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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. [ABSTRACT FROM AUTHOR]

While cancer screening guidelines increasingly recommend incorporating life expectancy estimates to inform screening decisions for older adults, little is known about how this happens in practice. This review summarizes current knowledge about primary care clinician and older adult (65+) perspectives about use of life expectancy to guide cancer screening decisions. Clinicians report operational barriers, uncertainty, and hesitation around use of life expectancy in screening decisions. They recognize it may help them more accurately weigh benefits and harms but are unsure how to estimate life expectancy for individual patients. Older adults face conceptual barriers and are generally unconvinced of the benefits of considering their life expectancy when making screening decisions. Life expectancy will always be a difficult topic for clinicians and patients, but there are advantages to incorporating it in cancer screening decisions. We highlight key takeaways from both clinician and older adult perspectives to guide future research. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Decision aid developers have to convey complex task-specific numeric information in a way that minimizes bias and promotes understanding of the options available within a particular decision. Whereas our companion paper summarizes fundamental issues, this article focuses on more complex, task-specific aspects of presenting numeric information in patient decision aids. Methods: As part of the International Patient Decision Aids Standards third evidence update, we gathered an expert panel of 9 international experts who revised and expanded the topics covered in the 2013 review working in groups of 2 to 3 to update the evidence, based on their expertise and targeted searches of the literature. The full panel then reviewed and provided additional revisions, reaching consensus on the final version. Results: Five of the 10 topics addressed more complex task-specific issues. We found strong evidence for using independent event rates and/or incremental absolute risk differences for the effect size of test and screening outcomes. Simple visual formats can help to reduce common judgment biases and enhance comprehension but can be misleading if not well designed. Graph literacy can moderate the effectiveness of visual formats and hence should be considered in tool design. There is less evidence supporting the inclusion of personalized and interactive risk estimates. Discussion: More complex numeric information. such as the size of the benefits and harms for decision options, can be better understood by using incremental absolute risk differences alongside well-designed visual formats that consider the graph literacy of the intended audience. More research is needed into when and how to use personalized and/or interactive risk estimates because their complexity and accessibility may affect their feasibility in clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: Parents who face goals-of-care tracheostomy decisions may lack an understanding of challenges affecting their child's and family's long-term quality of life (QOL) to accurately forecast possible outcomes for decision making. We sought to examine whether and how parents' narratives of the child's and family's long-term QOL influence parental tracheostomy decisions and forecasting. Method: We recruited US adult Amazon Mechanical Turk participants (N = 1966) who self-reported having a child (<6 y old) or planning a pregnancy within 5 y. Participants read a vignette about making a tracheostomy decision for their hypothetical neurologically impaired baby. They were randomized to 1 of the following 4 conditions: 1) Baby QOL narratives, 2) Family QOL narratives, 3) Baby QOL + Family QOL narratives, and 4) control: no narratives. They then made a decision about whether or not to pursue tracheostomy, forecasted their concerns about the baby's and family's QOL, reported their values and social norm beliefs about tracheostomy, comfort care, and parental medical decision making, and completed individual differences scales and demographics. Results: Controlling for individual characteristics, participants in the Baby QOL and Baby QOL + Family QOL conditions were less likely to choose tracheostomy as compared with the control (odds ratio [OR] = 0.38 and 0.25, respectively, P < 0.001). Fewer participants in the Family QOL condition chose tracheostomy compared with the control, but this difference was not statistically significant (OR = 0.70, P = 0.11). Moreover, narratives increased pessimistic forecasting, which was associated with less interest in tracheostomy. Conclusion: Narratives clarifying long-term implications of pursuing tracheostomy have the potential to influence forecasting and decisions. Narrative-based interventions may be valuable in other situations in which forecasting errors are common. [ABSTRACT FROM AUTHOR]

