The research, published in SSM – Population Health, was led by Hanyul Lee and colleagues, who applied an analytical framework known as MAIHDA—Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy—to a question that has long resisted conventional methods. Unmet medical need, or UMN, refers to situations in which people perceive a need for healthcare but cannot obtain appropriate or sufficient care. Previous studies have typically treated UMN as a single aggregate outcome, or examined risk factors one at a time using standard regression. The problem, the authors argue, is that additive approaches cannot capture what intersectionality theorists have described since Kimberlé Crenshaw’s foundational work: social categories do not simply stack. A woman with a parental role does not experience the sum of ‘female disadvantage’ plus ‘parental disadvantage.’ The intersection generates a qualitatively distinct experience that cannot be reconstructed from its component parts.

MAIHDA addresses this by treating each combination of social characteristics—144 unique strata in this study—as a group in a multilevel logistic regression model, with individuals nested within strata. The method models strata as random effects, which stabilizes estimates even for small groups through statistical shrinkage, a major advantage over stratified analyses that lose power or interaction-term models that become uninterpretable as axes multiply. The researchers fitted two models for each outcome: a null model capturing total between-stratum variation, and a main-effect model adding the average associations of each axis. The difference between the two reveals whether social positions interact in ways that additive averages cannot explain. The team also disaggregated UMN by cause, separating time-related barriers—such as inconvenient clinic hours, inability to leave work, or lack of childcare—from cost-related barriers, where the expense of care itself is prohibitive.

The main effects told a story of two different barriers. For time-related UMN, age, sex, and employment dominated: younger adults had more than three times the odds of older adults, women had 58 percent higher odds than men, and employed individuals had roughly three times the odds of those not employed. Living with children also raised the odds. For cost-related UMN, the picture inverted. Income was the decisive factor—the lowest-income group had more than four and a half times the odds of the highest—and living alone nearly quadrupled the odds. Employment, meanwhile, was protective: employed people had 45 percent lower odds of cost-related UMN than those not employed. Sex and age showed no significant association with cost-related barriers at all. The same social variable, in other words, can push in opposite directions depending on which barrier to care is being measured.

The variance decomposition underscored why disaggregation matters. Intersectional strata explained 18.6 percent of the variation in time-related UMN and 27.3 percent in cost-related UMN in the null models, but only 4.8 percent for overall UMN. When causes are collapsed into a single outcome, effects associated with different barriers partially offset one another, masking the true extent of social patterning. The authors note that even 4.8 percent is not trivial by MAIHDA standards, where values below five percent are common, particularly given that no health-condition variables were included. Discriminatory accuracy followed the same gradient: the area under the receiver operating characteristic curve reached 0.80 for cost-related UMN, compared with 0.60 for overall UMN, meaning that cause-specific models identify high-risk individuals far more effectively.

After accounting for average additive effects, the residual variation attributable to intersectional interaction effects shrank substantially—the proportional change in variance exceeded 80 percent for all outcomes. But the residual effects, though small in aggregate, were concentrated in a handful of strata that proved to be the study’s most revealing finding. For time-related UMN, the three highest interaction effects all belonged to a single social location: younger women who were not employed and living with children. Their interaction effects reached odds ratios of 2.10, 2.06, and 1.59 across the middle-, lowest-, and highest-income tertiles respectively. These women’s predicted probabilities of time-related UMN were comparable to those of employed young adults—an anomaly, since non-employment would ordinarily be expected to free up time. No comparable pattern appeared among non-employed young men.

The authors offer a plausible explanation rooted in the sociology of care. The ideology of intensive mothering prescribes continuous maternal availability and prioritization of children’s needs, which may render non-employment not as relief from time pressure but as an expectation of full-time caregiving. Under such norms, mothers who prioritize their own health needs can experience guilt, leading to deferred care. The pattern is consistent with stark gender asymmetries in unpaid labor: in South Korea, non-employed women in single-earner households with children spend roughly seven hours per day on unpaid household work, about double the time of non-employed men in the reverse configuration. International evidence similarly shows that male unemployment does not translate into equivalent increases in men’s unpaid care work. Gendered role expectations, in other words, operate in both directions—directing women toward child-centered domestic routines while discouraging men from assuming caregiving responsibilities.

