There were also issues regarding blinding of research staff, with staff visiting intervention groups during the study period in two of the trials [52,55].
For all other studies there was no comment regarding blinding.
However, some difficulties regarding blinding must be mentioned.
Regarding blinding, those studies in which the outcome was explicitly predefined, the outcome assessment was blinded, or both, were considered adequately masked [ 15].
We tried to design the trial as good as possible but all trials, especially acupuncture trials, have their advantages and disadvantages regarding blinding, treatment, and investigators: Blinding in acupuncture trials as one method to reduce bias is difficult.
Among the 30 surgical RCTs in this study, only 17% made a clear statement about blinding of patients, and only 33% made a statement regarding blinding of outcome assessors.
36 Consistent with published reviews of psychological interventions 21 37 two items regarding blinding of participants and therapists will not be scored in the present review, as these criteria are not appropriate for the studies under review.
One limitation of this study is the possibility of a high risk of bias regarding blinding because we will use usual care as a control instead of a sham procedure.
Among the three RCTs, only one [ 6] was of moderate quality; the other two [ 20, 21] were of low quality because of concerns regarding blinding, allocation and reporting of outcomes (Table 2).
A common problem regarding the blind multiuser detectors used in MC-CDMA systems is that they are extremely sensitive to the complex channel environment.
Addendum regarding the "blind-folded" horse My post about Chester County included a photograph of a "blind-folded" white horse.
