What are the chances? Evaluating risk and benefit information in consumer health materials.

Much consumer health information addresses issues of disease risk or treatment risks and benefits, addressing questions such as "How effective is this treatment?" or "What is the likelihood that this test will give a false positive result?" Insofar as it addresses outcome likelihood, this information is essentially quantitative in nature, which is of critical importance, because quantitative information tends to be difficult to understand and therefore inaccessible to consumers. Information professionals typically examine reading level to determine the accessibility of consumer health information, but this measure does not adequately reflect the difficulty of quantitative information, including materials addressing issues of risk and benefit. As a result, different methods must be used to evaluate this type of consumer health material. There are no standard guidelines or assessment tools for this task, but research in cognitive psychology provides insight into the best ways to present risk and benefit information to promote understanding and minimize interpretation bias. This paper offers an interdisciplinary bridge that brings these results to the attention of information professionals, who can then use them to evaluate consumer health materials addressing risks and benefits.

[1]  Wibecke Brun,et al.  Verbal probabilities: Ambiguous, context-dependent, or both? , 1988 .

[2]  L. Cosmides,et al.  Are humans good intuitive statisticians after all? Rethinking some conclusions from the literature on judgment under uncertainty , 1996, Cognition.

[3]  M. Ruffin,et al.  Patients' interpretation of qualitative probability statements. , 1994, Archives of family medicine.

[4]  Thomas S. Wallsten,et al.  Base rate effects on the interpretations of probability and frequency expressions , 1986 .

[5]  J. G. Hollands,et al.  The visual communication of risk. , 1999, Journal of the National Cancer Institute. Monographs.

[6]  A. Tversky,et al.  Judgment under Uncertainty: Heuristics and Biases , 1974, Science.

[7]  Michael Theil,et al.  The role of translations of verbal into numerical probability expressions in risk management: a meta-analysis , 2002 .

[8]  The accuracy of patients' judgments of disease probability and test sensitivity and specificity. , 1998, The Journal of family practice.

[9]  Dennis T. Kennedy,et al.  An Applied Study Using the Analytic Hierarchy Process to Translate Common Verbal Phrases to Numerical Probabilities , 1997 .

[10]  D. Grimes,et al.  Patients' understanding of medical risks: implications for genetic counseling. , 1999, Obstetrics and gynecology.

[11]  R. Croyle,et al.  Risk communication in genetic testing for cancer susceptibility. , 1999, Journal of the National Cancer Institute. Monographs.

[12]  S. Epstein,et al.  Conflict between intuitive and rational processing: when people behave against their better judgment. , 1994, Journal of personality and social psychology.

[13]  Gerd Gigerenzer,et al.  Adaptive Thinking: Rationality in the Real World , 2000 .

[14]  B. Rimer,et al.  General Performance on a Numeracy Scale among Highly Educated Samples , 2001, Medical decision making : an international journal of the Society for Medical Decision Making.

[15]  L. Baker,et al.  Consumer Health Information for Public Librarians , 2002 .

[16]  Lisa M. Schwartz,et al.  How can we help people make sense of medical data? , 1999, Effective clinical practice : ECP.

[17]  C. McHorney,et al.  Frequency or Probability? A Qualitative Study of Risk Communication Formats Used in Health Care , 2001, Medical decision making : an international journal of the Society for Medical Decision Making.

[18]  S. Epstein,et al.  The Generality of the Ratio-Bias Phenomenon , 1995 .

[19]  R. Rudd,et al.  Health and Literacy: A Review of Medical and Public Health Literature , 1999 .

[20]  D. Budescu,et al.  Preferences and reasons for communicating probabilistic information in verbal or numerical terms , 1993 .

[21]  Junji Otaki,et al.  Interpretation of and preference for probability expressions among Japanese patients and physicians. , 2002, Family practice.

[22]  Lisa M. Schwartz,et al.  The Role of Numeracy in Understanding the Benefit of Screening Mammography , 1997, Annals of Internal Medicine.

[23]  Peter Sedlmeier BasicBayes: A tutor system for simple Bayesian inference , 1997 .

