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Counselling issues in perinatal screening
Semin Neonato/1998; 3: 67-71
Counselling issues in perinatal screening J. G. Thornton
University of Leeds, UK
Key words: decision aids, decision analysis, counselling, heurislics
Screening for treatable disease is justified if it reduces serious disease. If the only options are altered reproductive decisions, screening is only justified because il increases parental choice, not because it reduces handicap . Parents can make such choices only if they are given information appropriately. This means risks should be presented in ways they can understand, they should be given sufficient time 10 assimilate the information and appropriale decision aids should be available for complicated decisions.
Counselling is the gIVIng, or offering, of advice. Doctors are happy to do this when no personal values are involved, and surgeons do not worry too much about how to tell people that they need their appendix removed. However, if people have differing views, which might affed their decision, it is usually only justifiable to give fadual information, and let patients decide for themselves how to ad on it. Since there are almost always some risks from treatments, and the patient is the one undergoing these risks and the one who will benefit, it is right that the patient should decide whether the benefits outweigh the risks. Difficulties arise if patients need help interpreting the information. It is easy for such help to be coloured by the counsellor's own values, and for the patient to be influenced towards a particular course of adion. Many counsellors try to avoid such coercion, and claim to provide 'non-directive' counselling. Nevertheless coercion, albeit often subtle and unintended, is an ever present risk since if doctors offer something free, patients can easily be coerced into accepting it. The problem matters most for those types of perinatal screening where the options include reprodudive decisions, such as choice of partner, whether to have children, or to undergo abortion, Correspondence: Centre for Reproduction. Growth and Development. University of Leeds, 34 Hyde Terra ce. LS2 9L'< (email J.G. Thornton (ff,leeds.ac.uk) 1084-2756/98/010067 +05 $12.00/00
which are all affeded by personal values. Such screening tests are not, or should not be offered because they reduce handicap or illness. Given people's differing values, no-one can say whether they do that or not, and anyway trying to reduce handicap by altering reproductive behaviour is eugenic, and has all the dangers inherent in that activity. The justification is that such tests increase parents' reprodudive choice. To do this, patients offered screening should be adequately informed about the potential benefits and limitations of the screening test, and such tests should always be offered as an option which may be accepted or rejected. The test offer must not be coercive. This is not easy. Patients may assume that doctors would not offer the test unless they felt it was of overall benefit. In pregnancy women are often reluctant to ask questions [1] and may accept tests by default, so called compliant behaviour [2]. Compliant acceptance of screening tests has been demonstrated in two randomized controlled trials. Women given extra information about prenatal testing for CF carrier status were less likely to accept [3] and in a trial comparing different settings for offering CF screening outside pregnancy, more people accepted an offered test performed immediately, than bothered to return for the same test on another day [4]. There are other reasons why giving information about screening programmes may be difficult. © 1998 W.B. Saunders Company Ltd
J. G. Thornton
68
Information itself may cause anxiety, however it is given, patients may not understand what they are told, and the way information is given may influence the patient towards a particular decision. In the remainder of this chapter I will discuss the evidence that these problems occur, and ways in which they can be minimized.
Information may cause anxiety If patients are unaware that they are at risk of disease, telling them about it, and offering a screening test, usually causes some unavoidable anxiety [5]. The benefits of screening must outweigh this and it should be minimized as far as possible. The main way to do this is to give participants full information to allay unwarranted fears. However, many clinicians mistakenly believe that information makes patients more anxious rather than less. The belief arises because information seeking is a typical response of anxious patients, who tend, as a result, to be given more information. The extra information does not cause the anxiety. Randomized trials of extra information provision have either shown that the extra information has little or no effect on anxiety, or even that it reduces it [6, 7]. Our group performed a randomized controlled trial of giving extra information about screening to parents early in pregnancy. In the extra information group risks were given pictorially, orally and in writing, and care was taken to frame them both ways. Overall there was very little difference in anxiety at any stage in pregnancy or the puerperium, although the trend was for lower levels in the extra information group [3]. Since most patients claim, when asked, that they would have liked more information [8], there is no justification for limiting patients information about screening tests. Screening also causes anxiety if the screening test is positive, although not all such results will later be confirmed. Although there are anecdotal reports of persistent anxiety, it usually resolves when the diagnostic test result is available, so long as this indicates no disease [9, 10]. It is therefore important that diagnostic tests are completed and results released quickly, whether positive or negative. Patients will be waiting just as anxiously for the latter, and should never be told that 'no news is good news'. This practice is not always followed [11].
