MCAT Physics and Math Review

Chapter 11: Reasoning About the Design and Execution of Research

11.4 Ethics

In medicine, there are four core ethical tenets: beneficence, or the obligation to act in the patient’s best interest; nonmaleficence, or the obligation to avoid treatments or interventions in which the potential for harm outweighs the potential for benefit; respect for patient autonomy, or the responsibility to respect patients’ decisions and choices about their own healthcare; and justice, or the responsibility to treat similar patients with similar care, and to distribute healthcare resources fairly.


The key ethical tenets of medicine are also discussed in Chapter 11 of MCAT Behavioral Sciences Review in conjunction with an analysis of major institutions in the United States.

In research, these four principles are replaced by a slightly modified set. The Belmont Report, a landmark document published by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research in 1979, delineates the three necessary pillars of research ethics: respect for persons, justice, and a slightly more inclusive version of beneficence.


Respect for persons includes the need for honesty between the subject and the researcher, and generally—but not always—prohibits deception. Respect for persons also includes the process of informed consent, in which a patient must be adequately counseled on the procedures, risks and benefits, and goals of a study to make a knowledgeable decision about whether or not to participate in the study. Further, the investigator cannot exert a coercive influence over the subjects, or they will not be acting autonomously. This coercive influence may be the result of a natural power imbalance, such as that between a teacher and a student, or may be the result of an extreme financial incentive or the inability to otherwise receive treatment for a condition. Respect for persons also includes the need to respect the subjects’ wishes to continue with or cease participation in a study. The subject may withdraw consent that was previously granted at any time.

Many older studies did not abide by respect for persons. For example, sentinel studies on the severity of untreated syphilis were conducted without the participants’ knowledge or consent. Many early psychological and sociological studies involved significant deception, which was not always disclosed after the fact. In current practice, hospital or university institutional review boards have put into place systematic protections against unethical studies. Vulnerable persons, which include children, pregnant women, and prisoners, require special protections above and beyond those taken with the general population. Confidentiality is also generally considered as part of respect for persons during research.


The Tuskegee syphilis experiment was a notorious forty-year study (1932–1972) by the United States Public Health Service that was fraught with extreme violations of the ethical principle of respect for persons. In this study, poor African-American men were enrolled into a study on the natural progression of syphilis. These men were given sham treatments, barred from accessing appropriate healthcare, and repeatedly deceived by investigators—including the fact that they were never told they had syphilis! This study was so significant in bioethical history that it is actually considered the primary impetus for the writing of the Belmont Report.


Justice in research applies to both the selection of a research topic and the execution of the research. In a world where all individuals and all questions are ethically the same, the only way to determine the selection of a research question to maintain justice is through random chance, in theory. Thankfully, we live in a world with morally relevant differences as established by our cultures. Morally relevant differences are defined as those differences between individuals that are considered an appropriate reason to treat them differently. For example, age is a significant moral difference in ethical deliberations: all else being equal, a transplant that is as likely to benefit a young child or an elderly adult may be given to the child because of a longer life expectancy. Population size is often morally relevant in study design because a study that impacts a large population will generally have more potential to do good than one that impacts a small population. In contrast, race, ethnicity, sexual orientation, and financial status are generally not considered morally relevant differences. It should be noted that religion may or may not be a valid moral criterion, depending on the context; for example, certain interventions that are prohibited by a given religion are grounds to avoid that treatment in an individual of that religion—this is in keeping with patient autonomy.

Justice is also important in the selection of subjects and the execution of research. When there is risk associated with a study, it must be fairly distributed so as not to unduly harm any group. This generally corresponds to seeking a diverse group for a study. Note that this also has a side benefit of increasing external validity, which will be discussed later in the chapter. However, the population that is most likely to benefit from the study may be required to bear a greater proportion of the risk. This apparent discrepancy—that all individuals should equally share the burden of risk, and that the target population may assume a higher proportion of risk—is reflective of the fact that likelihood of benefit is a morally relevant difference between individuals. Therefore, in studies in which there is no perceived difference in the likelihood of benefit between individuals, all individuals should assume equal risk; in those for which a particular population is most likely to benefit, that population should assume a higher proportion of risk. Finally, be aware that in some cases, such as drug trials, it may necessary to test the intervention in healthy individuals unaffected by the illness for which the drug has been designed. In this case, the burden of risk falls on a secondary population. This is permissible as long as the potential risks and benefits for the subjects have been addressed through informed consent and respect for persons has been maintained.


Beneficence is the easiest concept to understand in the context of research ethics. It must be our intent to cause a net positive change for both the study population and general population, and we must do our best to minimize any potential harms. This benefit may be as intangible as a feeling of personal satisfaction, and it may be unrelated to the original purpose of the study, such as small financial incentives. It may also be a future benefit if the participant is a member of the target population.

Research should be conducted in the least invasive, painful, or traumatic way possible. For example, a measurement that could be taken with either a finger stick or an indwelling catheter should be taken with a finger stick because it is far less painful and invasive. In addition, in studies comparing two potential treatment options, one cannot approach the research with the knowledge that one treatment is superior to the other. This is termed equipoise. If it becomes evident that one treatment option is clearly superior before a study is scheduled to finish, the trial must be stopped because providing an inferior treatment is a net harm.

MCAT Concept Check 11.4:

Before you move on, assess your understanding of the material with these questions.

1.    What is the difference between autonomy in medical ethics and respect for persons in research ethics?

2.    During study design, a company wishing to market a drug to severe diabetics proposes to enroll only mild diabetics. Which principle of research ethics is the company violating? Are there any research concerns in this proposed study besides ethics?

3.    What is the difference between a coercive influence and monetary compensation for a research study?

4.    What are some populations that must receive special consideration for coercion?