200. Selection of Research Participants

Updated July 1, 2021

Investigators should use fair and equitable recruitment practices in research and avoid practices that place participants at risk for coercion or undue influence. The requirement for equitable selection flows from the ethical principle of justice. Justice is intended in the sense of distributive justice where no group is unduly burdened or will unfairly benefit from the research. IRBs are required to make a specific determination that the selection of participants for a research project is equitable (45 CFR 46.111 item (a)(3)). In making this determination, the IRB will consider the scientific design, susceptibility to risk, likelihood of benefit, practicability, and fairness. Equitable selection does not mean that all groups are represented in proportion to the population. It means that selection criteria should be both fair and appropriate to the research question.

Investigators are required to provide the following information to allow the IRB to determine whether the selection of participants is equitable:

  1. The purpose of the research and the setting in which the research would be conducted.
  2. Whether prospective participants would be vulnerable to coercion or undue influence.
  3. The selection (inclusion/exclusion) criteria.
  4. Participant recruitment and enrollment procedures.
  5. The amount and timing of payments to participants.

The IRB must also confirm that risks to participants are reasonable in relation to anticipated benefits (§45.111 item (a)(2)). In making this determination, the IRB evaluates the number of participants the investigator expects to enroll with consideration for procedures for data collection and analysis. Therefore, increasing (or decreasing) the expected number of enrolled participants constitutes a change to an approved protocol. As with any other protocol change, researchers wishing to enroll more or fewer participants than noted in the application must obtain prior IRB approval for a protocol amendment.

Selection of Research Participants

Research populations should be selected for reasons related to the problem being studied. Use of appropriate populations helps to ensure a fair distribution of the burdens and benefits of research (based on the principle of Justice in the Belmont Report).

Those who are already burdened (e.g., by disabilities, low socio-economic status) should not be asked to accept the burdens of research unless the research is relevant to their condition or circumstances, or if other appropriate participants cannot be found. Investigators and IRBs must also be careful not to overprotect populations to the extent these are consistently excluded from participating in research. While the inclusion of disproportionate numbers of institutionalized persons, or racial or ethnic minorities in research studies might overburden these groups relative to the anticipated benefits of the research, underrepresentation assures they will not benefit from the research.

In determining whether selection of participants is equitable, consideration should be given to the following points:

  • Equitable selection of participants requires that researchers attempt to recruit potential participants who are appropriate to answer the scientific question. The nature of the research should require inclusion of the proposed subject population.
  • Benefits resulting from the research should be distributed fairly. Other groups of potential participants should be considered for inclusion if they have a greater need to receive any of the anticipated benefits.
  • Burdens resulting from the research should be distributed fairly. If the proposed subject population is already burdened, it may be unfair to ask them to accept an extra burden.
  • The researcher must justify the involvement of participants who may either be susceptible to pressure or who are already burdened (i.e., vulnerable populations).
  • The selection process should not overprotect potential participants who are considered vulnerable so that they are denied opportunities to participate in research.
  • Evaluate the selection criteria (inclusion and exclusion criteria) to determine that participants are not excluded for non-scientific reasons. For example, if recruitment of minorities into a research study would be more expensive, this fact does not count as a reason why minorities should be excluded from participation in research.
  • If there are any groups of people who might be more susceptible to the risks presented by the study and therefore ought to be excluded from the research, the procedures for identifying such individuals should be adequate.
  • A research study may have fair selection criteria but use recruitment methods that lead to inequitable selection. If the participants are susceptible to pressures, there should be mechanisms in place that may reduce the pressures or minimize their impact.

The amount of payment to participants, the proposed method of payments and/or the timing of disbursement of payments should not present undue influence or coercion. For more information and the guidelines provided to investigators. The IRB gives special consideration to protecting the welfare of participants that are vulnerable to coercion or undue influence such as children, prisoners, individuals with impaired decision-making capacity, or economically or educationally disadvantaged persons. The IRB reviews proposed research to determine whether the study protocol includes enrollment of vulnerable participants and whether appropriate safeguards are in place. When some or all the participants are likely to be vulnerable, the IRB should ensure that additional safeguards are included in the research design to protect the rights and welfare of these participants. As applicable, the IRB considers the following elements when reviewing research involving vulnerable participants:

  • Inclusion/exclusion criteria;
  • Over-selection or exclusion of certain groups based on perceived limitations (i.e., targeting prisoners as research participants because they are a readily available "captive" population);
  • Knowledge of applicable or local laws that bear on the decision-making process (i.e., emancipated individuals, legally authorized representatives, age of majority for research consent).