Patients may not understand the information they are given Most people can understand the main issues involved in screening so long as information is presented clearly, and they are given sufficient time to assimilate it. Although not all doctors are good communicators most could do better by following a few simple rules. When telling patients about a screening programme. other distractions should be avoided as far as possible. This means not doing it in the middle of a busy ward, or the public area of an antenatal clinic. Patients should be fully clothed and seated comfortably. The counsellor should introduce themselves to the patient, place themselves on the same level and face the patient when talking. Even when verbal information is given clearly, it is often poorly retained. Recall is much improved by also giving it in writing. either as a letter summarizing the consultation. or in an information leaflet. There is good evidence that use of such leaflets improves information recall [12]. The preparation of such leaflets requires care. They do not need to be glossy or expensive but the information contained in them must be correct, and the language appropriate. This means avoiding jargon, unnecessary long or medical words, and the passive tense, and keeping sentences short. Leaflet readability can be measured objectively, and can be done automatically by some word processing packages. For example, the Flesch reading ease score estimates the percentage of the adult population who can read a document with ease [13]. A document for general population use should have a reading ease of at least 70%. Many information leaflets fail this test.
Risk information Interpreting risks Most people use a limited number of heuristics, or logical systems, for converting numeric risks to a subjective degree of belief that the event will or will not occur. These work well most of the time but occasionally lead to predictable biases [14]. The three main heuristics for estimating probability are representativeness. availability and anchoring. When using the represenlaliueness heuristic, people estimate the probability that a particular
Counselling issues in perinatal screening
object belongs to a set of objects by estimating the degree to which it resembles a typical member of the set. For example, a person trying to decide whether an unknown fruit was an apple or a citrus might base their decision on how it looked, felt and tasted. A green skin might make them rate the probability that the fruit was an apple very high. Such a method usually works well but would mislead if limes were common in the area. Ultrasound markers of Down's syndrome, often alarm parents more than a serum test result with the same likelihood ration, because a scan abnormality seems more representative of Down's. Using the availability heuristic, the person estimates the probability that an object is a member of a set by considering how easily another member of that set can be recalled. For example one woman who has a previous child affected with spina bifida, a low serum alphafetoprolein and a normal ultrasound scan may have the same posterior risk of spina blfida, say 1 in 1000, as another low risk woman who has undergone no testing at all. However, the women with a previous affected child is likely to perceive her risk as much greater because she can easily imagine such an outcome. The availability heuristic is the reason why the way risks are framed is important. A risk of 1 in 100 that the baby has Downs's, seems worse than a 99% chance that the baby is not affected. If people have any prior estimate of the probability of an event, they tend to estimate the changed probability of the event in the light of new information, by making some adjustment from the earlier estimate. This is anchoring, If the initial estimate was wrong then future estimates are likely to be wrong. Even if the original estimate was correct, adjustments from anchored values are typically insufficient, leading to predictable bias. If patients have suffered a problem themselves, or had a previous affected child, availability typically leads them to overestimate the risk of recurrence. They then anchor to this high risk, when given a negative screening test result. Doctors presenting risk information should be aware of these biases. If they want to permit patients to make their own well-informed decisions they should do what they can to minimize or avoid them. There are a number of ways to help. First, doctors should avoid presenting risks in semiquantitative ways. Expressions such as common, rare, unlikely, etc., are frequently used when transmiHing risk information. They have two major disadvantages. First, they cause misunderstanding
69
since people interpret words differently. In one report doctors interpretation of 'unlikely' had an inter-quartile range from 6 to 22% [15]. Second, such words are not value neutral. If a doctor says that a risk of handicap is 'low', patients may interpret that it is too low for termination of pregnancy to be a reasonable option. We have observed that use of semi-quantitative words appears to carry a diredive message [16]. For conditions where parents had to decide whether to continue a pregnancy with a risk, rather than certainty of handicap, all parents chose termination if the risk word implied a high risk, and chose to continue if it implied a low one. In contrast, the decisions of patients given numeric risks were individualized. Some parents continued the pregnancy at the relatively 'high' risk of 50% and some chose termination at the relatively 'low' risk of 5% For those who want to be non-directive, numeric risks are preferable. Use of value laden words also permits the counsellors views to influence the patient. Bias has been clearly documented in taped consultations of screening test offers [17]. For example, 0.5% chance of Down's syndrome was typically described as a 'high risk', while a 1% miscarriage risk after diagnostic testing was typically described as 'low' risk. Even if numbers are used to describe risks there is a possibility of biasing patients by framing the risks one way or another. To minimize anchoring and availability, risks should be framed