Fewer people die following heart surgery when league tables are published, a study has concluded.
The research looked at deaths following heart surgery
Researchers in Manchester looked at 26,000 patients who underwent heart bypass operations between 1997 and 2005, Heart journal reports.
Public disclosure of death rates began in 2001, after the report on the deaths of child heart patients in Bristol.
Heart experts said information was useful, but warned it had to be presented accurately.
The inquiry which considered the implications of the deaths of up to 35 children who underwent heart surgery at the Bristol Royal Infirmary between 1991 and 1995, found they died unnecessarily as a result of "less than adequate care".
The study, by a team at South Manchester University Hospital, looked at four hospitals in north-west England and compared death rates before and after the Bristol report's recommendations were published.
They looked for changes in expected and predicted death rates, and for any evidence that surgeons were taking on less complicated or risky cases to "enhance" their figures, as opponents of public disclosure had suggested.
The death rate for coronary artery bypass graft (CABG) patients after public disclosure was significantly lower than it had been before, falling from 2.4% to 1.8%.
However, the predicted death rate steadily rose from 3% to 3.5%, suggesting that more complicated cases or elderly patients were being taken on.
The proportions of elderly patients aged over 80, and those with kidney disease, a recent heart attack, or peripheral vascular disease all significantly increased.
Caution over raw data
The researchers, led by Mr Ben Bridgewater, said: "If publication of surgical mortality data had driven surgeons to turn down significant numbers of high risk patients we would expect to see that reflected in the number of high risk cases coming to surgery.
"This study suggests that the effect may not be as large as is feared.
"If public disclosure can drive data collection and analysis, but does not create significant risk averse behaviour, its introduction may be beneficial in other areas of medicine."
Ellen Mason, cardiac nurse at the British Heart Foundation (BHF) said: "It is great news that cardiac surgery outcomes have continued to improve over the last few years.
"Whilst working under more public scrutiny than ever before, surgeons and their highly skilled teams have reduced mortality rates in bypass surgery.
"League tables can help to provide health professionals and patients alike with useful information, but still require careful consideration.
"Raw data and information that is included but not adjusted properly can unnecessarily alarm patients and affect confidence in their doctors."
A spokeswoman for the Healthcare Commission said that, at present, every heart unit in England and Wales, except for St Mary's in Paddington, London, provides details on survival rates.
St Mary's had made a commitment to join the website in future, she said.
And 27 out of 39 units also provided details on success rates for individual surgeons, and this is expected to rise to 29 out of 39 by June, she added.