Syndemic theory, methods, and data

Syndemic Theory and Its Use in Developing Health Interventions and Programming: A Scoping Review

PURPOSE OF REVIEW

The central tenet of syndemics theory is that disease interactions are driven by social factors, and that these factors have to be understood in order to reduce the health burdens of local populations. Without an understanding of the theory and how it is being put into practice, there is a strong possibility of losing the potential for syndemic theory to positively impact change at community and individual level.

METHODS

Following an initial database search that produced 921 articles, we developed a multi-stage scoping review process identifying invention studies that employ syndemic theory. Inclusion was defined as the presence of healthcare interventions examining multiple social-biological outcomes, refering to a specific (local) at risk population, developing or attempting to develop interventions impacting upon multiple health and/or social targets, and explicit employment of syndemic theory in developing the intervention.

RESULTS

A total of 45 articles contained a substantial engagement with syndemic theory and an original healthcare intervention. However, only eleven studies out of all 921 articles met the inclusion criteria.

DISCUSSION/CONCLUSION

It is strongly suggested that when employing syndemic theory researchers focus close attention to demonstrating disease interactions, providing evidence of the social drivers of these disease interactions, and constructing interventions grounded in these analytical findings. We conclude that although frequently referred to, syndemic theory is rarely employed in its entirety and recommend that interventions be developed using a more thorough grounding in this important and powerful theory.

A historical syndemic? The impact of synergistic epidemics of measles and scarlet fever on life expectancy in Victoria, Australia (1860s-1870s)

OBJECTIVES

To explore whether synergistic epidemics of measles and scarlet fever in 1860s-1870s Victoria, Australia could be characterized as syndemics, we apply the methods of Sawchuk, Tripp, and Samakaroon (Social Science & Medicine 2022, 295, 112956) to quantify the impact of each of the two major co-occurring epidemic events (1867, 1875) in terms of life expectancy (LE) changes. Sawchuk et al. posit the presence of a harvesting effect, indicated by a statistically significant increase in LE in the immediate post-epidemic "fallow period", as a criterion for identification of a historical syndemic. We test an alternate hypothesis that the same methods can identify a short-term scarring effect.

MATERIALS AND METHODS

Using annual age- and cause-specific death statistics and census population data, we constructed abridged period life tables for baseline period, potential syndemic year, and "fallow" year for each of the two periods (1860s and 1870s). We compared LE at birth using Z-tests. We decomposed age-cause-specific mortality according to Arriaga's method to identify age-and cause-specific contributions to LE change.

RESULTS

LE was significantly lower than baseline (1864-1865) in 1867 but not in the "fallow" year (1869). LE in 1875 and the 1878 "fallow" year were both significantly below baseline (1871-1873). Age-cause-specific decomposition showed similar patterns for 1867 and 1875 for measles and scarlet fever combined effects.

DISCUSSION

Evidence of a scarring effect following the 1875 measles/scarlet fever combined peak supports the interpretation of this event as a syndemic. We suggest the short-term scarring effect can be a useful additional criterion for identifying historical syndemics.

Examining the Relationship between Anti-Black Racism, Community and Police Violence, and COVID-19 Vaccination

In 2020, the COVID-19 pandemic emerged against a backdrop of long-standing racial inequities that contributed to significant disparities in COVID-19 mortality, morbidity, and eventually, vaccination rates. COVID-19 also converged with two social crises: anti-Black racism and community and police violence. The goal of this study was to examine the associations between community violence, police violence, anti-Black racism, and COVID-19 vaccination. Survey data were collected from a sample of 538 Black residents of Chicago between September 2021 and March 2022. Structural equation modeling was used to test associations between neighborhood violence, police violence, racism, medical mistrust, trust in COVID-related information, depressive symptoms, and having received a COVID-19 vaccination. In line with predictions, neighborhood violence had a significant indirect effect on vaccination via trust in COVID-related information from a personal doctor. Additionally, racism had a significant indirect effect on vaccination via trust in COVID-related information from a personal doctor, as well as via medical mistrust and trust in COVID-related information from a personal doctor. These findings add to the growing body of literature demonstrating the importance of medical mistrust when examining COVID-19 vaccination disparities. Furthermore, this study highlights the importance of considering how social and structural factors such as violence and racism can influence medical mistrust.