both ways, i.e. they should be presented both as the risk of the bad outcome, and as that of the good outcome. For example, a 1 in 250 risk of Down's syndrome should also be presented as a 249 in 250 chance that the fetus does not have Down's. Similarly, a procedure-related miscarriage risk of 1% should also be presented as a 99% chance that it will not cause miscarriage. Parents often have little idea of the background risks of adverse pregnancy outcomes and find it difficult to set them in context. It is important when giving a miscarriage risk of say 1% to remind parents that even without the test, assuming the fetus is alive, they have a baseline risk of at least that rate. Similarly, with risks of abnormality parents frequently do not realize that the overall risk of significant congenital abnormality in the general population is around 2%. Finally, it is good pradice to present risks pictorially where possible. Special risk wheels and other decision aids are available, but marking risks by filling in squares of graph paper is a simple alternative easily done even in a busy clinic.
70
There are more sophisticated ways to help people incorporate risk and value information into decisions in a structured way. Decision analysis is the most sophisticated [18, 19]. This is widely used in business but still little used as an everyday decision aid. We are currently evaluating it in a randomized controlled trial to help parents make the amniocentesis decision after serum screening.
Appropriate counselling Counselling should be appropriate both to the problem and the patient. Since patients and decisions both vary, the amount and type of counselling should also vary.
Patient factors Patients differ in the degree to which they perceive that they have control over their destiny. Some feel that their views make little difference to what happens, and that events are shaped by other people, the government, God, or fate. Others feel the opposite. Psychologists use the term 'locus of control'. The former group have an external locus, and the latter an internal one. Individuals lie on a spedrum, and can be classified by their speech patterns, or according to their response to standard questions. There is some evidence that people with an internal locus of control prefer to be given more information about health issues, while those with an external one are happy to be given less. Similarly, those with an external locus may ask for advice on decision making, even for value-led decisions where the decision properly belongs to the patient. It may be appropriate to tell such patients what others generally decide in a similar situation.
Decision factors Decisions vary in their complexity and structure, in the time required or available to make them, and in the possibility of using mathematical or other decision aids. It is, therefore, sensible for decision makers to use a range of strategies. A popular classification of decision strategies places them in a range from intuitive, through peer aided, to analytic modes, and has been called the cognitive continuum [20]. It has been suggested that intuition
J. G. Thornton
is appropriate for unstructured, time-limited, routine problems and analysis more suited to complex, well-structured problems where more time is available. For most screening it is appropriate for patients to make an intuitive decision after being told the risks and benefits. Guthrie testing of the new-born for phenylketonuria (chapter 1) is an example. It is a good test, which identifies children for a simple cheap treatment that prevents brain damage and saves lives. The programme runs well with minimal counselling, and many parents are hardly even aware of it. Other decisions are more complex but not well structured, The effediveness of screening may be disputed, the tests may have side effeds, or people may disagree whether screening is worthwhile. Newborn screening for Duchenne Muscular Dystrophy is more like this. The tests are less than perfed, having both false positives and false negatives, and there is no treatment, so the only benefits are the possibility of choosing not to reproduce at all, or the seledive abortion of male siblings. It is appropriate for patients to ask an expert, typically their dodor for advice. Even if the experts cannot directly incorporate their personal values, they can tell them what other similar patients have chosen. This is peer-aided judgement. Finally, some complex decisions are very well structured and suited to a more analytical mode of decision making. Perhaps the best structured prenatal screening decision is whether to undergo an invasive test when a screening test reveals a risk of fetal abnormality such as Down's syndrome or neural tube defed. The chance of preventing the birth of an abnormal child has to be weighed against the chance of the diagnostic test causing miscarriage. Decision analysis is well suited to this sort of problem. The appropriate level of counselling may also depend on whether the programme is new or established. When serum screening for Down's syndrome was introduced screen positive patients (often with a posterior risk of less than 1%) were almost all extremely anxious, believing that they had a high risk of carrying an affeded child. They required help to understand what a 1 in 100 risk really means. As the programme has become widespread, and is regularly written about in popular magazines, and discussed on television, and as patients know personally individuals who have had screen positive results and delivered healthy babies, people's interpretation of a screen positive result has become more accurate. Thus, it is appropriate
Counselling issues in perinatal screening
71
that patients now receive less counselling on average than they did when the test was new. 8
Summary points 9
• Giving full information about screening does not usually cause anxiety. • Avoid distractions when imparting complex information. • Give information in writing as well as orally. • Check the readability of information leaflets. • Avoid using semi-quantitative words for risk. • Frame risks both as the 'chance of a bad outcome' and 'chance of a good outcome'. • Present risks pictorially.
