Defining and evaluating the #HawthorneEffect in primary care: systematic review & meta-analysis https://pubmed.ncbi.nlm.nih.gov/36425097/

Aware or unconscious #behaviorchange in a study environment, related to the interaction of: #selectionbias; commitment and congruence bias; conformity and #socialdesirabilitybias; and, observation and measurement #bias." It overlaps with the #placeboeffect, and regression to the mean. Shifts Rx fx by avg >40% in binary outcomes, less in well-designed studies. #psychology #RCTs