Synergistic effects of exposure to multiple types of violence on non-fatal drug overdose among women who inject drugs in Indonesia

BACKGROUND

While research has demonstrated associations between experiencing violence from intimate and non-intimate partners and non-fatal drug overdose among women who inject drugs, existing studies focus predominantly on the Global North and are analytically limited. Guided by syndemics theory, this study examined whether different forms of gender-based violence exert independent and interactive effects on non-fatal drug overdose among women who inject drugs in Indonesia.

METHODS

We recruited 731 cisgender adult women who injected drugs in the preceding year via respondent-driven sampling. We used multivariate logistic regressions to examine associations between self-reported intimate partner violence (IPV), police sexual violence, and police extortion, and non-fatal drug overdose, with covariance adjustment for factors drawn from the risk environment. We tested for interaction effects among violence measures by calculating metrics for attributable proportion (AP), relative excess risk due to interaction (RERI), and synergy index (S).

RESULTS

Experiencing IPV (AOR 2.5; 95 % CI 1.2, 5.1; p = 0.012), police extortion (AOR 2.2; 95 % CI 1.5, 3.2; p ≤ 0.001), and police sexual violence (AOR 3.7; 95 % CI 1.5, 9.4; p = 0.005) each independently predicted non-fatal overdose, after adjusting for potential confounders. A significant positive interaction was detected between IPV and police sexual violence on drug overdose (AP=0.6, p = 0.001; S = 3.8, p = 0.015) such that the joint effect of these two forms of violence was associated with a nearly fourfold increase in non-fatal overdose risk compared to the main effects of each violence exposure.

CONCLUSION

This is the first study to show that concurrent IPV and police sexual violence exert an amplifying effect on non-fatal overdose beyond the additive effects of each exposure. Supporting the value of gender-responsive harm reduction services that integrate violence and overdose responses, results suggest that eliminating one form of violence when multiple forms of GBV are present could magnify the expected reduction in overdose.

Quality Improvement Intervention Using Social Prescribing at Discharge in a University Hospital in France: Quasi-Experimental Study

BACKGROUND

Social prescription is seen as a public health intervention tool with the potential to mitigate social determinants of health. On one side, social prescription is not yet well developed in France, where social workers usually attend to social needs, and historically, there is a deep divide between the health and social sectors. On the other side, discharge coordination is gaining attention in France as a critical tool to improve the quality of care, assessed indirectly using unplanned rehospitalization rates.

OBJECTIVE

This study aims to combine social prescription and discharge coordination to assess the need for social prescription and its effect on unplanned rehospitalization rates.

METHODS

We conducted a quasi-experimental study in two departments of medicine in a French university hospital in a disadvantaged suburb of Paris over 2 years (October 2019-October 2021). A discharge coordinator screened patients for social prescribing needs and provided services on the spot or referred the patient to the appropriate service when needed. The primary outcome was the description of the services delivered by the discharge coordinator and of its process, as well as the characteristics of the patients in terms of social needs. The secondary outcome was the comparison of unplanned rehospitalization rates after data chaining.

RESULTS

A total of 223 patients were included in the intervention arm, with recruitment being disrupted by the COVID-19 pandemic. More than two-thirds of patients (n=154, 69.1%) needed help understanding discharge information. Slightly less than half of the patients (n=98, 43.9%) seen by the discharge coordinator needed social prescribing, encompassing language, housing, health literacy, and financial issues. The social prescribing covered a large range of services, categorized into finding a general practitioner or private sector nurse, including language-matching; referral to a social worker; referral to nongovernmental organization or group activities; support for transportation issues; support for health-related administrative procedures; and support for additional appointments with nonmedical clinicians. All supports were delivered in a highly personalized way. Ethnic data collection was not legally permitted, but for 81% (n=182) of the patients, French was not the mother tongue. After data chaining, rehospitalization rates were compared between 203 patients who received the intervention (n=5, 3.1%) versus 2095 patients who did not (n=51, 2.6%), and there was no statistical difference.