The 10-item validated Medical Maximizer-Minimizer Scale (MMS-10) assesses patients' preferences for aggressive v. more passive approaches to health care. However, because many research or clinical situations do not allow for use of a 10-item scale, we developed a single-item maximizer-minimizer elicitation question (the MM1) based on our experiences describing the construct to patient groups, clinical researchers, and the public. In 2 large samples of US adults (N = 368 and N = 814), the correlation between MMS-10 scores and the MM1 was.52 and.60, respectively. Both measures were robust predictors of medical preferences in a set of 12 hypothetical scenarios, and both had strong (and roughly equivalent) associations with 7 self-report measures of health care utilization. Our results demonstrate that the MM1 is a valid, brief elicitation of maximizing-minimizing preferences that can be used in clinical or research contexts where the 10-item scale is infeasible. [ABSTRACT FROM AUTHOR]

Background. High-quality health decisions are often defined as those that are both evidence informed and values congruent. A values-congruent decision aligns with what matters to those most affected by the decision. Values clarification methods are intended to support values-congruent decisions, but their effects on values congruence are rarely evaluated. Methods. We tested 11 strategies, including the 3 most commonly used values clarification methods, across 6 between-subjects online randomized experiments in demographically diverse US populations (n 1 = 1346, n 2 = 456, n 3 = 840, n 4 = 1178, n 5 = 841, n 6 = 2033) in the same hypothetical decision. Our primary outcome was values congruence. Decisional conflict was a secondary outcome in studies 3 to 6. Results. Two commonly used values clarification methods (pros and cons, rating scales) reduced decisional conflict but did not encourage values-congruent decisions. Strategies using mathematical models to show participants which option aligned with what mattered to them encouraged values-congruent decisions and reduced decisional conflict when assessed. Limitations. A hypothetical decision was necessary for ethical reasons, as we believed some strategies may harm decision quality. Later studies used more outcomes and covariates. Results may not generalize outside US-based adults with online access. We assumed validity and stability of values during the brief experiments. Conclusions. Failing to explicitly support the process of aligning options with values leads to increased proportions of values-incongruent decisions. Methods representing more than half of values clarification methods commonly in use failed to encourage values-congruent decisions. Methods that use models to explicitly show people how options align with their values offer more promise for helping people make decisions aligned with what matters to them. Decisional conflict, while arguably an important outcome in and of itself, is not an appropriate proxy for values congruence. [ABSTRACT FROM AUTHOR]

Purpose. People vary in their general preferences for more v. less health care, and the validated Medical Maximizing-Minimizing Scale (MMS) reliably measures this orientation. Medical maximizers (people scoring highly on the MMS) prefer to receive more health care visits, medications, tests, and treatments, whereas minimizers prefer fewer services. However, it is unclear how maximizing-minimizing preferences relate to willingness to pursue appropriate health care. We hypothesized that minimizers are at increased risk of rejecting evidence-based high-benefit care and that maximizers are at risk of wanting low-benefit care. Design. In total, 785 US adults recruited through an online panel expressed preferences to receive or forgo a health care intervention in 18 hypothetical scenarios. In 8 scenarios, the intervention was high benefit per evidence-based guidelines. In the remaining 10 scenarios, the intervention was low benefit. We assessed associations between participants' MMS score and their preferences for medical intervention in each scenario using regression analyses that adjusted for hypochondriasis, health risk tolerance, health status, and demographic variables. Results. MMS score was significantly associated with preferences in all 18 scenarios after adjusting for other variables. The MMS uniquely explained 11% of the variance in preferences for high-benefit care and 29% of the variance in preferences for low-benefit care. Differences between strong minimizers (10th percentile) and strong maximizers (90th percentile) across the 18 scenarios ranged from 5.6 to 32.3 points on a 1 to 100 preference scale. Conclusions. The MMS reliably predicts people's willingness to pursue appropriate care, both when appropriate care means taking high-benefit actions and when appropriate care means avoiding low-benefit actions. Targeting and tailoring messages according to maximizing-minimizing preferences might increase the effectiveness of both efforts to reduce overutilization of low-benefit services and campaigns to support uptake of high-benefit care. [ABSTRACT FROM AUTHOR]

