The Absence Of Evidence Should Not Deter Healing

A good friend of mine speaks frequently about medical decision-making, and often quotes the astronomer Carl Sagan, who said, “the absence of evidence is not evidence of absence.” That quote has broader application to the work of caring for patients with illness, I think, and its applicability can be illustrated using myself as an example.

As time works its insidious magic upon my body, long-ago injuries and accumulated repetitive stresses have created stiffness and creakiness in my neck, shoulders, and knees. Fortunately, I have little pain at this point, but my joints often make noises that are disconcerting, to say the least. A few weeks ago, I decided to try chondroitin/glucosamine, a dietary supplement that some of my acquaintances have found helpful for similar problems. I have noticed some relief of my symptoms since beginning the supplement.

This success echoes the results that I obtained from the use of St. John’s Wort, a mood stabilizer that helped me with grief and depression stemming from my brother’s death a few years ago.  I have continued using St. John’s Wort ever since with apparent success.

Neither of these supplements has ever been definitively proven to work, although St. John’s Wort probably has better support for its use. Online resources describe chondroitin glucosamine as “unproven, and likely no better than placebo.” So, what’s up?

Scientific proof requires that a statistically significant difference be observed between a drug and the alternative, whether a placebo or another therapy, or that therapeutic equivalence be proven statistically. Statistical proof looks at the overall study population, and not at individual responses. There are always outliers, at each end of the bell-shaped curve. I may be an outlier who responds to these drugs, or perhaps not.

The lesson for caregivers is that illness and the response to therapy is unique for each person. Healing is subjective—despite the science, I feel better, and if that’s all in my mind, so what? The pills are not free, to be sure, but if I can afford them, and they are not causing harm, why shouldn’t I take them? Doctors need to set aside their biases when faced with alternative or unproven therapies that are not harmful and seem to be helpful. Folk remedies evolved because they worked, at least frequently enough to be remembered. Let’s not turn away from science, but neither should we submit to the tyranny of scientific proof in our quest to relieve suffering and help those with disease.