For cost-related UMN, the most deviant strata told an unexpected story about men. The highest interaction effect of all belonged to middle-aged men who were not employed and living alone in the highest-income tertile—an odds ratio of 2.60, despite their objective affluence. Two other middle-aged male strata living alone, one non-employed and low-income and one employed and low-income, ranked among the top four. The authors suggest that cost-related unmet need in this group may reflect perceived affordability or the prioritization of healthcare spending rather than genuine financial constraint. Gendered divisions of household labor have historically positioned women as managers of family health, monitoring symptoms and facilitating medical visits; men without a co-residing partner may be less likely to act on health needs at all. In South Korea, where breadwinner norms are particularly strong, non-employment in midlife may also represent a disruptive role failure that further deprioritizes healthcare spending.

The policy implications are pointed. Interventions targeting formal workplaces—flexible hours, sick leave—would reach employed adults but miss the non-employed young mothers whose time-related unmet need was among the highest of any group. Conversely, means-tested subsidies for healthcare costs would capture low-income households but overlook affluent middle-aged men living alone who forgo care for reasons that may be social and psychological rather than financial. The authors caution that their study is cross-sectional and descriptive, that respondents could report only one reason for unmet need, and that binary sex categories cannot fully capture gender diversity. Yet the sensitivity analyses—adjusting for hypertension and diabetes, and excluding those with no perceived need—left the key findings intact. The broader message is that equitable access under universal coverage requires attention not only to entitlement and affordability, but to the gendered organization of work, care, and household responsibility that determines who, in practice, can walk through the clinic door.

Subject of Research: Intersectional gendered disparities in cause-specific unmet medical need in South Korea

Article Title: Gendered experiences of cause-specific unmet medical need: An intersectional analysis using MAIHDA

Article References: Lee, H., Choi, W., Lee, W., & Kim, H. (2026). Gendered experiences of cause-specific unmet medical need: An intersectional analysis using MAIHDA. SSM – Population Health, Article 101980. https://doi.org/10.1016/j.ssmph.2026.101980

Image Credits: AI Generated

DOI: 10.1016/j.ssmph.2026.101980

Keywords: unmet medical need, intersectionality, MAIHDA, gender inequality, South Korea, universal health coverage, healthcare access, time poverty, caregiving, household composition, health equity, multilevel analysis

The World Health Organization’s definition of health as a state of complete physical, mental, and social well-being has driven decades of frameworks built around the social determinants of health. Income, education, housing, and employment all feature prominently in these models. Time, however, remains largely absent, treated instead as a technical parameter within epidemiology. It appears in calculations of disability-adjusted life years, in critical periods of vulnerability, or as an implicit resource that people need to exercise, eat well, attend appointments, and maintain relationships. But this framing assumes everyone has roughly comparable access to time, an assumption the new paper argues is demonstrably false.

Sociology offers a richer picture. Time is not only measured by clocks and calendars but lived as duration, pace, and anticipation, all shaped by economic relations and the finite span of human life. Critically, perceptions of time are tied to identity and a person’s sense of control over their own existence. When people report lacking time, they are not simply reporting an insufficient number of hours; they are describing how their time is structured, valued, and constrained by forces beyond their individual choosing. Reframing time this way transforms it from a methodological convenience into a structural exposure—one that can be measured, modeled, and, in principle, changed through policy.

The paper identifies two interrelated dimensions through which time operates on health: availability and intensity. Availability refers to the absolute quantity of discretionary time a person commands. Intensity captures the lived experience of rushing, acceleration, and constant pressure. In many market-driven societies, emphases on productivity have accelerated daily rhythms at work and at home, intensified by technological change, urbanization, and flexible labor markets that blur the boundary between employment and the rest of life. The result is what researchers describe as boundaryless work—employment that seeps into evenings, weekends, and mental space—alongside the persistent devaluation of unpaid care.

