OBJECTIVES: Informed decisions about cancer screening require accurate knowledge regarding cancer risks and screening. This study investigates: (1) European women's knowledge of their risk of developing breast, ovarian, cervical or endometrial cancer, (2) their knowledge about mammography screening and (3) whether an evidence-based leaflet improves their knowledge. DESIGN: Cross-sectional online intervention survey. SETTING: National samples from five European countries (Czech Republic, Germany, UK, Italy and Sweden)-drawn from the Harris Interactive and the Toluna panel, respectively, in January 2017-were queried on their knowledge of age-specific risks of developing breast, cervical, ovarian or endometrial cancer within the next 10 years and of mammography screening before and after intervention. PARTICIPANTS: Of 3629 women (inclusion criteria: age 40-75 years) invited, 2092 responded and 1675 completed the survey (response rate: 61.4%). INTERVENTION: Evidence-based leaflet summarising information on age-adjusted female cancer risks, mammography and aspects of cancer prevention. PRIMARY OUTCOME MEASURES: Proportion of women (1) accurately estimating their risk of four female cancers, (2) holding correct assumptions of mammography screening and (3) changing their estimations and assumptions after exposure to leaflet. FINDINGS: Across countries, 59.2% (95% CI 56.8% to 61.6%) to 91.8% (95% CI 90.3% to 93.0%) overestimated their female cancer risks 7-33 fold (mediansacross tumours: 50.0 to 200.0). 26.5% (95% CI 24.4% to 28.7%) were aware that mammography screening has both benefits and harms. Women who accurately estimated their breast cancer risk were less likely to believe that mammography prevents cancer (p<0.001). After leaflet intervention, knowledge of cancer risks improved by 27.0 (95% CI 24.9 to 29.2) to 37.1 (95% CI 34.8 to 39.4) percentage points and of mammography by 23.0 (95% CI 21.0 to 25.1) percentage points. CONCLUSION: A considerable number of women in five European countries may not possess the prerequisites for an informed choice on cancer screening. Evidence-based information in patient leaflets can improve this situation.

Center for Adaptive Rationality Max Planck Institute for Human Development Berlin Germany

Department of Laboratory Medicine Karolinska Institutet Stockholm Sweden

Department of Obstetrics and Gynecology Charles University Prague Prague UK

Department of Women's Cancer University College London London UK

Harding Center for Risk Literacy Max Planck Institute for Human Development Berlin Germany

Laboratory Karolinska University Hospital Karolinska University Stockholm Sweden

Unit of Gynecology Humanitas Research Hospital Milan Italy

Unit of Preventive Gynecology European Institute of Oncology Milan Italy

Zobrazit více v PubMed

Etzioni R, Penson DF, Legler JM, et al. . Overdiagnosis due to prostate-specific antigen screening: lessons from U.S. prostate cancer incidence trends. J Natl Cancer Inst 2002;94:981–90. 10.1093/jnci/94.13.981 PubMed DOI

Welch HG, Black WC. Overdiagnosis in cancer. J Natl Cancer Inst 2010;102:605–13. 10.1093/jnci/djq099 PubMed DOI

Marcus PM, Prorok PC, Miller AB, et al. . Conceptualizing overdiagnosis in cancer screening. J Natl Cancer Inst 2015;107 djv014 10.1093/jnci/djv014 PubMed DOI PMC

Buys SS, Partridge E, Black A, et al. . Effect of screening on ovarian cancer mortality: the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Randomized Controlled Trial. JAMA 2011;305:2295–303. 10.1001/jama.2011.766 PubMed DOI

Schröder FH, Hugosson J, Roobol MJ, et al. . Screening and prostate cancer mortality: results of the European Randomised Study of Screening for Prostate Cancer (ERSPC) at 13 years of follow-up. The Lancet 2014;384:2027–35. 10.1016/S0140-6736(14)60525-0 PubMed DOI PMC

Atkin WS, Edwards R, Kralj-Hans I, et al. . Once-only flexible sigmoidoscopy screening in prevention of colorectal cancer: a multicentre randomised controlled trial. Lancet 2010;375:1624–33. 10.1016/S0140-6736(10)60551-X PubMed DOI

Autier P, Boniol M, Koechlin A, et al. . Effectiveness of and overdiagnosis from mammography screening in the Netherlands: population based study. BMJ 2017;359:j5224 10.1136/bmj.j5224 PubMed DOI PMC

Welch HG, Prorok PC, O’Malley AJ, et al. . Breast-cancer tumor size, overdiagnosis, and mammography screening effectiveness. N Engl J Med 2016;375:1438–47. 10.1056/NEJMoa1600249 PubMed DOI

