In Reply Walach et al suggest that randomized clinical trials (RCTs) should not be used to evaluate meditation programs. While we agree that cohort studies provide valuable information, we disagree with the rationale that conscious choice and active engagement are eliminated in RCTs. Individuals make a conscious choice to join meditation trials, and since meditation requires engagement by the participant, it cannot become a passive activity merely by the act of randomization any more than exercise could. Both cohort studies and RCTs have inherent strengths and weaknesses in terms of generalizability and the extent to which “causal” conclusions can be drawn. Cohort studies are useful early in establishing short- and long-term outcomes of a risk or risk reduction factor. Randomized clinical trials then provide evidence as to the “causal” role of this factor through manipulating, ideally, only the factor of interest. The Institute of Medicine report cited by Dr Loucks makes a point of this value of RCTs.1 Following high-quality RCTs, cohort studies can further establish the circumstances that optimize and promote engagement over long periods.
Goyal M, Bass EB, Haythornthwaite JA. Meditation Intervention Reviews—Reply. JAMA Intern Med. 2014;174(7):1195. doi:10.1001/jamainternmed.2014.1393