Reynaldo is reviewing a study on the effectiveness of a new drug-free remedy for depression. In the study, a group of participants was given a natural supplement for a period of six weeks. They rated their mood both before and after treatment. Two-thirds of the group reported a marked improvement after the trial. What change in this study would do the most to increase Reynaldo's confidence that sound scientific practices were followed?
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
HANDING OUT A PLACEBO
cross groups. ie give the placebo to one group and the supplement to another, then switch groups.
Or a double blind study would be good too: one in which the clinicians interacting with patients don't know which group gets the placebo.
Double blind clinical trials are the "gold standard" of statistical medicine.