10
11
12
13
References 1 Schapiro MC, Najman A. Change J, Keeping D, Morrison J, Western JS. Information control and the exercise of power in the obstetrical encounter. SocSci Med 1983; 17: 139-146. 2 Marleau TM, Johnston M, Shaw RW, Slack J. Factors influencing the uptake of screening for open neural tube defects and amniocentesis to test for Downs syndrome. Br I Obslef Gynaeco! 1989; 96: 739-748. 3 Thornton JG, Hewison J, Lilford RJ, Vail A. A Randomised Trial of Three Methods of Giving Information about Prenatal Testing. Br Med 11995; 311: 1127-1130. 4 Bekker H, Modell M, Dennis G, Silver A, Mathew C, Bobrow M, Matteau T. Uptake of cystic fibrosis testing in primary care: supply push or demand pull? Br Med 11993; 306: 1584-1586. 5 Green J. Calming or harming. Golion lnsliiuie Occnsiollnl papers, 2nd series, no. 2, 1990. 6 Ley P. Satisfaction compliance and communication. Br I Clin Psychol 1982; 21: 241-254. 7 Simes RJ. Tattersall MH, Coates AS, Raghaven D, Solomon HG, Smartt H. Randomised comparison of
14 15
16
17
18 19
20
procedures for obtaining informed consent in clinical trials of treatment for cancer. Br Med I 1986; 293: 1065-1068. Reid M. Consumer orientated studies in relation to prenatal screening tests. ElIr I Obslel Gvneco! Reprod BioI 1988; 28: 79-92. Burton BK, Dillard RG. Clark EN. The psychological impact of false positive elevations of maternal serum alphafetoprotein. Am I Obslel GYllecol 1985; 151: 77-82. Burton BK, Dillard RG, Clark EN. Maternal serum alphafetoprotein screening: the effect of participation on anxiety and attitude toward pregnancy in women with normal results. Am I Obslel Gyllecoll985; 152: 540-543. Allanson A. Michie S. Marleau TM . Presentation of screen negative results on serum screening for Down's syndrome: variations across Britain. I Med Screen 1997; 4: 21-22. Ley P. Communicating with Patients: Improving Communication, Satisfaction and Compliance. London: Chapman and Hall. 1992. Flesch RR. A new readability yardstick. I Applied Psychol 1948; 32: 221-223. Tversky A, Kahnemann D. Judgement under uncertainty: heuristics and biases. Science 1974; 185: 1124-1131. Thornton JG, van den Borne MPJ, de Bruijn AJE. Risk communication the patient's view . Early Human Development 1996; 47(Suppl.): S13-S17. Marleau TM, Plenicar M, Kidd J. Obstetricians presenting amniocentesis to pregnant women: practice observed. I Reprod lnjan! Psycholl993; 11: 3-10. Pauker SP, Pauker SG. The amniocentesis decision: ten years of decision analytic experience. Birth defects; origina! article series 1987; 23(2): 151-169. March of Dimes Birth Defects Foundation. Thornton JG, Lilford RJ, Johnson N. Decision analysis in Medicine. Br Med 11992; 304: 1099-1103. Hamm RM. Clinical intuition and clinical analysis: expertise and the cognitive continuum. In: Dowie J, Elstein A (cds) Projessional [udgenteni. Cambridge: Cambridge University Press. 1998; pp 78-105. Ley P, Llewelyn S. Improving patients' understanding. recall. satisfaction and compliance. In: Healil: Psychology; Processes and Applications. 2nd cd. London: Chapman and Hall. 1995.
