Once you or a loved one has received a terminal diagnosis it’s natural to ask about the future. Yet doctors can and do get prognoses wrong. Why?
If we are, or someone we care for is, critically ill, we’ll expect the doctor to tell us how our future looks. That’s understandable on our part; after all, the very measure of a doctor lies in their predictive abilities, their grasp of the crystal ball. Yet it’s not easy to know just when someone who is sick is going to die.
For example: in a study, the results of which were published in the British Medical Journal, doctors habitually overestimated survival.
What makes accurate prognostication so tricky?
* The diagnosis may or may not be correct
* We’re all unique. So how one person responds to an illness will be different from how your friend or relatives does.
* Every disorder is different and every disorder within a disorder is different.
* If the doctor gets it wrong, in the USA, at least, there is the fear of litigation
Consultant neurologist at the Royal Free hospital in London, Jules Montague, relates an episode in his very first week as an intern. The 85-year-old patient ‘lay gasping, racked by sepsis, her legs swollen from heart failure, her consciousness clouded.’ When her family asked him how long she had, he responded, ‘We’ll be lucky if she’s here in the morning.’
He continues: ‘We were indeed lucky the next morning. We were also lucky for the next week and the month after that, at which point [she] went home, happy and healthy.’
His conclusion? It takes experience to know that sometimes you don’t know. *  The Guardian (3:06:15)
Then there’s the story of the rock world’s cult figure Wilko Johnson. Diagnosed with terminal pancreatic cancer, he gave a farewell tour – which ‘passed off in a blur of emotionally charged gigs, tearful fans literally waving goodbye as he played Chuck Berry’s Bye Bye Johnny.’
‘One of the ways I dealt with [the prognosis of 10 months to live] was to absolutely accept it, and think, “Right, I just want to do it. I don’t want to spend 10 months running around after second opinions or false hopes.” In a way it was kind of a comfort zone, accepting that I was going to die and all the questions of mortality had been sorted out for me.’
The prognosis initiated ‘a kind of intensity of just being that I’ve never felt since youth. Sometimes the insights and ecstasies were so intense, I’d think, “Man, this is almost worth it! Not quite, but almost”.’
He recorded a new album and was part of a film, supposedly the documentation of his final months. Then, through a fan, who happened to be a doctor, he was seen by an oncologist who thought the cancer was operable, albeit with a 15% chance of his surviving surgery. He survived and last October he was told he was cancer-free – just 18 months after he’d been told he was going to die imminently. 
He’s bemused that he’s still alive, ‘I’ve found myself back in the land of the living, and it’s kind of difficult to adjust my consciousness back from the idea that death is a terrible thing in the imminent future.’
How helpful is your attitude?
We’re written elsewhere about whether ‘positive thinking’ can affect your chances of recovery. [See Positive Thinking or Realism and The Biology of Belief] An upbeat attitude ‘convincingly helps quality of life and resilience in chronic illness,’ Montague says, ‘but the effect of positive attitude on fortitude has sadly been extrapolated to survival.’
One study, among many, of over 1,000 patients with cancer showed no impact of emotional wellbeing on survival. James Coyne, who authored the study, later commented: ‘We urge positive psychologists to rededicate themselves to a positive psychology based on scientific evidence rather than wishful thinking.’
When ‘not-knowing’ is the only real option
When the prognosis is mistakenly premature – such as in the anecdotes of the 85-year old woman and of Wilko Johnson – patients might not receive ongoing treatment that could prolong their survival. They might also just go ahead and die within the predicted time, even if on post-mortem all evidence of the original illness has gone – the nocebo effect.
On the other hand when, when their imminent end hasn’t been recognised, patients are denied palliative care and the chance to take practical measures such as creating an Advance Decision and preparing psychologically and spiritually.
One woman who was told she only had months to live and who is still alive 20 years later says – in response to that misprognosis – ‘I feel no bitterness. Doctors give us time frames so that we can put our affairs in order. That doctor was just trying to be kind.’ 
In conclusion, Montague repeats, ‘we know that we don’t know.’
1) The Guardian 03:06:15
2) The Guardian 11:07:15