Patients undergoing emergency surgery are more likely to survive if treated in hospitals with more doctors, consultants and nurses.
Research over five years involving almost 300,000 cases of emergency surgery at 156 British locations has found hospitals with the highest staffing levels had the lowest death rates.
This was despite the fact their patients were often sicker before surgery and more likely to suffer complications.
Researcher say the "ground-breaking" study suggests the way complications are identified and managed is key in determining whether patients live.
The research also found patients admitted on weekends have lower chances of survival than those admitted during the week.
Previous British research also indicated a lack of consultants on wards contributes to higher death rates.
The new study, published in the British Journal of Anaesthesia, looked at patients admitted to hospitals in England for emergency surgery for bowel problems, peptic ulcers, removal of the appendix, hernia repair and pancreatitis.
Their chance of dying within 30 days of admission was analysed.
Those facilities with lower than expected death rates had more nurses, consultant surgeons and surgical junior doctors per bed than those with the higher death rates. They also had more critical care beds and operating theatres.
Compared to those with the higher death rates, facilities that performed the best had 44 per cent more doctors of any grade or speciality, 40 per cent more surgical doctors, 40 per cent more consultant surgeons, 38 per cent more junior surgical doctors per patient admitted and 24 per cent more nurses.
They also had 65 per cent more critical care beds and 32 per cent more operating theatres.
Overall, in those facilities with least nurses and doctors per bed, patients were 7 per cent more likely to die.
Patients were also 11 per cent more likely to die if admitted on a weekend.
