The death rate for COVID-19 intensive care patients has dropped by about one-third since the start of the pandemic, due at least in part to better hospital care, a review of published studies found.
The global analysis of 24 observational studies of COVID-19, the disease caused by the novel coronavirus, was published on Wednesday in the journal Anaesthesia.
The research, led by Professor Tim Cook of England's Royal United Hospitals Bath, found the overall mortality rate of COVID-19 patients in intensive care units (ICUs) has fallen from almost 60% since the end of March to 42% at the end of May. The rate was not significantly different across Europe, Asia and North America.
Study authors offered several explanations, including "rapid learning that has taken place on a global scale due to the prompt publication of clinical reports early in the pandemic." They also suggested that hospital ICUs might have been under greater pressure early in the pandemic.
Doctors have reported progress in learning enough about the highly contagious virus to have a better grasp of key problems for many patients, although much work remains to be done on the development of treatments and preventive vaccines.
The researchers said their findings could reflect the time for long ICU stays to show up in the data, noting that nearly a third of UK ICU admissions lasted more than 28 days and 9% lasted more than 42 days.
The authors emphasized that the recent COVID-19 ICU mortality rate of around 40% is still much higher than the 22% for other viral pneumonias.
"Optimistically, as the pandemic progresses, we may be coping better with COVID-19," they said.