The research, conducted within the Dutch INSIGHT study and embedded in the national BETER survivorship-care infrastructure, examined how much adult Hodgkin lymphoma survivors know about their own long-term health risks and which factors predict better or worse knowledge. Led by Sophia K. Smith of Duke University together with Annelies Nijdam, Flora E. van Leeuwen, Michael Schaapveld, and a broad network of Dutch hematology and radiation oncology specialists, the study surveyed 370 survivors with a median age of 55.2 years at the time of the survey, 53 percent of whom were women. Participants completed a multi-domain questionnaire probing their awareness of five categories of late effects: endocrine complications such as thyroid dysfunction and infertility, cardiovascular disease, subsequent cancers, infection risk, and treatment-related symptoms.

To quantify knowledge in a way that allowed comparison across respondents, the team constructed a 12-item sex-comparable knowledge index. Items were scored using partial-credit rules, meaning respondents could receive recognition for partially correct answers rather than facing an all-or-nothing scoring scheme. Because some participants left questions unanswered, the researchers used multiple imputation—a statistical technique that fills in missing values by drawing plausible values repeatedly from predictive distributions, thereby preserving uncertainty rather than pretending missing answers were known. This approach, grounded in the work of Rubin and refined through fully conditional specification methods, is considered methodologically preferable to simply deleting incomplete cases, which can bias results when data are not missing at random.

The headline finding is sobering. Overall survivorship knowledge was low, with a median score of just 38.9 percent correct responses across the index. In other words, the typical survivor in the study answered fewer than four of the knowledge items correctly, even though all participants were part of a national program specifically designed to deliver risk-based long-term follow-up. The researchers emphasize that knowledge was also highly heterogeneous: some survivors demonstrated solid understanding of their risk profile, while others knew very little about the threats most relevant to their treatment history.

Perhaps the most consequential finding is what predicted knowledge. When the team applied multiple linear regression models—estimated with heteroskedasticity-consistent standard errors to guard against unequal variability in residuals—the strongest independent associations were not clinical but demographic. Female sex and younger age showed the largest relationships with higher knowledge scores, even after accounting for treatment exposures and survivorship-care utilization. This means that men and older survivors, two groups with substantial late-effect burdens, systematically knew less about the risks they face. The implication is uncomfortable: the patients who may need to be most vigilant about screening and prevention may be the least equipped to engage with that vigilance.

Treatment-related factors did matter, however. Survivors who had received chemotherapy, those exposed to splenic radiotherapy or who had undergone splenectomy, and those who had attended a greater number of survivorship-care visits all demonstrated higher knowledge scores. The first two associations make intuitive sense from an information-exposure standpoint: patients who received visibly consequential treatments, or who lost their spleen—a well-known cause of lifelong susceptibility to encapsulated bacterial infections—were more likely to have been counseled about specific risks such as the need for vaccinations against pneumococcus, meningococcus, and Haemophilus influenzae. The association between visit frequency and knowledge suggests that repeated contact with survivorship services does translate into better-informed patients, even if the overall level of knowledge remains discouragingly modest.

One of the most technically interesting aspects of the study concerns how knowledge was measured. The researchers distinguished between categorical knowledge items, which ask survivors to identify whether a given late effect is a recognized risk, and numeric risk-estimation items, which require respondents to estimate magnitudes—for example, roughly quantifying their elevated risk of a second cancer. Numeric items showed consistently lower correct response rates than categorical items. This pattern aligns with cognitive science literature on risk approximation, which shows that even numerate adults struggle to reason with probabilistic quantities under objective risk. Survivors may know that cardiovascular disease is “a risk” without grasping how large that risk is, when it peaks, or how it compares to the general population—and it is precisely this quantitative understanding that drives informed screening decisions.

The stakes of this knowledge gap are far from abstract. Long-term follow-up studies of Hodgkin lymphoma patients, including the Dutch group’s own work on cause-specific mortality and the landmark analysis of second cancer risk up to 40 years after treatment published in the New England Journal of Medicine, have documented elevated and persistent excess risks of cardiovascular disease and secondary malignancies decades after curative therapy. Effective risk-based care depends on survivors recognizing symptoms that warrant attention, adhering to surveillance protocols such as echocardiography or mammography, adopting preventive behaviors, and seeking timely care. A survivor who does not know that chest irradiation raises lifetime cardiac risk is unlikely to prioritize cardiovascular screening; one who does not understand post-splenectomy infection risk may skip recommended vaccinations. Knowledge, in this sense, is the cognitive foundation on which the entire architecture of risk-based survivorship care rests.

The study’s authors argue that their findings call for a shift in how survivorship education is designed and delivered. Because knowledge varied primarily by demographic characteristics rather than by clinical risk alone, uniform educational materials appear insufficient. Instead, the researchers propose targeted, demographically tailored educational strategies—approaches that specifically reach male survivors and older survivors, the two groups with the lowest knowledge in this cohort. The finding that numerical risk comprehension is especially poor suggests that communication should move beyond bare percentages toward formats known to improve risk understanding, such as natural frequencies, icon arrays, and visual risk portrayal. Encouragingly, prior work within this same research lineage, including a pilot randomized controlled trial of an online intervention designed to increase late-effects knowledge and screening awareness among Hodgkin lymphoma survivors, suggests that digital educational tools can move the needle on knowledge outcomes.

The study also carries implications for health equity within survivorship care. Risk-based survivorship programs—increasingly codified in guidelines from bodies such as the National Comprehensive Cancer Network—allocate surveillance intensity according to each patient’s treatment exposures. But such a system only works if patients understand and engage with their prescribed follow-up. If knowledge is systematically lower among men and older adults, these groups may derive less benefit from otherwise well-designed programs, compounding existing disparities. The authors note that as cancer survivor populations grow rapidly worldwide, ensuring equitable engagement in long-term follow-up becomes a public health priority, not merely a patient-communication nicety.

The INSIGHT study itself represents an unusually rigorous framework for asking these questions. As a multicenter retrospective cohort study with a quasi-experimental design, it draws on patients recruited across a national network of Dutch hematology and radiation oncology departments, from the Netherlands Cancer Institute and Amsterdam UMC to Erasmus MC, Leiden University Medical Center, University Medical Center Utrecht, University Medical Center Groningen, and multiple regional hospitals. The study was supported by the Netherlands Organization for Health Research and Development (ZonMw), the Dutch Cancer Society, the Dutch Ministry of Health, Welfare, and Sport, and the Duke University School of Nursing. Data availability is restricted by privacy regulations, but datasets can be obtained from the corresponding author with appropriate approvals.

For survivors, the message of this research is simultaneously cautionary and empowering. Being cured of Hodgkin lymphoma does not mean the medical story ends at remission; it means entering a decades-long phase in which informed self-advocacy matters enormously. For clinicians, the study is a reminder that delivering risk information is not the same as transmitting it, and that comprehension must be verified, not assumed—particularly for male and older patients. For health systems, it suggests that survivorship programs should embed structured knowledge assessment and tailored education into routine care, treating patient understanding as an outcome to be measured and improved, just like blood pressure or screening adherence. As the population of Hodgkin lymphoma survivors continues to expand, closing this knowledge gap may prove as important to long-term survival as any advance in front-line therapy.