Understanding of Blinding and its reporting in Randomized Controlled Trials Blinding in Randomized Controlled Trials

Abstract

To generate reliable evidence regarding public health care/ clinical practice, a well designed randomized controlled trial (RCT) is an ultimate answer for assessing efficacy of a newly proposed intervention/ drug and/ or to identify more efficacious intervention/ drug regarding any of the health problems. In such RCTs, to avoid known as well as unknown biases, role of random allocation (i.e., randomization) of considered patients in different intervention/ drug arms is already discussed in another continuing medical education (CME) published in the previous issue of this journal. In spite of avoiding allocation bias in every RCT, if feasible, one may also avoid intentional/ unintentional bias through blinding to further strengthen the credentials of observed findings. To be more specific, if feasible, study participants and/ or researchers/ observers/ outcome assessors and/ or data analysts in a RCT need not to be aware about specific intervention/ drug being received by study participants in various arms. Keeping in view of feasibility, one of the various types of blinding (e.g., single; double; triple) may be used.  Further, recently reviews of reported RCTs have very well documented about incomplete as well as inaccurate reporting of blinding in the articles.  The present write up therefore addresses  important issues related to possible blinding under RCT, its type & method, and its reporting in the reports/ articles.