If a person dies by assisted suicide or euthanasia after being told in error that they have less than six months to live when they may have many years of life ahead of them then that is a wrongful death – with no remedy.
A survey of the medical literature on prognosis indicates that an accurate prognosis is notoriously difficult to make.
A study on the accuracy of prognoses in oncology found that “discrimination between patients who would survive for one year and those who would not was very poor”.
Another paper describes doctors’ ability at predicting survival at 1 year as “only slightly better than a random guess”.
Australia’s National Consensus Statement: essential elements for safe and high-quality end-of-life carewisely observes: (on page 17)
Predicting prognosis and the timing of dying can be difficult. For some patients, it may be difficult to distinguish clinical deterioration that is reversible from deterioration that is irreversible and part of the normal dying process. In such cases, it may be appropriate to consider a trial of treatment for a defined period to assess reversibility of a patient’s deterioration.
One recent study of prognostic accuracy for brain cancer found that “All physicians had individual patient survival predictions that were incorrect by as much as 12-18 months, and 14 of 18 physicians had individual predictions that were in error by more than 18 months. Of the 2700 predictions, 1226 (45%) were off by more than 6 months and 488 (18%) were off by more than 12 months.” Of particular relevance to the use of a prognosis of expected death to grant access to assisted suicide is the finding that “In this study all physicians were unable to accurately predict longer term survivors. Despite valuable clinical data and predictive scoring techniques, brain and systemic management often led to patient survivals well beyond estimated survivals.”
A study published in 2000 in the British Medical Journal found that physicians only made accurate (within 33% margin either way) prognoses in 20% of cases for terminally ill patients.
Significantly for the use of a prognosis in allowing access to assisted suicide or euthanasia is the finding that in 17% of cases physicians were overly pessimistic in their prognosis by more than 33% and out by a factor of 2 in 11.3% of cases.
In other words, perhaps more than one in ten people given a prognosis of 12 months to live may live for 2 years or more.