Patients' interpretations of verbal expressions of probability: implications for securing informed consent to medical interventions

Effect of Communication Style on Perceptions of Medication Side Effect Risk among Pharmacy Students

Objective. To assess the effect of communication style, and frequency and severity of medication side-effects, on pharmacy students' perception of risk of experiencing side effects. Methods. One hundred responses from pharmacy students were obtained using an online survey. Participants were presented with a drug information box containing drug name, drug usage, and one side-effect associated with the drug. Information on side-effect for each drug was presented in one of eight experimental conditions, in a 2 (side-effect frequency: low, high), X2 (side-effect severity: mild, severe) X2 (communication style: verbal, verbal + natural frequency) factorial design. Risk perception of experiencing side effects was measured. Results. Communication style was found to have a significant impact on risk perception depending on the context of frequency and severity associated with the side effect. Conclusion. Communication style plays a significant role in formulating risk perceptions of medication side effects. Training in pharmaceutical counseling should include special emphasis on effective language use.

Making sense of a new technology in clinical practice: a qualitative study of patient and physician perspectives

BACKGROUND

The number of new technologies for risk assessment available in health care is increasing. These technologies are intended to contribute to both improved care practices and improved patient outcomes. To do so however, there is a need to study how new technologies are understood and interpreted by users in clinical practice. The objective of this study was to explore patient and physician perspectives on the usefulness of a new technology to detect Cardiovascular Autonomic Neuropathy (CAN) in a specialist diabetes clinic. The technology is a handheld device that measures resting heart rate and conducts three cardiac autonomic reflex tests to evaluate heart rate variability.

METHODS

The study relied on three sources of data: observations of medical consultations where results of the CAN test were reported (n = 8); interviews with patients who had received the CAN test (n = 19); and interviews with physicians who reported results of the CAN test (n = 9). Data were collected at the specialist diabetes clinic between November 2013 and January 2014. Data were analysed using the concept of technological frames which is used to assess how physicians and patients understand and interpret the new technology.

RESULTS

Physicians generally found it difficult to communicate test results to patients in terms that patients could understand and to translate results into meaningful implications for the treatment of patients. Results of the study indicate that patients did not recall having done the CAN test nor recall receiving the results. Furthermore, patients were generally unsure about the purpose of the CAN test and the implications of the results.

DISCUSSION

Involving patients and physicians is essential when a new technology is introduced in clinical practice. This particularly includes the interpretation and communication processes related to its use.

CONCLUSIONS

The integration of a new risk assessment technology into clinical practice can be accompanied by several challenges. It is suggested that more information about the CAN test be provided to patients and that a dialogue-based approach be used when communicating test results to patients in order to best support the use of the technology in clinical practice.

The interpretation of phrases used to describe uncertainty in pathology reports

Histopathological reports frequently contain phrases describing the degree of uncertainty of the diagnosis. We examined the interpretations of such terms by cellular pathologists, other doctors, and medical students. 203 respondents estimated the degree of certainty they would associate with the following phrases in a cellular pathology report: the features are indicative of; raise the possibility of; are compatible with; are probably those of; are diagnostic of; are in keeping with; and are suggestive of. For all phrases assessed other than "diagnostic of", all groups showed a wide spread in the interpreted probability. For example, the probability associated with the term "in keeping with" by individual consultant pathologists ranged from 25 to 100%. This study demonstrates that pathologists vary widely in how they interpret the meaning of phrases describing probability that are commonly used in pathology reports. We suggest that this potential risk is highlighted during pathology training.

Is 15 per cent very common? Informing people about the risks of medication side effects

Objectives

To assess the general public's interpretation of the verbal descriptors for side effect frequency recommended for use in medicine information leaflets by a European Union (EU) guideline, and to examine the extent to which differences in interpretation affect people's perception of risk and their judgments of intention to comply with the prescribed treatment.

Method

Two studies used a controlled empirical methodology in which people were presented with a hypothetical, but realistic, scenario about visiting their general practitioner and being prescribed medication. They were given an explanation that focused on the side effects of the medicine, together with information about the probability of occurrence using either numerical percentages or the corresponding EU verbal descriptors. Interpretation of the descriptors was assessed. In study 2, participants were also required to make various judgments, including risk to health and intention to comply.

Key findings

In both studies, use of the EU recommended descriptors led to significant overestimations of the likelihood of particular side effects occurring. Study 2 further showed that the “overestimation” resulted in significantly increased ratings of perceived severity of side effects and risk to health, as well as significantly reduced ratings of intention to comply, compared with those for people who received the probability information in numerical form.

