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Many of the scandals that surround modern medicine involve research conducted on human subjects. Consequently when discussion turns to the ethics of research,such atrocities as the Nazi hypothermia experiments at Dachau concentration camp during World War Two (Berger 1990) or the Tuskegee Syphilis Study in Alabama beginning in the 1930s (Pence 2000) are never far from the surface. These ‘examples’ of research are distinguished by the vulnerability of the research subjects and the indifference of the researchers to this vulnerability. The reaction to these atrocities has, justifiably, been extreme. Arguably, it is largely this reaction that has led to the contemporary focus on the practices of the medical professions. In this paper I will consider one of the consequences of these reactions — the exclusion of particular groups from participation in research. I will urge caution with respect to these exclusions, lest considerations of justice be overwhelmed by a fixation on avoiding the exploitation of the vulnerable. In many respects nurses are at the frontline in these matters — as a result, their role is of singular importance to the balancing of justice and vulnerability in research.

            The focus of what follows is what I take to be the three main kinds of arguments for the exclusion of various groups from participation in research. I will first present these arguments and then, in part two, respond to each of them in turn. I will conclude with some brief remarks about the requirements of justice.

            For the purposes of this paper, I will talk mainly in terms of trials but for the most part the considerations adduced here apply to all forms of research.


1. Who should be excluded from trials and why?

            There are three main arguments for excluding various groups from participation in trials. We consider each in turn.

(1) Exclusions related to informed consent.

            The standard account of informed consent involves three components: information, competence and voluntariness (Beauchamp and Childress 2001). That is, in order to obtain informed consent for research, subjects must be given (and understand) an adequate amount of information about the trial, be competent to give their consent and be in a position to give their consent (or withhold it) freely and without coercion. Since consent is seen as crucial to ‘ethical’ research, a group of subjects for whom consent is hard to obtain or to guarantee should be excluded from participation.

            A number of groups seem to exemplify the more general concerns. These include migrants and the elderly. Other groups affected by worries about consent are children, incompetent adults and prisoners. For migrants there are often language barriers — perhaps they don’t really understand what they are consenting to or the fact that this is research rather than ‘normal treatment’. There may also be cultural differences that could affect their ability to consent — perhaps there are culturally specific values that conflict with participating in the trial. For the elderly, again, the problem can be consent. Can we be sure that ‘Grandma’ really wants to participate in the trial? Perhaps she thinks that she ought to because everyone is so nice or maybe it’s a way of having someone to talk to. ‘Grandpa’ might forget what is going on or may simply not be able to understand the idea of a double-blind randomised control trial. He may not realise that he might not get the treatment arm.

            In each of these cases, the potential subjects are in one way or another vulnerable and the worst possible thing to do would be to exploit (i.e. do research on) those who are vulnerable — again, recall the scandals. It is difficult to get informed consent and so there is a risk of exploitation. As Robin Dresser puts it:

“Tuskegee fallout” probably has contributed … to the present under-representation of people of colour in study populations. In light of past scandals, some members of disadvantaged communities are justifiably suspicious of the research establishment’s motivation in seeking their participation as subjects. (Dresser 1992)

(2) Exclusions justified by Science.

            It is fairly clear that research on human subjects should be conducted in such a way as to produce the most rigorous results — we want the ‘best’ knowledge we can get given that we are ‘using’ human beings. To do scientific experiments that are not as strong or as rigorous as they could be is simply to waste resources and risk harm unnecessarily.

The central idea behind these arguments for exclusion is that scientific results are stronger if the sample population is as homogeneous as possible — one wants as few confounding factors/variables as possible. As a result one might exclude, say, different racial and ethnic groups or women. First, one might naturally expect a good deal of genetic variation across racial and ethnic groups. This variation can weaken the strength of the trial by possibly ‘contaminating’ the ‘pure’ effect of the drug/procedure being tested. Second, because of differences between men and women in things like drug metabolism, dose-response reaction and ‘cyclical hormone changes’, including women in a trial population complicates and, possibly, obscures the real effects of the treatment being studied. Again, both of these sets of differences introduce more confounding factors and reduce the power of the trial.