[24]  K. Ballard,et al.  Making decisions about hormone replacement therapy , 2003, BMJ : British Medical Journal.

[25]  PhD Dr. Dennis J. Mazur MD,et al.  How age, outcome severity, and scale influence general medicine clinic patients’ interpretations of verbal probability terms , 2007, Journal of General Internal Medicine.

[26]  How medical professionals evaluate expressions of probability. , 1987, The New England journal of medicine.

[27]  J. Rudski,et al.  Pictorial versus Textual Information and the Ratio-Bias Effect , 2002, Perceptual and motor skills.

[28]  K W Gish,et al.  The Patient Informatics Consult Service (PICS): an approach for a patient-centered service. , 2001, Bulletin of the Medical Library Association.

[29]  Valerie A. Clarke,et al.  Ratings of Orally Presented Verbal Expressions of Probability by a Heterogeneous Sample , 1992 .

[30]  Gary L. Brase Which Statistical Formats Facilitate What Decisions? The Perception and Influence of Different Statistical Information Formats , 2002 .

[31]  M. Ruffin Cancer risk factors. , 1989, American family physician.

[32]  Eric Aaron,et al.  Frequency vs. Probability Formats: Framing the Three Doors Problem , 1998 .

[33]  K. Calman,et al.  Cancer: science and society and the communication of risk , 1996, BMJ.

[34]  E. McGlynn,et al.  What Cognitive Science Tells Us about the Design of Reports for Consumers , 2002, Medical care research and review : MCRR.

[35]  R Fuller,et al.  Risk communication and older people-understanding of probability and risk information by medical inpatients aged 75 years and older. , 2001, Age and ageing.

[36]  R F Nease,et al.  Perceptions of breast cancer risk and screening effectiveness in women younger than 50 years of age. , 1995, Journal of the National Cancer Institute.

[37]  Sirkka L. Jarvenpaa,et al.  Graphic displays in decision making — the visual salience effect , 1990 .

[38]  G Gigerenzer,et al.  Using natural frequencies to improve diagnostic inferences , 1998, Academic medicine : journal of the Association of American Medical Colleges.

[39]  D. Ellsberg Decision, probability, and utility: Risk, ambiguity, and the Savage axioms , 1961 .

[40]  Lisa M. Schwartz,et al.  Assessing Values for Health: Numeracy Matters , 2001, Medical decision making : an international journal of the Society for Medical Decision Making.

[41]  R Fuller,et al.  How informed is consent? Understanding of pictorial and verbal probability information by medical inpatients , 2002, Postgraduate medical journal.

[42]  Gerd Gigerenzer,et al.  How to Improve Bayesian Reasoning Without Instruction: Frequency Formats , 1995 .

[43]  Donald A. Norman,et al.  Things That Make Us Smart: Defending Human Attributes In The Age Of The Machine , 1993 .

[44]  Gary L. Brase,et al.  Individuation, counting, and statistical inference: The role of frequency and whole-object representations in judgment under uncertainty , 1998 .

[45]  M. Biehl,et al.  Adolescents' and adults' understanding of probability expressions. , 2001, The Journal of adolescent health : official publication of the Society for Adolescent Medicine.

[46]  G. Gigerenzer,et al.  Teaching Bayesian reasoning in less than two hours. , 2001, Journal of experimental psychology. General.

[47]  S. Bogardus,et al.  Perils, Pitfalls, and Possibilities in Talking About Medical Risk , 2000 .

[48]  R. Gardiner,et al.  Making decisions about treatment for localized prostate cancer , 2002, BJU international.

[49]  I. Erev,et al.  Verbal versus numerical probabilities: Efficiency, biases, and the preference paradox☆ , 1990 .

[50]  G. Gigerenzer Ecological intelligence: An adaptation for frequencies , 1997 .

[51]  B Fischhoff,et al.  A New Scale for Assessing Perceptions of Chance , 2000, Medical decision making : an international journal of the Society for Medical Decision Making.

[52]  Michael J. Olson,et al.  Patterns of preference for numerical and verbal probabilities. , 1997 .

[53]  Amnon Rapoport,et al.  Measuring the Vague Meanings of Probability Terms , 1986 .