Surrogates under scrutiny: fallible correlations, fatal consequences

We live in a time when much disease is measured not by symptoms but by numbers, determined by biomarkers in our blood or bone. Transforming a healthy person’s risk of disease into a chronic condition has been a key characteristic of modern medicine, creating vast new markets for “preventive” pills designed to reduce suffering and extend life. The annual global spend on cholesterol lowering drugs alone has exceeded £10bn (€11bn; $16bn), while more generally widening definitions and lowering thresholds continue to expand the patient pool.Well funded campaigns urge the public to know their numbers, and professionals are rewarded for treating to target. Yet the grand assumption underpinning this approach—that helping a person’s numbers will automatically improve their health—is a delusion as dangerous as it is seductive