Assessment of blinding may be inappropriate after the trial : [Letter]

In their paper discussing the assessment of blinding in clinical trials, Bang et al. based their analysis on the premise that "all participants randomly guess their assignment... This is the most ideal scenario in reality". However, this premise makes an implicit assumption that the drug does not differ from placebo in any physiological effects that a person could observe subjectively, which is a very strong assumption. If a drug is truly effective, such as penicillin for pneumococcal pneumonia, both the patient and the physician can infer the treatment with high certainty by subjective observations. Thus, when the drug is truly effective, we are expecting "breaking of blindness".Non peer reviewe