CONCLUSIONS

First, our study revealed the breadth of patient's unmet social needs in our university hospital, which caters to an area where the immigrant population is high. The study also revealed the complexity of the discharge coordinator's work, who provided highly personalized support and managed to gain trust. Hospital discharge could be used in France as an opportunity in disadvantaged settings. Eventually, indicators other than the rehospitalization rate should be devised to evaluate the effect of social prescribing and discharge coordination.

Editorial: COVID-19 pandemic and the social determinants of health

As we learn to co-exist with COVID-19, this Research Topic highlights significant research contributions that examine the interaction of COVID-19 and the social determinants of health. To emphasize the impactful research in this area, this Research Topic features scholarly contributions in the fields of Epidemiology, specifically Aging and Life-course Epidemiology, and Public Health, specifically Public Health Policy. This theme is intentionally broad in scope, and our editorial provides an overview of the key findings of the papers published in the Research Topic on COVID-19 pandemic and the social determinants of health. The types of articles received in response to this Research Topic are summarized below.

Using Routine Data to Improve Lesbian, Gay, Bisexual, and Transgender Health

The collection of sexual orientation in routine data, generated either from contacts with health services or in infrastructure data resources designed and collected for policy and research, has improved substantially in the United Kingdom in the last decade. Inclusive measures of gender and transgender status are now also beginning to be collected. This viewpoint considers current data collections, and their strengths and limitations, including accessing data, sample size, measures of sexual orientation and gender, measures of health outcomes, and longitudinal follow-up. The available data are considered within both sociopolitical and biomedical models of health for individuals who are lesbian, gay, bisexual, transgender, queer, or of other identities including nonbinary (LGBTQ+). Although most individual data sets have some methodological limitations, when put together, there is now a real depth of routine data for LGBTQ+ health research. This paper aims to provide a framework for how these data can be used to improve health and health care outcomes. Four practical analysis approaches are introduced-descriptive epidemiology, risk prediction, intervention development, and impact evaluation-and are discussed as frameworks for translating data into research with the potential to improve health.

Is Pollution the Primary Driver of Infectious Syndemics?

Syndemics, the adverse interaction of two or more coterminous diseases or other negative health conditions, have probably existed since human settlement, plant and animal domestication, urbanization, and the growth of social inequality beginning about 10-12,000 years ago. These dramatic changes in human social evolution significantly increased opportunities for the spread of zoonotic infectious diseases in denser human communities with increased sanitation challenges. In light of a growing body of research that indicates that anthropogenic air pollution causes numerous threats to health and is taking a far greater toll on human life and wellbeing than had been reported, this paper proposes the possibility that air pollution is now the primary driver of infectious disease syndemics. In support of this assertion, this paper reviews the growth and health impacts of air pollution, the relationship of air pollution to the development and spread of infectious diseases, and reported cases of air pollution-driven infectious disease syndemics, and presents public health recommendations for leveraging the biosocial insight of syndemic theory in responding to infectious disease.

Weathering the Storm: Syringe Services Program Laws and Human Immunodeficiency Virus During the COVID-19 Pandemic

BACKGROUND

Syringe services programs (SSPs) are community-based prevention programs that provide a range of harm reduction services to persons who inject drugs. Despite their benefits, SSP laws vary across the United States. Little is known regarding how legislation surrounding SSPs may have influenced HIV transmission over the COVID-19 pandemic, a period in which drug use increased. This study examined associations between state SSP laws and HIV transmission among the Medicaid population before and after the COVID-19 pandemic.

