Epidemiological studies are often used inappropriately for common illnesses like cardiovascular disease and cancer, according to British cardiologist Guy Lloyd.
Randomized controlled trials are more reliable. Epidemiology is most effective in identifying large risks in rare diseases. Just in the field of cardiology, the results of observational studies are often seriously flawed.
Observational studies of the cardioprotective effects of female sex hormones, the usefulness of antioxidants or homocysteine lowering strategies, and rhythm control for atrial fibrillation suggested a clear treatment effect and greatly influenced practice. But subsequent randomised trials refuted each hypothesis.
The main problem, he explained, is all of the interacting factors among cohorts that can't be statistically accounted for in an epidemiological study.
Concerns with the reporting of medical studies are multiplying. A recent blog on Junkfoodscience highlights the efforts of a new project, STROBE (Strengthening the Reporting of Observational Studies in Epidemiology). We wish them all success.