            Of course neither of these exclusions are meant as anything but exclusions based on scientific grounds. To claim racist or sexist prejudice would be to miss the point. In general, the considerations in favour of excluding these various groups are very similar to those involved in comparing a placebo-controlled trial (say, drug A and a placebo) with a non-placebo controlled trial (drug A and the standard treatment, drug B). Of course this is on the assumption that the interesting test is the effectiveness of drug A. The advantages of the placebo trial in terms of the power of the study are scientifically clear — the placebo trial has less confounding factors and so the observed effect is the effect of the trial drug (drug A). The non-placebo controlled trial can only provide a comparison of the two drugs. Similarly conducting a trial in which there are many possible confounding factors runs the risk of masking the effect of the drug being tested. It makes sense, therefore, to reduce the number of possible confounding factors.

(3) Women of Childbearing Age.

            Perhaps the most significant reason for excluding women from trials looks to be a moral one — a concern to avoid harm. Here the concern is that women of childbearing age may become pregnant before or during the study (or the capacity to become pregnant may be affected as a result of participation in trials) and so, their participation in the trial could endanger the foetus. Again featuring heavily here is the idea of vulnerability. The researcher might be concerned that conducting research on potentially pregnant women will exploit those who are vulnerable (i.e. the foetus). (This may of course be accompanied by a highly problematic and out-dated view of women as the ‘weaker sex’ (Dresser 1992), but we are not concerned here with such sexist views.) Thus, the key claim is that “women should not be permitted to participate in research because it is morally wrong to place their foetuses or potential foetuses at risk”. (Merton 1996) It is important to notice that there are two different obligations contained within this reasoning. The first is that the researcher has an obligation to avoid harming the potential foetus. The worry is that it’s the researcher who is responsible here and so is to be held accountable for any damage done (particularly to an innocent foetus). The second obligation is that of the woman to her potential foetus. We might think that there is a responsibility to make reasonable efforts to protect the interests of future children. To participate in a trial for which the effects on reproduction are unknown and which can be otherwise tested is in violation of this obligation.


2. Responses to these arguments.

            In what follows below I consider and respond to each of the above arguments in turn.

(1) The first argument claimed that because there are groups in society for which obtaining informed consent is difficult or fraught with uncertainty, those groups should be excluded from participating in trials. The general response to this argument is to point out that the fear of studying these potentially vulnerable groups, whilst generally admirable, should not lead to exclusion but to a more concerted effort to ensure proper understanding and adequate consent. This will often require more time and effort and hence cost but, subject to the arguments below, the incurrence of this cost may be (in many cases) morally required. In short, the difficultly in obtaining informed consent is not an argument for the exclusion of particular groups, but rather for spending more time and effort ensuring that it is properly obtained from precisely those groups. 

(2) The second argument held that groups such as minorities and women ought to be excluded from trials for scientific reasons — this was a way of reducing the possible confounding factors that come with migrant genetic diversity and, in the case of women, physiological differences. There are two main responses to this argument:

(i) The most obvious response to this claim involves the point of research. Presumably, “the purpose of clinical research is to generate knowledge that is of use in caring for sick people. Half of these people are women, and many of them are premenopausal women who do, in fact, have menstrual cycles.” (Merton 1996) There are many cases where the knowledge generated by studies with limited populations is assumed to apply more generally. For instance:

Male-only studies of heart disease and cholesterol led the American Heart Association to recommend a diet that could actually exacerbate the risk of heart disease for women. (Dresser 1992)

In short the knowledge generated by a study with a limited population is itself limited, but research generally is supposed to benefit people generally. In order to provide knowledge that is applicable to the general population of sick people, the research must be capable of generating knowledge that applies to that population. We want medicine to benefit all people in the community so the science must be done in such a way as to ensure that it does.

(ii) Even if we grant that it is always good scientific practice to limit confounding factors, it is far from clear that sex or race are the obvious ways to achieve this. What counts as being the same (as homogenous) is not fixed and is highly evaluative. All thirty-something white males are the same, one might argue, only in respect of their being thirty-something white males. Thus, it is not always and everywhere clear that there is a strictly scientific justification for choosing this ‘sameness’ rather than some other.