Social justice dictates there be an order of preference in the selection of classes of participants:

  1. adults before children,
  2. competent individuals before incompetent individuals, and
  3. non-institutionalized persons before institutionalized persons.

The IRB follows applicable federal and state regulations and IRB policy to assist in reviewing and approving proposed research that involves vulnerable participants such as:

  • Pregnant Women, Human Fetuses and Neonates (45 CFR 46, Subpart B)
  • Research Involving Prisoners (45 CFR 46, Subpart C)
  • Research Involving Children (45 CFR 46, Subpart D, 21 CFR 50, Subpart D, U.S. Department of Education, Subpart D, and OHRP Guidance on Special Protections for Children as Research Subjects)
  • Research Involving Individuals with Impaired Consent Capacity
  • Research involving university students
  • Research involving K-12 students

Convenience Sampling

Students, employees, and institutionalized, or economically or educationally disadvantaged persons should not be selected based on convenience (i.e., participants are readily available) when not otherwise appropriate for inclusion in the research study.

Reliance on populations of convenience is generally prohibited but may be acceptable when:

  1. the risk posed by the research is no more than minimal;
  2. adequate steps have been taken to minimize potential undue influence during recruitment and consent;
  3. the harms that may arise in the research would not be exacerbated by the ease of availability of the population; and
  4. investigators do not generalize the results beyond the research populations.

Use of Student Participants and Online Participant Pools

The IRB recognizes that additional populations such as students may qualify as vulnerable populations and need safeguards in place for their protection during study participation. University students and students enrolled in other institutions within the Nevada System of Higher Education (e.g., TMCC) may be offered the opportunity to participate in research for credit as part of a course requirement via the University’s Department of Psychology SONA Subject Pool or the Undergraduate Research Pool (for students enrolled in humanities, social, managerial and behavioral sciences). NOTE: Documentation of site permission is required to enroll students from other institutions, including those within NSHE.

When students in subject pools constitute the research population, the research must conform to the requirements of both the subject pool and the IRB.

Recruiting from established groups of individuals who are willing to participate in research, including online pools of paid participants and student subject pools, may enhance recruitment efforts but may limit the generalizability of results.

Individuals recruited from participant groups must be free to decline to participate or withdraw from participation at any point without penalty. Parental permission and youth assent are required to enroll participants who meet the regulatory definition of children.

IRB Assessment of Equity in Participant Selection

The IRBs evaluate inclusion/exclusion criteria with consideration for research design and participant risk. Adequate representation of women, racial/ethnic minorities, or other underrepresented groups is particularly important in studies of diseases, disorders, and conditions that disproportionately affect these populations. When appropriate, the IRBs will ensure such populations are adequately represented so that the research findings will be meaningful for these groups.

The IRBs consider the researchers' evaluations of potentially vulnerable populations to determine if any subgroups within the research population might be more susceptible to the risks presented by the study and assess safeguards to determine if the risk susceptibility has been sufficiently addressed.

The IRBs review recruitment methods, locations, and materials to:

  • encourage recruitment of a broad cross-section of research participants, and
  • ensure safeguards are in place to minimize pressures on prospective participants to enroll in a research study.

The IRBs evaluate the risks and inconveniences associated with research procedures with consideration for research benefits, with the understanding that the populations subject to the risks and burdens of being research participants should be among those most likely to benefit from the research.

Recruitment Best Practices

The IRB strongly recommends the following recruitment approach:

  • research team makes initial contact with the prospective participant in person or by letter prior to initiating any telephone contact, unless there is written documentation that the participant is willing to be contacted by telephone about the study in question or a specific kind of research;
  • initial contact must provide a telephone number or other means that the prospective participant can use;
  • partner with a community organization who works closely with the population you are trying to reach;
  • be prepared to provide information or answer questions about the role of research in health and society;
  • social media and the internet are how many people receive information. Make use of these tools to increase recruitment efficiency and cost effectiveness;
  • be friendly, personable, and confident with participants. Say "Thank you" often;
  • use of culturally-sensitive recruitment materials.