2.

SCREENING OVERVIEW

The committee was asked to address the screening of the populations of uranium miners, millers and ore transporters, and downwinders and onsite nuclear-test participants for a broad set of malignant and nonmalignant diseases compensable under RECA. However, not all the compensable diseases are considered to be radiogenic. Although the objective of the screening process used by the grantees should be consistent with accepted rationales for screening populations or patients, many persons in the RECA-covered populations do not have clinical evidence of disease. The HRSA program addresses the identification and compensation of people who have developed diseases covered under RECA. The dual goals of the program may, and at times do appear to be, in conflict. The program assumes that screening exposed people will provide health benefits to them. However, such benefits have not been established on the basis of evidence; indeed, the committee has heard testimony that some of the screening anticipated by the legislation may be harmful.

The decision to screen for purely medical reasons rests on a hierarchy of assumptions that

  • A disease exists in the population, and effective treatment for or prevention of preclinical or early-stage disease is available.

  • An accurate, practical screening test is available.

  • Early detection improves clinical outcomes (such as survival or quality of life) of the disease.

  • An effective treatment for, or a means of prevention of, a preclinical or early-stage disease is available.

  • The benefits of screening exceed its harms.

  • The cost of a screening program (including its induced costs) justifies the use of resources.

  • An existing health-care system has the resources to provide referral services that address follow-up (further evaluation and continuing care) of patients identified through the screening program, including the noncompensable diseases coincidentally identified.

It remains difficult to establish that screening programs in actual practice meet those criteria, in part because of confounders such as lead-time and length bias. Furthermore, any program may be considerably less effective in practice than in theory. Effectiveness in practice depends on a long chain of causal reasoning that is subject to “failure” at many of its steps.



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2. SCREENING OVERVIEW The committee was asked to address the screening of the populations of uranium miners, millers and ore transporters, and downwinders and onsite nuclear-test participants for a broad set of malignant and nonmalignant diseases compensable under RECA. However, not all the compensable diseases are considered to be radiogenic. Although the objective of the screening process used by the grantees should be consistent with accepted rationales for screening populations or patients, many persons in the RECA-covered populations do not have clinical evidence of disease. The HRSA program addresses the identification and compensation of people who have developed diseases covered under RECA. The dual goals of the program may, and at times do appear to be, in conflict. The program assumes that screening exposed people will provide health benefits to them. However, such benefits have not been established on the basis of evidence; indeed, the committee has heard testimony that some of the screening anticipated by the legislation may be harmful. The decision to screen for purely medical reasons rests on a hierarchy of assumptions that A disease exists in the population, and effective treatment for or prevention of preclinical or early-stage disease is available. An accurate, practical screening test is available. Early detection improves clinical outcomes (such as survival or quality of life) of the disease. An effective treatment for, or a means of prevention of, a preclinical or early-stage disease is available. The benefits of screening exceed its harms. The cost of a screening program (including its induced costs) justifies the use of resources. An existing health-care system has the resources to provide referral services that address follow-up (further evaluation and continuing care) of patients identified through the screening program, including the noncompensable diseases coincidentally identified. It remains difficult to establish that screening programs in actual practice meet those criteria, in part because of confounders such as lead-time and length bias. Furthermore, any program may be considerably less effective in practice than in theory. Effectiveness in practice depends on a long chain of causal reasoning that is subject to “failure” at many of its steps.