Counselling issues in perinatal screening J. G. Thornton
University of Leeds, UK
Key words: decision aids, decision analysis, counselling, heurislics
Screening for treatable disease is justified if it reduces serious disease. If the only options are altered reproductive decisions, screening is only justified because il increases parental choice, not because it reduces handicap . Parents can make such choices only if they are given information appropriately. This means risks should be presented in ways they can understand, they should be given sufficient time 10 assimilate the information and appropriale decision aids should be available for complicated decisions.
Counselling is the gIVIng, or offering, of advice. Doctors are happy to do this when no personal values are involved, and surgeons do not worry too much about how to tell people that they need their appendix removed. However, if people have differing views, which might affed their decision, it is usually only justifiable to give fadual information, and let patients decide for themselves how to ad on it. Since there are almost always some risks from treatments, and the patient is the one undergoing these risks and the one who will benefit, it is right that the patient should decide whether the benefits outweigh the risks. Difficulties arise if patients need help interpreting the information. It is easy for such help to be coloured by the counsellor's own values, and for the patient to be influenced towards a particular course of adion. Many counsellors try to avoid such coercion, and claim to provide 'non-directive' counselling. Nevertheless coercion, albeit often subtle and unintended, is an ever present risk since if doctors offer something free, patients can easily be coerced into accepting it. The problem matters most for those types of perinatal screening where the options include reprodudive decisions, such as choice of partner, whether to have children, or to undergo abortion, Correspondence: Centre for Reproduction. Growth and Development. University of Leeds, 34 Hyde Terra ce. LS2 9L'< (email J.G. Thornton (ff,leeds.ac.uk) 1084-2756/98/010067 +05 $12.00/00
which are all affeded by personal values. Such screening tests are not, or should not be offered because they reduce handicap or illness. Given people's differing values, no-one can say whether they do that or not, and anyway trying to reduce handicap by altering reproductive behaviour is eugenic, and has all the dangers inherent in that activity. The justification is that such tests increase parents' reprodudive choice. To do this, patients offered screening should be adequately informed about the potential benefits and limitations of the screening test, and such tests should always be offered as an option which may be accepted or rejected. The test offer must not be coercive. This is not easy. Patients may assume that doctors would not offer the test unless they felt it was of overall benefit. In pregnancy women are often reluctant to ask questions [1] and may accept tests by default, so called compliant behaviour [2]. Compliant acceptance of screening tests has been demonstrated in two randomized controlled trials. Women given extra information about prenatal testing for CF carrier status were less likely to accept [3] and in a trial comparing different settings for offering CF screening outside pregnancy, more people accepted an offered test performed immediately, than bothered to return for the same test on another day [4]. There are other reasons why giving information about screening programmes may be difficult. © 1998 W.B. Saunders Company Ltd
J. G. Thornton
68
Information itself may cause anxiety, however it is given, patients may not understand what they are told, and the way information is given may influence the patient towards a particular decision. In the remainder of this chapter I will discuss the evidence that these problems occur, and ways in which they can be minimized.
Information may cause anxiety If patients are unaware that they are at risk of disease, telling them about it, and offering a screening test, usually causes some unavoidable anxiety [5]. The benefits of screening must outweigh this and it should be minimized as far as possible. The main way to do this is to give participants full information to allay unwarranted fears. However, many clinicians mistakenly believe that information makes patients more anxious rather than less. The belief arises because information seeking is a typical response of anxious patients, who tend, as a result, to be given more information. The extra information does not cause the anxiety. Randomized trials of extra information provision have either shown that the extra information has little or no effect on anxiety, or even that it reduces it [6, 7]. Our group performed a randomized controlled trial of giving extra information about screening to parents early in pregnancy. In the extra information group risks were given pictorially, orally and in writing, and care was taken to frame them both ways. Overall there was very little difference in anxiety at any stage in pregnancy or the puerperium, although the trend was for lower levels in the extra information group [3]. Since most patients claim, when asked, that they would have liked more information [8], there is no justification for limiting patients information about screening tests. Screening also causes anxiety if the screening test is positive, although not all such results will later be confirmed. Although there are anecdotal reports of persistent anxiety, it usually resolves when the diagnostic test result is available, so long as this indicates no disease [9, 10]. It is therefore important that diagnostic tests are completed and results released quickly, whether positive or negative. Patients will be waiting just as anxiously for the latter, and should never be told that 'no news is good news'. This practice is not always followed [11].
