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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.

Richard Doll seminars IN Public health and epidemiology

 Richard Doll

Forthcoming events

What is new in Polygenic Risk Scores?

Tuesday, 11 October 2022, 1pm to 2pm

Infectious Disease Seminar Series: Lessons learned - Will suffering through one pandemic help prevent another?

Monday, 17 October 2022, 1pm to 2pm @ Big Data Institute / OxPop Building, Old Road Campus, Headington, OX3 7LF

Infectious Disease Seminar Series: Global molecular epidemiology of HIV-1

Monday, 31 October 2022, 1pm to 2pm @ BDI Seminar Room LG 0-1, Old Road Campus, Headington, OX3 7LF

Infectious Disease Seminar Series: COVID-19 and Kids: what have we learnt after 3 years?

Monday, 07 November 2022, 1pm to 2pm @ BDI Seminar Room LG 1, Old Road Campus, Headington, OX3 7LF