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In the context of the screening program anticipated by HRSA, an additional set of issues might be considered: Most prior analyses of medical screening have considered programs that addressed a single disease; the HRSA program screens for a multitude of diseases simultaneously. (Indeed, multiphasic screening programs were popular about 2 decades ago (for example, for executives) until it became clear that the problem of false positive, and red herrings limited their utility). Screening for medically marginal indications compete in the same resource pool as screening for more-accepted indications (such as diabetes, hypertension, hyperlipidemia, and colon cancer), and the screening and follow-up of people in the HRSA program may make such more-accepted approaches to preventive care unavailable to this population. Compensation to some of the people subjected to a potentially harmful screening program may partially offset the risks and might be a consideration for some people in deciding whether to participate in the HRSA program. Although the committee heard testimony that the issues of medical benefits or harms and of compensation should be kept separate, the issues must come together for people in the RECA populations to make an informed decision about participation in the program. The committee believes that people eligible for a screening program should be well informed about the potential harms and the benefits of such screening. Most screening programs address a single disease, a disease for which early detection makes a difference and for which a highly specific, typically binary test is available (for example, leading to a positive or negative result). That is not the case for most of the diseases covered under RECA. Several independent guideline-producing agencies have not recommended a number of the RECA targeted diseases for screening. In the case of lung cancer, this can be attributed to the lack of demonstrated medical benefit from early detection and the lack of a practical, highly specific test. The same is true, for example, for thyroid cancer. Because screening programs such as those being proposed to HRSA involve testing for diseases with low prevalence, false-positive rates will be high and will be accompanied by increased risks and costs associated with further testing. Bayes’ rule shows that the probability of disease among patients with a positive (screening) test (the positive predictive value) depends most strongly on the test’s specificity and the probability of disease in the population to be screened. If both are relatively low (likely the case in the HRSA program), the positive predictive value will be low, and the majority of positively labeled people will, in fact, be false positives. The false-positive problem is exacerbated when one screens for several diseases or when the test under

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consideration is an imaging study (for example, a chest x-ray, a CT scan, or an ultrasound procedure). Such studies can produce more than one result, not just a simple yes or no for lung cancer. For example, a chest x-ray may reveal a tiny nodule, a widened mediastinum, borderline cardiomegaly, and an elevated hemidiaphragm. Each of those findings could incur further workup, and more than one of those observations could be a false positive in an otherwise healthy person. HRSA has asked the committee to make recommendations about the quality of the screening programs the agency now supports in uranium workers and downwinders. The committee is addressing whether there is a sufficient scientific basis for going beyond accepted recommendations for screening the population in general such as colonoscopy, Pap-smears, and mammograms, as well as routine contact with a physician. The major way in which uranium workers, downwinders, and onsite participants differ from the general population might be that they have a higher prevalence of diseases. It remains unclear to the committee whether the increase in prevalence is enough to justify a change in currently-accepted screening recommendations. The committee recognizes that some of the populations involved in the RECA screening program may be medically underserved and ones that are perhaps reluctant to make contact with the medical system (for example, native Americans). In those settings, the committee suggests that it might be more beneficial to provide additional resources to facilitate such contact rather than to devote resources to enhanced screening. Once such contact has been established, generally accepted screening and preventive health recommendations could suffice (see U.S. Preventive Health Services Task Force, Canadian Task Force and American College of Physicians recommendations). The committee suggests that both current grantees and new applicants for funding under this program address the general principles of screening and the special concerns raised in this section about the proposed screening program. As is the case with many population-based programs, one must distinguish between benefits (and harms and costs) to individuals and to the population in the aggregate. One must also appreciate that such medical benefits may be limited by the age and co-morbidities of individuals in the population proposed to be screened. Although the benefits and harms of a screening program affect individuals, each of whom will make an informed choice about participation and each of whom will or will not have one or more of the diseases in question, decisions about the structure of each screening program (and, in fact, whether to offer a screening program) are typically made at the population level. 2.1 Ethics of Screening The decision to screen, especially beyond the accepted recommendations for screening, the population in general needs to involve the physician or other health-care

