Description: How many things (life events, situations, crimes, illnesses, etc.) would it be good to be able to predict? We could take the stance that things are in the hand of fate and there is nothing we can do so why bother trying to predict. But what if we could identify people who will, if nothing is done, suffer a potentially fatal illness (that could be avoided with early prevention/treatment efforts? What if we could identify (bad) driving habits that could result in fatal collisions and fix the behaviors before the collisions happen (think about drunk driving). And, what if we could predict which recently conceived fetuses were carrying particular genetic patterns or abnormalities that would, if present, result in fatal conditions that would lead to the death of the resulting newborn soon after birth? Now, before we get any further in this thought exercise lets add a few variables. There is no arguing that fatal outcomes are bad and should be predicted and prevented if possible. However, we also have to consider that in some, in fact in virtually all, of these situations our prediction efforts and our attempts at early prediction (that would provide more lead time to fix or address problems) are not perfect and, in addition, predictive assessment (tests) can be expensive and for many the cost and side-risks of such tests go up quite dramatically as the accuracy of the tests increases. Add to that the very real possible course of action after a positive test (one that says the potentially fatal things WILL happen) might mean that powerfully troubling decisions may be placed on the table. For example, to be perfectly safe we may have to consider a lifetime driving ban for those who test as “at risk” for drunk driving; or our only possible course of action following a positive screen for a fatal illness is to give the person who was tested the bad news; or, in the case of prenatal genetic abnormalities, the parents may get to consider the option of terminating the pregnancy. Now, lets assume that in any and all such cases the involvement of therapists/counsellors would be a necessity. Let’s also assume that the costs associated with such tests, in terms of both money and test related additional risk, increase as the accuracy of the chosen test increase. Also, we will need to find out about and consider how accurate the possible tests are that we could consider using.
So, here is the several faceted challenge in this thought experiment. First think about how you would want to define accuracy. What data would you want to get or be provided? Second, who would/should be offered a test? Who would be offered which test? Would the test be mandatory? Post-testing, who would/should decide what to do next? Think one more time about the accuracy question. Now read the first of the two articles linked below with your thoughts about these questions in mind and see if the article provides you with most of what you feel you need to know to work through this thought experiment. If not, what is missing? Why is that important? Finally, read the second article linked below written by someone who essentially did a version of this thought experiment in relation to the first article and wrote about what they came up with.
Source: First Read: When Thye Warn of Rare Disorders, These Prenatal Tests are Usually Wrong. Sarah Kliff and Aatish Bhatia The New York Times Jan 1, 2022
Second Read: What the New York Times Got Wrong on Prenatal Screening, Ellen Matloff, Forbes.
Date: January 1 and 6, 2022
Article Link: First Read: https://www.nytimes.com/2022/01/01/upshot/pregnancy-birth-genetic-testing.html Second Read: https://www.forbes.com/sites/ellenmatloff/2022/01/06/what-the-nytimes-got-wrong-on-prenatal-screening
When potentially bad things could arise in life, we sometime engage in something called screening. As the second article suggested, we use questions and x-ray equipment to screen people’s carry-on luggage as they move through security at the airport but that is only the beginning as suspicious screens are followed up by detailed searches of luggage and even of the people carrying that luggage which is more expensive but also more intensive and more likely to correctly identify genuine risks. We cut costs by only screening those people who are actually going to get onto planes (rather than everyone at the airport). At the level of first screening, we accept a number of false positives (bags that could contain sharp things or dangerous liquids but actually do not when looked at in a more detailed inspection) because only having to take the time and effort to search “positively screened travelers” saves time and money. However, there is something else we have to consider too isn’t there? What about false negatives? Yes, what about dangerous things or people that do NOT get picked up in screening? Are you thinking that false negative rates could lead to screening tests being seen a useless, right? Now think about these questions not just as they apply to airport screening but as they apply to medical screening (e.g., rapid tests versus laboratory tests); or to potential drunk drivers; or to prenatal genetic abnormalities. So, consider that; Screening assessment are indicative but NOT diagnostic; a test’s ability to identify true positives is called its Sensitivity and its ability to identify true negatives is its Specificity. These definitions and limitations outline the HUGE challenge in planning to address any of the examples discussed above. Who to test, how to test, when to test, and what to do with the results and how to manage the risks associated with the screening and diagnostic assessment and as well as the risks associated with NOT testing with testing and then being right or being wrong? Complicated stuff, huh?
Questions for Discussion:
- What are some things that we currently regularly screen for?
- How well do we screen for each of the thing you came up with in responding to the previous question?
- Walk through the issues and details of screening program for a prenatal/congenital issue or other medical condition/illness and detail your data, practical, ethical, and counselling challenges at each stage of the process?
References (Read Further):
Society for Maternal Fetal Medicine (2002) Practice Bulletin #226, Screening for Chromosomal Abnormalities, American Journal of Obstetrics and Gynecology. Link
Benn, P., Borrell, A., Chiu, R. W., Cuckle, H., Dugoff, L., Faas, B., … & Yaron, Y. (2015). Position statement from the Chromosome Abnormality Screening Committee on behalf of the Board of the International Society for Prenatal Diagnosis. Prenatal diagnosis, 35(8), 725-734. Link
Gekas, J., Langlois, S., Ravitsky, V., Audibert, F., van den Berg, D. G., Haidar, H., & Rousseau, F. (2016). Non-invasive prenatal testing for fetal chromosome abnormalities: review of clinical and ethical issues. The application of clinical genetics, 9, 15. Link
Westerfield, L., Darilek, S., & Van den Veyver, I. B. (2014). Counseling challenges with variants of uncertain significance and incidental findings in prenatal genetic screening and diagnosis. Journal of clinical medicine, 3(3), 1018-1032. Link
Dondorp, W., De Wert, G., Bombard, Y., Bianchi, D. W., Bergmann, C., Borry, P., … & Cornel, M. C. (2015). Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening. European Journal of Human Genetics, 23(11), 1438-1450. Link
Tuohey, R. J., & Repenshek, M. (2008). Ethical Considerations Concerning Screening for Chromosome Aneuploidy: A Response to a 2007 American College of Obstetricians and Gynecologists Practice Bulletin. The Linacre Quarterly, 75(2), 96-111. Link