METHODS

State-by-month counts of new HIV diagnoses among the Medicaid population were produced using administrative claims data from the Transformed Medicaid Statistical Information System from 2019 to 2020. Data on SSP laws were collected from the Prescription Drug Abuse Policy System. Associations between state SSP laws and HIV transmission before and after the start of the COVID-19 pandemic were evaluated using an event study design, controlling for the implementation of COVID-19 nonpharmaceutical interventions and state and time fixed effects.

RESULTS

State laws allowing the operation of SSPs were associated with 0.54 (P = 0.044) to 1.18 (P = 0.001) fewer new monthly HIV diagnoses per 100,000 Medicaid enrollees relative to states without such laws in place during the 9 months after the start of the COVID-19 pandemic. The largest effects manifested for population subgroups disproportionately affected by HIV, such as male and non-Hispanic Black Medicaid enrollees.

CONCLUSION

Less restrictive laws on SSPs may have helped mitigate HIV transmission among the Medicaid population throughout the COVID-19 pandemic. Policymakers can consider implementing less restrictive SSP laws to mitigate HIV transmission resulting from future increases in injection drug use.

DISCLAIMER

The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

A self-management plus mind body intervention for adolescents and young adults with type 2 diabetes: Trial design and methodological report

BACKGROUND

The onset of type 2 diabetes (T2D) is increasingly common in adolescents and young adults (AYAs). Improving self-management skills and the mental health of this population is important, but understudied.

METHODS

The goal of this research was to develop a mind-body intervention which could serve as an adjunctive therapy to support AYAs with T2D (INTEND intervention). Toward that end, we used an iterative process, including use of focus groups, advisory board, and cognitive semi-structured interviews with patients, parents of patient and clinical providers, to understand the gaps in the current information provided to AYAs with T2D. Based on the data gathered from the focus groups and interviews, we enhanced an existing self-management intervention for adults with T2D to include an additional mind body intervention for AYAs with T2D. The INTEND intervention will be piloted in a group of AYAs with T2D.

RESULTS

This report describes the methodology and design of the InterveNTion for Early oNset type 2 Diabetes (INTEND) study. The details of this single arm pre-post pilot feasibility trial are described.

DISCUSSION

If successful, the INTEND approach has the potential to advance care for vulnerable youth with T2D.

Dengue and COVID-19 Co-Circulation in the Peruvian Amazon: A Population-Based Study

The COVID-19 pandemic affected the main Amazon cities dramatically, with Iquitos City reporting the highest seroprevalence of anti-SARS-CoV-2 antibodies during the first COVID-19 wave worldwide. This phenomenon raised many questions about the possibility of a co-circulation of dengue and COVID-19 and its consequences. We carried out a population-based cohort study in Iquitos, Peru. We obtained a venous blood sample from a subset of 326 adults from the Iquitos COVID-19 cohort (August 13-18, 2020) to estimate the seroprevalence of anti-dengue virus (DENV) and anti-SARS-CoV-2 antibodies. We tested each serum sample for anti-DENV IgG (serotypes 1, 2, 3, and 4) and SARS-CoV-2 antibodies anti-spike IgG and IgM by ELISA. We estimated an anti-SARS-CoV-2 seroprevalence of 78.0% (95% CI, 73.0-82.0) and an anti-DENV seroprevalence of 88.0% (95% CI, 84.0-91.6), signifying a high seroprevalence of both diseases during the first wave of COVID-19 transmission in the city. The San Juan District had a lower anti-DENV antibody seroprevalence than the Belen District (prevalence ratio, 0.90; 95% CI, 0.82-0.98). However, we did not observe these differences in anti-SARS-CoV-2 antibody seroprevalence. Iquitos City presented one of the highest seroprevalence rates of anti-DENV and anti-SARS-CoV-2 antibodies worldwide, but with no correlation between their antibody levels.

