Patient mortality rates are significantly affected by the number of registered nurses on a ward, a major US study has shown.
The research, published in the New England Journal of Medicine, adds to a growing body of evidence that qualified nurse staffing levels affect patient safety.
The results also chime with data analysis by Nursing Times two years ago, which showed the more nurses that a trust employs per bed the fewer of its patients are likely to die or experience long hospital stays (news, page 1, 31 March 2009)
The US researchers compared nursing shift data with the records of 198,000 patients in 43 wards at a large hospital. This included looking at the number of nurses on each eight hour shift.