Woloshin S, Schwartz LM. Numbers needed to decide. J Natl Cancer Inst 2009;101:1163–5. 10.1093/jnci/djp263 PubMed DOI

Wegwarth O, Gigerenzer G. Improving evidence-based practices through health literacy--reply. JAMA Intern Med 2014;174:1413–4. 10.1001/jamainternmed.2014.846 PubMed DOI

Shieh Y, Eklund M, Madlensky L, et al. . Breast cancer screening in the precision medicine era: Risk-based screening in a population-based trial. J Natl Cancer Inst 2017;109:djw290 10.1093/jnci/djw290 PubMed DOI

Jacobs IJ, Menon U, Ryan A, et al. . Ovarian cancer screening and mortality in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a randomised controlled trial. Lancet 2016;387:945–56. 10.1016/S0140-6736(15)01224-6 PubMed DOI PMC

Moss HA, Berchuck A, Neely ML, et al. . Estimating cost-effectiveness of a multimodal ovarian cancer screening program in the United States: secondary analysis of the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS). JAMA Oncology 2017. 4:190–195. PubMed PMC

Andrae B, Kemetli L, Sparén P, et al. . Screening-preventable cervical cancer risks: evidence from a nationwide audit in Sweden. J Natl Cancer Inst 2008;100:622–9. 10.1093/jnci/djn099 PubMed DOI

Gigerenzer G, Mata J, Frank R. Public knowledge of benefits of breast and prostate cancer screening in Europe. J Natl Cancer Inst 2009;101:1216–20. 10.1093/jnci/djp237 PubMed DOI PMC

Wegwarth O, Gigerenzer G. Less is more: Overdiagnosis and overtreatment: evaluation of what physicians tell their patients about screening harms. JAMA Intern Med 2013;173:2086–7. 10.1001/jamainternmed.2013.10363 PubMed DOI

Dierks ML, Schmacke N. Mammografie-Screening und informierte Entscheidung: mehr Fragen als Antworten [Mammography screening and informed consent: more questions than answers] In: Boecker J, Braun B, Meierjuergen R, eds Gesundheitsmonitor 2014: Buergerorientierung im Gesundheitswesen Bertelsmann Stiftung, 2014:55–91.

Steckelberg A, Berger B, Köpke S, et al. . Kriterien für evidenzbasierte Patienteninformationen. Zeitschrift für ärztliche Fortbildung und Qualität im Gesundheitswese 2005;99:343–51. PubMed

Gøtzsche PC, Jørgensen KJ. Cochrane Breast Cancer Group. Screening for breast cancer with mammography. Cochrane Database Syst Rev 2013;156 10.1002/14651858.CD001877.pub5 PubMed DOI PMC

Schwartz LM, Woloshin S, Welch HG. The drug facts box: providing consumers with simple tabular data on drug benefit and harm. Med Decis Making 2007;27:655–62. 10.1177/0272989X07306786 PubMed DOI

McDowell M, Rebitschek FG, Gigerenzer G, et al. . A simple tool for communicating the benefits and harms of health interventions: A guide for creating a fact box. MDM Policy Pract 2016;1:2381468316665365 10.1177/2381468316665365 PubMed DOI PMC

Schwartz LM. Using a drug facts box to communicate drug benefits and harms. Ann Intern Med 2009;150:516–27. 10.7326/0003-4819-150-8-200904210-00106 PubMed DOI

Kaatsch P, Spix C, Katalinic A, et al. . Gesundheitsbereichterstattung des Bundes: Krebs in Deutschland 2011/2012 [Public health reports of the goverment: cancer in Germany 2011/2012]. Berlin: Robert Koch Institute 2015.

Wegwarth O, Kurzenhäuser-Carstens S, Gigerenzer G. Overcoming the knowledge-behavior gap: The effect of evidence-based HPV vaccination leaflets on understanding, intention, and actual vaccination decision. Vaccine 2014;32:1388–93. 10.1016/j.vaccine.2013.12.038 PubMed DOI

Bodemer N, Müller SM, Okan Y, et al. . Do the media provide transparent health information? A cross-cultural comparison of public information about the HPV vaccine. Vaccine 2012;30:3747–56. 10.1016/j.vaccine.2012.03.005 PubMed DOI

Neumeyer-Gromen A, Bodemer N, Müller SM, et al. . Ermöglichen Medienberichte und Broschüren informierte Entscheidungen zur Gebärmutterhalskrebsprävention? [Do media reports and public brochures facilitate informed decision making about cervical cancer prevention?]. Bundesgesundheitsblatt 2011;54:1197–210. PubMed

Slaytor EK, Ward JE. How risks of breast cancer and benefits of screening are communicated to women: analysis of 58 pamphlets. BMJ 1998;317:263–4. 10.1136/bmj.317.7153.263 PubMed DOI PMC

