Will genetics revolutionize medicine?
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Genetic Diseases, Inborn↗
Biomedical subjects
T M Marteau
Publications and source records attributed to T M Marteau.
Psychological consequences for parents of false negative results on prenatal screening for Down's syndrome: retrospective interview study.
OBJECTIVE: To determine the psychological consequences for parents of children with Down's syndrome of having received a false negative result on prenatal screening. DESIGN: Comparison of adjustment of parents who received a false negative result with that of parents not offered a test and those who declined a test. SETTING: Parents were interviewed in their own homes. PARTICIPANTS: Parents of 179 children with Down's syndrome (mean age 4 (range 2-6) years). MAIN OUTCOME MEASURES: Anxiety, depression, parenting stress, attitudes towards the child, and attributions of blame for the birth of the affected child. RESULTS: Overall, regardless of screening history, parents adjusted well to having a child with Down's syndrome. Compared with mothers who declined a test, mothers in the false negative group had higher parenting stress (mean score 81.2 v 71.8, P=0.016, 95% confidence interval for the difference 1.8 to 17.0) and more negative attitudes towards their children (124.9 v 134.2, P=0. 009, -16.2 to -2.4). Fathers in the false negative group had higher parenting stress test scores (77.8 v 70.0, P=0.046, 1.5 to 14.2) than fathers not offered a test. Mothers in the false negative group were more likely to blame others for the outcome than mothers who had not been offered the test (28% v 13%, P=0.032, 3% to 27%). Mothers and fathers in the false negative group were more likely to blame others for this outcome than parents who had declined a test (mothers 28% v 0%, P=0.001, 19% to 37%; fathers 27% v 0%, P=0.004, 17% to 38%). Blaming others was associated with poorer adjustment for mothers and fathers. CONCLUSIONS: A false negative result on prenatal screening seems to have a small adverse effect on parental adjustment evident two to six years after the birth of an affected child.
Adult↗
Numbers or words? A randomized controlled trial of presenting screen negative results to pregnant women.
The Objective of this study was to test the hypothesis that presenting risk information using numbers rather than words is a more effective way of communicating the residual risk inherent in a screen negative test result. We used a randomised controlled trial in a large UK teaching hospital. Two hundred and twenty pregnant women who received negative results on serum screening for Down syndrome participated. Presentation of screen negative test results were given either as a numerical probability (e.g. you have a 1:650 chance of having a baby with Down syndrome) or as a verbal probability (your chance of having a baby with Down syndrome is low). In both interventions the verbal anchor 'it is unlikely that your baby has Down syndrome' was used. Our aims were to measure the understanding of the residual risk in a screen negative result, and anxiety. Immediately after receipt of the results, 97% of those receiving their results in the form of a numerical probability and 91% of those receiving their results in the form of a verbal probability correctly understood that their baby probably did not have Down syndrome (95% CI for difference: 0% to 12%; p=0.04). All those who were incorrect believed that their baby definitely did not have Down syndrome. Subgroup analysis showed that this effect was confined to those with lower levels of education (i.e. those without a university degree), amongst whom understanding was poorer. There was no difference between intervention groups in understanding the results at four months. There were no differences between intervention groups in the levels of anxiety at one week or four months after receiving their results. In conclusion, communicating residual risks using numbers rather than words has a small beneficial effect of increasing awareness of residual risks without raising anxiety. Further work is needed to estimate the size of this effect in less well-informed and less highly educated populations.
Adult↗
The psychological impact of a cancer family history questionnaire completed in general practice.
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Adult↗
Perceptions of multiple risk factors for heart attacks.
There is increasing evidence that in some diseases such as coronary heart disease, risk factors may interact synergistically, resulting in greater likelihood of disease than would be produced by the sum of the risk factors. These two studies aimed to examine the extent to which 210 undergraduate students and 28 heart attack patients perceive risk factors to combine synergistically. Respondents read one of four vignettes, describing information about risk factors (with high and low smoking and family history), and estimated a man's likelihood of a heart attack in a hypothetical case. In both studies an interaction was found with either a family history or smoking eliciting ratings of high likelihood of heart attack, providing no evidence of synergistic models. This finding may reflect respondents' beliefs or the insensitivity of this paper-and-pencil method in detecting synergistic effects.