Generalised anxiety disorder, depressive symptoms and their subjective change after the first wave of COVID-19 among gamers in Poland

Previous studies have indicated that levels of emotional distress were considerably elevated during the COVID-19 pandemic; however, some longitudinal studies did not confirm these findings. There is a very limited number of studies on specific subpopulations, such as video gamers in this particular period. Playing video games may have either a beneficial influence on mental health by diminishing stress or a detrimental impact in terms of increasing depression and anxiety. It is, therefore, important to establish whether regular gamers differ from the general population in terms of symptoms of depression and anxiety during COVID-19. A total of 1023 participants (aged 18-50) participated in the study. The sample was composed of gamers and was representative of the Polish population. Participants completed a modified version of GAD-7, PHQ-9 online, addressing subjective change in anxiety and depressive symptoms. 25% of the sample reported clinically significant anxiety levels, and 35% mentioned depression. There were no differences in anxiety and depression levels between the investigated sample of gamers and the general population. However, up to 30% of individuals reported an increase in subjective change in anxiety or depressive symptoms during COVID-19. A further 30% reported a downward subjective change in anxiety or depressive symptoms during COVID-19. The remaining 40% declared a lack of change in the subjective change in anxiety or depressive symptoms during COVID-19. Those who reported an increase scored substantially higher in anxiety and depression than other groups. This indicates that the COVID-19 pandemic may have impacted people's mental health along a syndemic-syndaimonic continuum. COVID-19 might have been harmful to those with already poorer mental health and beneficial to those with good mental health. It is also important to plan interventions targeting vulnerable individuals who report clinically significant levels of anxiety and depression - women and younger adults and those who subjectively perceive their emotional condition to deteriorate during the COVID-19 lockdown.

Maternal depression, alcohol use, and transient effects of perinatal paraprofessional home visiting in South Africa: Eight-year follow-up of a cluster randomized controlled trial

BACKGROUND

South African mothers confront synergistic challenges from depression, alcohol use, and HIV/AIDS. The importance of maternal functioning for child development motivates interventions, yet long-term outcomes seldom are tracked. Furthermore, little is known about trajectories and the role of social-cultural factors in maternal depression and alcohol use across parenthood in low- and middle-income countries.

METHODS

We examined maternal outcomes at 5- and 8-years' post-birth, from the Philani Intervention Program (PIP), a randomized controlled trial of a prenatally-initiated home visiting intervention lasting through 6 months' post-birth which yielded some benefits for children and mothers through 3 years. Longitudinal Bayesian mixed-effects models assessed intervention effects for maternal depression and alcohol use from pre-birth through 8 years post-birth. We plotted trajectories of depression and alcohol use and analyzed their relationship over time.

RESULTS

Maternal benefits appeared limited and intervention outcomes differed at 5 and 8 years. Reduced depression in PIP versus standard care (SC) mothers at 3 years disappeared by 5 and 8 years. Depression prevalence declined from 35.1% prenatally to 5.5% at 8 years, independent of intervention or alcohol use. Alcohol use in both groups rebounded from a post-birth nadir; fewer PIP than SC mothers drank alcohol and reported problematic use at 5 but not 8 years. HIV+ prevalence did not differ by condition and increased from 26% to 45% over the reported period.

CONCLUSIONS

Dissipation of early child benefits from home visiting by age 8 years likely reflects lack of durable change in maternal behaviors compounded by social-cultural factors and cumulative effects of community deprivation. High prenatal rates warrant screening and treatment for depression in standard antenatal care. Low-and-middle income countries may need sustained interventions, including alcohol use reduction, to capitalize on initial gains from targeted interventions and address community social-cultural factors. HIV/AIDS continues to spread in this population.

The impact of COVID-19 and bushfires on the mental health of Australian adolescents: a cross-sectional study

BACKGROUND

When COVID-19 spread to Australia in January 2020, many communities were already in a state of emergency from the Black Summer bushfires. Studies of adolescent mental health have typically focused on the effects of COVID-19 in isolation. Few studies have examined the impact of COVID-19 and other co-occurring disasters, such as the Black Summer bushfires in Australia, on adolescent mental health.

