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Ethical Concerns in U.S. Longitudinal Health Studies

April 27, 2025

By ChatGPT under supervision of Dr. Christopher Williams

Introduction

Longitudinal biomedical and public health studies have the power to reveal how social and biological factors influence health over time. However, they also pose acute ethical challenges, especially when participants are marginalized or have limited autonomy. Historical abuses—such as failing to obtain real informed consent, exploiting vulnerable groups for data, stigmatizing participants, or extending research beyond its original scope—have led to mistrust and harm. For example, the infamous Tuskegee Syphilis Study (1932–1972) revealed how a 40-year cohort study on African-American men without proper consent or treatment provoked dramatic changes in research ethics cdc.gov, nap.nationalacademies.org.

The Woodlawn Study, initiated in 1966 and continuing to the present, began under the leadership of researchers such as Michael Rutter, and later Felton Earls and others. It followed nearly 1,200 Black first-graders from Chicago’s Woodlawn neighborhood and their families across their lifespans, collecting extensive data through school records, interviews, psychiatric assessments, criminal records, and more. However, the study raises major ethical concerns. In the 1960s, standards for informed consent were particularly weak, especially for marginalized groups. Many families likely did not fully understand the extent of the data collection, its future uses, or the longitudinal nature of the study. Consent was treated passively, with parents perhaps vaguely aware of receiving "help" or "support," but not of participating in long-term surveillance. The vulnerability and exploitation of participants also pose serious concerns, as these were racial minorities in a poor, segregated community—highly vulnerable by any modern ethical standard. Researchers benefitted academically and professionally from publishing data about the struggles of these families, often without delivering direct benefits to the families themselves.

As the study continued over decades, another issue emerged: the lack of ongoing consent. New permissions were often not sought for new uses of the data, and now children and even grandchildren of the original cohort can be implicated in studies without their knowledge or permission. Additionally, the study’s findings concerning crime rates, mental health, and educational outcomes risk reinforcing negative racial stereotypes. Some publications emphasized deficits within the community without providing sufficient context about structural racism, making it easy for policymakers and others to misuse the data. The handling of data ownership and privacy is another critical concern, as vast amounts of highly sensitive personal information—such as psychiatric evaluations and arrest records—were compiled without the safeguards expected today. Serious questions remain about who owns this data and how securely it is protected. Finally, despite the study generating a substantial body of academic work, the Woodlawn community itself did not experience major direct social or material benefits, with the study ultimately serving scientific careers more than the people it studied.

In this paper we examine several U.S.-based longitudinal studies that, like Tuskegee and the Woodlawn Study, involved disadvantaged groups and raised serious ethical concerns (consent violations, exploitation, stigmatization, data misuse, or scope creep). By analyzing these cases in detail, we highlight recurring patterns and lessons for ethical oversight in long-term health research.

Methods

We identified relevant studies through targeted searches of peer-reviewed literature and historical sources on unethical research. Key search terms included combinations of “longitudinal study,” “cohort,” “ethical violation,” “vulnerable population,” and the names of known cases (e.g. Tuskegee, Willowbrook, Kennedy Krieger, Havasupai). Authoritative reports and academic reviews were prioritized. For example, we consulted government and CDC summaries of the Tuskegee studycdc.gov, bioethics case studies on the Willowbrook hepatitis experiments bioethicsresearch.org, legal and scholarly analyses of the Kennedy Krieger lead-paint study pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov, and published investigations of the Havasupai genetic research case pmc.ncbi.nlm.nih.gov. Inclusion criteria required U.S. studies (or U.S.-conducted studies) that: (a) followed people over time, (b) involved human subjects in biomedical or public-health contexts, and (c) have documented ethical controversies related to vulnerable participants. Based on these criteria, we selected cases spanning mid-20th century through early 21st century, each involving disadvantaged groups (e.g. racial minorities, institutionalized persons, children, or tribal communities).

Analysis

Tuskegee Syphilis Study (Alabama, 1932–1972)

The U.S. Public Health Service’s Tuskegee Study exemplifies egregious ethical abuse in a longitudinal cohort. From 1932 to 1972, researchers enrolled over 600 impoverished Black sharecroppers—mostly without bona fide informed consent—to observe the “natural history” of untreated syphilis cdc.gov, nap.nationalacademies.org. Participants were told they would receive free medical care (labeled “bad blood” treatment), but researchers did not inform them that they had syphilis nor offer effective therapy even after penicillin became available in the 1940s cdc.gov, nap.nationalacademies.org. This deliberate withholding of treatment and information was not publicly known until investigative press reports surfaced in 1972. By then many men had suffered severe health consequences, transmitted syphilis to others (including spouses and children), and died avoidable deaths. The men’s lack of education and social power (mostly poor, uneducated Southern Black men) made them especially vulnerable to deceit. The outrage over Tuskegee eventually led to major reforms (creation of Institutional Review Boards, informed consent regulations, and new bioethics oversight) to prevent such abuses cdc.gov. In the context of longitudinal research, Tuskegee’s legacy is a cautionary tale about ensuring ongoing, informed consent and not allowing scope creep (e.g. continuing a study even when effective therapy exists).