Purpose. Patient portals of electronic health record systems currently present patients with tables of laboratory test results, but visual displays can increase patient understanding and sensitivity to result variations. We sought to assess physician preferences and concerns about visual display designs as potential motivators or barriers to their implementation. Methods. In an online survey, 327 primary care physicians (>50% patient care time) recruited through the online e-community/survey research firm SERMO compared hemoglobin A1c (HbA1c) test results presented in table format to various visual displays (number line formats) previously tested in public samples. Half of participants also compared additional visual formats displaying target goal ranges. Outcome measures included preferred display format and whether any displays were unacceptable, would change physician workload, or would induce liability concerns. Results. Most (85%–89%) respondents preferred visual displays over tables for result communications both to patients tested for diagnosis purposes and to diagnosed patients, with a design with color-coded categories most preferred. However, for each format (including tables), 11% to 23% rated them as unacceptable. Most respondents also preferred adding goal range information (in addition to standard ranges) for diagnosed patients. While most physicians anticipated no workload changes, 19% to 32% anticipated increased physician workload while 9% to 28% anticipated decreased workload. Between 32% and 40% had at least some liability concerns. Conclusions. Most primary care physicians prefer visual displays of HbA1c test results over table formats when communicating results to patients. However, workload and liability concerns from a minority of physicians represent a barrier for adoption of such designs in clinical settings. [ABSTRACT FROM AUTHOR]

Academic writers and presenters need concrete activities to help them learn how to communicate more effectively. We describe such a tool, called “Half-Life Your Message,” which is adapted from a commonly used improvisational theater game and can be applied in three minutes to distill a central thesis for any communication effort. Users can increase the value provided by Half-Life Your Message by scaffolding its application with an introduction and opportunity to self-reflect and debrief. We emphasize the tool’s utility based on our experiences in using it ourselves and in teaching it to undergraduates, graduate students, and faculty. [ABSTRACT FROM AUTHOR]

Purpose: The recently developed Medical Maximizer-Minimizer Scale (MMS) assesses individual differences in preferences for active v. passive medical treatment. We hypothesized that men’s maximizing-minimizing preferences might have relevance in the case of prostate-specific antigen (PSA) screening, since there is considerable variability in men’s preference for being screened even among men who are informed that harm is more likely than benefit. The current research examined whether MMS preferences predict how men respond to didactic information and narrative stories about PSA screening. Design: US men 40+ years old (N = 1208) participated in an online survey. Men viewed information about PSA screening in 3 phases and provided their preference for screening after each phase. Phase 1 described what PSA screening is. Phase 2 added didactic information about screening risks and benefits. Phase 3 added narrative stories; men were randomized to receive stories about 1) physical harm, 2) emotional harm, 3) overdiagnosis, or 4) all 3 stories. Participants also completed the validated MMS. Results: After receiving basic information, 76.8% of men wanted PSA screening. After receiving information about risks and benefits, 54.8% wanted screening (a significant reduction, P < 0.001). Men who changed their preferences were significantly more likely to be minimizers than maximizers; most men with maximizing tendencies wanted screening after both the didactic information and narratives, whereas most men with minimizing tendencies did not want the test after receiving information. Conclusions: Men who prefer a more minimizing approach to medicine are more responsive to evidence supporting limiting or forgoing screening than men who prefer a maximizing approach. [ABSTRACT FROM AUTHOR]

While family history (FH) collection is a core responsibility of pediatric primary care providers (PCPs), few details about this practice are known. We surveyed a random national sample of 1200 pediatricians and family medicine physicians about FH collection practices. A total of 86% of respondents (n = 289 pediatricians; n = 152 family medicine physicians) indicated that they collect a FH “always” or “most of the time” with 77% reporting collection at the first visit, regardless of whether it is a health maintenance or problem-focused visit. Less than half ask about relatives other than parents, siblings, or grandparents (36.3%). Among respondents, 42% routinely update the FH at every health maintenance visit while 6% updated FH at every visit. Pediatric PCPs use a variety of methods to collect a FH that is limited in scope and variably updated. Our results suggest that interventions are needed to help pediatric PCPs collect a systematic, efficient, and updated FH. [ABSTRACT FROM AUTHOR]

