How does the side-effect information in patient information leaflets influence peoples' side-effect expectations? A cross-sectional national survey of 18- to 65-year-olds in England.

Objectives To establish how the terms recommended by the European Commission to describe side-effect risk in patient information leaflets ( PILs) influences expectations of side-effects and to identify factors associated with these side-effect expectations. Design A cross-sectional online survey was carried out by a market research company. Setting Data were collected in England between 18th March and 1st April 2016. Participants A total of 1003 adults aged between 18 and 65. Main outcome measures: Self-reported expectation that the described side-effects would affect participants if they took the medicine, measured on a likelihood scale from 1 (very unlikely) to 5 (very likely). Results Participants formed high expectations of side-effects for 'very common' and 'common' side-effects, with 51.9% and 45.0% of participants rating these as 'very likely' or 'likely' to happen to them, respectively. This fell to 8.1% for 'uncommon,' 5.8% for 'rare' and 4.1% for 'very rare.' For each descriptor, higher expectations of side-effects were more associated with women or being from an ethnic minority, or having less education, a household illness, high perceived sensitivity to medicines or negative beliefs about medicines. Discussion The current use of verbal descriptors to communicate side-effect risk in PILs leads to high side-effect expectations. These expectations could contribute to nocebo-induced medication side-effects experienced by patients. Additional work is required to identify ways to improve the way risk information is conveyed in PILs. [ABSTRACT FROM AUTHOR]