Conclusion

While it is recognised that the current findings require replication in a clinical setting, the European and national authorities should suspend the use of the EU recommended terms until further research is available to allow the use of an evidence-based approach.

How should risk be communicated to children: a cross-sectional study comparing different formats of probability information

BACKGROUND

Newborn screening, which identifies inherited disorders and sometimes carrier status, will increasingly involve health professionals in the provision of appropriate information and support to children and their families. The ability to understand carrier results relies on an understanding of probabilistic terms. However, little is known about how best to convey probabilistic medical information to children. Research with adult populations suggests information format significantly affects comprehension. This study aimed to explore which presentation format is most effective in conveying probabilistic information to children.

METHODS

A probabilistic task based on the cup game was used to measure which of five different formats was associated with greatest understanding in children aged 7-11 years old (n = 106). Formats used were verbal labels (e.g. rarely, sometimes), percentages, proportion-word (e.g. 1 in X), proportion-notation (e.g. 1:X) and pie charts. There was also an additional mixed format condition. In each trial a picture was presented of three cups, each with a different probability depicted beneath it, and the child was asked to select which cup was most likely to contain the ball. Three trials were presented per format. Children also rated how certain they were that they had answered correctly.

RESULTS

There was a significant relationship between format and comprehension scores. Post hoc tests showed children performed significantly better when probability was presented as a pie chart, in comparison to percentages, proportion-notation, proportion-word and mixed format trials. Furthermore, most children (84%) got all trials correct for this format and children were significantly more certain that their response was correct in the pie chart trials compared to all the other formats (p < 0.001). Significant positive correlations were found between self-ratings of certainty and comprehension of verbal labels, percentages and pie charts. Older age was also associated with better performance on all formats except percentages. Overall comprehension was calculated by summing the scores for the individual trials and this was independently associated with older age and higher IQ.

CONCLUSION

The results suggest that 7-11 year olds can understand probability information, but that the format used will significantly affect the accuracy and confidence with which children in this age group make judgements about the likelihood of an event. Of the formats studied, pie charts appear to be the optimal method of presenting probabilistic information to children in this age group. Health professionals and designers of health messages should be cognisant of this when communicating medical information to children aged 7-11 years old.

American society of clinical oncology clinical practice guideline update on the use of pharmacologic interventions including tamoxifen, raloxifene, and aromatase inhibition for breast cancer risk reduction

PURPOSE To update the 2002 American Society of Clinical Oncology guideline on pharmacologic interventions for breast cancer (BC) risk reduction. METHODS A literature search identified relevant randomized trials published since 2002. Primary outcome of interest was BC incidence (invasive and noninvasive). Secondary outcomes included BC mortality, adverse events, and net health benefits. An expert panel reviewed the literature and developed updated consensus guidelines. Results Seventeen articles met inclusion criteria. In premenopausal women, tamoxifen for 5 years reduces the risk of BC for at least 10 years, particularly estrogen receptor (ER) -positive invasive tumors. Women < or = 50 years of age experience fewer serious side effects. Vascular and vasomotor events do not persist post-treatment across all ages. In postmenopausal women, raloxifene and tamoxifen reduce the risk of ER-positive invasive BC with equal efficacy. Raloxifene is associated with a lower risk of thromboembolic disease, benign uterine conditions, and cataracts than tamoxifen in postmenopausal women. No evidence exists establishing whether a reduction in BC risk from either agent translates into reduced BC mortality. Recommendations In women at increased risk for BC, tamoxifen (20 mg/d for 5 years) may be offered to reduce the risk of invasive ER-positive BC, with benefits for at least 10 years. In postmenopausal women, raloxifene (60 mg/d for 5 years) may also be considered. Use of aromatase inhibitors, fenretinide, or other selective estrogen receptor modulators to lower BC risk is not recommended outside of a clinical trial. Discussion of risks and benefits of preventive agents by health providers is critical to patient decision making.

Assessing and Improving Research Participants' Understanding of Risk: Potential Lessons from the Literature on Physician-Patient Risk Communication

Evidence that lay people frequently misinterpret risk raises concerns for the ethical conduct of human research, which requires adequate disclosure, understanding, and appreciation of risk information. Review of the risk communication research literature suggests new directions for empirical research on human research ethics: Investigation is needed on how to best assess and improve potential and enrolled subjects' understanding of risk information. Preferences regarding the presentation of risk information and the effects of alternative presentation formats and decision aids on knowledge, trust, satisfaction, risk/benefit analysis, and perceptions of respectful treatment should be studied. Research is also needed on the effects of payment for research participation, the order in which study information is presented, and having one's own physician present risk information.

