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Drug Safety

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01-01-2003 | Current Opinion

Patients’ Understanding of Risk Associated with Medication Use

Impact of European Commission Guidelines and Other Risk Scales

Authors: Professor Dianne C. Berry, D.K. Raynor, Peter Knapp, Elisabetta Bersellini

Published in: Drug Safety | Issue 1/2003

Abstract

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.

This work was carried out in collaboration with Dr Wendy Holden from the Royal Berks and Battle Hospitals Trust.

From compliance to concordance: achieving shared goals in medicine taking. London: Royal Pharmaceutical Society of Great Britain and Merck, Sharp & Dohme, 1997

National plan for the NHS. London: Department of Health, 2000

Doyal L. Informed consent: moral necessity or illusion? Qual Health Care 2001; 10: 29–33CrossRef

Calman K, Royston G. Risk language and dialects. BMJ 1997; 315: 939–42PubMedCrossRef

European Commission. A guideline on the readability of the label and package leaflet of medicinal products for human use. EC Pharmaceuticals Committee, 1998

European Commission. European Commission Council Directive 92/27/EEC (OJ NoL 113 of 30.4.1992, p.8) 1992

Dickinson D, Raynor DK Duman M. Patient information leaflets for medicines: using consumer testing to determine most effective design. Patient Educ Couns 2001; 43: 147–59PubMedCrossRef

Berry DC, Knapp PR, Raynor DK. Is 15% very common: informing people about the risks of medication side effects. Int J Pharm Pract 2002; 10: 145–51CrossRef

Bryant GD, Norman GR. Expressions of probability: words and numbers [letter]. N Engl J Med 1980; 302: 411a

10.

Mazur DJ, Merz JF. Patients’ interpretations of verbal expressions of probability: implications for securing informed consent to medical interventions. Behav Sci Law 1994; 12: 417–26PubMedCrossRef

11.

Reagan RT, Mosteller F, Youtz C. Quantitative meanings of verbal probability expressions. J Appl Psychol 1989; 74: 433–42PubMedCrossRef

12.

Timmermans D. The roles of experience and domain of expertise in using numerical and verbal probability terms in medical decisions. Med Decis Making 1994; 14: 146–56PubMedCrossRef

13.

Wallsten S, Budescu DV, Rapoport A, et al. Measuring the vague meaning of probability terms. J Exp Psychol Gen 1986; 115: 348–65CrossRef

14.

Berry DC, Michas IC, Gillie T, et al. What do patients want to know about their medicines and what do doctors want to tell them? A comparative study. Psych Health 1997; 12: 467–80CrossRef

15.

Berry DC, Michas IC, DeRosis F. Evaluating explanations about drug prescriptions: effects of varying the nature of information about side effects and its relative position in explanations. Psych Health 1998; 13: 767–84CrossRef

16.

Berry DC, Michas IC, Bersellini E. Communicating information about medication side effects: effects on satisfaction, perceived risk to health and intention to comply. Psych Health 2002; 17: 247–67CrossRef

17.

Berry DC, Michas IC, Bersellini E, Communicating information about medicine: the benefits of making it personal. Psych Health. In press

18.

Berry DC, Knapp PR, Raynor DK. Provision of information about drug side effects to patients. Lancet 2002; 359: 853–4PubMedCrossRef

19.

Berry DC, Raynor DK, Knapp PR. Communicating risk of medication side effects: an empirical evaluation of EC recommended terminology. Psych Health Med. In press

20.

Cartwright A. Medicine taking by people aged 65 or more. Br Med Bull 1990; 46: 63–76PubMed

21.

Claesson S, Morrison A, Wertheimer AI, et al. Compliance with prescribed drugs: challenges for the elderly population. Pharm World Sci 1999; 21: 256–9PubMedCrossRef

22.

Kane RL, Ouslander JG, Abbrass IB. Essentials of clinical geriatrics. New York: McGraw Hill, 1994

23.

