January 29, 2018

Philosophiae naturalis

Studying Studies: Part IV – randomization and confounding

Randomization helps us in our quest to not fool ourselves. Confounding? Not so much.

by Peter Attia

Read Time 10 minutes

Randomization: the major strength (and limitation) of studies
We left off in Part III discussing the motivation for observational studies and the types of studies employed in observational epidemiology (i.e., retrospective and prospective cohort studies), and some of the major limitations of those types of studies. As we mentioned, observational studies are prone to bias and confounding. A confounder can create a spurious association between an exposure and outcome being observed in an observational study. We introduced this “confounding bias” in Part III of Studying Studies.

Randomization, a method based on chance alone by which study participants are assigned to a treatment group, is a key component in distinguishing cause and effect, and eliminating confounding. By randomly assigning subjects to an intervention or control group, investigators can measure the effect of the intervention without the subjects self-selecting their lot in the experiment, as happens in observational st...

It looks like you’ve tried to access a page only available to Nerd Safari members.

Not a member yet? Sign up for free.

Get Started

Already a member? Login here.

Disclaimer: This blog is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this blog or materials linked from this blog is at the user's own risk. The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard, or delay in obtaining, medical advice for any medical condition they may have, and should seek the assistance of their health care professionals for any such conditions.


Read Our Comment Policy

Send this to friend

Facebook icon Twitter icon Instagram icon Pinterest icon Google+ icon YouTube icon LinkedIn icon Contact icon