A Randomized Trial of Tai Chi for Fibromyalgia.

To the Editor: Although the study by Wang and colleagues (Aug. 19 issue)(1) showed a benefit of tai chi in improving the outcome of patients with fibromyalgia, it should be noted that there were many possible differences between the tai chi treatment and the control intervention, including the duration of in-class exercise (unspecified in the tai chi group vs. 20 minutes in the control group), the duration of instruction in each class (unspecified vs. 40 minutes), instructional content (tai chi for beginners vs. topics relating to fibromyalgia), instructors (a single tai chi master vs. a variety of health professionals), and . . .