METHODS

We conducted a cross-sectional survey to examine the impact of COVID-19 and the Black Summer bushfires on the mental health of Australian adolescents. Participants (N = 5866; mean age 13.61 years) answered self-report questionnaires about COVID-19 diagnosis/quarantine (being diagnosed with and/or quarantined because of COVID-19) and personal exposure to bushfire harm (being physically injured, evacuated from home and/or having possessions destroyed). Validated standardised scales were used to assess depression, psychological distress, anxiety, insomnia, and suicidal ideation. Trauma related to COVID-19 and the bushfires was also assessed. The survey was completed in two large school-based cohorts between October 2020 and November 2021.

RESULTS

Exposure to COVID-19 diagnosis/quarantine was associated with increased probability of elevated trauma. Exposure to personal harm by the bushfires was associated with increased probability of elevated insomnia, suicidal ideation, and trauma. There were no interactive effects between disasters on adolescent mental health. Effects between personal risk factors and disasters were generally additive or sub-additive.

CONCLUSIONS

Adolescent mental health responses to community-level disasters are multi-faceted. Complex psychosocial factors associated with mental ill health may be relevant irrespective of disaster. Future research is needed to investigate synergistic effects of disasters on young mental health.

Work-related experiences of consultant psychiatrists during the COVID-19 response: qualitative analysis

BACKGROUND

Research has begun to draw attention to the challenges mental health professionals faced in delivering services during the COVID-19 pandemic response. However, few studies have examined the specific experiences of consultant psychiatrists.

AIMS

To examine the work-related experiences and psychosocial needs of consultant psychiatrists situated in the Republic of Ireland arising from the COVID-19 response.

METHOD

We interviewed 18 consultant psychiatrists and analysed data using inductive thematic analysis.

RESULTS

Work-related experience of participants was characterised by increased workload associated with assumption of guardianship of physical and mental health of vulnerable patients. Unintended consequences of public health restrictions increased case complexity, limited availability of alternative supports and hindered the practice of psychiatry, including inhibiting peer support systems for psychiatrists. Participants perceived available psychological supports as generally unsuitable for their needs given their specialty. Long-standing under-resourcing, mistrust in management and high levels of burnout exacerbated the psychological burden of the COVID-19 response.

CONCLUSIONS

The challenges of leading mental health services were evident in the increased complexity involved in caring for vulnerable patients during the pandemic, contributing to uncertainty, loss of control and moral distress among participants. These dynamics worked synergistically with pre-existing system-level failures, eroding capacity to mount an effective response. The longer-term psychological well-being of consultant psychiatrists - as well as the pandemic preparedness of healthcare systems - is contingent on implementation of policies addressing long-standing under-investment in the services vulnerable populations rely on, not least community mental health services.

The Role of Anti-Racist Community-Partnered Praxis in Implementing Restorative Circles Within Marginalized Communities in Southern California During the COVID-19 Pandemic

The COVID-19 pandemic has exacerbated the adverse influence of structural racism and discrimination experienced by historically marginalized communities (e.g., Black, Latino/a/x, Indigenous, and transgender people). Structural racism contributes to trauma-induced health behaviors, increasing exposure to COVID-19 and restricting access to testing and vaccination. This intersection of multiple disadvantages has a negative impact on the mental health of these communities, and interventions addressing collective healing are needed in general and in the context of the COVID-19 pandemic. The Share, Trust, Organize, and Partner COVID-19 California Alliance (STOP COVID-19 CA), a statewide collaborative of 11 universities and 75 community partners, includes several workgroups to address gaps in COVID-19 information, vaccine trial participation, and access. One of these workgroups, the Vaccine Hesitancy Workgroup, adopted an anti-racist community-partnered praxis to implement restorative circles in historically marginalized communities to facilitate collective healing due to structural racism and the COVID-19 pandemic. The project resulted in the development of a multilevel pre-intervention restorative process to build or strengthen community-institutional partnerships when procurement of funds has been sought prior to community partnership. This article discusses this workgroup's role in advancing health justice by providing a community-based mental health intervention to marginalized communities in Southern California while using an antiracist praxis tool to develop a successful community-institutional partnership and to live up to the vision of community-based participatory research.

