Combined verbal and numerical expressions increase perceived risk of medicine side-effects: a randomized controlled trial of EMA recommendations

Using Separate Single-Outcome Risk Presentations Instead of Integrated Multioutcome Formats Improves Comprehension in Discrete Choice Experiments

INTRODUCTION

Despite decades of research on risk-communication approaches, questions remain about the optimal methods for conveying risks for different outcomes across multiple time points, which can be necessary in applications such as discrete choice experiments (DCEs). We sought to compare the effects of 3 design factors: 1) separated versus integrated presentations of the risks for different outcomes, 2) use or omission of icon arrays, and 3) vertical versus horizontal orientation of the time dimension.

METHODS

We conducted a randomized study among a demographically diverse sample of 2,242 US adults recruited from an online panel (mean age 59.8 y, s = 10.4 y; 21.9% African American) that compared risk-communication approaches that varied in the 3 factors noted above. The primary outcome was the number of correct responses to 12 multiple-choice questions asking survey respondents to identify specific numbers, contrast options to recognize dominance (larger v. smaller risks), and compute differences. We used linear regression to test the effects of the 3 design factors, controlling for health literacy, graph literacy, and numeracy. We also measured choice consistency in a subsequent DCE choice module.

RESULTS

Mean comprehension varied significantly across versions (P < 0.001), with higher comprehension in the 3 versions that provided separated risk information for each risk. In the multivariable regression, separated risk presentation was associated with 0.58 more correct responses (P < 0.001; 95% confidence interval: 0.39, 0.77) compared with integrated risk information. Neither providing icon arrays nor using vertical versus horizontal time formats affected comprehension rates, although participant understanding did correlate with DCE choice consistency.

CONCLUSIONS

In presentations of multiple risks over multiple time points, presenting risk information separately for each health outcome appears to increase understanding.

HIGHLIGHTS

When conveying information about risks of different outcomes at multiple time points, separate presentations of single-outcome risks resulted in higher comprehension than presentations that combined risk information for different outcomes.We also observed benefits of presenting single-outcome risks separately among respondents with lower numeracy and graph literacy.Study participants who scored higher on risk understanding were more internally consistent in their responses to a discrete choice experiment.

Verbal Descriptors of the Frequency of Side Effects: Implementation of EMA Recommendations in Patient Information Leaflets in Poland

Background

The European Medicines Agency (EMA) recommends a description of drug side effects based on the frequency format and the associated verbal description. Although the recommendations refer to English-speaking countries, in several non-English speaking states, official authorities have accepted the proposed recommendations on how the patient information leaflets should be designed for descriptions of side effect frequencies. The aim of the study was to examine how manufacturers of authorized medicines in Poland implement the EMA recommendations regarding the verbal descriptors of the frequency of side effects.

Methods

A qualitative study. As a first step, we identified which of the 150 pharmaceutical companies operating in Poland had the largest market share. Then, five manufacturers were selected at random from the list of the top fifteen drug manufacturers in Poland by market share of the pharmaceutical sector. Lists of medicinal products authorized for marketing in Poland were downloaded from manufacturers’ websites, and then five products from each manufacturer were selected based on random sampling. The study included only prescription medicines and excluded over-the-counter medicines and dietary supplements from the sample. Subsequently, for each of the 25 drugs relevant patient information leaflets were obtained from the manufacturers’ websites. We evaluated how information on the frequency of side effects was provided in each leaflet, including the use of EU-recommended terms (verbal descriptors such as "very common," "common," "uncommon," "rare," "very rare") and additional notes explaining their meanings.

Results

For all manufacturers, word labels of the frequencies of side effects selected for the study were the same but the additional notes explaining their meanings were different. There were various explanations of how to understand verbal descriptors of the frequency of side effects not only across different manufacturers but also across different medicines from one manufacturer.

Conclusions

There is no single standard in the Polish pharmaceutical industry for implementing the EMA recommendations into the written information about the frequency of side effects. The observed differences for an explanation of how to understand a given verbal term do not favor a uniform interpretation of the verbal frequency labels meaning by patients.

Thai Patients' Drug Safety Knowledge and Perceptions Relating to Different Forms of Written Medicine Information: A Comparative Study

PURPOSE

The aim of the study was to evaluate the medication safety knowledge, quality of the written medicine information (WMI), and perceptions of taking the medicines in patients receiving package inserts (PIs) in comparison with patient information leaflets (PILs).