McElnay JC, McCallion R. Adherence and the elderly. In: Myers LB, Midence K, editors. Adherence to treatment in medical conditions. London: Harwood, 1998

24.

Department of Health. UK National Health Service Framework for Older People. 2001

25.

Pander Maat H, Klaasan R. Side effects of side effect information in drug information leaflets. J Tech Writing Commun 1994; 24: 389–404

26.

Fischer K, Jungermann H. Rarely occurring headaches and rarely occurring blindness: is rarely rarely? The meaning of verbal frequentistic labels in specific medical contexts. J Behav Dec Mak 1996; 9: 153–72CrossRef

27.

Bennett P. Communicating about risks to public health: pointers to good practice. London: Department of Health, 1998

28.

Knapp PR, Berry DC, Raynor DK. Testing two methods of presenting side effect information about common medicines [abstract]. Int J Psychoanal Psychother 2001; 9: R6

29.

Cochrane Library. Update Software [online]. Issue 3, 2000; Oxford. Available from URL: http://www.update-software.com/cochrane/cochrane-frame.html [Accessed 2002 Dec 10]

30.

Annual Report, Proprietary Association of Great Britain. London: PAGB, 2001

31.

Berry DC, Bersellini E. Doctors’ and patients’ understanding of the Calman risk scale. Proceedings of the British Psychological Society. In press

32.

Kuipers B, Moskowitz AJ, Kassierer JP. Critical decisions under uncertainty: representation and structure. Cognit Sci 1988; 12: 177–210CrossRef

33.

Windschitl PD, Wells GL. Measuring psychological uncertainty: verbal versus numeric methods. J Exp Psych App 1996; 2: 343–64CrossRef

34.

Calman KC. Cancer: science and society and the communication of risk. BMJ 1996; 313: 799–802PubMedCrossRef

35.

Edwards A, Elwyn GJ, Stott N. Researchers should present results with both relative and absolute risk. BMJ 2001; 318: 7183

36.

Paling J. Up to your armpits in alligators: how to sort out what risks are worth worrying about. Gainesville (FL); Risk Communication and Environmental Institute, 1997

37.

Barclay P, Costigan S, Davies M. Lottery can be used to show risk. BMJ 1998; 316: 1242–3CrossRef

38.

Weber EC, Hilton, DJ. Contextual effects in words: perceived base rate and severity of events. J Exp Psychol Hum Percept Perform 1990; 16: 781–9CrossRef

39.

Lipkus IM, Hollands JG. The visual communication of risk. J Nat Cancer Inst Monogr 1999; 25: 149–63CrossRef

40.

Edwards A, Elwyn GJ, Mulley A. Explaining risks: turning numerical data into meaningful pictures. BMJ 2002; 324: 827–30PubMedCrossRef

41.

Calman K. Issues of risk: this unique opportunity [The William Pickles lecture]. Br J Gen Pract 2001; 51: 47–51PubMed

42.

Edwards A, Elwyn GJ. Risks: listen and don’t mislead. Br J Gen Pract 2001; 51: 259–60PubMed

43.

Edwards R, Wiholm BE, Martinez C. Concepts in risk benefit assessment: a simple merit analysis of a medicine. Drug Saf 1996; 15(1): 1–7PubMedCrossRef

44.

Edwards A, Pill R, Stott N. Use of standard terms is unlikely to result in standard communication [letter]. BMJ 1996; 313: 1483PubMedCrossRef

Title: Patients’ Understanding of Risk Associated with Medication Use
Impact of European Commission Guidelines and Other Risk Scales
Authors: Professor Dianne C. Berry
D.K. Raynor
Peter Knapp
Elisabetta Bersellini
Publication date: 01-01-2003
Publisher: Springer International Publishing
Published in: Drug Safety / Issue 1/2003
Print ISSN: 0114-5916
Electronic ISSN: 1179-1942
DOI: https://doi.org/10.2165/00002018-200326010-00001

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Patients’ Understanding of Risk Associated with Medication Use

Impact of European Commission Guidelines and Other Risk Scales

Abstract

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Abstract

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