Promoting the health of vulnerable populations: Three steps towards a systems-based re-orientation of public health intervention research

This paper proposes a novel framework for the development of interventions in vulnerable populations. The framework combines a complex systems lens with syndemic theory. Whereas funding bodies, research organizations and reporting guidelines tend to encourage intervention research that (i) focuses on singular and predefined health outcomes, (ii) searches for generalizable cause-effect relationships, and (iii) aims to identify universally effective interventions, the paper suggests that a different direction is needed for addressing health inequities: We need to (i) start with exploratory analysis of population-level data, and (ii) invest in contextualized in-depth knowledge of the complex dynamics that produce health inequities in specific populations and settings, while we (iii) work with stakeholders at multiple levels to create change within systems.

Proposing a New Conceptual Syndemic Framework for COVID-19 Vaccine Hesitancy: A Narrative Review

BACKGROUND

Discussions regarding syndemics have dominated research in recent years. Vaccine hesitancy has also been propelled to the forefront. In this narrative review, we aim to frame a novel syndemic framework to understand the interaction between vaccine hesitancy, COVID-19, and negative health outcomes.

METHODS

A non-systematic electronic search was conducted in PubMed and Google Scholar. Search criteria were limited to articles published between November 2019 and June 2022. Articles related to the COVID-19 syndemic and vaccine hesitancy were included.

RESULTS

Our review revealed that the adherence to COVID-19 regulations-although they were effective in preventing COVID-19 transmission, cases, and deaths-created a dynamically unstable 'vicious cycle' between undesirable health, economic, and social outcomes. The "accumulation" of complex stressors decreased individuals' cognitive flexibility and hindered them from making decisions and getting vaccinated. Furthermore, it increased individuals' risk of acquiring COVID-19, losing their employment, increasing poverty, and decreasing healthcare utilization. We illustrated how the amalgamation of sociodemographic and contextual factors associated with COVID-19 might impact people's vaccine decisions, making them more hesitant toward COVID-19 vaccination. Failing to receive vaccinations increases the chances of COVID-19 transmission, hospitalization, and other negative health outcomes.

CONCLUSIONS

Understanding the interaction between these factors is essential to provide policymakers with inspiration to set appropriate interventions for promoting COVID-19 vaccination acceptance to decrease the overall burden of pandemics.

Comorbid posttraumatic stress disorder and alcohol use disorder in low- and middle-income countries: A narrative review

Much of the research on posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) has been conducted in high-income countries (HICs). However, PTSD and AUD commonly co-occur (PTSD + AUD) are both associated with high global burden of disease, and disproportionately impact those in low- and middle-income countries (LMICs). This narrative review attempts to synthesize the research on prevalence, impact, etiological models, and treatment of PTSD + AUD drawing from research conducted in HICs and discussing the research that has been conducted to date in LMICs. The review also discusses overall limitations in the field, including a lack of research on PTSD + AUD outside of HICs, issues with measurement of key constructs, and limitations in sampling strategies across comorbidity studies. Future directions are discussed, including a need for rigorous research studies conducted in LMICs that focus on both etiological mechanisms and on treatment approaches.

Compounding vulnerabilities: Syndemics and the social determinants of disease in the past

OBJECTIVE

This article explores the theory and utility of a syndemic approach for the study of disease in the past. Syndemic principles are examined alongside other theoretical developments within bioarchaeology. Two case studies are provided to illustrate the efficacy of this approach: Tuberculosis and vitamin D deficiency in 18th and 19th century England, and malaria and helminth infections in Early Medieval England.

MATERIALS

Public health studies of present syndemics, in addition to published bioarchaeological, clinical and social information relating to the chosen case studies.

METHODS

The data from these two historical examples are revisited within a syndemic framework to draw deeper conclusions about disease clustering and heterogeneity in the past.

RESULTS

A syndemic framework can be applied to past contexts using clinical studies of diseases in a modern context and relevant paleopathological, archaeological, and historical data.