METHODS

A cross-sectional, comparative study was conducted from December 2020 to May 2021 at two university hospitals in Thailand. Outpatients who visited the pharmacy departments and were prescribed one of the three medicines: atorvastatin, celecoxib, or metformin were randomly selected by a permuted block randomization. The medication safety knowledge was measured using a set of validated and closed questions. The quality of the WMI was measured by the Consumer Information Rating Form (CIRF). Satisfaction with information and perceptions of the benefits and risks of medications were rated by the participants using a visual analog scale (0 to 10).

RESULTS

Of the 1150 invited patients, 750 completed the questionnaires (65.2%). A higher proportion of respondents with high level of medication safety knowledge was found in those reading the PILs than the PIs (44.5% and 20.8%, respectively). The type of leaflet received was a significant predictor of the high knowledge level (p < 0.001). The mean CIRF scores were significantly higher among those reading the PILs than the PIs (p < 0.001). Patients reading the PILs were also more satisfied with the information and had more positive perceptions of the benefits from taking medicines and intention to adhere than those reading the PIs. Patients' perceptions of risks after reading both leaflets were moderate (median score = 5.0), with the PIL group having slightly more concern about risks than the PI group.

CONCLUSION

The PILs showed superior effectiveness to the PIs in enhancing knowledge about medication safety, providing greater satisfaction with the information, and positive perceptions of benefit and intention to comply with the medications. PILs should be provided more frequently to patients receiving medicines than PIs.

Imprecision and Preferences in Interpretation of Verbal Probabilities in Health: a Systematic Review

INTRODUCTION

Many health providers and communicators who are concerned that patients will not understand numbers instead use verbal probabilities (e.g., terms such as "rare" or "common") to convey the gist of a health message.

OBJECTIVE

To assess patient interpretation of and preferences for verbal probability information in health contexts.

METHODS

We conducted a systematic review of literature published through September 2020. Original studies conducted in English with samples representative of lay populations were included if they assessed health-related information and elicited either (a) numerical estimates of verbal probability terms or (b) preferences for verbal vs. quantitative risk information.

RESULTS

We identified 33 original studies that referenced 145 verbal probability terms, 45 of which were included in at least two studies and 19 in three or more. Numerical interpretations of each verbal term were extremely variable. For example, average interpretations of the term "rare" ranged from 7 to 21%, and for "common," the range was 34 to 71%. In a subset of 9 studies, lay estimates of verbal probability terms were far higher than the standard interpretations established by the European Commission for drug labels. In 10 of 12 samples where preferences were elicited, most participants preferred numerical information, alone or in combination with verbal labels.

CONCLUSION

Numerical interpretation of verbal probabilities is extremely variable and does not correspond well to the numerical probabilities established by expert panels. Most patients appear to prefer quantitative risk information, alone or in combination with verbal labels. Health professionals should be aware that avoiding numeric information to describe risks may not match patient preferences, and that patients interpret verbal risk terms in a highly variable way.

Examining the Effectiveness of Genetic Counselors' Communication of Variant of Uncertain Significance Results of Breast Cancer Genes

Receiving a variant of uncertain significance (VUS) result is quite common for individuals who undergo genetic testing. Because VUS results are often unexpected and necessarily complex, they are challenging for genetic counselors to deliver. The current research sought to examine how three specific message features (risk estimate formats, establishment of a future plan, and linguistic agency), and message receivers' intolerance of uncertainty, influenced the effectiveness of genetic counselors' communication of a VUS result. A series of MANCOVAs and multiple regressions suggested that these message features affected message receivers' perception of a genetic counselor's credibility and receivers' uncertainty appraisal and information-seeking intentions. Specifically, establishing a future plan and assigning agency to a VUS result enhanced perceived counselor credibility. When results were presented in a numeric format, assigning agency to counselors resulted in heightened danger appraisal and greater information-seeking intentions. Individuals' intolerance of uncertainty moderated the association between risk formats and uncertainty appraisal. These results have both theoretical and practical implications for communication of uncertainty in the context of genetic counseling.

Current Best Practice for Presenting Probabilities in Patient Decision Aids: Fundamental Principles

BACKGROUND

Shared decision making requires evidence to be conveyed to the patient in a way they can easily understand and compare. Patient decision aids facilitate this process. This article reviews the current evidence for how to present numerical probabilities within patient decision aids.

