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Positively Framed Risk Information in Patient Information Leaflets Reduces Side Effect Reporting: A Double-Blind Randomized Controlled Trial

Research output: Contribution to journalArticlepeer-review

Original languageEnglish
Pages (from-to)920–929
JournalAnnals of Behavioral Medicine
Issue number11
Early online date25 Jan 2018
Accepted/In press24 Nov 2017
E-pub ahead of print25 Jan 2018
Published1 Nov 2018


King's Authors


Many medication side effects are the result of a psychologically mediated “nocebo effect,” triggered by negative expectations.

This study investigated if changing how side effect information is framed in patient information leaflets (PILs) reduces symptom reporting.

A total of 203 healthy volunteers aged 18 or over were recruited from December 1, 2015 to December 5, 2016 into a double-blind randomized controlled trial carried out at the Clinical Research Facility at King’s College Hospital. King’s Clinical Trial Unit randomized participants (stratified by gender) to receive a PIL for “a well-known tablet available without prescription” that used standard side effect risk information (e.g., “Common, 1 in 10 people will be affected”) or positively framed wording (e.g., “Uncommon, 90% of people will not be affected”). After reading their PIL, participants took the tablet (a placebo) and completed symptom reports 1 hr later. The main outcomes included the number of participants who attributed symptoms to the tablet, and the number and severity of attributed symptoms.

A total of 101 participants were assigned the standard PIL and 102 the positive framed PIL. Significantly more standard PIL participants attributed symptoms to the tablet (n = 55, 54.5%) compared to positively framed PIL participants (n = 40, 39.2%), odds ratio (OR) = 0.66, 95% CI: 0.46–0.93. Positive framing did not significantly reduce the total number (p = .148) or severity (p = .149) of symptoms attributed to the tablet.

Positive framing reduced the likelihood of participants attributing nocebo-induced side effects to the tablet. Work is needed to assess the effectiveness in a patient population.

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