Using mortality to measure quality of care is dead in the water
It is of course important that mortality figures for hospitals are carefully measured in a robust, transparent and meaningful manner.
But to use them as a primary means of measuring healthcare quality is absolutely ridiculous. At risk of stating the obvious here, death is final and (in hospital) it often happens right at the end of a complicated process, with many steps. To use mortailty rates as a primary marker for performance is wrong for at least three reasons:
a. It is too late. Telling us that hospital A has had an excess mortality for three years is like an air-traffic control system that tells us three jumbo jets crashed three years ago – important but I’d sort of like to know before the accident so I could do something about it, and at the very least inform the public not to go anywhere near that airline. We need systems that warn us before mortality goes up, i.e. when an organisation is beginning to fail.
b. It is an insensitive measure. Healthcare can be very, very bad even without causing increased deaths, or indeed the number of excess deaths can be hard to spot and missed as “within statistical variation”. What this means is that some organisations whose mortality rate is “normal” will be poorly performing organisations, causing unnecessary harm to their patients. This gives false reassurance to patients, staff and management alike.
c. It is unhelpful as a quality measure for most of the care delivered. The vast majority of healthcare (on which huge sums of money are spent and which affects millions of citizens) cannot be assessed using mortality figures. For example, huge amounts of preventive and public health policies do not aim to reduce short-term mortality but rather to increase long-term health and wellness. Most primary care, nearly all paediatrics (with the exception of cancer care) and treatments for psychiatry and mental illness are just a few examples where using mortality to measure care quality is close to worthless.
Of course mortality data has a role, but its importance should not be exagerrated nor allowed to distract us from the far more important, urgent and valuable task of measuring and disseminating those meaningful outcomes that can have the greatest impact on the greatest number of people. Such outcomes data are not exciting, they do not grab the headlines as do stories about “hospital caused deaths”, but done properly sharing measurements that are meangingful to patients and doctors will drive quality up and costs down.