The following mechanisms are in place for data collection staff to be masked to treatment assignment: 1) designating and tracking unmasked study staff; 2) excluding data collection staff from any part of intervention delivery; 3) performing outcome assessments in separate rooms than the intervention; and 4) reminding participants not to share their group assignment.
The researchers collecting the 6-month follow-up data will be masked to the practices' allocation status.
The participants will know the allocated group, but the outcome assessors and data analysts will be masked to the intervention allocation.
This information will have to be retained for a period of five years, but after six months, the data will be "masked out", i.e., stripped of the elements, such as name, address and contact details that may lead to the identification of individuals.
Those data could be "masked" by less relevant peak values and hence not be displayed in the eDISH plot.
These should be randomized controlled clinical trials, with homogenous and sufficiently large samples, in which validated instruments should be used to assess clinically meaningful variables, and in which randomization, patients' assessment and data analysis should be masked.
However data extractors will be masked, except when extracting audio and video related information which will be collected for the intervention arm only.
Both research assistants who perform the measurements and the researcher who performs the data analyses will be masked.
We found recurring potential sources of bias in study design, with 19 (61%) studies failing to report whether HRV data analysers were masked to the patient condition/outcome (Additional file 1).
Staff responsible for delivering the WL intervention will be masked to all outcome data until the end of trial.
