Aren’t you glad you’re not a surgeon? While GPs and physicians can sometimes get away with mixing up the blue tablet and the purple tablet, surgeons have their work scrutinised and published in league tables. The latest effort, printed in The Guardian listed some hospitals with nearly four times the expected mortality rate than others for abdominal aortic aneurysm (AAA) repair.1 Despite this, Bruce Keogh, a cardiac surgeon and now Medical Director at the Department of Health, assured us that no hospital was ‘unsafe.’
I suppose it all depends on your definition of safety. At the moment, it is left to patients to decide what to make of these league tables. Do they want to go to their local hospital with easy car parking, cheap coffee, and a mortality rate for their particular operation of 16%? Or would they be prepared to travel a hundred miles to a strange hospital with no parking spaces but a mortality rate of 8%?
Personally, I think the Department of Health and Royal College of Surgeons are ducking the issue. Someone has to bite the bullet and come up with a statistical definition of dangerous surgery that will trigger an investigation to find out why it has been exceeded. No one wants to do this because of the fear of litigation and the embarrassment of catching some great and good surgeon in the safety net.
This problem has been simmering since the General Medical Council found two Bristol heart surgeons guilty of failing to act on their poor results back in 1998,2 without defining poor. When should a surgical team stop operating and start investigating? When the death rates are double the average elsewhere in the NHS? Three times? Four times? Without a definition, no-one is sure when to stop and when to struggle on, hoping things might get better.
Now a team at St George’s hospital, London have finally grasped the nettle. They analysed elective AAA repair in England between 2001 and 2005.3 Hospitals with a statistically significant mortality rate more than twice the average in the rest of the English NHS were identified as dangerous. The average mortality rate was 7.4%. Three English hospitals had mortality rates above 14.8% and thirty had rates consistently greater than 7.4%. Units needed to be performing at least 32 operations a year to produce statistically meaningful results, and the units performing the most operations generally obtained better results. A similar (unpublished) analysis up to March 31st 2007, has again identified three dangerous units.
This survey method could be extended into other areas of medicine where there is a good measurement of an adverse event, and such methods will doubtless be applied to general practice in the future (e.g. double the rate of missed cancer diagnoses, double the rate of substandard medication for those who have had heart attacks). In the meantime, the new Care Quality Commission needs to find out where the three dangerous aneurysm units are and pay them a visit in a sensible, grown up sort of way. If patients need to be protected from unsafe surgery, it should happen sooner rather than later.
One lesson from Bristol is that if you collect outcomes, but don’t act on the results, you’re courting disaster. In the meantime, any patients wanting safe surgery should ask: ‘Do you do enough of these procedures to produce statistically meaningful results?’ and if so, ‘Is your death rate more than double the average elsewhere in the NHS?’ Then they have a choice… .