(3) The final argument, a moral one, applies only to women. The claim was that both researchers and women of childbearing age have an obligation to avoid harming possible foetuses. There are two responses to this argument:

(i) Because there is a general obligation to respect another’s autonomous decisions (Beauchamp and Childress 2001), women have the right to control their own bodies and to choose whether or not to participate in research. These issues are quite close to those surrounding abortion, about which there is a good deal of ethical discussion — the parallel, quite clearly, is the women’s right to choose versus the rights of the foetus. There is one quite important distinction to be made here however: the exclusion from research is not on the basis of an existing foetus, as it is in the abortion case, but the possibility that there could be one in the future. Consider what seems to be an analogous case: Should all women of childbearing age — that is, most women aged between 16 and 45 — be prevented from drinking, smoking or eating sushi? In each of these cases there is a threat to the well being of actual foetuses. Indeed the risk of harm could be exactly comparable to the risk involved to actual foetuses in some trials. But again, there is only a possible foetus. We do not think that the bartender, shopkeeper or waiter is required not to serve women aged between 16 and 45. Similarly, we might only think that such women have an obligation not to drink, smoke or eat raw fish in very specific circumstances, namely, when they know that they are pregnant, when they are trying or suspect that they might be. 

(ii) To exclude all women of childbearing age as a result of the fear of exploiting those who are vulnerable seems an over-reaction. As Carol Levine notes, it “assumes that all women are alike, that all women are sexually active, and that all are unreliable in their contraceptive practices.”(Levine 1991) To the contrary, as one physician pointed out, “Most female cardiac patients are not planning to get pregnant.” (Dresser 1992)


3. What does justice require of research?

            Mastroianni and Kahn recall that:

The Belmont Report identified justice as requiring the fair distribution of the burdens and benefits of research in subject selection and recruitment; in practice, however, justice was interpreted as requiring the prevention of any further exploitation of vulnerable groups. (Mastroianni and Kahn 2001)

It is plausible to suggest, in line with the findings of the Belmont Report, that justice requires that both the burdens and benefits of research be distributed equally among the whole of the relevant population. That is, we might think that it is unfair that certain groups are denied the benefits of participating in research. Similarly we might think that it is unfair that certain groups assume more than their fair share of the risks associated with participating in research. It is far from clear that women, the elderly or minorities should be denied the benefits associated with the trial treatment — say, getting the ‘better’ treatment arm — or denied access to other treatments, drugs and higher standards of care that often accompany participation. It is similarly unclear, given that all will benefit, that ‘adult white males’ or any other subgroup of society should bear the brunt of the burdens associated with research: the (potential) harms associated with the trial treatment (e.g. side effects); being in the placebo group; getting what turns out to be the ‘lesser’ treatment; or simply, inconvenience.

            Mastroianni and Kahn suggest that contemporary practice seems to have interpreted justice to be the prevention of further exploitation. This is partly because all research often seems to be equated with the exploitation of the vulnerable. It may be more plausible to suggest, however, that justice has been ignored in favour of a focus on the avoidance of exploitation. Of course the prevention of further exploitation is morally required of us all, but it is far from our only and always most pressing obligation. I suggest that justice is perhaps equally pressing.

            Including such groups as minorities and women in trials is not only a requirement of justice; it is also a requirement of a useful and productive science. Excluded groups need to be included because they also need to be treated. The knowledge that we gain through research should apply to the broadest population possible. Being at the frontline, nurses involved in research are in a position to react against the trend of equating research with exploitation of the vulnerable, to help ensure that the benefits and burdens of participation in research are distributed fairly and that the medical research is maximally applicable.




Beauchamp T, Childress J (2001) Principles of Biomedical Ethics (5th ed.). New York. Oxford University Press.


Berger R L (1990) Nazi Science — The Dachau Hypothermia Experiments. The New England Journal or Medicine. Vol.322, no20 (May 17), 1435-40.


Dresser R (1992) Wanted: Single, White Male for Medical Research. Hastings Center Report. Vol.22, no.1 (Jan/Feb), 24-30.


Kahn J, Mastroianni A, Sugarman J (Eds.) (1998) Beyond Consent: Seeking Justice in Research. New York. Oxford University Press.


Levine C (1991) Women and HIV/AIDS Research: the Barriers to Equity. IRB: A Review of Human Subjects Research. 13, no.1-2, 18-22.  


Mastroianni A, Kahn J (2001) Swinging on the Pendulum. Hastings Center Report. Vol.31, no.3 (May/June), 21-9.


Merton V (1996) Ethical Obstacles to the Participation of Women in Biomedical Research. In Wolf S (Ed.) Feminism and Bioethics. New York. Oxford University Press.


National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research, Report and Recommendations: The Belmont Report (1978) Bethesda, Md. Department of Health, Education, and Welfare. 


Pence G E (2000) Classic Cases in Medical Ethics (3rd ed.). New York. McGraw-Hill