Adult↗
Is recruitment more difficult with a placebo arm in randomised controlled trials? A quasirandomised, interview based study.
OBJECTIVE: To investigate whether including a placebo arm in a clinical trial of hormone replacement therapy influenced women's stated willingness to participate. DESIGN: Quasirandomised, interview based study. SETTING: 10 group practices in the Medical Research Council's General Practice Research Framework. PARTICIPANTS: 436 postmenopausal women aged 45-64 who had not had a hysterectomy. MAIN OUTCOME MEASURES: Stated willingness to enter a trial and reasons for the decisions made. RESULTS: Of 218 women told about the trial without a placebo arm, 85 (39%) indicated their willingness to enter compared with 65 (30%) of the 218 women told about the trial with the placebo arm (P=0.06). Part of this difference was due to explicit reluctance to take a placebo. Altruism and personal benefit were the reasons most frequently given for wanting to take part in a trial. The reasons most frequently cited for not wanting to take part were reluctance to restart periods, not wanting to take unknown or unnecessary tablets, or not wanting to interfere with present good health. CONCLUSION: For preventive trials the inclusion of a placebo arm may reduce patients' willingness to participate.
Algorithms↗
Prenatal tests: how are women deciding?
Women offered prenatal tests should be given sufficient information to enable them to make an informed decision. We compared the decision-making of 261 women who underwent serum screening for Down syndrome with 63 who did not. A questionnaire completed at 16 weeks' gestation assessed systematic decision-making (the weighing up of pros and cons on the basis of information presented), knowledge, anxiety and demographic information. Those undergoing screening were older but, with age partialled out, they had more knowledge about the test and made decisions less systematically than those not screened.
Adult↗
Incorrect recall of residual risk three years after carrier screening for cystic fibrosis: a comparison of two-step and couple screening.
OBJECTIVE: This study was undertaken to compare long-term recall of the meaning of test results after a negative result of 2-step or couple antenatal screening. STUDY DESIGN: In a randomized controlled trial a subject-completed questionnaire was sent to 275 women who had undergone couple testing 3 years earlier and 83 women who had undergone 2-step testing 3 years earlier (n = 263/358 for a response rate of 73%). The main outcome measure was understanding of test results. RESULTS: Three years after testing women who had undergone couple testing were 4.5 times (95% confidence interval 2.4-8.4 times) more likely than those who had undergone 2-step testing to accurately recall that the test result meant that they were unlikely to be carriers for cystic fibrosis (80%, 95% confidence interval 74%-86%, versus 49%, 95% confidence interval 36%-61%). Anxiety level, plans to have more children, and age were unrelated to recall. CONCLUSION: The results of this study, together with those from other evaluations, suggest that not only does couple testing avoid the high levels of anxiety associated with 2-step testing but it also results in greater awareness of the residual risk inherent in a negative screening test result.
Adult↗
Will genetic testing for predisposition for disease result in fatalism? A qualitative study of parents responses to neonatal screening for familial hypercholesterolaemia.
OBJECTIVE: to describe parents' perceptions of familial hypercholesterolaemia (FH), an inherited predisposition to heart disease, following population-based neonatal screening. DESIGN: a qualitative analysis of semi-structured interviews with the parents of 24 children who had received a positive screening test result informing them that their child was at-risk for having FH. RESULTS: responses to screening seemed to vary according to perceptions of the underlying cause of the positive screening test result. When parents perceived the test as detecting raised cholesterol the condition was perceived as familiar, dietary in origin, controllable and less threatening. When the test was seen as detecting a genetic problem, the condition was perceived as uncontrollable and, hence, more threatening. CONCLUSION: these pilot data raise questions about the extent to which assessing disease risks by DNA analysis may result in a sense of fatalism, adversely affecting motivation to change behaviour and to reduce risks.
Adult↗
Psychological impact of predicting individuals' risks of illness: a systematic review.
