Chronic back pain is common, disabling, and expensive. Essentially all people will have some back pain during their lives, but in a minority of individuals acute back pain will become chronic, with symptoms lasting longer than 3 months and severe enough that some daily activities are impaired. In several recent studies, the proportion of the adult population affected by chronic back pain seems to be rising, with medical and social costs rising as well.1,2 Given these circumstances, our society has an urgent need for effective, relatively inexpensive treatments to improve patient functional status and reduce pain. The field of chronic low back pain treatment is characterized by a large number of available treatments, but we have relatively poor information regarding how these treatments compare with each other.3 In such situations of uncertainty, treatment choice may vary, and use of ineffective treatments may proliferate. The United States is currently markedly increasing research activities comparing active treatments with each other, rather than no treatment or placebo. These studies, termed comparative effectiveness research (CER), are needed to address these situations of uncertainty and high practice variation.