The methodology flaws in Hinman's acupuncture clinical trial, Part II: Zelen design and effectiveness dilutions

In the October 2014 publication of JAMA, Dr. Hinman and colleagues published the study “Acupuncture for Chronic Knee Pain: A Randomized Clinical Trial,” which concluded that “in patients older than 50 years with moderate or severe chronic knee pain, neither laser nor needle acupuncture conferred benefit over sham for pain or function. Our findings do not support acupuncture for these patients”. As pointed out in my former article, Part I, there were serious flaws in the trial design and statistics, as well as in the interpretation of the results. This article attempts to address problems in the Zelen design used by Hinman et al. There are some advantages to using a Zelen design for a randomized controlled trial (RCT). First, a Zelen design has a post-randomization consent design, which means that consent is only sought for one treatment each time, without the uncertainty of randomization. Researchers can be more comfortable knowing that they have the participants’ consent each time they undergo a treatment. Patients can also be more comfortable with this design because they know which type of treatment they are receiving; unlike traditional RCTs, patients are not ignorant of whether they are receiving the placebo or experimental treatment. Effects such as resentful demoralization and what is known as the “Hawthorne effect” (altered behavior or performance resulting from awareness of being a part of an experimental study) become less of an issue as patients are not weary of being part of a new alternative group, only the “standard” therapy will applies to them. However, it does have some disadvantages, and therefore can cause biases, which will be discussed in detail below.