The aim of this review is to determine the frequency and circumstances under which predicting individuals' risk of illness has adverse psychological effects. Using systematic review methodology, the literature was searched for studies that had assessed the adverse psychological outcomes of risk assessment programmes. The outcomes investigated are emotional (anxiety, depression, distress) cognitive (intrusive thoughts, perceptions of health) and behaviour (work absenteeism). The impact of both positive and negative test results are summarised in terms of the number of studies showing significant effects between and within groups in the short (one month or less) and longer term (more than one month). Where sufficient data were available, a meta-analysis was conducted to assess effect size. Fifty-four studies met the criteria for inclusion. The studies assessed the impact of informing individuals about cardiovascular risk (21), risk of AIDS (eight), risk of cancer (10), risk of Huntington's disease (10), risk of diabetes (two), risk of spinocerebellar ataxia (one) and risk of osteoporosis (two). Overall, the quality of studies assessed was limited, with only two using a randomised design to determine the psychological impact of risk assessment. Receiving a positive test result was associated in the short term in the great majority of studies with depression, anxiety, poorer perceptions of health and psychological distress. Data were available for a quantitative synthesis of results on three outcomes, anxiety, depression and distress. Anxiety and depression were significantly higher in those tested positive compared with those tested negative in the short term but not the longer term. Distress could only be assessed in the longer term: there was no evidence of an increase for those receiving positive test results. The five experimental studies that reported interventions aimed at preventing some of these adverse effects all reported favourable results. There was little evidence of any adverse psychological effects of receiving an unfavourable test result. Adverse psychological effects are a common immediate consequence of positive test results following risk assessment. Results from the few experimental studies reviewed suggest that these adverse outcomes should not be seen as inevitable.
Acquired Immunodeficiency Syndrome↗
The future of genetic counselling: an international perspective.
The focus of clinical genetics, and thus genetic counselling, is forecast to expand from the diagnosis and prediction of rare, often untreatable conditions, to the prediction of common, often treatable or preventable conditions. Whether this evolution is likely to proceed rapidly or at a pace that permits sensible integration of molecular genetic tools is unknown and a source of debate. It is clear, however, that genetic discoveries will modify the way in which disease and risk are conceptualized. Here, we predict how genetic counselling, specifically for more common diseases, might be provided in the decades to come. We envisage an expansion of professional roles and expertise for many health care providers and highlight the need for counselling practices to become more evidence based. Although we support an evidentiary-based approach to the integration of genetic testing into practice, genetic advance is unlikely to occur in an orderly and standardized manner within countries, much less among different countries and health care systems. Geneticists will become increasingly involved in professional education and policy-making regarding genetic testing and screening programs.
Delivery of Health Care↗
The choice to have a disabled child.
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Adult↗
Breast screening: GPs' beliefs, attitudes and practices.
OBJECTIVES: We aimed to describe GPs' knowledge, beliefs and attitudes towards breast screening, and their association with practice-based organizations of breast screening. METHOD: A stratified randomized sample of 158 GPs from within the North-East and North-West Thames Health Regions were interviewed. RESULTS: Sixty-five per cent of GPs report checking the accuracy of invitation lists, and differ from those who do not, in having more knowledge about risk factors for breast cancer. Thirty-seven per cent of GPs report a policy of following up non-attendees for screening and differ from those who do not in three ways: a greater perception of the threat of breast cancer; a greater belief in the importance of GPs' role in increasing attendance of women for breast screening; and, a less-negative attitude towards breast screening. CONCLUSION: Women's attendance for breast screening may be increased by raising GPs' perceptions of the threat of breast cancer, addressing their concerns about breast screening and enhancing their views of the importance of the role of primary care in a national screening programme.
Breast Neoplasms↗
Communicating genetic risk information.
It is envisaged that genetic information will be used, together with other types of information, to assess individuals' risks of developing a variety of common conditions. Such risk assessments will involve providing probabilistic information partly based upon results of genetic tests in order to facilitate behaviour change without causing excessive anxiety. The behaviours targeted for change are likely to include adherence to prescribed medication, alteration to diet, increasing levels of exercise and quitting smoking. This paper reviews research already conducted on perceptions of risk and genes, methods of facilitating behaviour change and reducing anxiety following various types of risk assessment. Although risk assessment and interventions to reduce risks have been conducted for over 20 years, very little rigorous research exists. For the investments in the new genetics to be realised, research is now needed both in how individuals respond to risk information that involves the use of genetic information and in how to facilitate and maintain behaviour change to reduce such risks.