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workers and the participant. At the one extreme, overriding or ignoring a person’s freedom to participate in medical-decision making (in this case, the decision to be screened) is generally supported by the principle of nonmaleficence—the belief that ignoring or overriding the patient’s wishes will prevent the patient from harming himself or herself. When justified for this reason, the action is paternalistic. The easiest type of paternalism to justify ethically is a weak form, wherein the person’s freedom to decide is hampered, that is, the person is substantially nonautonomous (Beauchamp and Childress, 2001). But many things affect one’s ability to govern oneself, including age, education, and socioeconomic conditions. Erroneous beliefs about the efficacy of medical practices affect the degree to which a person can make independent choices. In some populations covered by RECA, people may come from cultures that either devalue modern medicine or supplement it with alternative medical practices. A participant’s beliefs about the effectiveness of allopathic medicine or alternative medical practices are not by themselves sufficient evidence to judge that a participant lacks the characteristics needed to exercise independent judgment. At the other extreme, the decision of whether to pursue screening protocols might be thought to rest solely with the individual. This view is supported by the principle of autonomy. However, the screening practice introduces the risk of ignoring medical realities that may ultimately harm the subject. It also denies the validity of other ethical considerations derived from values of equity and justice. Among those considerations is the wise allocation of resources available to HRSA, under the RECA legislation, for a larger good. The committee, in its initial meetings, considered those issues and decided that further definition was needed for the different populations and conditions in question. The ethics of screening is a complex matter. The costs and benefits of screening are often uncertain and, as is the case for some underserved RECA populations, other diseases (such as obesity-related diabetes) are increasing much more rapidly than the compensable diseases for which screening might be considered. The committee noted the 131I screening recommendation made in the 1999 Institute of Medicine-National Research Council report Exposure of the American People to Iodine-131 from Nevada Nuclear-Bomb Tests: “It is appropriate for a clinician who sees a concerned patient to discuss that patient’s concerns and history and decide jointly about screening” (IOM-NRC, 1999, p. 108). Patients and physicians should share in decision-making. This is particularly important in situations where the balance between risks and benefits is uncertain. To this end, it may be wise for the grant proposal process to include information to educate the proposers about the current knowledge of the linkages between carcinogenic and noncarcinogenic disease and radiation (e.g., the points highlighted in Section 1 above), so that the grant awardees can properly advise their participants.

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2.2. Ethics and Follow-up Services The committee notes that the Bureau of Primary Health Care (BPHC) Policy Information Notice 2002–17 mandates that the required core services be adequately and persuasively described. Among those core services are referrals for medical treatment. The same notice expects the applicant to demonstrate an appropriate system for follow-up of patients. Public Law 106–245 (July 10, 2000) also requires that competitive grants issued to entities include the provision of “appropriate referrals for medical treatment of individuals screened under paragraph (1) and to ensure, to the extent practicable, the provision of appropriate follow-up services.” The committee believes that the HRSA program entails an ethical obligation to address how these referrals and follow-up services will be provided for people who have detected diseases, both compensable and noncompensable. The detection of a disease among RECA populations in impoverished or remote areas raises ethical concerns for this committee regarding nonmaleficence and beneficence. Both the strong obligation in medical practice “to do no harm” and the obligation “to provide good” to participants must be observed. RECA legislation appears to disavow any obligation under “Health Coverage Plans Unaffected”, but the committee asks that HRSA inquire of its applicants the details of follow-up plans for all its targeted populations. On the basis of the above discussion, the committee finds that Currently, there is no evidence to support the notion that screening for radiogenic diseases in this population will result in measurable health benefit for eligible participants. In fact, a screening program could be harmful because of false-positive test results (for example, the physical risks that their work-up entails and the psychological and social consequences of labeling individuals as potentially affected), as well as other factors. In cases where populations involved in the RECA screening program may be medically underserved or reluctant to make contact with the medical system, it might be more beneficial to provide additional resources to facilitate such contact rather than to devote resources to enhanced screening. The RECA legislation provides compensation for radiogenic and nonradiogenic diseases. We recognize that people may wish to be evaluated to establish eligibility for compensation. Informed decision-making by them acting with a physician is needed because these evaluations have potential benefits and harms. An explicit statement on a plan for appropriate follow-up services for compensable and noncompensable diseases is needed.