Patients may not understand the information they are given Most people can understand the main issues involved in screening so long as information is presented clearly, and they are given sufficient time to assimilate it. Although not all doctors are good communicators most could do better by following a few simple rules. When telling patients about a screening programme. other distractions should be avoided as far as possible. This means not doing it in the middle of a busy ward, or the public area of an antenatal clinic. Patients should be fully clothed and seated comfortably. The counsellor should introduce themselves to the patient, place themselves on the same level and face the patient when talking. Even when verbal information is given clearly, it is often poorly retained. Recall is much improved by also giving it in writing. either as a letter summarizing the consultation. or in an information leaflet. There is good evidence that use of such leaflets improves information recall [12]. The preparation of such leaflets requires care. They do not need to be glossy or expensive but the information contained in them must be correct, and the language appropriate. This means avoiding jargon, unnecessary long or medical words, and the passive tense, and keeping sentences short. Leaflet readability can be measured objectively, and can be done automatically by some word processing packages. For example, the Flesch reading ease score estimates the percentage of the adult population who can read a document with ease [13]. A document for general population use should have a reading ease of at least 70%. Many information leaflets fail this test.
Risk information Interpreting risks Most people use a limited number of heuristics, or logical systems, for converting numeric risks to a subjective degree of belief that the event will or will not occur. These work well most of the time but occasionally lead to predictable biases [14]. The three main heuristics for estimating probability are representativeness. availability and anchoring. When using the represenlaliueness heuristic, people estimate the probability that a particular
Counselling issues in perinatal screening
object belongs to a set of objects by estimating the degree to which it resembles a typical member of the set. For example, a person trying to decide whether an unknown fruit was an apple or a citrus might base their decision on how it looked, felt and tasted. A green skin might make them rate the probability that the fruit was an apple very high. Such a method usually works well but would mislead if limes were common in the area. Ultrasound markers of Down's syndrome, often alarm parents more than a serum test result with the same likelihood ration, because a scan abnormality seems more representative of Down's. Using the availability heuristic, the person estimates the probability that an object is a member of a set by considering how easily another member of that set can be recalled. For example one woman who has a previous child affected with spina bifida, a low serum alphafetoprolein and a normal ultrasound scan may have the same posterior risk of spina blfida, say 1 in 1000, as another low risk woman who has undergone no testing at all. However, the women with a previous affected child is likely to perceive her risk as much greater because she can easily imagine such an outcome. The availability heuristic is the reason why the way risks are framed is important. A risk of 1 in 100 that the baby has Downs's, seems worse than a 99% chance that the baby is not affected. If people have any prior estimate of the probability of an event, they tend to estimate the changed probability of the event in the light of new information, by making some adjustment from the earlier estimate. This is anchoring, If the initial estimate was wrong then future estimates are likely to be wrong. Even if the original estimate was correct, adjustments from anchored values are typically insufficient, leading to predictable bias. If patients have suffered a problem themselves, or had a previous affected child, availability typically leads them to overestimate the risk of recurrence. They then anchor to this high risk, when given a negative screening test result. Doctors presenting risk information should be aware of these biases. If they want to permit patients to make their own well-informed decisions they should do what they can to minimize or avoid them. There are a number of ways to help. First, doctors should avoid presenting risks in semiquantitative ways. Expressions such as common, rare, unlikely, etc., are frequently used when transmiHing risk information. They have two major disadvantages. First, they cause misunderstanding
69
since people interpret words differently. In one report doctors interpretation of 'unlikely' had an inter-quartile range from 6 to 22% [15]. Second, such words are not value neutral. If a doctor says that a risk of handicap is 'low', patients may interpret that it is too low for termination of pregnancy to be a reasonable option. We have observed that use of semi-quantitative words appears to carry a diredive message [16]. For conditions where parents had to decide whether to continue a pregnancy with a risk, rather than certainty of handicap, all parents chose termination if the risk word implied a high risk, and chose to continue if it implied a low one. In contrast, the decisions of patients given numeric risks were individualized. Some parents continued the pregnancy at the relatively 'high' risk of 50% and some chose termination at the relatively 'low' risk of 5% For those who want to be non-directive, numeric risks are preferable. Use of value laden words also permits the counsellors views to influence the patient. Bias has been clearly documented in taped consultations of screening test offers [17]. For example, 0.5% chance of Down's syndrome was typically described as a 'high risk', while a 1% miscarriage risk after diagnostic testing was typically described as 'low' risk. Even if numbers are used to describe risks there is a possibility of biasing patients by framing the risks one way or another. To minimize anchoring and availability, risks should be framed