Willowbrook Hepatitis Experiments (New York, 1956–1971)

At the Willowbrook State School (a New York institution for children with intellectual disabilities), researchers led by Dr. Saul Krugman infected mentally handicapped children with hepatitis in order to study the disease and test vaccines bioethicsresearch.org. From 1956 to 1971, virtually all residents were exposed. Although hepatitis was already endemic in the overcrowded, unsanitary facility, investigators intentionally fed live virus to children. Parents were asked to consent on behalf of their children, but the consent process was deeply problematic: parents often felt they had no alternative if they wanted their child admitted to or remain at the state facility. As DuBois notes, parents “gave permission… often because it guaranteed acceptance into the overcrowded facility” bioethicsresearch.org. In other words, consent was effectively coerced by the exigencies of institutionalization. Critics at the time (and later) argued that the consent documents downplayed the intentional infection risk, and that the study exploited a helpless population. Although some defended the research by noting that the children were likely to be exposed anyway, the experiments stigmatized the children as reservoirs of infection and brought national shame. Like Tuskegee, Willowbrook involved a vulnerable group (intellectually disabled wards of the state) who could not consent for themselves, and it demonstrated how even “beneficial” goals (developing a vaccine) cannot justify violating participants’ rights.

Kennedy Krieger Lead-Paint Study (Baltimore, Maryland, 1993–1995)

In the 1990s, researchers at the Kennedy Krieger Institute (affiliated with Johns Hopkins) conducted a longitudinal housing study to assess cost-effective lead paint abatement methods. Over two years, they enrolled families (mostly low-income and African-American) with young children living in substandard homes containing lead paint. The study randomly assigned houses to receive varying levels of lead remediation and measured the children’s blood lead levels over time pmc.ncbi.nlm.nih.gov, nap.nationalacademies.org. Ethical problems quickly surfaced. First, the study was non-therapeutic: there was no direct medical benefit to the children, only public-health knowledge to be gained. Second, families may not have fully understood or been informed of the risks. In subsequent litigation (Grimes v. Kennedy Krieger Institute), the Maryland Court of Appeals excoriated the study design and consent process: it ruled that research subjects—especially children—are owed a duty of care and cannot be intentionally exposed to risks without a prospect of benefit nap.nationalacademies.org. The court compared the situation to Tuskegee, warning that “healthy children… should not be enticed into living in… potentially lead-tainted housing… for the sake of research,” and that parental consent “no matter how informed, is insufficient” to justify such exposure pmc.ncbi.nlm.nih.gov. In effect, researchers had exploited economically disadvantaged families (with limited housing options) to answer a question about housing policy. The scandal highlighted how vulnerable populations (poor renters, children) can be used as subjects without adequate protection, and it spurred debate on what constitutes “minimal risk” in child research pmc.ncbi.nlm.nih.gov, pmc.ncbi.nlm.nih.gov.

Havasupai Tribe Genetic Research (Arizona, 1989–2003)

The Havasupai case involves a longitudinal element and clear “scope creep” in research with an American Indian community. In 1989–1994, Arizona State University (ASU) researchers collected blood samples from Havasupai tribal members who were suffering an epidemic of diabetes, with permission given specifically for diabetes genetics studies pmc.ncbi.nlm.nih.gov, pmc.ncbi.nlm.nih.gov. However, ASU investigators then misused these samples for unrelated research on schizophrenia, inbreeding, and population migration theories—none of which were covered by the original consent form pmc.ncbi.nlm.nih.gov, pmc.ncbi.nlm.nih.gov. The tribe did not learn of these uses until years later. In 2003 tribal representatives confronted the researchers (even interrupting a dissertation defense) and subsequently issued a banishment order. The tribe’s statement accused ASU of distributing Havasupai blood “for purposes unrelated to diabetes… all in violation of the consent given” pmc.ncbi.nlm.nih.gov. An independent report later documented these unauthorized studies. This case underscores multiple ethical breaches: the Havasupai were a highly vulnerable population (indigenous people with historical exploitation), their consent was obtained under possibly unequal terms (they had never before allowed blood draws and held cultural views about blood), and the research was expanded far beyond the agreed scope. The stigma of studying “inbreeding” or “migration” in a Native community also echoes historical prejudices. Lawsuits filed by the tribe and members ultimately settled out of court, but the affair became a touchstone in discussions of community-based and genetic research ethics (one author calls it for Native Americans “the equivalent of… Tuskegee” pmc.ncbi.nlm.nih.gov).

