Groups that should, if possible, be blinded to intervention allocation
| Group | Rationale for encouraging blinding |
| Participants | To avoid placebo effects or differences in adherence to treatment |
| Healthcare providers | To prevent differential administration of therapies (including cointerventions) that affect the outcomes of interest |
| Data collectors | To prevent bias in data collection |
| Outcome adjudicators | To prevent bias in decisions as to whether a participant has improved or deteriorated on the outcome of interest |
| Data analysts | To avoid bias in decisions regarding how data is analysed |
Adopted from JAMA Users’ Guides to the Medical Literature (2015).