The powerful placebo effect: fact or fiction?
Kienle and Kiene examine Henry Beecher's 1955 article, often cited as establishing the placebo effect, in which a placebo was reported to relieve about 35 per cent of 1,082 patients across 15 trials. Their reanalysis of those trials found no evidence of a placebo effect, and they attribute the reported improvements to other factors such as spontaneous improvement, regression to the mean and response bias. They argue that the placebo topic invites loose methodological thinking and that researchers need to recognise Beecher's errors when interpreting current placebo research.
Kienle and Kiene examine Henry Beecher's 1955 article, often cited as establishing the placebo effect, in which a placebo was reported to relieve about 35 per cent of 1,082 patients across 15 trials. Their reanalysis of those trials found no evidence of a placebo effect, and they attribute the reported improvements to other factors such as spontaneous improvement, regression to the mean and response bias. They argue that the placebo topic invites loose methodological thinking and that researchers need to recognise Beecher's errors when interpreting current placebo research.
Written from the abstract, Europe PMC record, 2026-11-03.
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Kienle, G. S., & Kiene, H. (1997). The powerful placebo effect: fact or fiction? Journal of Clinical Epidemiology, 50(12), 1311-1318. doi:10.1016/s0895-4356(97)00203-5 https://doi.org/10.1016/s0895-4356(97)00203-5