Communicating the uncertainty of harms and benefits of medical interventions

BACKGROUND

There is growing interest in shared medical decision making among patients, physicians, and policy makers. This requires patients to interpret increasing amounts of medical information, much of which is uncertain. Little is known about the optimal approaches to or outcomes of communicating uncertainty about the risks and benefits of treatments.

METHODS

The authors reviewed the literature on various issues related to uncertainty in decision making: conceptualizing uncertainty, identifying its potential sources, assessing uncertainty, potential methods of communicating uncertainty, potential outcomes of communicating uncertainty, and current practices and recommendations by expert groups on communicating uncertainty.

RESULTS

There are multiple sources of uncertainty in most medical decisions. There are conceptual differences in how researchers define uncertainty and its sources, as well as in its measurement. The few studies that have assessed alternate means of communicating uncertainty dealt mostly with presenting uncertainty about probabilities. Both patients' and physicians' interpretation of and responses to uncertainty may depend on their personal characteristics and values and may be affected by the manner in which uncertainty is communicated.

CONCLUSIONS

Research has not yet identified best practices for communicating uncertainty to patients about harms and benefits of treatment. More conceptual, qualitative, and quantitative studies are needed to explore fundamental questions about how people process, interpret, and respond to various types of uncertainty inherent in clinical decisions.

Risky communication: pitfalls in counseling about risk, and how to avoid them

A genetic counselor is often faced with the difficult task of conveying a set of complex and highly abstract factors associated with the client's risk of developing a familial disorder. The client is faced with the even more difficult task of making significant health-related decisions about an event which may or may not eventuate. Although there is a large corpus of research on this topic, much of the knowledge on risk communication is difficult to apply in a practical context. In this paper we draw together some insights on risk communication and decision-making under conditions of uncertainty, and apply them directly to the problem of communicating familial cancer risk. In particular, we focus on the distinction between individual risk and observed frequencies of adverse events, various framing effects, and contextualizing risk communication. We draw attention to some of the potential pitfalls in counseling about risk and offer avenues for circumventing them.

Do Notions of Risk Inform Patient Choice? Lessons from a Study of Prenatal Genetic Counseling

Risk modeling is an increasingly important part of clinical medicine; however, "risk status" is a complex notion, understood differently by patients and clinicians. Patients' ability to make informed choices about clinical procedures often requires that they interpret risk statistics, which may be difficult to understand and apply. In this article, which is based on a study of prenatal care in South Texas, we consider how notions of risk affect patient decisions about prenatal genetic testing. The term "risk" carries multiple meanings for clinicians and patients. These meanings may conflate concepts of danger and probability as well as muddle population risk and individual risk. We propose that failure to articulate the varied and contrasting meanings of risk held by clinicians and patients can undermine clinical communication and, thereby, hamper patients' ability to make autonomous, informed choices. Attending to these differences may prove useful in empowering patients to make truly informed decisions.

Systolic hypertension in older persons: complexities in clinical decision making

While the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) challenges clinicians to aggressively manage systolic hypertension, few data are available to guide clinicians in treating older persons with this condition. In older persons, hypertension treatment decisions must often rely on extrapolations and fall into a gray area where optimal choice for an individual patient may be unclear. In these instances, patients must understand the probable outcomes of options, consider the personal value they place on benefits vs. risks, and participate with their practitioners in deciding on treatment. Shared decision making is the process by which the health care provider and patient share all stages of the decision-making process and both discuss treatment preferences and agree on a final management plan. Our challenge as clinicians is to ensure that all older patients have the opportunity to be treated in a way that is evidence-based and patient-centered. As with most health care decisions in older persons, those regarding blood pressure control should promote evidence-based care that is complementary with individualized risk, benefit ratios, patient preferences, and treatment goals.

Improving patient safety through informatics tools for shared decision making and risk communication

This paper describes how informatics tools can support shared decision making and risk communication and thereby play an important role in enhancing patient safety. Using preference elicitation techniques and knowledge on risk communication, such tools can help patients understand their treatment options and associated short- and long-term benefits and risks, assist in the elicitation of patient preferences, and help patients and clinicians in making treatment choices with the highest likelihood of achieving desired patient outcomes. Important features of such tools are proposed, including: (1) Interactive tutorials to improve risk comprehension and prepare patients and clinicians for the decision making task; (2) choices between different presentation modes to meet patients' individual reading levels and presentation preferences; (3) risk calculations that account for individual risk profiles; (4) performance of necessary calculations to reach the actual decision; (5) automatic updates of evidence; and (6) the use of different preference-elicitation techniques.

