Fact, Truth & Treatment

No mystery, I remarked as my friend marveled at the difference between fact and truth. Fact is something people observe and can agree they observed. If there are things you don’t observe, they don’t count as fact, but they count as truth.

Medical testing is a good example. The accepted way to compare different treatments for a disease is a “randomized double-blind clinical trial.” Identify a lot of people who have the disease, randomly divide them into equal groups, give each group a different treatment, and measure how much each patient improves. To avoid subjective bias, neither the patient, nor the person who measures the results, knows which treatment each patient received. If one of the the treatments is measurably better than the others by a statistically significant difference, then that treatment is factually better than the others.

The truth - which this protocol ignores - is that for every treatment there are patients who improve dramatically and other patients who don’t improve at all. The truth is that the best treatment for each patient is not the same as the treatment that is best on average over a large number of patients. Different patients may need different treatments.

A skilled and knowledgeable physician knows this. Such a doctor will try the most likely treatment with a patient, and if that doesn’t seem to be working will try another treatment. But because the doctor’s judgment is subjective, and the patient’s clinical record is private, that search for truth can’t become fact.

That may be why there is so much interest in trying to identify genetic markers that can tell which treatments are best for which patient. A large randomized trial in which treatments are selected on the basis of genetic tests would be fact. But at present, genetic testing is more expensive than the good doctor’s trial and error (though it may be quicker and more reliable), and the technology is far into the future.