METHODS

Following the 2013 review method, we assembled a group of 9 international experts on risk communication across Australia, Germany, the Netherlands, the United Kingdom, and the United States. We expanded the topics covered in the first review to reflect emerging areas of research. Groups of 2 to 3 authors reviewed the relevant literature based on their expertise and wrote each section before review by the full authorship team.

RESULTS

Of 10 topics identified, we present 5 fundamental issues in this article. Although some topics resulted in clear guidance (presenting the chance an event will occur, addressing numerical skills), other topics (context/evaluative labels, conveying uncertainty, risk over time) continue to have evolving knowledge bases. We recommend presenting numbers over a set time period with a clear denominator, using consistent formats between outcomes and interventions to enable unbiased comparisons, and interpreting the numbers for the reader to meet the needs of varying numeracy.

DISCUSSION

Understanding how different numerical formats can bias risk perception will help decision aid developers communicate risks in a balanced, comprehensible manner and avoid accidental "nudging" toward a particular option. Decisions between probability formats need to consider the available evidence and user skills. The review may be useful for other areas of science communication in which unbiased presentation of probabilities is important.

Facilitating sender-receiver agreement in communicated probabilities: Is it best to use words, numbers or both?

Organizations tasked with communicating expert judgments couched in uncertainty often use numerically bounded linguistic probability schemes to standardize the meaning of verbal probabilities. An experiment (N = 1,202) was conducted to ascertain whether agreement with such a scheme was better when probabilities were presented verbally, numerically or in a combined “verbal + numeric” format. Across three agreement measures, the numeric and combined formats outperformed the verbal format and also yielded better discrimination between low and high probabilities and were less susceptible to the fifty-fifty blip phenomenon. The combined format did not confer any advantage over the purely numeric format. The findings indicate that numerically bounded linguistic probability schemes are an ineffective means of communicating information about probabilities to others and they call into question recommendations for use of the combined format for delivering such schemes.

Communicating tailored risk information of cancer treatment side effects: Only words or also numbers?

BACKGROUND

The increased availability of patient reported outcome data makes it feasible to provide patients tailored risk information of cancer treatment side effects. However, it is unclear how such information influences patients' risk interpretations compared to generic population-based risks, and which message format should be used to communicate such individualized statistics.

METHODS

A web-based experiment was conducted in which participants (n = 141) read a hypothetical treatment decision-making scenario about four side effect risks of adjuvant chemotherapy for advanced colon cancer. Participants were cancer patients or survivors who were recruited from an online Dutch cancer patient panel. All participants received two tailored risks (of which the reference class was based on their age, gender and tumor stage) and two generic risks conveying the likelihood of experiencing the side effects. The risks were presented either in words-only ('common' and 'very common'), or in a combination of words and corresponding numerical estimates ('common, 10 out of 100' and 'very common, 40 out of 100'). Participants' estimation of the probability, accuracy of their estimation, and perceived likelihood of occurrence were primary outcomes. Perceived personal relevance and perceived uncertainty were secondary outcomes.

RESULTS

Tailored risks were estimated as higher and less accurate than generic risks, but only when they were presented in words; Such differences were not found in the verbal and numerical combined condition. Although tailoring risks did not impact participants' perceived likelihood of occurrence, tailored risks were perceived as more personally relevant than generic risks in both message formats. Finally, tailored risks were perceived as less uncertain than generic risks, but only in the verbal-only condition.

CONCLUSIONS

Considering current interest in the use of personalized decision aids for improving shared decision-making in oncology, it is important that clinicians consider how tailored risks of treatment side effects should be communicated to patients. We recommend both clinicians who communicate probability information during consultations, and decision aid developers, that verbal descriptors of tailored risks should be supported by numerical estimates of risks levels, to avoid overestimation of risks.

A systematic review of factors associated with side-effect expectations from medical interventions

BACKGROUND

Fear of side-effects can result in non-adherence to medical interventions, such as medication and chemotherapy. Side-effect expectations have been identified as strong predictors of later perception of side-effects. However, research investigating predictors of side-effect expectations is disparate.

OBJECTIVE

To identify factors associated with side-effect expectations.

SEARCH STRATEGY

We systematically searched Embase, Ovid MEDLINE, Global Health, PsycARTICLES, PsycINFO, Web of Science and Scopus.

INCLUSION CRITERIA

Studies were included if they investigated associations between any predictive factor and expectations of side-effects from any medical intervention.