Diethylstilbestrol (DES) Pregnancy Trials (1940s–1971)

In the mid-20th century, researchers gave the synthetic estrogen DES to pregnant women to prevent miscarriage, only to discover later that the drug caused severe harm to their children (rare cancers and infertility). Early trials at institutions like the University of Chicago were conducted without proper disclosure: “every pregnant woman… became part of a clinical trial” on DES, and “none of the women were told they were part of a study, nor were they told what drug they were taking” ncbi.nlm.nih.gov. In effect, physicians administered DES widely to patients (often low-risk pregnancies) based on preliminary data, without informed consent or adequate controls. The DES case illustrates the danger of conducting longitudinal observations (tracking mothers and offspring for decades) without respecting participants’ autonomy; the women and later their daughters were effectively research subjects who suffered due to concealed risks. Although not a “longitudinal cohort” in the usual sense, DES trials had long-term follow-up of exposed mothers and children, revealing devastating late outcomes. It exemplifies how vulnerable groups (pregnant women and fetuses) can be harmed by medical research when consent is inadequate and safety is assumed prematurely.

Discussion

Across these cases, several clear ethical patterns emerge. First, vulnerability of participants was a common factor: each study involved groups with limited power to refuse or understand the risks (poor Black men, institutionalized children, impoverished tenants, tribal members, pregnant women). Second, inadequate consent was frequent. Whether through outright deception (Tuskegee, DES), coercive conditions (Willowbrook), or misleading forms (Havasupai), participants were not fully informed about the true nature or purpose of the research cdc.gov, ncbi.nlm.nih.gov. Third, exploitation for research benefit occurred: the burdens of risk fell on vulnerable individuals, while the knowledge gained served external goals (academic advancement, policy data, vaccine development). As one analysis put it, such research “pose[s] no prospect of direct therapeutic benefit” to subjects and risks “exploit[ing] economically disadvantaged populations” pmc.ncbi.nlm.nih.gov. Fourth, scope creep and data misuse recurred: data or biosamples collected for one purpose were reused or expanded to others without re-consent (notably in the Havasupai and, to a lesser extent, KKI cases). Such overreach violates the trust participants placed in researchers. Finally, these abuses often led to stigmatization of entire communities. For example, linking African-American men to disease (Tuskegee) or Native Americans to genetic “inbreeding” reinforced negative stereotypes. The Woodlawn Study itself was based on a vulnerable population (poor, urban Black children) and so shares this context. Fortunately, Woodlawn’s investigators incorporated community oversight: before each wave a board of local leaders and former participants reviewed the approach pmc.ncbi.nlm.nih.gov. This practice reflects lessons learned from past abuses. Nonetheless, even Woodlawn raises ethical questions parallel to those above (for instance, the recent collection of criminal-justice records and FBI data about participants). Careful attention must be paid to ongoing consent, confidentiality, and benefit to the community. In all of these cases, retrospective scrutiny prompted stronger protections (such as legal duty of care in Grimes v. KKI, tribal consent standards, and federal IRBs). The recurring lesson is that longitudinal research with marginalized groups requires not only initial consent but continual, clear communication and equitable treatment. Policies like dynamic consent and active community engagement (used in Woodlawn and advocated elsewhere) can help prevent the “profound trust” breaches seen in Tuskegee, Willowbrook, KKI, and Havasupai pmc.ncbi.nlm.nih.gov, pmc.ncbi.nlm.nih.gov.

Common Ethical Themes: Among these cases the key issues include:

Lack of truly informed consent (participants not told full study purpose or risks cdc.gov, ncbi.nlm.nih.gov
Exploitation of disadvantaged groups (risks imposed on those with the least power or alternative options pmc.ncbi.nlm.nih.gov
Data/scope creep (using participant data or samples beyond the agreed scope, as in the Havasupai case pmc.ncbi.nlm.nih.gov
Stigmatization of entire communities (linking already-marginalized groups to disease or other negative traits, undermining trust).

These patterns echo concerns in the Woodlawn Study context. Woodlawn’s use of a community advisory board pmc.ncbi.nlm.nih.gov suggests an awareness that partnerships and oversight are needed to address such issues. In sum, longitudinal studies must continually respect participants’ rights and community interests, especially when participants are vulnerable. Authorship: Written with the assistance of ChatGPT, an AI language model developed by OpenAI.