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A recent systematic review found that almost half of participants who take placebos in clinical trials experience drug related adverse events (AEs), with 5% of participants dropping out due to ‘drug related’ intolerance. However the placebo per se cannot be the cause of these adverse events. Instead, there are two overlapping likely explanations:

  1. Misattribution. A patient may have an underlying condition whose natural history produces some event (such as a headache), then the patient misattributes the event to the placebo.
  2. Nocebo effects. Having been warned about side effects in the patient information sheets, the patient may expect an adverse event. This negative expectation could then produce the event.

Nocebo effects may be caused—at least partly—by sharing information about AEs in the wrong way. This causes a tension between the ethical requirements of autonomy and non-maleficence. On the one hand, autonomy demands that patients be fully informed about treatment (adverse events). On the other hand, non-maleficence demands that patients be informed about AE’s in the right way. Ethical discussions of informed consent have focused almost exclusively on autonomy and may therefore been violating the requirement to do no harm. I will discuss ways in which autonomy and non-maleficence can be balanced in future clinical trials and ethical debates.

Forthcoming events

Infectious Disease Seminar Series: Epidemiology of the NHS COVID-19 app: design, evaluation and future considerations

Monday, 12 June 2023, 1pm to 2pm @ BDI/OxPop Building Seminar Room LG 0-1, Old Road Campus, Headington, OX3 7LF

Alcohol phenotypes and how they are related to fMRI derived brain health measurements

Tuesday, 13 June 2023, 11am to 12pm @ Big Data Institute LG 0 Seminar room

Update on folic acid and disease prevention

Tuesday, 13 June 2023, 1pm to 2pm @ Richard Doll Lecture Theatre, Richard Doll Building, Old Road Campus, Headington, OX3 7LF

Infectious Disease Seminar Series: 40 years of combating meningococcal disease: are we nearly there yet?

Monday, 19 June 2023, 1pm to 2pm @ BDI Seminar Room LG 0-1, Old Road Campus, Headington, OX3 7LF

Environmental sensing and it’s association with chronic disease

Tuesday, 11 July 2023, 11am to 12pm @ Big Data Institute LG 0 Seminar room