Overdiagnosis: when good intentions meet vested interests—an essay by Iona Heath

Underpinned by webs of financial imperatives and conflicted interests, overdiagnosis and overtreatment have become disturbingly pervasive within contemporary medicine and are now deeply embedded within healthcare systems around the world. They have permeated and polluted the drug and medical technology industries, medical research and regulatory bodies, clinical practice, payment systems, guideline production, and national healthcare systems. They are the cause of an astonishing amount of waste and harm.

The main engine is the medical technology industry, which enables healthcare professionals to investigate more and more minutely and to measure and assign numbers to an ever increasing number of biometric parameters. These numbers are almost always normally distributed along a continuum, with one extreme representing a degree of abnormality that begins to correlate with symptoms and suffering that can be ameliorated or cured by medical treatment. So far, so good. The problem is that a toxic combination of vested interest and good intentions produces continual pressure to extend the range of abnormal, shifting the demarcation point further into the territory previously considered normal. This is encouraged by entrenched belief in such old adages as “prevention is better than cure” and “a stitch in time saves nine.” These ancient sayings are imbibed at such a young age that they seem to assume an almost mythological aura of truth, and we have neglected the popperian imperative of investigating why they might be wrong.1