DATA EXTRACTION AND SYNTHESIS

We extracted information about participant characteristics, medication, rates of side-effects expected and predictors of side-effect expectations. Data were narratively synthesized.

MAIN RESULTS

We identified sixty-four citations, reporting on seventy-two studies. Predictors fell into five categories: personal characteristics, clinical characteristics, psychological traits and state, presentation format of information, and information sources used. Using verbal risk descriptors (eg 'common') compared to numerical descriptors (eg percentages), having lower quality of life or well-being, and currently experiencing symptoms were associated with increased side-effect expectations.

DISCUSSION AND CONCLUSIONS

Decreasing unrealistic side-effect expectations may lead to decreased experience of side-effects and increased adherence to medical interventions. Widespread communications about medical interventions should describe the incidence of side-effects numerically. Evidence suggests that clinicians should take particular care with patients with lower quality of life, who are currently experiencing symptoms and who have previously experienced symptoms from treatment. Further research should investigate different clinical populations and aim to quantify the impact of the media and social media on side-effect expectations.

Communicating treatment risks and benefits to cancer patients: a systematic review of communication methods

PURPOSE

Cancer patients are increasingly involved in decision-making processes. Hence, clinicians need to inform patients about the risks and benefits of different treatment options in order for patients to make well informed decisions. The aim of this review is to determine the effects of methods of communicating prognostic information about (1) disease progression (survival, progression, recurrence and remission), (2) side effects and complications and (3) health-related quality of life (HRQL) on cognitive, affective and behavioral outcomes in cancer patients.

METHODS

A literature search was performed to select articles that were published up to  November 2019 and that examined verbal and/or visual risk communication interventions in an oncological clinical setting.

RESULTS

The search yielded 14,875 studies; 28 studies were ultimately included. For disease progression information, we found that framing affects treatment choice. Furthermore, limiting the amount of progression information in a graphical display could benefit patients' understanding of risks and benefits. For prognostic information about side effects and complications, precise and defined risk information was better understood than information presented in words. When displaying HRQL data, no consensus was found on which graph type to use.

CONCLUSION

Great heterogeneity in the results and methodology and in the compared communication formats precluded us from drawing any further conclusions. Practical implications for clinicians are to consider the effects that different types of framing might have on the patient and to not rely exclusively on words to describe risks, but rather include at least some form of numbers or visualization.

Verbal Descriptions Accompanying Numeric Information About the Risk: The Valence of Message and Linguistic Polarity

The aim of this study was to investigate the effect of presenting risk on decision making and evaluations with regard to the valence (positive vs. negative) and the linguistic polarity (direct vs. indirect). Participants were presented with a message in which patients were informed about risk associated with some diagnostic medical procedures. In the presented text, before obtaining statistical information about risk (e.g., 1 in 1000), four types of the verbal descriptions were used (risk is high/risk is not low/risk is low/risk is not high). The valence of information influenced the decision and respondent's evaluation. Participants receiving a verbal description with a positive valence were more positive about the patient' decision, and more positively evaluated the doctor and patient's mood than participants receiving a description with a negative valence. Neither main nor interaction effects with linguistic polarity were found. The research does not support that indirect wording mitigates the meaning of a message on risk and highlights the strength and persistence of relying on the verbal description, particularly their affective valence.

How is cervical cancer screening information communicated in UK websites? Cross-sectional analysis of content and quantitative presentation formats

OBJECTIVES

To investigate whether UK websites about cervical cancer screening targeted to the public include (1) information about benefits and risks of screening, possible screening results and cervical cancer statistics, (2) quantitative presentation formats recommended in the risk communication literature and (3) appeals for participation and/or informed decision-making.

DESIGN

Cross-sectional analysis of websites using a comprehensive checklist of information items on screening benefits, risks, possible results and cervical cancer statistics.

OUTCOME MEASURES

We recorded the number of websites that contained each of the information items, and the presentation format used for probabilistic information (no quantification provided, verbal quantifiers only, different types of numerical formats and/or graphs). We also recorded the number of websites containing appeals for participation and/or informed decision-making.

SETTING

Websites were identified through the most common Google search terms used in the UK to find information on cervical screening, according to GoogleTrends and a commercial internet-monitoring programme. Two additional websites were identified by the authors as relevant.