Patients' understanding of risk associated with medication use: impact of European Commission guidelines and other risk scales

Patients want and need comprehensive and accurate information about their medicines so that they can participate in decisions about their healthcare. In particular, they require information about the likely risks and benefits that are associated with the different treatment options. However, to provide this information in a form that people can readily understand and use is a considerable challenge to healthcare professionals. One recent attempt to standardise the language of risk has been to produce sets of verbal descriptors that correspond to specific probability ranges, such as those outlined in the European Commission (EC) Pharmaceutical Committee guidelines in 1998 for describing the incidence of adverse effects. This paper provides an overview of a number of studies involving members of the general public, patients, and hospital doctors, that evaluated the utility of the EC guideline descriptors (very common, common, uncommon, rare, very rare). In all studies it was found that people significantly over-estimated the likelihood of adverse effects occurring, given specific verbal descriptors. This in turn resulted in significantly higher ratings of their perceived risks to health and significantly lower ratings of their likelihood of taking the medicine. Such problems of interpretation are not restricted to the EC guideline descriptors. Similar levels of misinterpretation have also been demonstrated with two other recently advocated risk scales (Calman's verbal descriptor scale and Barclay, Costigan and Davies' lottery scale). In conclusion, the challenge for risk communicators and for future research will be to produce a language of risk that is sufficiently flexible to take into account different perspectives, as well as changing circumstances and contexts of illness and its treatments. In the meantime, we urge the EC and other legislative bodies to stop recommending the use of specific verbal labels or phrases until there is a stronger evidence base to support their use.

Care not cure: dialogues at the transition

Physicians and patients find it hard to communicate when treatment fails to cure or control cancer. Communication barriers include fear of "giving up," losing the medical team, and discussing death. The quality of physician-patient communication affects important outcomes including patient distress, coping, and quality of life, and physician burnout. Communication skills that can be taught, learned, and maintained for physicians at all levels of training, and effective educational programs have been described. Research on communication skills training should focus on the best method of delivery, the "dose-response" effect, and how to measure success of training in complex health care environments.

Understanding risk and lessons for clinical risk communication about treatment preferences

This paper defines risk and its component elements and describes where clinical practice may be starting from in terms of what is reported in the literature about understanding risks and the information requirements of consumers. It notes briefly how theoretical models in the literature contribute to our understanding by providing a basis from which to summarise current evidence about the effects of healthcare interventions which address risks and risk behaviour. The situations or types of interventions in which risk related interventions are most effective are described, but a significant caveat is noted about the types of outcomes which have been reported in the literature and which are most appropriate to evaluate. The effects of "framing" variations in the information given to consumers and the ethical dilemmas these raise for a debate about "informed choice" in healthcare programmes are discussed. In response to both the practical and ethical dilemmas that arise from the current evidence, some of the areas where attention should be focused in the future are outlined so that both health gain and informed choice might be achieved. These include the use of decision aids, although their implementation is not widespread at present. Lessons from the current literature on how further progress can be made towards improved communication, discussion between professionals and consumers, and enhancing informed choice are discussed.

Increasing informed uptake and non-uptake of screening: evidence from a systematic review

OBJECTIVE

To report data relating to the informed uptake of screening tests.

SEARCH STRATEGY

Electronic databases, bibliographies and experts were used to identify relevant published and unpublished studies up until August 2000.

INCLUSION CRITERIA

RCTs, quasi-RCTs and controlled trials of interventions aimed at increasing the informed uptake of screening. All participants were eligible as defined by the entry criteria of individual programmes. Studies had to report actual uptake and meet three out of four criteria used to define informed uptake.

DATA EXTRACTION AND SYNTHESIS

Relevant studies were identified, data extracted and their validity assessed by two reviewers independently. Outcome data included screening uptake, knowledge, informed decision-making and attitudes to screening. A random-effects model was used to calculate individual relative risks and 95% confidence intervals.

MAIN RESULTS

Six controlled trials (five RCTs and one quasi-RCT), focusing on antenatal and prostate specific antigen screening, were included. All reported risks/benefits of screening and assessed knowledge. Two also assessed decision-making. Two reported risks/benefits to all randomized groups and evaluated different ways of presenting information. Neither found that interventions such as videos, information leaflets with decision trees, or touch screen computers conveyed any additional benefits over well-prepared leaflets.

