People’s Understanding of Verbal Risk Descriptors in Patient Information Leaflets: A Cross-Sectional National Survey of 18- to 65-Year-Olds in England

Abstract

IntroductionEvidence suggests the current verbal risk descriptors used to communicate side effect risk in patient information leaflets (PILs) are overestimated.ObjectivesThe aim was to establish how people understand the verbal risk descriptors recommended for use in PILs by the European Commission (EC), and alternative verbal risk descriptors, in the context of mild and severe side effects.MethodsA cross-sectional online survey was carried out by a market research company recruiting participants aged between 18 and 65 years living in England. Data were collected between 18 March and 1 April 2016. Participants were given a hypothetical scenario regarding the risk of mild or severe medication side effects and asked to estimate how many out of 10,000 people would be affected for each of the verbal risk descriptors being tested.ResultsA total of 1003 participants were included in the final sample. The risks conveyed by the EC recommended verbal risk descriptors were greatly overestimated by participants. Two distinct distributions were apparent for participant estimates of side effect risks: those for ‘high risk’ verbal descriptors (e.g. ‘common’, ‘likely’, ‘high chance’) and those for ‘low risk’ verbal descriptors (e.g. ‘uncommon’, ‘unlikely’, ‘low chance’). Within these two groups, the distributions were near to identical regardless of what adverb (e.g. very, high, fair) or adjective (e.g. common, likely, chance) was used. The EC recommended verbal risk descriptors were more likely to be understood in accordance with their intended meanings when describing severe side effects. Very few demographic or psychological factors were consistently associated with how well participants understood the EC recommended verbal risk descriptors.DiscussionThe current verbal risk descriptors used in PILs are ineffective at best and misleading at worst. Discontinuing the use of verbal risk descriptors would limit the likelihood of people overestimating the risk of side effects.Electronic supplementary materialThe online version of this article (doi:10.1007/s40264-017-0542-1) contains supplementary material, which is available to authorized users.

Advertising of Over-the-Counter Codeine-Containing Medicines in the EU: Differences in the Regulation of Advertising Between Member States

“…It should be noted that all medicines must, under EU regulation, include PILs providing information on the safe and appropriate use of the medicine. However, studies have shown that patients' often fail to read and/or understand the information provided in the PIL (21). It is also important in the future to establish if direct sale of OTC codeine in countries with fewer restrictions of sale correlate with national figures for codeine-specific SUD, adverse drug reactions, intoxication and mortality.…”

Most family physicians report communicating the risks of adverse drug reactions in words (vs. numbers)

“…For example, the frequent use of verbal frequencies could be problematic as this particular quantifier is perceived as conveying risks that are largely superior to what they should convey according to the EU commission guidelines (Berry et al, 2003;Berry, Knapp, & Raynor, 2002;Knapp et al, 2009;Knapp et al, 2010;Knapp, Raynor, & Berry, 2004;Webster et al, 2017). Numerical formats are not immune to discrepancies either.…”

“…First, within the same format, quantifier types have implications for the recipients' probability perceptions (Koehler, ; Monahan et al, ; Slovic, Monahan, & MacGregor, ). For example, the frequent use of verbal frequencies could be problematic as this particular quantifier is perceived as conveying risks that are largely superior to what they should convey according to the EU commission guidelines (Berry et al, ; Berry, Knapp, & Raynor, ; Knapp et al, ; Knapp et al, ; Knapp, Raynor, & Berry, ; Webster et al, ). Numerical formats are not immune to discrepancies either.…”

“…First, the flexibility of the meaning of verbal quantifiers can be seen as a weakness because patients often do not understand those quantifiers as expected by practitioners (Brun & Teigen, 1988). Verbal quantifiers used to describe a drug's adverse effects in leaflets in Europe (see Table 1 , European Commission, 1998), consistently lead to an overestimation of the risks (Berry, Raynor, & Knapp, 2003;Knapp, Gardner, Carrigan, Raynor, & Woolf, 2009;Knapp, Gardner, Raynor, Woolf, & McMillan, 2010;Knapp, Gardner, & Woolf, 2016;Peters, Hart, Tusler, & Fraenkel, 2014;Webster, Weinman, & Rubin, 2017;Young & Oppenheimer, 2006). For example, the verbal frequency "common" is used to mean a 1-10% probability, but it is psychologically perceived by patients as meaning a 45% probability (Berry, Holden, & Bersellini, 2004).…”

“…For example, the verbal frequency "common" is used to mean a 1-10% probability, but it is psychologically perceived by patients as meaning a 45% probability (Berry, Holden, & Bersellini, 2004). Patients feel that an adverse effect that is common is actually "very likely" (Webster et al, 2017), and this overestimation makes people less willing to take a recommended treatment (Peters et al, 2014). The vagueness of verbal quantifiers also makes them vulnerable to contextual biases (e.g., severity: Harris & Corner, 2011;base rate: Villejoubert, Almond, & Alison, 2008;Wallsten, Fillenbaum, & Cox, 1986; and on both severity and base rate: Weber & Hilton, 1990).…”