics We searched the medical literature widely for randomised controlled trials that investigated the effects of progesterone in people with TBI up to 30 September 2016. Randomised controlled trials provide the most robust medical evidence. .
Key results: We included five studies with a total of 2392 participants, and identified three ongoing studies. The studies all compared a group of participants who received progesterone within 24 hours of TBI against a group who received a pretend – or dummy – medicine (known as a placebo) that looked the same as the progesterone. The results of our review did not find evidence that, when compared to placebo, progesterone could reduce death and disability in people with TBI. There were too few data available on the other outcomes that we were interested in (pressure inside the skull (intracranial pressure), blood pressure, body temperature and adverse events (harms)), for us to be able to analyse these in detail. However, although the information available shows no evidence of a difference in effect between the progesterone and control groups for intracranial pressure, blood pressure or body temperature, one study showed an increased level of an adverse event called phlebitis (inflammation in the vein) in the progesterone group, possibly because the progestreone was given into the vein through an intravascular infusion (‘drip’).
Quality of the evidence We judged the quality of the evidence to be low for the data on risk of death, and moderate for the data on risk of disability. These judgements resulted from differences across studies, including different doses of progesterone and different time points for assessment of participants in the included studies. This means that we have limited confidence in the conclusions of this review.