Doctors face a dilemma. Many patients insist that they need to know their chances, and how long they have, putting the doctors on the spot to make estimates. The doctors may know statistics that give the average time that previous patients have lived or been disease-free in similar circumstances, but if they report this to a patient without sufficient caveats, a number of problems can result:
- At the frightening and emotional time of diagnosis, patients don't always understand what the doctor says.
- Patients may take a statistic as a prognosis for them personally, not as an average life expectancy for a group of people that may or may not match them well.
- For rare diseases, the statistics we have are based on small sample populations, making the results less accurate for making predictions.
- It may not be clear which group to put a patient in. An initial diagnosis of MDS will probably have a prognosis based on the subtype, since MDS is a set of diseases. You get different survival statistics for each group, and if the diagnosis changes to AML then the statistics change once again.
- Statistics are based on previous patients and can become out of date as treatment improves, diagnoses are made earlier or more accurately or with new classification schemes, and as survival rates increase. The improvements are good, but can make the prognosis pessimistic.
- When you hear from patients who "beat the odds", you can get the impression that their doctors gave them a bad estimate. But those who beat the odds are the ones who survived to tell people about it. Just because they lived longer than average doesn't mean the average is wrong.
- Many people don't understand just what a statistic means. For example, the figure they hear may be the length of time for which 50% of patients have disease-free survival. It doesn't mean that most patients will live for that length of time. It means that half the patients do better than that and half worse than that. It also doesn't tell you if the patients who reach that milestone will live 1 year more or decades more.
No doctor should claim to know just how long a patient will survive. But doctors who refuse to make predictions will displease many of their patients, since new patients are usually starved for information and trying hard to understand what the diagnosis means and just how serious it is.
I think that a good doctor should be willing to say "we don't know" when that is the case but also be willing to offer some guidance about what the diagnosis means for the future and to offer an explanation of what the statistics tell us, not just the raw numbers. I also think that a good patient has to be willing to listen and to accept that nobody knows their future for certain.
Hooray for your dad, Kim, for being "above average" in multiple ways.