Bias control in trials of bodywork: a review of methodological issues.
OBJECTIVE
To review and summarize the methodological challenges in clinical trials of bodywork or handson mind-body therapies such as Feldenkrais Method, Alexander Technique, Trager Work, Eutony, Body Awareness Therapy, Breath Therapy, and Rolfing, and to discuss ways these challenges can be addressed.


METHODS
Review and commentary.


METHODS
Search of databases PubMed and EMBASE and screening of bibliographies. Published clinical studies were included if they used individual hands-on approaches and a focus on body awareness, and were not based on technical devices.


RESULTS
Of the 53 studies identified, 20 fulfilled inclusion criteria. No studies blinded subject to the treatment being given, but 5 used an alternative treatment and blinded participants to differential investigator expectations of efficacy. No study used a credible placebo intervention. No studies reported measures of patient expectations. Patient expectations have been measured in studies of other modalities but not of hands-on mind-body therapies. Options are presented for minimizing investigator and therapist bias and bias from differential patient expectations, and for maintaining some control for nonspecific treatment effects. Practical issues with recruitment and attrition resulting from volunteer bias are addressed.


CONCLUSIONS
Rigorous clinical trials of hands-on complementary and alternative therapy interventions are scarce, needed, and feasible. Difficulties with blinding, placebo, and recruitment can be systematically addressed by various methods that minimize the respective biases. The methods suggested here may enhance the rigor of further explanatory trials.
Mehling
Wolf E
WE
Osher Center for Integrative Medicine, University of California San Francisco, San Francisco, CA, USA. mehling@itsa.ucsf.edu
DiBlasi
Zelda
Z
Hecht
Frederick
F
D015982:Bias; D019317:Evidence-Based Medicine / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D026441:Mind-Body Therapies / Q000379:methods / Q000592:standards; D011597:Psychomotor Performance; D012107:Research Design / Q000592:standards*; D012648:Self Care / Q000379:methods