Background. Breast cancer patients’ misunderstanding of their systemic cancer recurrence risk has consequences on decision-making and quality of life. Little is known about how women derive their risk estimates. Methods. Using Los Angeles and Georgia’s SEER registries (2014–2015), a random sample of early-stage breast cancer patients was sent surveys about 2 to 3 months after surgery (N = 3930; RR, 68%). We conducted an inductive thematic analysis of open-ended responses about why women chose their risk estimates in a uniquely large sub-sample (N = 1,754). Clinician estimates of systemic recurrence risk were provided for patient sub-groups with DCIS and with low-, intermediate-, and high-risk invasive disease. Women’s perceived risk of systemic recurrence (0% to 100%) was categorized as overestimation, reasonably accurate estimation, or underestimation (0% for invasive disease) and was compared across identified factors and by clinical presentation. Results. Women identified 9 main factors related to their clinical experience (e.g., diagnosis and testing; treatment) and non-clinical beliefs (e.g., uncertainty; spirituality). Women who mentioned at least one clinical experience factor were significantly less likely to overestimate their risk (12% v. 43%, P < 0.001). Most women who were influenced by “communication with a clinician” had reasonably accurate recurrence estimates (68%). “Uncertainty” and “family and personal history” were associated with overestimation, particularly for women with DCIS (75%; 84%). “Spirituality, religion, and faith” was associated with an underestimation of risk (63% v. 20%, P < 0.001). Limitations. The quantification of our qualitative results is subject to any biases that may have occurred during the coding process despite rigorous methodology. Conclusions. Patient-clinician communication is important for breast cancer patients’ understanding of their numeric risk of systemic recurrence. Clinician discussions about recurrence risk should address uncertainty and relevance of family and personal history. [ABSTRACT FROM AUTHOR]

Few national studies have asked parents how to improve the childhood vaccination process. We surveyed a nationally representative online panel of parents on how to improve this process, rationales for nonstandard approaches, and alternatives to the standard schedule. Twelve percent of the 1222 respondents reported using nonstandard approaches: 3.2% used a specific schedule, 6.0% had no specific schedule, and 2.5% declined all vaccinations. The most common rationales were that too many vaccines are given at once, and discomfort with vaccine ingredients. Regarding how to improve the process, parents using the standard schedule most often said nothing could be improved (51%), or better vaccine information (22%). Those using nonstandard approaches most often would have liked more choice (40%) or better vaccine information (26%). Parents’ experiences with the vaccination process could be improved by offering information prior to visits, giving more information about side effects, and allowing more flexibility about vaccine scheduling. [ABSTRACT FROM AUTHOR]

Background. Online tools such as Adjuvant! provide tailored estimates of the possible outcomes of adjuvant therapy options available to breast cancer patients. The graphical format typically displays 4 outcomes simultaneously: survival, mortality due to cancer, other-cause mortality, and incremental survival due to adjuvant treatment. Objective. To test whether simpler formats that present only baseline and incremental survival would improve comprehension of the relevant risk statistics and/or affect treatment intentions. Design. Randomized experimental manipulation of risk graphics shown included in Internet-administered survey vignettes about adjuvant therapy decisions for breast cancer patients with ER + tumors. Participants. Demographically diverse, stratified random samples of women ages 40 to 74 y recruited from an Internet research panel. Intervention. Participants were randomized to view either pictographs (icon arrays) that displayed all 4 possible outcomes or pictographs that showed only survival outcomes. Measurements. Comprehension of key statistics, task completion times, graph evaluation ratings, and perceived interest in adjuvant chemotherapy. Results. In the primary study (N = 832), participants who viewed survival-only pictographs had better accuracy when reporting the total chance of survival with both chemotherapy and hormonal therapy (63% v. 50%, P < 0.001), higher graph evaluation ratings (x = 7.98 v. 7.67, P = 0.04), and less interest in adding chemotherapy to hormonal therapy (43% v. 50%, P = 0.04; adjusted odds ratio [OR] = 0.68, P = 0.008). A replication study (N = 714) confirmed that participants who viewed survival-only graphs had higher graph evaluation ratings (x = 8.06 v. 7.72, P = 0.04) and reduced interest in chemotherapy (OR=0.67,P=0.03). Limitations. Studies used general public samples; actual patients may process risk information differently. Conclusions. Taking a ‘‘less is more’’ approach by omitting redundant mortality outcome statistics can be an effective method of risk communication and may be preferable when using visual formats such as pictographs. [ABSTRACT FROM PUBLISHER]

