Communicating the frequency of adverse drug reactions to female patients

Objectives: Research suggests that patients may vary in their interpretation of frequentist expressions used to communicate risk information. Because frequentist expressions are usually used when communicating the likelihood of experiencing an adverse drug reaction (ADR), misinterpretation of this risk information may prevent informed patient decision making. This study examined the association of frequentist expression interpretations with the following four factors: 1. Context effect, 2. ADR severity, 3. Second or third-person phrasing, and 4. Perceived base rates of ADRs. Furthermore, patients' preference for numerical as opposed to the use of frequentist expressions was also recorded. Methods: A cross-sectional field design was used to collect the data from a systematic random sample of women residing in a Midwestern State. Analysis of variance methods were used to assess the interpretation of three frequentist expressions (rarely, occasionally, and frequently) across 18 different scenarios. Results: Analysis of 74 useable surveys showed that context effects and ADR severity were significant main effects. Furthermore, ANOVA results suggested three significant interactions: phrasing and ADR severity, context and frequentist expression, and severity and frequentist expression. Additionally, respondents preferred numerical presentation of risk information. Conclusions: These results suggest there may be significant variability in patient interpretation of ADR risks. When communicating risk information to patients, health care providers should assure that patients fully understand the meaning of frequentist expressions. Because patients are increasingly becoming active health care participants, efforts to clarify their interpretation of risks will encourage more informed medical decisions.