CONCLUSIONS

There is some evidence to suggest that changing the format of informed choice interventions in screening does not alter knowledge, satisfaction or decisions about screening. It is not clear whether informed choice in screening affects uptake. More well-designed RCTs are required and further research should also be directed towards the development of a valid instrument for measuring all components of informed choice in screening.

Adolescents' and adults' understanding of probability expressions

PURPOSE

To examine whether there are differences between adolescents and adults in their interpretation of probability terms.

METHODS

Participants were 20 fifth graders, 54 seventh graders, 45 ninth graders, and 34 young adults (mean adult age = 26.24 years, standard deviation = 2.09) from the San Francisco Bay area. They completed a self-administered survey asking them to assign percentage estimates (0% to 100%) to 30 randomly ordered probability terms.

RESULTS

Significant age differences in the mean percentage estimates for 8 of the 30 terms were shown. Moreover, we found large variation in the interpretation of most probability terms studied, with larger variation among the adolescents than adults. Finally, all age groups had some difficulty correctly differentiating between "possibly" and "probably".

CONCLUSIONS

Owing to wide variation in the interpretation of probability terms, both within and across age groups, we suggest health practitioners use percentages rather than probability terms to convey risk to both adolescents and adults.

The effectiveness of one-to-one risk communication interventions in health care: a systematic review

OBJECTIVES

To assess whether risk-communication interventions are associated with changes in patient knowledge, attitudes, and behaviors, and to identify aspects of these interventions that modify these effects.

DESIGN

Systematic review.

DATA SOURCES

96 studies from the period 1985-1996 retrieved by electronic searching of eight databases, hand searching of four journals, contacting key authors, and reference list searching.

MAIN OUTCOME MEASURES

The effect size of the principal outcome was identified from each study. Outcomes measuring behavioral change were preferred; if these were not available, knowledge, anxiety, or risk perceptions were used, according to the focus of the study. Data were available to calculate the principal effect sizes for 82 of the studies.

ANALYSIS

Meta-regression.

RESULTS

The methodologic qualities of the studies varied. Nevertheless, risk-communication interventions generally had positive (beneficial) effects. Interventions addressing treatment choices were associated with larger effects than were those in other contexts, such as prevention or screening. Interventions using individual risk estimates were associated with larger effects than were those using more general risk information. Two design variables were identified as effect modifiers: randomized controlled trials were associated with smaller effects than other designs, and dichotomous outcomes were associated with larger effects than continuous outcomes.

CONCLUSIONS

Risk communication interventions may be most productive if they include individual risk estimates in the discussion between professional and patient. Patient decisions about treatment appear more amenable to change by these interventions than attendance for screening or modification of risky behavior.

Patients' perceptions of omitted examinations and tests: A qualitative analysis

OBJECTIVES

To understand the nature of patients' expectations for parts of the physical examination and for diagnostic testing and the meaning patients ascribe to their desires.

DESIGN

Qualitative inquiry based on patient interviews and focused on perceived diagnostic omissions as "critical incidents."

SETTING

Three general internal medicine practices (21 practitioners) in one mid-sized northern California city.

PATIENTS

Of 687 patients visiting these practice sites and completing a detailed questionnaire, 125 reported one or more omissions of care and 90 completed an in-depth telephone interview. This study focuses on the 56 patients interviewed who did not receive desired components of the physical examination or diagnostic tests.

MEASUREMENTS

Qualitative analysis of key themes underlying patients' unmet expectations for examinations and tests, as derived from verbatim transcripts of the 56 interviews.

MAIN RESULTS

The 56 patients perceived a total of 113 investigative omissions falling into four broad categories: physical examination (47 omissions), conventional tests (43), high-cost tests (10), and unspecified investigations (13). Patients considered omitted investigations to have value along both pragmatic and symbolic dimensions. Diagnostic maneuvers had pragmatic value when they were seen to advance the technical aims of diagnosis, prognosis, or therapy. They had symbolic value when their underlying purpose was to enrich the patient-physician relationship. Patients in this study were often uncomfortable with clinical uncertainty, distrusted empiric therapy, endorsed early detection, and frequently interpreted failure to examine or test as failure to care.

CONCLUSIONS

When patients express disappointment at failing to receive tests or examinations, they may actually be expressing concerns about the basis of their illness, the rationale for therapy, or the physician-patient relationship.