The author reflects on whether it is useful or counterproductive to provide patients with the other side of the equation in vivid detail and whether doctors should seek to provide patients with a realistic preview of the experiences they will face. It provides the reasons why realistic previews may be useful in medicine such as giving the patient time before the experience to imagine how he or she will cope with the challenges and recalibrating patient expectations.

Purpose. When making medical decisions, people often care not only about what happens but also about whether the outcome was a result of actions voluntarily taken or a result of inaction. This study assessed the proportion of people choosing nonoptimal treatments (treatments which reduced survival chances) when presented with hypothetical cancer scenarios which varied by outcome cause.Methods. A randomized survey experiment tested preferences for curing an existent cancer with 2 possible treatments (medication or surgery) and 2 effects of treatment (beneficial or harmful). Participants were 112 prospective jurors in the Philadelphia County Courthouse and 218 visitors to the Detroit-Wayne County Metropolitan Airport.Results. When treatment was beneficial, 27% of participants rejected medication, whereas only 10% rejected surgery with identical outcomes ( 2 = 5.87, P < 0.02). When treatment was harmful, participants offered surgery were significantly more inclined to take action (65% v. 38%, 2= 11.40, P = 0.001), even though doing so reduced overall survival chances.Conclusions. Faced with hypothetical cancer diagnoses, many people say they would pursue treatment even if doing so would increase their chance of death. This tendency toward active treatment is notably stronger when the treatment offered is surgery instead of medication. Our study suggests that few people can imagine standing by and doing nothing after being diagnosed with cancer, and it should serve to remind clinicians that, for many patients, the best treatment alternative may not only depend on the medical outcomes they can expect to experience but also on whether those outcomes are achieved actively or passively. [ABSTRACT FROM PUBLISHER]

The author discourages the use of the 1-in-X risk communication format in clinical practice. He cites the results of a study which support the conclusion that 1-in-X formats reduced patient understanding of risk information and tended to increase risk perceptions. He also comments on a meta-analysis of five separate studies further exploring the 1-in-X effect published within the issue.

The author discusses the use of 1-in-X formats to communicate risk. An overview of the results of economists David Grether and Charlie Plott's series of experiments designed to disprove the existence of preference reversals is given. The author notes the use of the formats in medical risk communication, particularly in the fields of genetic counseling and obstetrics. He notes that continued use of the formats in medical risk communication is intolerable.

An essay is presented on the role of simplifying medical data for more educated patient risk and treatment decisions. It offers studies on modern systems, such as Adjuvant! Online, which transforms medical data into more graphic and streamlines information relevant to the patient's information needs. The author relates how he ventured in his studies after meeting with Dr. Dan Hayes to discuss patient decision-making problems in breast cancer care.

While patients often receive risk information, exactly what constitutes being “informed” about health risks is often unclear. Patients have specific needs, such as avoiding being surprised by a possible outcome and making complex risk trade-off decisions. Yet all risk information is not equally informative for those needs. In this article, I present a taxonomy of seven risk concepts that vary in their inherent precision and evaluability. Congruent with the “less is more” concept, I argue that risk communications should use formats that are tailored to message recipients’ specific informational needs. Simpler formats can be used when patients only need to order risks, while more complex numerical probability statements will be necessary when patients need to assess differences in risk magnitude and put those differences into meaningful context. Selecting need-congruent formats when designing communications about risks to patients is a novel approach that may better support patients’ health care decision making. [ABSTRACT FROM AUTHOR]