both ways, i.e. they should be presented both as the risk of the bad outcome, and as that of the good outcome. For example, a 1 in 250 risk of Down's syndrome should also be presented as a 249 in 250 chance that the fetus does not have Down's. Similarly, a procedure-related miscarriage risk of 1% should also be presented as a 99% chance that it will not cause miscarriage. Parents often have little idea of the background risks of adverse pregnancy outcomes and find it difficult to set them in context. It is important when giving a miscarriage risk of say 1% to remind parents that even without the test, assuming the fetus is alive, they have a baseline risk of at least that rate. Similarly, with risks of abnormality parents frequently do not realize that the overall risk of significant congenital abnormality in the general population is around 2%. Finally, it is good pradice to present risks pictorially where possible. Special risk wheels and other decision aids are available, but marking risks by filling in squares of graph paper is a simple alternative easily done even in a busy clinic.
70
There are more sophisticated ways to help people incorporate risk and value information into decisions in a structured way. Decision analysis is the most sophisticated [18, 19]. This is widely used in business but still little used as an everyday decision aid. We are currently evaluating it in a randomized controlled trial to help parents make the amniocentesis decision after serum screening.
Appropriate counselling Counselling should be appropriate both to the problem and the patient. Since patients and decisions both vary, the amount and type of counselling should also vary.
Patient factors Patients differ in the degree to which they perceive that they have control over their destiny. Some feel that their views make little difference to what happens, and that events are shaped by other people, the government, God, or fate. Others feel the opposite. Psychologists use the term 'locus of control'. The former group have an external locus, and the latter an internal one. Individuals lie on a spedrum, and can be classified by their speech patterns, or according to their response to standard questions. There is some evidence that people with an internal locus of control prefer to be given more information about health issues, while those with an external one are happy to be given less. Similarly, those with an external locus may ask for advice on decision making, even for value-led decisions where the decision properly belongs to the patient. It may be appropriate to tell such patients what others generally decide in a similar situation.
Decision factors Decisions vary in their complexity and structure, in the time required or available to make them, and in the possibility of using mathematical or other decision aids. It is, therefore, sensible for decision makers to use a range of strategies. A popular classification of decision strategies places them in a range from intuitive, through peer aided, to analytic modes, and has been called the cognitive continuum [20]. It has been suggested that intuition
J. G. Thornton
is appropriate for unstructured, time-limited, routine problems and analysis more suited to complex, well-structured problems where more time is available. For most screening it is appropriate for patients to make an intuitive decision after being told the risks and benefits. Guthrie testing of the new-born for phenylketonuria (chapter 1) is an example. It is a good test, which identifies children for a simple cheap treatment that prevents brain damage and saves lives. The programme runs well with minimal counselling, and many parents are hardly even aware of it. Other decisions are more complex but not well structured, The effediveness of screening may be disputed, the tests may have side effeds, or people may disagree whether screening is worthwhile. Newborn screening for Duchenne Muscular Dystrophy is more like this. The tests are less than perfed, having both false positives and false negatives, and there is no treatment, so the only benefits are the possibility of choosing not to reproduce at all, or the seledive abortion of male siblings. It is appropriate for patients to ask an expert, typically their dodor for advice. Even if the experts cannot directly incorporate their personal values, they can tell them what other similar patients have chosen. This is peer-aided judgement. Finally, some complex decisions are very well structured and suited to a more analytical mode of decision making. Perhaps the best structured prenatal screening decision is whether to undergo an invasive test when a screening test reveals a risk of fetal abnormality such as Down's syndrome or neural tube defed. The chance of preventing the birth of an abnormal child has to be weighed against the chance of the diagnostic test causing miscarriage. Decision analysis is well suited to this sort of problem. The appropriate level of counselling may also depend on whether the programme is new or established. When serum screening for Down's syndrome was introduced screen positive patients (often with a posterior risk of less than 1%) were almost all extremely anxious, believing that they had a high risk of carrying an affeded child. They required help to understand what a 1 in 100 risk really means. As the programme has become widespread, and is regularly written about in popular magazines, and discussed on television, and as patients know personally individuals who have had screen positive results and delivered healthy babies, people's interpretation of a screen positive result has become more accurate. Thus, it is appropriate
Counselling issues in perinatal screening
71
that patients now receive less counselling on average than they did when the test was new. 8
Summary points 9
• Giving full information about screening does not usually cause anxiety. • Avoid distractions when imparting complex information. • Give information in writing as well as orally. • Check the readability of information leaflets. • Avoid using semi-quantitative words for risk. • Frame risks both as the 'chance of a bad outcome' and 'chance of a good outcome'. • Present risks pictorially.