Communication↗
Termination rates after prenatal diagnosis of Down syndrome, spina bifida, anencephaly, and Turner and Klinefelter syndromes: a systematic literature review. European Concerted Action: DADA (Decision-making After the Diagnosis of a fetal Abnormality).
The aims of this systematic literature review are to estimate termination rates after prenatal diagnosis of one of five conditions: Down syndrome, spina bifida, anencephaly, and Turner and Klinefelter syndromes, and to determine the extent to which rates vary across conditions and with year of publication. Papers were included if they reported (i) numbers of prenatally diagnosed conditions that were terminated, (ii) at least five cases diagnosed with one of the five specified conditions, and (iii) were published between 1980 and 1998. 20 papers were found which met the inclusion criteria. Termination rates varied across conditions. They were highest following a prenatal diagnosis of Down syndrome (92 per cent; CI: 91 per cent to 93 per cent) and lowest following diagnosis of Klinefelter syndrome (58 per cent; CI: 50 per cent to 66 per cent). Where comparisons could be made, termination rates were similar in the 1990s to those reported in the 1980s.
Abortion, Therapeutic↗
The new genetics. Psychological responses to genetic testing.
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Attitude to Health↗
Mixed messages: presentation of information in cystic fibrosis-screening pamphlets.
Written pamphlets are an important source of information for individuals deciding whether to undergo carrier testing for cystic fibrosis (CF). Adequate understanding of the condition and reproductive options following the diagnosis of a fetus with CF are critical to informed decision making. The information given about CF and reproductive options in 28 pamphlets about carrier testing, from commercial and noncommercial organizations in the United States and the United Kingdom, aimed at prenatal and other populations, was assessed. The amount of information provided about CF showed a range of 1-37 sentences (median 6.5), with most being relatively neutral and with a minority conveying a positive or a negative image. Positive sentences were less common in British, U.S. commercial, and prenatal pamphlets. Statements about life expectancy also varied considerably, both in the ages provided and in the degree of optimism conveyed. In addition, the pamphlets varied in the amount of information they provided about reproductive options following the diagnosis of a fetus with CF. Abortion was mentioned in just 15 pamphlets, more often in the United Kingdom than in the United States and more frequently in pamphlets from noncommercial than in those from commercial organizations. Wide variation in the descriptions of CF and the reproductive options presented raises concerns about the extent to which any one pamphlet may present balanced information. The choices about what information to include in educational materials need to be explicitly considered on the basis of the message intended to be sent.
Cystic Fibrosis↗
Objectives of genetic counselling: differing views of purchasers, providers and users.
BACKGROUND: This study aimed to compare the views of purchasers, providers and users about the objectives of genetic counselling. METHODS: A modified Delphi technique was used, incorporating two postal questionnaires that were sent to six study groups with a three-month interval: purchasers (public health doctors (n = 37) and regional advisers in general practice (n = 35)); providers (clinical geneticists (n = 33) and genetic counsellors (n = 25)); and users (out-patients (n = 36) and members of genetic support groups (n = 32)). The response rate for the first questionnaire was 115/198 (58 per cent) and for the second, 102/198 (52 per cent). The first questionnaire asked an open-ended question about what the objectives of genetic counselling should be and asked respondents to rank order them. The second questionnaire summarized the views expressed in the first questionnaire and asked respondents to rank order the most frequently cited and most highly ranked five objectives. RESULTS: The five most frequently cited and highly ranked objectives from Questionnaire One were, in descending order: provide information, give support, facilitate decision-making, assess risk and achieve understanding. In response to Questionnaire Two, purchasers differed from providers and users in rating 'facilitate decision-making' more highly than did providers and users. By contrast, providers and users rated 'give information' more highly than did purchasers. CONCLUSIONS: Purchasers hold different views from providers and users about what the objectives of genetic counselling should be. This raises two questions: (1) Which views are or should be most influential in the future development of genetic counselling? (2) By what processes can more than one view on genetic counselling be integrated?
Attitude of Health Personnel↗