CONCLUSIONS

This approach provides a means for providing a deeper, contextualised understanding ancient diseases, and integrates well with extant theoretical tools in bioarchaeology SIGNIFICANCE: Syndemics provides scholars a deep-time perspective on diseases that still impact modern populations.

LIMITATIONS

Many of the variables essential for a truly syndemic approach cannot be obtained from current archaeological, bioarchaeological, or historical methods.

SUGGESTIONS FOR FURTHER RESEARCH

More detailed and in-depth analysis of specific disease clusters within the past and the present, which draws on a comprehensive analysis of the social determinants of health.

Type 2 diabetes and depressive symptoms in the adult population in Mexico: a syndemic approach based on National Health and Nutrition Survey

Background

The syndemic approach allows the analysis of clusters of diseases that affect a population in contexts of geographic, social and economic inequalities at the same moment and time. This study aims to analyze, from a syndemic perspective, the relationship between type 2 diabetes (T2D) and depressive symptoms in Mexican adults and its association with individual, contextual and structural factors.

Methods

Observational, cross-sectional study based on secondary data from Mexico’s National Health and Nutrition Survey 2018–19. The sample of this study consisted of 16 835 adults, which represented a total of 78 463 734 persons aged ≥ 20 years. Bivariate descriptive analyses were performed and logistic regression models were estimated to analyze the association between T2D and depressive symptoms with various co-variables. In addition, interactions between T2D and depressive symptoms with obesity, educational level, and socioeconomic status were tested.

Results

In the study population, 12.2% of adults aged 20 years and older self-reported having T2D, 14.7% had depressive symptoms and 2.8% had both diseases. There was a statistically significant relationship between T2D and depressive symptoms. The prevalence of T2D and depressive symptoms was higher compared to people who did not have these two conditions. Obesity increased the probability of having T2D, while violence was statistically associated with people having depressive symptoms. A low level of education increased the odds ratio of having T2D and depressive symptoms.

Conclusion

The availability of analytical frameworks such as the syndemic perspective could help to identify areas of opportunity for decision making and actions for population groups that–because of their individual, contextual and structural disadvantages–are at greater risk of experiencing poorer health outcomes due to the presence of T2D and depressive symptoms.

Nonmedical Social Determinants, Syndemic Conditions, and Suicidal Thoughts and Behaviors in a Treatment-seeking Community Sample: A Latent Class Analysis

OBJECTIVE

Knowledge gaps remain regarding whether syndemic conditions identify treatment-seeking individuals most at risk for suicidal thoughts and behaviors (STB). We employed latent class analysis to: (1) model treatment-seeking individuals' syndemic conditions, (2) examine latent classes across nonmedical social determinants, and (3) assess associations between class membership and STB.

METHOD

Participants were 982 individuals presenting at a community mental health clinic between October 2014 and February 2020. The three-step latent class analytic approach was used. Regression analyses were employed to examine nonmedical social determinants and STB outcomes associated with class membership.

RESULTS

Participants were aged 18 to >72 (75.8% White; 76.7% heterosexual; 53.7% cisgender woman; 73.8% earned ≥$20,000 annually). Latent class analysis resulted in a three-class solution. Participants in Class 1 were characterized by low probabilities across syndemic conditions. Class 2 was characterized by high probabilities of anxiety and depression. Class 3 was characterized by high probabilities of eating disorders, anxiety, and depression. Participants of color, sexual minority participants, cisgender women, and those experiencing financial distress were more likely to be in classes characterized by syndemic conditions. Classes characterized by syndemic conditions, relative to no syndemic conditions, were associated with greater risk of STB.

CONCLUSION

Findings confirm the concentrated clustering of co-occurring syndemic conditions among marginalized groups and highlight differing risks for those considering suicide or who have attempted suicide vs. those engaging in self-harm. Results underscore the need for resource allocation and multilevel interventions targeting syndemic conditions and suicidality for minority populations and those experiencing financial distress.