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References 1 Schapiro MC, Najman A. Change J, Keeping D, Morrison J, Western JS. Information control and the exercise of power in the obstetrical encounter. SocSci Med 1983; 17: 139-146. 2 Marleau TM, Johnston M, Shaw RW, Slack J. Factors influencing the uptake of screening for open neural tube defects and amniocentesis to test for Downs syndrome. Br I Obslef Gynaeco! 1989; 96: 739-748. 3 Thornton JG, Hewison J, Lilford RJ, Vail A. A Randomised Trial of Three Methods of Giving Information about Prenatal Testing. Br Med 11995; 311: 1127-1130. 4 Bekker H, Modell M, Dennis G, Silver A, Mathew C, Bobrow M, Matteau T. Uptake of cystic fibrosis testing in primary care: supply push or demand pull? Br Med 11993; 306: 1584-1586. 5 Green J. Calming or harming. Golion lnsliiuie Occnsiollnl papers, 2nd series, no. 2, 1990. 6 Ley P. Satisfaction compliance and communication. Br I Clin Psychol 1982; 21: 241-254. 7 Simes RJ. Tattersall MH, Coates AS, Raghaven D, Solomon HG, Smartt H. Randomised comparison of
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procedures for obtaining informed consent in clinical trials of treatment for cancer. Br Med I 1986; 293: 1065-1068. Reid M. Consumer orientated studies in relation to prenatal screening tests. ElIr I Obslel Gvneco! Reprod BioI 1988; 28: 79-92. Burton BK, Dillard RG. Clark EN. The psychological impact of false positive elevations of maternal serum alphafetoprotein. Am I Obslel GYllecol 1985; 151: 77-82. Burton BK, Dillard RG, Clark EN. Maternal serum alphafetoprotein screening: the effect of participation on anxiety and attitude toward pregnancy in women with normal results. Am I Obslel Gyllecoll985; 152: 540-543. Allanson A. Michie S. Marleau TM . Presentation of screen negative results on serum screening for Down's syndrome: variations across Britain. I Med Screen 1997; 4: 21-22. Ley P. Communicating with Patients: Improving Communication, Satisfaction and Compliance. London: Chapman and Hall. 1992. Flesch RR. A new readability yardstick. I Applied Psychol 1948; 32: 221-223. Tversky A, Kahnemann D. Judgement under uncertainty: heuristics and biases. Science 1974; 185: 1124-1131. Thornton JG, van den Borne MPJ, de Bruijn AJE. Risk communication the patient's view . Early Human Development 1996; 47(Suppl.): S13-S17. Marleau TM, Plenicar M, Kidd J. Obstetricians presenting amniocentesis to pregnant women: practice observed. I Reprod lnjan! Psycholl993; 11: 3-10. Pauker SP, Pauker SG. The amniocentesis decision: ten years of decision analytic experience. Birth defects; origina! article series 1987; 23(2): 151-169. March of Dimes Birth Defects Foundation. Thornton JG, Lilford RJ, Johnson N. Decision analysis in Medicine. Br Med 11992; 304: 1099-1103. Hamm RM. Clinical intuition and clinical analysis: expertise and the cognitive continuum. In: Dowie J, Elstein A (cds) Projessional [udgenteni. Cambridge: Cambridge University Press. 1998; pp 78-105. Ley P, Llewelyn S. Improving patients' understanding. recall. satisfaction and compliance. In: Healil: Psychology; Processes and Applications. 2nd cd. London: Chapman and Hall. 1995.