RESULTS

After applying exclusion criteria, 14 websites were evaluated, including websites of public and private health service providers, charities, a medical society and a pharmacy. The websites mentioned different benefits, risks of screening and possible results. However, specific content varied between websites. Probabilistic information was often presented using non-recommended formats, including relative risk reductions to express screening benefits, and verbal quantifiers without numbers to express risks. Appeals for participation were present in most websites, with almost half also mentioning informed decision-making.

CONCLUSIONS

UK websites about cervical cancer screening were generally balanced. However, benefits and risks were presented using different formats, potentially hindering comparisons. Additionally, recommendations from the literature to facilitate understanding of quantitative information and facilitate informed decisions were often not followed. Designing websites that adhere to existing recommendations may support informed screening uptake.

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

Introduction

Evidence suggests the current verbal risk descriptors used to communicate side effect risk in patient information leaflets (PILs) are overestimated.

Objectives

The 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.

Methods

A 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.

Results

A 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.

Discussion

The 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 material

The online version of this article (doi:10.1007/s40264-017-0542-1) contains supplementary material, which is available to authorized users.

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.

The effect of counseling on willingness to use a hypothetical medication and perceptions of medication safety

BACKGROUND

Poor medication adherence is an ongoing issue, and contributes to increased hospitalizations and healthcare costs. Although most adverse effects are rare, the perceived risk of adverse effects may contribute to low adherence rates.

OBJECTIVES

The objective of this study was to determine how adverse effect likelihood and pharmacist counseling on adverse effect prevention affects individuals': (1) willingness to use a hypothetical medication and (2) perceptions of medication safety.

METHODS

This study used a 3 × 3 experimental design. Participants (n = 601) viewed a hypothetical scenario asking them to imagine being prescribed an anti-asthma medication that could cause fungal infections of the throat. Participants were randomized to 1 of 9 scenarios that differed on: probability of developing an infection (5%, 20%, no probability mentioned) and whether they were told how to reduce the risk of infection (no prevention strategy discussed, prevention strategy discussed, prevention strategy discussed with explanation for how it works). Participants were recruited through Amazon Mechanical Turk.

RESULTS

Participants were less willing to take the medication (F = 12.86, p < 0.0001) and considered it less safe (F = 13.11, p < 0.0001) when the probability of fungal infection was presented as 20% compared to 5% or when no probability information was given. Participants were more willing to take the medication (F = 11.78, p < 0.0001) and considered it safer (F = 11.17, p < 0.0001) when a prevention strategy was given. Finally, there was a non-statistically significant interaction between the probability and prevention strategy information such that provision of prevention information reduced the effect of variation in the probability of infection on both willingness to use the medication and perceived medication safety.

CONCLUSIONS

Optimal risk communication involves more than informing patients about possible adverse effects. Pharmacists could potentially improve patient acceptance of therapeutic recommendations, and allay medication safety concerns, by counseling about strategies patients can implement to reduce the perceived risk of adverse effects.

Presenting Numeric Information with Percentages and Descriptive Risk Labels: A Randomized Trial

BACKGROUND

Previous research demonstrated that providing (v. not providing) numeric information about the adverse effects (AEs) of medications increased comprehension and willingness to use medication but left open the question about which numeric format is best. The objective was to determine which of 4 tested formats (percentage, frequency, percentage + risk label, frequency + risk label) maximizes comprehension and willingness to use medication across age and numeracy levels.

METHODS

In a cross-sectional internet survey (N = 368; American Life Panel, 15 May 2008 to 18 June 2008), respondents were presented with a hypothetical prescription medication for high cholesterol. AE likelihoods were described using 1 of 4 tested formats. Main outcome measures were risk comprehension (ability to identify AE likelihood from a table) and willingness to use the medication (7-point scale; not likely = 0, very likely = 6).

RESULTS

The percentage + risk label format resulted in the highest comprehension and willingness to use the medication compared with the other 3 formats (mean comprehension in percentage + risk label format = 95% v. mean across the other 3 formats = 81%; mean willingness = 3.3 v. 2.95, respectively). Comprehension differences between percentage and frequency formats were smaller among the less numerate. Willingness to use medication depended less on age and numeracy when labels were used. Generalizability is limited by the use of a sample that was older, more educated, and better off financially than national averages.

CONCLUSIONS

Providing numeric AE-likelihood information in a percentage format with risk labels is likely to increase risk comprehension and willingness to use a medication compared with other numeric formats.