Kurzenhäuser S. Welche Informationen vermitteln deutsche Gesundheitsbroschüren über die Screening-Mammographie? [What information do German health brochures provide on mammography screening?]. Zeitschrift für ärztliche Fortbildung und Qualitätssicherung 2003;97:53–7. PubMed

Perneger TV, Agoritsas T. Doctors and patients' susceptibility to framing bias: a randomized trial. J Gen Intern Med 2011;26:1411–7. 10.1007/s11606-011-1810-x PubMed DOI PMC

Malenka DJ, Baron JA, Johansen S, et al. . The framing effect of relative and absolute risk. J Gen Intern Med 1993;8:543–8. 10.1007/BF02599636 PubMed DOI

Gigerenzer G, Gaissmaier W, Kurz-Milcke E, et al. . Helping doctors and patients make sense of health statistics. Psychol Sci Public Interest 2007;8:53–96. 10.1111/j.1539-6053.2008.00033.x PubMed DOI

Woloshin S, Schwartz LM. How a charity oversells mammography. BMJ 2012;345:e5132 10.1136/bmj.e5132 PubMed DOI

Welch HG, Schwartz LM, Woloshin S. Are increasing 5-year survival rates evidence of success against cancer? JAMA 2000;283:2975–8. 10.1001/jama.283.22.2975 PubMed DOI

The Swedish National Board of Health and Welfare. Screening for breast cancer – Recommendation and basis for assessment. Socialstyrelsen online 2017. http://www.socialstyrelsen.se/SiteCollectionDocuments/screening-brostcancer-rekommendation.pdf.

Federal Joint Committee in Germany. Mammographie-Screening: Frauen erhalten neue Entscheidungshilfe. https://www.g-ba.de/institution/presse/pressemitteilungen/712/2017.

McGettigan P, Sly K, O’Connell D, et al. . The effects of information framing on the practices of physicians. J Gen Intern Med 1999;14:633–42. 10.1046/j.1525-1497.1999.09038.x PubMed DOI PMC

Moxey A, O’Connell D, McGettigan P, et al. . Describing treatment effects to patients: How they are expressed makes a difference. Journal of General Internal Medicine 2003;18:948–59. PubMed PMC

Jain BP. Number needed to treat and relative risk reduction. Ann Intern Med 1998;128:72–3. 10.7326/0003-4819-128-1-199801010-00019 PubMed DOI

Sethuraman R, Cole C, Jain D. Analyzing the effect of information format and task on cutoff search strategies. Journal of Consumer Psychology 1994;3:103–36. 10.1016/S1057-7408(08)80001-0 DOI

Covey J. A meta-analysis of the effects of presenting treatment benefits in different formats. Med Decis Making 2007;27:638–54. 10.1177/0272989X07306783 PubMed DOI

Eddy DM. Probabilistic reasoning in clinical medicine: Problems and opportunities : Kahneman D, Slovic P, Tversky A, Judgment under uncertainty: Heuristics and biases. Cambridge: Cambridge University Press, 1982:249–67.

Casscells W, Schoenberger A, Graboys TB. Interpretation by physicians of clinical laboratory results. N Engl J Med 1978;299:999–1001. 10.1056/NEJM197811022991808 PubMed DOI

Bramwell R, West H, Salmon P. Health professionals' and service users' interpretation of screening test results: experimental study. BMJ 2006;333:284–6. 10.1136/bmj.38884.663102.AE PubMed DOI PMC

Hoffrage U, Gigerenzer G. Using natural frequencies to improve diagnostic inferences. Acad Med 1998;73:538–40. 10.1097/00001888-199805000-00024 PubMed DOI

Wegwarth O, Gaissmaier W, Gigerenzer G. Deceiving numbers: survival rates and their impact on doctors' risk communication. Med Decis Making 2011;31:386–94. 10.1177/0272989X10391469 PubMed DOI

Wegwarth O, Schwartz LM, Woloshin S, et al. . Do physicians understand cancer screening statistics? A national survey of primary care physicians in the United States. Ann Intern Med 2012;156:340–9. 10.7326/0003-4819-156-5-201203060-00005 PubMed DOI

Black WC, Nease RF, Tosteson AN. Perceptions of breast cancer risk and screening effectiveness in women younger than 50 years of age. J Natl Cancer Inst 1995;87:720–31. 10.1093/jnci/87.10.720 PubMed DOI

Miller AM, Champion VL. Attitudes about breast cancer and mammography: racial, income, and educational differences. Women Health 1997;26:41–63. 10.1300/J013v26n01_04 PubMed DOI

Do cancer risk and benefit-harm ratios influence women's consideration of risk-reducing mastectomy? A scenario-based experiment in five European countries