The findings are based on 12,461 patients, 706 of whom were over 80 years of age at the time of surgery. All of them were operated on between 1996 and 2003 in one specialist unit in England.
The proportion of surgical patients who were in their 80s more than doubled over the study period, from just over 4% to nearly 10%.
But they were more likely to undergo emergency surgery than younger patients. This suggests a tendency to treat them conservatively until the crisis arose rather than offering them surgery earlier, suggest the authors.
The degree of urgency and the length of the procedure predicted whether a patient was likely to live or die, over and above the traditional protocols used to assess the likely risk of death.
The risk of dying was higher in the elderly group, and they spent longer in intensive care than their younger counterparts. But their chances of survival were 50% better after the first year of surgery than those of their peers in the general population