Within labor markets, temporal pressure is organized through two dimensions of working time: control and variability. Working time control describes how much autonomy employees have over when, where, and how they work, which shapes their capacity to protect time for rest, care, and other non-market activities. Working time variability captures how much hours fluctuate, reflecting the predictability of daily rhythms. Evidence from across Europe shows that higher variability, especially when combined with low control, is associated with worse self-rated health, more psychosomatic complaints, and more frequent sleep problems. Meanwhile, indicators such as discretionary time, subjective time scarcity, time poverty, and time excess appear to mediate the well-documented association between socioeconomic status and health—and the health consequences of time poverty differ sharply between high- and low-income groups.

The burdens are not distributed equally. People working multiple jobs, and those combining paid employment with caregiving, face severe constraints on both the amount and the intensity of their time. Women are overrepresented in these situations and globally spend on average 2.8 more hours per day than men on unpaid care and domestic work. Because women, particularly those with lower incomes, perform the largest share of unpaid domestic and care labor, inequalities in time constitute a key mechanism through which social and gender disparities in health are reproduced. Migration, armed conflict, and economic instability deepen these patterns further, as uncertainty and chronic temporal strain become defining features of everyday life.

The relationship between time and health is also bidirectional, creating cycles that entrench disadvantage. Time constraints limit engagement in health-promoting behaviors such as physical activity or preparing nutritious meals, while fostering fatigue, negative mood, and stress-related physiological responses. Conversely, living with illness or disability reshapes how people can use and control their time, restricting participation in paid work, caregiving, and social life. Research on treatment burden shows that managing chronic illness entails substantial unpaid labor—information seeking, medication management, appointments, self-monitoring, lifestyle changes, financial tasks, and navigating health systems. These burdens are socially patterned too: most treatment burden measures were developed in high-income settings and may fail to reflect the experiences of people with lower health literacy or greater socioeconomic constraints. The result is a self-reinforcing loop in which poor health consumes time, and scarce time worsens health.

Healthcare systems themselves are built on temporal assumptions that often fail patients. Care is organized around clock time, standardized schedules, and linear treatment trajectories that rarely match the lived temporalities of chronic illness, disability, or long-term care. Patients juggling paid work and caregiving, or living with limited material resources, must navigate overlapping temporal scales and trade present time for uncertain future benefits. The misalignment disproportionately harms the socially disadvantaged. One promising response is coordinated care that aligns multiple appointments or services within a single visit, reducing the time costs of fragmented care—a model with demonstrated potential for patients with multimorbidity.

Making time visible in epidemiology has direct methodological consequences. Conventional models that treat time as neutral or exogenous obscure how temporal scarcity, acceleration, and uncertainty function as socially patterned exposures, and may systematically misattribute responsibility to individual behavior in ways that reproduce inequity. Existing infrastructures already make measurement feasible: the Harmonised European Time Use Surveys and the Multinational Time Use Study provide harmonised 24-hour diary data on paid work, unpaid care, personal care including sleep, travel, and leisure, alongside sociodemographic information. Incorporating these temporal dimensions into study design would allow research to better reflect lived experience across social groups and countries.

At the level of primordial prevention, the paper calls for engagement through public health diplomacy—advocating health in all policies beyond the health sector. That includes social protection systems that buffer economic uncertainty, labor policies regulating working hours and job security, housing policies shaping residential stability and commuting time, and transport infrastructure that reduces time poverty. Family-related policies such as paid parental leave, accessible childcare, and elder care support can ease the temporal pressures on working-age adults caring across generations. The ultimate claim is ambitious but straightforward: ensuring that people have the temporal conditions necessary to exercise choice, participate in society, and live healthy lives is not a luxury but a prerequisite for health equity, and reclaiming time as a determinant of health is fundamental to advancing population well-being.

Subject of Research: Time as a socially structured determinant of health and health equity

Article Title: Reclaiming time as a fundamental determinant of health equity

Article References: Reclaiming time as a fundamental determinant of health equity. (n.d.). https://doi.org/10.1016/j.ssmph.2026.101939

Image Credits: AI Generated

DOI: 10.1016/j.ssmph.2026.101939

Keywords: health equity, social determinants of health, time poverty, working time, unpaid care work, gender inequality, treatment burden, chronic illness, public health policy, epidemiology, time use surveys, social acceleration