Background . Although many researchers have examined patient involvement and patient-provider interactions within specific clinical environments, no nationally representative data exist to characterize patient perceptions of decision making and patient-provider communications across multiple common medical decisions.Objective. To identify deficits and variations in the patient experience of making common medical decisions about initiation of prescription medications for hypertension, hypercholesterolemia, or depression; screening tests for colorectal, breast, or prostate cancer; and surgeries for knee or hip replacement, cataracts, or lower back pain, as well as to identify factors associated with patient confidence in the decisions.Setting. National sample of US adults identified by random-digit dialing.Design . Cross-sectional survey conducted from November 2006 to May 2007. Participants. Included 2473 English-speaking adults age 40 and older who reported undertaking 1 or more of the above 9 medical actions or discussing doing so with a health care provider within the past 2 years. Measurements. Patients reported who initiated discussions and made the final decisions, how much discussion of pros and cons occurred, whether they were asked about their preferences, and their confidence that the decision “was the right one.”Results. The proportion of patient-driven decisions varied significantly across decisions (range: blood pressure: 16% to knee/hip replacement: 48%). Most patients (78%—85%) reported that providers made a recommendation, and such recommendations generally favored taking medical action. Fewer patients reported that providers asked them about their preferences (range: colon cancer screening: 34% to knee/hip replacement: 80%) or discussed reasons not to take action (range: breast cancer screening: 20% to lower back surgery: 80%). Decision confidence was higher among patients who reported primarily making the decision themselves (odds ratio [OR] = 14.6, P < 0.001) or having been asked for their preference (OR = 1.32, P < 0.01) and was lower among patients whose patient-provider discussions included cons (OR = 0.74, P = 0.008).Limitations. Recall biases may affect patients’ memories of their decision-making processes.Conclusions. DECISIONS participants reported wide variations in the proportion of discussions that included a conversation about reasons not to take action or a conversation about patients’ preferences about what they would like to do. These factors appear directly related to patients’ confidence that the decision was “right.” [ABSTRACT FROM PUBLISHER]

Background. To make informed decisions, patients must have adequate knowledge of key decision-relevant facts.Objective.To determine adults’ knowledge about information relevant to common types of medication, screening, or surgery decisions they recently made.Setting.National sample of US adults identified by random-digit dialing.Design. Cross-sectional survey conducted between November 2006 and May 2007.Participants. A total of 2575 English-speaking adults aged 40 y or older who reported having discussed the following medical decisions with a health care provider within the previous 2 y: prescription medications for hypertension, hypercholesterolemia, or depression; screening tests for colorectal, breast, or prostate cancer; or surgeries for knee/hip replacement, cataracts, or lower back pain.Measurements. Participants answered knowledge questions and rated the importance of their health care provider, family/friends, and the media as sources of information.Results.Accuracy rates varied widely across questions and decision contexts. For example, patients considering cataract surgery were more likely to correctly estimate recovery time than those patients considering lower back pain or knee/hip replacement (78% v. 29% and 39%, P < 0.001). Similarly, participants were more knowledgeable of facts about colorectal cancer screening than those who were asked about breast or prostate cancer. Finally, respondents were consistently more knowledgeable on comparable questions about blood pressure medication than cholesterol medication or antidepressants. The impact of demographic characteristics and sources of information also varied substantially. For example, blacks had lower knowledge than whites about cancer screening decisions (odds ratio [OR] = 0.57; 95% confidence interval [CI] = 0.43, 0.75; P = 0.001) and medication (OR = 0.77; 95% CI = 0.60, 0.97; P = 0.03) even after we controlled for other demographic factors. The same was not true for surgical decisions.Limitations. The questions did not measure all knowledge relevant to informed decision making, were subject to recall biases, and may have assessed numeracy more than knowledge.Conclusions.Patient knowledge of key facts relevant to recently made medical decisions is often poor and varies systematically by decision type and patient characteristics. Improving patient knowledge about risks, benefits, and characteristics of medical procedures is essential to support informed decision making. [ABSTRACT FROM PUBLISHER]