In a study that examined the use of acupuncture to treat migraine headaches, consenting patients on a waiting list for treatment for migraine were randomly assigned in a 2:1:1 ratio to acupuncture...

In a study that examined the use of acupuncture to treat migraine headaches, consenting patients on a waiting list for treatment for migraine were randomly assigned in a 2:1:1 ratio to acupuncture treatment, a “sham” acupuncture treatment in which needles were inserted at non-acupuncture points, and waiting-list patients whose only treatment was self-administered (Linde et al., 2005). (The “sham” acupuncture treatment was described to trial participants as an acupuncture treatment that did not follow the principles of Chinese medicine.) Analyze the following two tables. What, in each case, are the conclusions that should be drawn from the analyses? Comment on implications for patient treatment and for further research:

(a) Outcome is classified according to numbers of patients who experienced a greater than 50% reduction in headaches over a four-week period, relative to a pre-randomization baseline:

(b) Patients who received the acupuncture and sham acupuncture treatments were asked to guess their treatment. Results were: