Social Science & Medicine

Study question: Does twin status and zygosity (monozygotic vs. dizygotic; same-sex vs. opposite-sex) predict fertility outcomes and intergenerational reproductive patterns compared with singletons? Summary answer: Among females, dizygotic twins had modestly higher completed fertility than singletons and monozygotic twins and were more likely to have a twin birth. Fertility did not differ meaningfully among males. These differences were restricted to the twin generation and did not persist in the next generation, indicating sex-specific and generation-specific effects rather than intergenerational transmission. What is known already: Dizygotic twinning is associated with heritable hyperovulation and higher natural fertility but less is known about whether being a twin or zygosity influences reproductive outcomes across generations. Study design, size, duration: A population-based longitudinal cohort study using part of the Finnish Twin Cohort and national population registers. Participants included monozygotic (MZ; N = 4,068), same-sex dizygotic (SSDZ; N = 8,890), opposite-sex dizygotic (OSDZ; N = 8,474) twins, and singleton controls (N = 1,193,404) born between 1945-1957 (total N =1,254,103; 49.1% female), their mothers, their children, and their grandchildren. Participants/materials, setting, methods: Fertility outcomes (number of biological children, age at first birth, childlessness, multiple births) were derived from Finnish population registers. Analyses followed a preregistered plan (https://osf.io/qbwv3) Main results and the role of chance: Differences in fertility between singletons and twins were modest and varied by sex and zygosity. Differences were observed generally in the mothers of twins and female twins themselves, with limited differences in the offspring of twins as compared to the offspring of singletons. Twins were slightly older at first birth, had fewer total biological offspring, but were more likely to have a twin birth. Dizygotic twins in particular differed from monozygotic twins and singletons. Limitations, reasons for caution: Findings are limited to individuals born in mid-20th-century Finland and thus generalizability to recent populations or non-Nordic contexts may be restricted. Further, analyses are observational, and causal inference is limited due to alternative motivation behind fertility rates like social or cultural reasons. Wider implications of the findings: These findings suggest that zygosity and sex interact to shape reproductive outcomes, offering insight into genetic and environmental contributions to fertility. They highlight the value of large twin cohorts for studying intergenerational reproductive trends and the representativeness of twins in population-based fertility research.

Research on under-vaccination often segments populations using demographic or administrative variables that are operationally useful but fail to capture identity dimensions relevant to vaccination decisions. Drawing on social identity theory, we propose an identity-landscape approach distinguishing identity membership, identity centrality, and multidimensional identity structure. Using a cross-sectional survey of 1,000 UK parents, we measured 65 identity indicators, identity-importance ratings, and their association with attitudinal and behavioural hesitancy toward childhood vaccination using validated scales. Beyond established socio-demographic predictors, alternative-medicine and natural-lifestyle identities, as well as affiliation with social media networks, were linked to greater hesitancy. Greater centrality of religion and political affiliation within personal identity was also associated with higher hesitancy. Principal component analysis suggested that individuals actively engaged across multiple societal issues were more hesitant, whereas stereotypically male-gendered engagement was associated with lower hesitancy. An identity-focused population segmentation may identify previously unrecognized undervaccinated groups and inform innovative tailored immunization campaigns.

Objective: Cross-sectional studies indicate associations between self-reported social media use and adolescent wellbeing outcomes. We aimed to evaluate longitudinal associations of objectively measured smartphone and social media use with psychosocial wellbeing. Design: Observational study with one year of follow-up Setting: High schools in Finland from 2022 to 2023 Population: 259 adolescent girls (mean age 16.3 years at baseline) Main outcome measures: screenshots depicting smartphone and social media use, Bergen Social Media Addiction Scale (BSMAS), Generalized Anxiety Disorder-7 questionnaire, Body Appreciation Scale 2 (BAS-2) and visual analogue scales (VAS) of mood, tiredness, and loneliness Results: Across one year of follow-up, anxiety, body appreciation, and mood improved, but possible social media addiction increased from 15% to 17%. Social media addiction at baseline was associated with increased anxiety (r=0.29, p<0.001), lower body appreciation (r=-0.15, p=0.022), and more loneliness (r=0.20, p=0.001) at follow-up. Anxiety at baseline was associated with social media addiction at follow-up (r=0.19, p=0.005). The highest quartile of TikTok users reported more social media addiction (BSMAS 19 [IQR 16-21] vs. 17 [IQR 14-20]; p=0.009) and lower body appreciation (BAS-2 32 [IQR 28-38] vs. 35 [IQR 29-40]; p=0.003) than did others. The highest quartile of Snapchat users reported more social media addiction (BSMAS 19 [IQR 15-21] vs. 17 [IQR 14-20]; p=0.007) and tiredness (VAS 21 [IQR 13-32] vs. 26 [IQR 15-35]; p=0.049) than did others. Conclusions: Consistent with cross-sectional studies, social media addiction was associated with poorer psychosocial outcomes across follow-up. Policies to protect adolescents from social media addiction are urgently needed.

Background: The Universal Periodic Review (UPR) is a peer-review mechanism established to hold UN Member States accountable for human rights including the right to health, yet evidence on its impact on health outcomes is limited. We evaluated whether UPR engagement is associated with accelerated improvements in maternal health trajectories. Methods and Findings: We conducted a longitudinal ecological analysis of 89 countries with a baseline maternal mortality ratio (MMR) of 70 or greater per 100,000 live births in 2005. Outcomes were trajectories of annual MMR, skilled birth attendance (SBA), and contraceptive prevalence rate (CPR), from 2005 to 2023. The exposure was the volume of health-related UPR recommendations received across three cycles, thematically classified using a validated rule-based algorithm. Mixed-effects models adjusted for time-varying GDP per capita and historical fragility. The 89 countries received 41,733 UPR recommendations across three cycles, of which 405 (1%) were related to maternal health. Maternal health recommendations were preferentially directed at countries with higher baseline MMR and lower SBA. After adjustment, each additional maternal health recommendation was associated with a 0.24% [95% confidence interval (CI): 0.08, 0.40] faster annual reduction in MMR, a 0.52% [0.12, 0.91] faster annual gain in the odds of SBA, and a 0.21% [0.09, 0.34] faster annual gain in the odds of CPR. Broader recommendations on women's health and health systems and services were also associated with faster annual improvements in trajectories across all three outcomes; recommendations on abortion, family planning, sexual health and wellbeing, and sexual education tended to be directed towards lower-burden countries and were not associated with differences in any trajectories. It is important to note that the ecological design precludes causal inference. Conclusions: Receiving UPR recommendations on the themes of maternal health, womens health, and health systems and services are associated with accelerated improvements in maternal health trajectories among high-burden countries. These findings suggest that international human rights accountability mechanisms may have a role in supporting national progress on maternal health.

While SARS-CoV-2 and influenza continue to place a significant burden on population health, within-household differences in decisions towards vaccination and seeking care across these two pathogens, and across sociodemographic groups, remain largely unexplored. By conducting a household-level survey in Illinois, we found that many individuals made inconsistent decisions about vaccination: among all adults, 29% were vaccinated for only one of COVID-19 or influenza, and among those with children in the home, 39% lived with a child whose influenza or COVID-19 vaccination status differed from their own. A higher proportion of adults were vaccinated against COVID-19 compared to influenza, while the opposite was true for those younger than 18 years old. These differences hold even when accounting for disparities in coverage by age, race/ethnicity, political affiliation, and socioeconomic status. While vaccinated individuals consistently reported wanting to protect themselves or others, those who declined vaccination reported highly heterogeneous reasons ranging from resource constraints to distrust or misconceptions about vaccination. These differences are even more pronounced for COVID-19, with larger partisan gaps and higher refusal driven by safety concerns, lack of trust, or religious reasons than those who decide not to get the influenza vaccine. In contrast to vaccination, the decision to seek medical care when sick showed opposite sociodemographic trends, that are likely attributable to illness severity. Our findings highlight that closing gaps in COVID-19 and influenza vaccination coverage will require an integrative strategy that accounts for diverse motivations, fears, and barriers to access, while addressing social inequalities common to both diseases.

Background Fertility rates in Australia have been declining over recent decades, reaching a record low total fertility rate of 1.48 births per woman in 2024. Concurrently, vasectomy remains widely accessible and increasingly normalised as a permanent contraceptive option. Despite extensive commentary on falling birth rates, no contemporary Australian study has examined vasectomy rates relative to birth rates over time. We aimed to compare population level vasectomy and birth rates across Australian jurisdictions and age groups. Study design Nationwide retrospective time-series study. Retrospective population-based study using Medicare Benefits Schedule item 37623 to identify vasectomy procedures performed between July 2015 and December 2024. Rates were calculated per 100,000 male population using quarterly Australian Bureau of Statistics (ABS) population estimates and summarised as rolling 12-month averages. Birth rates were derived using matched ABS data for women across equivalent age strata (18-24, 25-34, 35-44 years). Results: Vasectomy rates increased nationally from 32 per 100,000 in 2016 to 55 per 100,000 in 2023 before declining modestly in 2024. Birth rates declined from 5,200 to 3,800 per 100,000 over the same period. Trends were consistent across states and age groups, with the greatest vasectomy uptake in men aged 35-44 years. Conclusion: Australia is undergoing a demographic shift characterised by rising vasectomy uptake and declining fertility. While vasectomy rates remain lower than birth rates, their convergence signals changing reproductive intentions and contraceptive behaviours. Ongoing monitoring of permanent and long-acting contraception is essential to understand evolving population dynamics and inform reproductive health policy.

Background: Observational studies have consistently reported associations between social media use (SMU) and poorer mental health outcomes; however, such designs cannot establish causality. This study synthesised evidence from randomized experiments to estimate the effects of restricting SMU on mental health outcomes. Methods: A systematic search was conducted across MEDLINE, Embase, PsycINFO, and Cochrane CENTRAL to identify experimental trials evaluating interventions that constrained SMU for at least 24 hours and included an unconstrained control condition. Multilevel random-effects meta-analyses were used to synthesise effect estimates. Prespecified meta-regressions explored study-level moderators, and population-level impact fractions were estimated relative to global SMU prevalence. Results: From 7,784 screened records, 37 reports representing 35 distinct studies were included (pooled N = 7,160). Most interventions lasted one to three weeks and targeted college-aged youth. Pooled estimates favoured SMU constraints across outcomes, with magnitude and precision varying by domain. Confidence intervals were entirely above zero, consistent with a beneficial response for depressive symptoms (g = 0.22; 95% CI, 0.12 to 0.32), perceived stress (g = 0.15; 95% CI, 0.01 to 0.29), anxiety symptoms (g = 0.19; 95% CI, 0.05 to 0.34), fear of missing out/nomophobia (g = 0.14; 95% CI, 0.04 to 0.24), and well-being (g = 0.36; 95% CI, 0.10 to 0.63). Heterogeneity was substantial for several outcomes (I2 > 75%). In bivariate meta-regressions, higher baseline SMU was associated with larger effects for anxiety symptoms ({beta} = 0.13; 95% CI, 0.03 to 0.22), and longer interventions were associated with larger effects for depressive symptoms ({beta} = 0.16; 95% CI, 0.02 to 0.30). Inferences revealed that a short-term reduction in SMU globally could plausibly mitigate 17.5% and 15.4% of depressive and anxiety symptom cases, respectively. Conclusions: Experimental design-based evidence supports the causal case for an effect of SMU on mental health, with constraints producing improvements across multiple outcomes and no evidence of harm. Population-level inferences suggest that even individually modest effects may translate into meaningful public health benefits given the high prevalence of SMU exposure. These findings suggest that reducing SMU may represent a low-intensity, low-cost, scalable strategy to support mental health and improve well-being.

Introduction Perinatal Empowerment is widely referenced in maternity care research, yet its use often lacks clear conceptual definitions and validated measures. Existing instruments do not capture the multidimensional nature of perinatal empowerment, including both external dimensions (e.g., gender equity, resource access), and internal dimensions (e.g., confidence, agency and informed decision making). This gap has limited the ability to rigorously evaluate how healthcare experiences shape empowerment during pregnancy, birth, and the postpartum period. Aim To develop a valid and reliable instrument that measures dimensions of perinatal empowerment, both external and internal. Methods Instrument development followed the seven-step MEASURE framework. Initial item generation was guided by a concept analysis, a scoping review of existing instruments, and feedback from international midwifery experts. A preliminary 51-item instrument underwent expert content validity review, resulting in 48 items, which were then pilot-tested with six pregnant and postnatal women. A large-scale validation study was conducted via an international online survey (N=155). Psychometric testing included exploratory factor analysis (EFA), reliability assessment using Cronbachs , known-groups validity testing, and regression analyses adjusting for potential confounders. Results EFA supported two overarching dimensions--external and internal empowerment--with six factors across 30 final items (18 external, 12 internal). Sampling adequacy was high, and item loadings exceeded recommended thresholds. Internal consistency was strong for both dimensions (=0.88 external; =0.87 internal). Women receiving midwifery continuity of care reported significantly higher empowerment scores across total, external, and internal dimensions compared with other care models (p<.001). Differences between primiparous and multiparous women were not statistically significant. Conclusion The MPower instrument represents a conceptually grounded, psychometrically robust measure of multidimensional perinatal empowerment in high-income settings. Further validation in more diverse populations is needed to refine the instrument and expand its applicability across clinical and research contexts.

Given the growing crisis in youth mental health, there is a critical need to rebuild and sustain healthy social environments. Cooperative experiences (e.g., sports, clubs) may promote mental health but we lack rigorously tested measures to drive research and evaluation. This study sought to develop a measure of cooperative experiences and test associations with health. We developed and revised a measure of cooperative experiences based on interdisciplinary literature and 20 cognitive interviews. We recruited youth aged 13-25 years (N = 262) through youth-serving organizations and snowball sampling to complete an investigator-administered (n = 50) or self-administered (n = 212) survey assessing cooperative experiences (48 items), mental and physical health, and demographics. We assessed item characteristics, dimensionality, reliability, and construct validity. Multivariable linear regressions were used to estimate the association between the total score and self-reported health. Participants were 57% female, 69% Latino, 55% high school students, and 25% college students. The measure was reduced to 35 items (alpha = 0.90) with six subscales: sense of a unified group (7 items, alpha = 0.83), goal alignment (3 items, alpha = 0.80), inclusion and shared purpose (10 items, alpha = 0.88), social exclusion (2 items, alpha = 0.91), positive interdependence (7 items, alpha = 0.77), and negative interdependence (6 items, alpha = 0.87). A higher total score was associated with better self-reported mental health (beta = 0.25 standard deviation change in health score for each standard deviation change in cooperation scale, 95% CI [0.108, 0.394], p = 0.001) and self-reported general health (beta = 0.25, 95% CI [0.107, 0.395], p = 0.001). The study provides preliminary support for the reliability and validity of a new measure of exposure to cooperative experiences among youth. The measure holds promise as a tool to examine the relationship between social environments and health outcomes in real-world settings.

Introduction Education is a core social determinant of health for children and adolescents. Unfortunately, academic achievement, health, and wellbeing of adolescents have decreased in many developed countries in the past decade. The purpose of the Wellbeing and Education linkages in school-aged children (WELL-ED) study is to examine associations of school absences and academic achievement with use of school-based and community-based health and social welfare services. In addition, we will assess user experiences and multi-sector services pathways of school-aged children for a better understanding of how the service system could respond to the needs of children. Methods and analysis WELL-ED is a large population-based study that combines register data on school absences and educational support from municipalities with register data on healthcare and social service use collected from wellbeing services counties in Finland. The study cohort includes all children who attended mandatory education in public schools in Southern Finland in school year 2023-2024. A smaller cohort of adolescents in school year 8 was invited to complete a user experience survey. The primary outcomes of this study are related to equity of service use. Ethics and dissemination The Regional Committee on Medical Research Ethics of the Helsinki and Uusimaa Hospital District (2803/2024) has approved the WELL-ED study protocol. For the survey, adolescents in year 8 and parents of adolescents younger than 15 provided informed consent. Results will be published in peer-reviewed journals, summaries will be sent to participating municipalities and wellbeing services counties and press releases will be written on key findings.

Introduction: Even though state minimum wage (MW) is a policy lever that affects income and poverty and can prevent of violence, no prior study has comprehensively evaluated its impact in the United States (US). In this study, we estimated the impact of at least a $1 USD increase in state MW above the federal MW on overall, firearm, and non-firearm homicide mortality and examined its impact on racialized inequities. Methods: We conducted a quasi-experimental study using controlled interrupted time series (CITS) and synthetic controlled interrupted time series (SCITS) approaches to examine immediate and sustained impact of state MW increases. We used state-month level homicide victimization mortality data from 2010-2019. Homicide victimization death was identified using International Classification of Disease codes, 10th revision. State MW data was obtained from the Bureau of Labor Statistics. Results: Demographic and social variables from intervention, never-exposed, and always-exposed states were similar to each other and representative of the total US population from all 50 states. The CITS results show that after MW increases in the intervention states, these states experienced a sustained decline of -0.22 (-0.37, -0.07) homicide victimizations/ 100,000 person-years/ year relative to the never-exposed states and -0.39 (-0.59, -0.18) relative to always-exposed states. This resulted in 5,657 fewer homicide victimization deaths in the intervention states over four years of post-MW increase period compared to the never-exposed states. SCITS results were similar to the CITS results, and the majority of sustained declines were observed in firearm-related deaths and among Black population. Conclusion: MW increase was associated with a reduction in homicide victimization rates, which were robust in multiple sensitivity analyses, more pronounced for firearm-related homicide deaths, and reduced homicide victimization inequities for Black Americans.

Background: Many mental health problems originate in childhood, highlighting the need for early preventive approaches. Preventive services to promote children's mental health are offered in the health, education, and social sectors (H-E-S) but are often not used by certain at-risk groups or early enough. To identify children at-risk and provide needs-oriented support, professionals from all sectors must be well trained, collaborate closely to refer to specialized services for specific mental health problems or risk factors, and understand the regional psychosocial support system and its services. A comprehensive approach to preventing mental health problems requires structured planning and a systematic overview of all institutions and services in the region and their collaboration. This study aims to map the preventive mental health and psychosocial support service system and the collaboration between institutions across three sectors (H-E-S) in two exemplary city districts. The study is integrated into a whole-district approach to child mental health promotion that is being implemented in one of the researched city districts, and its results will inform further activities there. Methods: We use a mixed-methods approach, combining qualitative interviews with a quantitative survey to map psychosocial services for children aged 4 to 10 and their families across the H-E-S sectors in two socioeconomically disadvantaged city districts in East and West Germany. All institutions that potentially offer psychosocial services for children and families will be approached to recruit professionals (e.g., schools, practices, counseling centers). To understand the regional psychosocial support system, we will analyze existing services and their characteristics (e.g., target groups, intervention types) descriptively. Social network analysis will be applied to gain an in-depth understanding of collaboration between institutions, to identify potential gaps in services and pathways, and to inform an intervention aimed at improving interinstitutional and intersectoral collaboration. Discussion: To our knowledge, this is the first study to comprehensively analyze regional preventive psychosocial support systems for children and families across sectors at the community level. Previous mappings of psychosocial services have focused on a single sector (e.g., health) or specific diagnoses only. The psychosocial preventive landscape spanning the H-E-S sectors involves complex financing structures and referral logics. Understanding the characteristics of the existing support landscape requires a systematic and comprehensive approach. Our study advances service mapping and operationalization methods in public health research. Additionally, the findings will inform recommendations for improving comprehensive prevention approaches in the selected city districts.

Mental health problems, including emotional problems, are linked to adverse educational outcomes among children and adolescents. This study examines the association between early onset of mental health problems generally, and emotional problems specifically, at ages 5-14, and outcomes from the General Certificate of Secondary Education (GCSE), a secondary education qualification, at age 16 for 4,783 students in England, using the Millennium Cohort Study dataset linked to the National Pupil Database. We found that the onset of mental health problems at ages 5, 7, 11 and 14 had a significant and negative association with all GCSE outcomes. We also found negative associations between early onset emotional problems and GCSE outcomes, although results were most stark for emotional problems that onset at age 11, with statistically significant negative associations with all GCSE outcomes. School absence was identified as a potential mediator of the negative association. Furthermore, this study found that the potential loss of productivity related to mental health problems in general and emotional problems in particular was over 23,000 sterling and 11,000 sterling per affected individual, respectively, which could translate into approximately 2.57 billion sterling and 1.6 billion sterling, respectively at the population level for England. These findings highlight the importance of early intervention for children and adolescents with mental health problems to improve educational and future outcomes.

Evidence from many countries shows that later life cognitive health is shaped by childhood poverty. However, whether it is associated with neurodegenerative biomarkers measured in population settings remains unclear. Methods We conducted a pooled analysis of 5,473 adults aged [&ge;]50 years from Denmark, Sweden and Germany participating in Wave 6 (2015) of the Survey of Health, Ageing and Retirement in Europe. Neurodegenerative biomarkers (neurofilament light chain, glial fibrillary acidic protein and phosphorylated tau) were assayed from dried blood spots. Childhood poverty was constructed as a latent variable from retrospective life histories. Weighted Poisson regression models estimated associations adjusting for age, sex, education, marital status and wealth in later life. Marginal predictions along age and across country were derived. Results Childhood poverty was strongly associated with higher NfL concentrations ({beta}=1.66, p<0.001), but not with GFAP or p-tau217. Predicted values indicated substantially elevated NfL among the childhood poor (10.3 pg/mL vs 2.0 pg/mL for the non-poor). Age profiles showed widening disparities: the childhood poor in midlife exhibited higher NfL levels than the oldest old who grew up not poor. No consistent differences were observed for GFAP or p-tau217. Findings were robust and similar across all three countries with different histories and health systems. Conclusions Childhood poverty is associated with markedly elevated levels of NfL in later life, suggesting long-term neuroaxonal injury consistent with life course shaping of brain health. Moreover, the evidence implies substantial acceleration of neurobiological ageing. These findings emphasise the importance of early-life interventions for brain health in ageing populations.

Objective: To estimate the adjusted relative risk (RR) of administrative grant disruption faced by first-time and mechanism-first principal investigators (PIs) during the 2025 National Institutes of Health (NIH) grant disruptions. Design: Retrospective cohort study linking NIH RePORTER data to a publicly curated registry of grants disrupted in 2025. Setting: All NIH active research grants in fiscal years 2024 to 2025. Participants: 80,976 active projects: 4,961 disrupted during the wave that peaked in May 2025, 76,015 non-disrupted controls. Main outcome measures: Adjusted RR of disruption by two pre-specified first-time PI constructs: absolute first-time PI (no prior NIH grant) and mechanism-first PI (no prior NIH grant with the same activity code). Modified Poisson regression with institution-clustered standard errors adjusted for project, institutional, and geographic covariates. A pre-specified fiscal year 2024 common-anchor analysis addressed year-of-disruption confounding. Results: Of 4,961 disrupted grants, 237 (4.8%) had an absolute first-time PI and 396 (8.0%) had a mechanism-first PI. After adjustment, absolute first-time PIs faced 77% elevated risk of disruption (RR 1.77, 95% CI 1.34 to 2.32) and mechanism-first PIs faced 57% elevated risk (RR 1.57, 1.16 to 2.11). Under the common-anchor analysis, the absolute first-time effect attenuated to RR 1.22 (0.95 to 1.58); the mechanism-first effect persisted (RR 1.48, 1.07 to 2.06). The elevated risk was concentrated in research-mechanism grants (RR 1.78, 1.26 to 2.52) and was robust across 8 of 9 pre-specified sensitivity analyses. The Track A start-time construct, which asks whether the disrupted project was the PI's debut grant, yielded null estimates (RR 0.98, 0.93 to 1.04), with any effect concentrated entirely in newly started projects. Conclusions: First-time and mechanism-first PIs faced disproportionately elevated risk of disruption during the 2025 NIH wave, concentrated in research-mechanism grants and robust to year-confounding-free identification. The relevant exposure was being early-career at the moment of administrative action, not at project initiation. The findings have direct implications for workforce equity in US biomedical research.

Background Multimorbidity is increasingly prevalent, and associated with worse clinical and psychosocial burdens. Interoception, the brain's ability to sense and interpret internal bodily signals, may contribute to multimorbidity, through its link with health behaviors, stress regulation, and mental health. This study examines whether self-reported interoceptive accuracy and attention is associated with multimorbidity, by identifying multimorbid subgroups and their interoceptive profiles. Methods Morbidity classes were identified through latent class analyses in two Dutch survey datasets, focusing on depression and alexithymia (DA-dataset; N = 671) and lifestyle factors (L-dataset; N = 1022). Linear regression analyses were used to assess interoceptive accuracy and attention (by the Interoceptive Accuracy Scale and Interoceptive Attention Scale respectively) among different subgroups. Results Multimorbid subgroups were characterized by older age, low socioeconomic position, and elevated physical, psychological, and behavioral problems. Multimorbid classes exhibited lower interoceptive accuracy (DA-dataset: B = -1.14, 95% CI = [-2.89, 0.62]; L-dataset: B = -2.36, 95% CI = [-3.83, -0.89]) and higher attention (DA-dataset: B = 3.62, 95% CI = [0.97, 6.27]; L-dataset: B = 1.07, 95% CI = [-1.42, 3.56]) compared to healthier classes. Conclusion Multimorbid populations demonstrated lower interoceptive accuracy and higher interoceptive attention. This highlights the psychosocial complexity of multimorbid populations which may impact their self-management and health behavior. These findings underscore the need to expand treatments to include psychosocial domains for multimorbid patients.

Background: Psychological distress is common in chronic kidney disease (CKD) and is associated with reduced quality of life, treatment non-adherence, and worse clinical outcomes. Distress in CKD is also linked to difficulties adjusting to the demands of illness management. Despite this, psychological support remains inconsistently integrated within kidney care pathways, and existing interventions often lack clear theoretical specification and explicit targeting of mechanisms underpinning adjustment to CKD. Objectives: To describe the systematic development of iADJUST, a theory-informed patient co-designed digital psychological intervention targeting key cognitive and behavioural mechanisms involved in adjustment to CKD. Methods: Intervention development was guided by the Medical Research Council framework for complex interventions. A structured, iterative process integrated empirical evidence, psychological theory, and patient and public involvement and engagement. The Common-Sense Model of Self-Regulation and cognitive behavioural theories informed the identification of modifiable maintaining mechanisms associated with adjustment to CKD. Intervention components were mapped onto these mechanisms and refined through co-design with people living with CKD. Results: iADJUST is a six-session self-guided digital psychological intervention delivered over 12 weeks and supplemented by therapist contact. The intervention targets illness-related uncertainty, fatigue-related activity dysregulation, catastrophic what-if thinking, self-critical evaluation, and behavioural withdrawal. It integrates psychoeducation, cognitive and behavioural strategies, maintenance planning, and elements from acceptance and commitment therapy and compassion-focused approaches. Content is delivered through video, audio, and guided tasks and activities. Conclusion: iADJUST provides a theory-informed, evidence-based psychological intervention for CKD explicitly mapping intervention components to maintaining cognitive and behavioural mechanisms implicated in adjustment. Feasibility evaluation is underway.

Sex work is diverse and includes a broad range of people and settings. Over the last thirty years, a large proportion of public health emergencies of international concern (PHEIC) have involved infections transmitted through sexual or close contact and in sexual networks (WHO 2024). Sex workers can face increased disadvantage in relation to these public health emergencies. Given the significant health inequalities sex workers can face, they should be eligible to receive targeted and tailored health support to reduce health protection risks (Hester 2019; Jeal and Salisbury 2004a). However, they are often not explicitly eligible for targeted and tailored support due to a lack of information on incidence, prevalence of disease, and even more basic data such as reliable estimates of the number of sex workers in the UK. Accordingly, the aim of this paper is to determine a population size estimate, with uncertainty, that is more robust than those currently available. In this study, we apply Bayesian Evidence Synthesis to bring together historic estimation efforts with recent ONS National Population Estimates and Genito-Urinary Medicine Clinics Attendance Data (GUMCAD) from the UK Health Security Agency (UKHSA). A key feature of our model is the embedding of uncertainty from each input study in model priors, hence propagating it through to our final estimate. The Bayesian evidence synthesis model estimated a total of 84,000 sex workers in the United Kingdom (95% credible interval: 49,000-130,000), representing 0.121% of the current UK population.

Background: Biopsychosocial factors associated with functional changes, including changes in personality, communication, movement, and weight, were evaluated in individuals with Down syndrome (DS) during the COVID-19 pandemic. Method: Caregivers of individuals with DS (aged [&ge;]12, n = 118) completed an online survey. Elastic net regression with bootstrap resampling assessed 31 candidate predictors. Results: Pandemic-related mental health was most strongly associated with functional changes ({beta} = 0.388). Healthcare access barriers were also reliably selected: inability to access mental health treatment, difficulty affording insurance, difficulty accessing specialists, and residing in a low-income health professional shortage area. The model explained 35.2% of variance. Conclusions: Mental health and healthcare access barriers were biopsychosocial correlates of functional changes for people with DS during COVID-19.

Background: Physical activity is a well-established modifiable risk factor for depression and anxiety. However, whether vigorous intermittent lifestyle physical activity (VILPA), defined as short, sporadic bouts embedded in daily life, confers mental health benefits remains unclear. We aimed to examine the associations of accelerometer-measured VILPA with risks of incident depression and anxiety among non-exercising adults. Methods: This prospective cohort study included 19,962 non-exercising adults (mean age 62.3 years) from the UK Biobank, free of depression and anxiety at baseline (2013-2015), with 7-day wrist-worn accelerometry data. Cox proportional hazards models and restricted cubic splines were used to examine associations between average daily duration of VILPA bouts lasting up to 1 or 2 minutes and these outcomes. Findings: Over an average follow-up of 7.8 years, 469 participants developed depression and 536 developed anxiety. Approximately 94.6% of participants engaged in VILPA bouts lasting up to 1 minute. Daily VILPA duration exhibited L-shaped associations with both depression and anxiety. Compared with participants who accumulated no VILPA, the whole-sample median daily VILPA duration for bouts lasting up to 1 minute, 4.1 minutes, was associated with a hazard ratio of 0.70 (95% confidence interval [CI]: 0.56-0.88) for depression and 0.79 (95% CI: 0.64-0.97) for anxiety. Findings were similar for VILPA bouts lasting up to 2 minutes. Interpretation: Among non-exercisers, even small amounts of VILPA were associated with substantially lower risks of depression and anxiety, highlighting the potential of high-intensity incidental physical activity as a feasible strategy for preventing depression and anxiety, particularly among individuals unable or unwilling to engage in structured exercise.