Immigrant maternal depression and social networks. A multilevel Bayesian spatial logistic regression in South Western Sydney, Australia

Critical Realism in Symptom Science - A Scoping Review

There has been an increasing interest in research positioned within critical realism (CR). This analysis aimed to determine how CR has been applied in symptom science through a scoping review of the literature. Fifty-two articles were identified through searches in seven databases and search engines, and grey literature. Quantitative and qualitative analyses were performed using Excel and ATLAS.ti 8.0. Review findings indicate that CR has been used to examine two key aspects of symptoms - symptom experiences and symptom interventions. The details of how CR was operationalized are presented. This first scoping review highlights how a critical realist lens would help examine individual and contextual factors that influence symptom experiences, response to interventions, and outcomes.

The relationship between social capital and postpartum depression symptoms of lactating women in minority areas—A cross-sectional study from Guangxi, China

Background

Postpartum depression (PPD) is the most common mental illness affecting women during lactation, and good social capital is considered a protective factor. This study aimed to investigate PPD symptoms, and explore the relationships between social capital and PPD symptoms of lactating women in southwest minority areas in China.

Materials and methods

This cross-sectional study was conducted among 413 lactating women in Guangxi, China. Data were collected using the Edinburgh Postnatal Depression Scale and the Chinese version of the Social Capital Assessment Questionnaire. Hierarchical regression analysis was conducted to explore the factors influencing PPD symptoms, and a structural equation model was used to examine how social participation and cognitive social capital mediated PPD symptoms.

Results

The total prevalence of PPD symptoms (score > 12) was 16.46%, and that of mild depression symptoms (9–12 score) was 22.03%. Nine variables predicted PPD symptoms and explained 71.6% of the variance in the regression model: higher age, lack of medical security, fixed occupation, breastfeeding time, self-caregiver, maternity leave, social participation, social trust, and social reciprocity. Furthermore, cognitive social capital mediated the relationship between social participation and PPD symptoms, with a mediation effect rate was 44.00%.

Conclusion

The findings of this study highlight that social capital, support from family members, maternity leave, and medical insurance play protective roles in the PPD symptoms of lactating women. It is necessary to improve social capital as a key strategy for interventions for PPD symptoms, and active social participation activities are critical to reducing PPD symptoms among lactating women in minority areas.

Perceived social support on postpartum mental health: An instrumental variable analysis

The postpartum period is a challenging transition period with almost one in ten mothers experiencing depression after childbirth. Perceived social support is associated with mental health. Yet empirical evidence regarding the causal effects of social support on postpartum mental health remains scarce. In this paper, we used a nationally representative panel data of women to examine causality between perceived social support and postpartum mental health. We used fixed-effect method and included dependent variable lags to account for past mental health condition before birth (i.e., the pre-pregnancy and prenatal periods). The study also used an instrumental variable approach to address endogeneity. We find a declining trend in postpartum mental health between 2002 to 2018. Our study also showed that past mental health (i.e., before childbirth) is positively correlated with postpartum mental health. A universal routine mental health screening for expectant and new mothers should remain a key priority to ensure mental wellbeing for the mothers and their infants.

Estimating mortality from coal workers' pneumoconiosis among Medicare beneficiaries with pneumoconiosis using binary regressions for spatially sparse data

Background

Coal workers' pneumoconiosis (CWP) is an occupational lung disease due to inhalation of coal dust. We estimated mortality from CWP and other pneumoconioses among Medicare beneficiaries.

Methods

We used the 5% Medicare Limited Claims Data Set, 2011–2014, to identify patients diagnosed with ICD‐9‐CM 500 (CWP) through 505 (Asbestosis, Pneumoconiosis due to other silica or silicates, Pneumoconiosis due to other inorganic dust, Pneumonopathy due to inhalation of other dust, and Pneumoconiosis, unspecified) codes. We applied binary regression models with spatial random effects to determine the association between CWP and mortality. Our inferences are based on Bayesian spatial hierarchical models, and model fitting was performed using Integrated Nested Laplace Approximation (INLA) algorithm in R/RStudio software.

Results

The median age of the sample was 76 years. In a sample of 8531 Medicare beneficiaries, 2568 died. Medicare beneficiaries with CWP had 25% higher odds of death (adjusted OR: 1.25, 95% CI: 1.07, 1.46) than those with other types of pneumoconiosis. The number of comorbid conditions elevated the odds of death by 10% (adjusted OR: 1.10, 95% CI: 1.09, 1.10).

Conclusion

CWP increases the likelihood of death among Medicare beneficiaries. Healthcare professionals should make concerted efforts to monitor patients with CWP to prevent premature mortality.

Psychosocial stratification of antenatal indicators to guide population-based programs in perinatal depression

BACKGROUND

There is increasing awareness that perinatal psychosocial adversity experienced by mothers, children, and their families, may influence health and well-being across the life course. To maximise the impact of population-based interventions for optimising perinatal wellbeing, health services can utilise empirical methods to identify subgroups at highest risk of poor outcomes relative to the overall population.

METHODS

This study sought to identify sub-groups using latent class analysis within a population of mothers in Sydney, Australia, based on their differing experience of self-reported indicators of psychosocial adversity. This study sought to identify sub-groups using latent class analysis within a population of mothers in Sydney, Australia, based on their differing experience of self-reported indicators of psychosocial adversity. Subgroup differences in antenatal and postnatal depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale.

RESULTS

Latent class analysis identified four distinct subgroups within the cohort, who were distinguished empirically on the basis of their native language, current smoking status, previous involvement with Family-and-Community Services (FaCS), history of child abuse, presence of a supportive partner, and a history of intimate partner psychological violence. One group consisted of socially supported 'local' women who speak English as their primary language (Group L), another of socially supported 'migrant' women who speak a language other than English as their primary language (Group M), another of socially stressed 'local' women who speak English as their primary language (Group Ls), and socially stressed 'migrant' women who speak a language other than English as their primary language (Group Ms.). Compared to local and not socially stressed residents (L group), the odds of antenatal depression were nearly three times higher for the socially stressed groups (Ls OR: 2.87 95%CI 2.10-3.94) and nearly nine times more in the Ms. group (Ms OR: 8.78, 95%CI 5.13-15.03). Antenatal symptoms of depression were also higher in the not socially stressed migrant group (M OR: 1.70 95%CI 1.47-1.97) compared to non-migrants. In the postnatal period, Group M was 1.5 times more likely, while the Ms. group was over five times more likely to experience suboptimal mental health compared to Group L (OR 1.50, 95%CI 1.22-1.84; and OR 5.28, 95%CI 2.63-10.63, for M and Ms. respectively).

CONCLUSIONS

The application of empirical subgrouping analysis permits an informed approach to targeted interventions and resource allocation for optimising perinatal maternal wellbeing.

Objectively Measured Built Environments and Cardiovascular Diseases in Middle-Aged and Older Korean Adults

This study assesses the association between the objectively measured built environment and cardiovascular diseases (CVDs) in 50,741 adults from the Korean Community Health Survey. The CVD outcomes of hypertension, diabetes, dyslipidemia, stroke, and myocardial infarction (MI) or angina were derived from self-reported histories of physician diagnoses. Using ArcGIS software and Korean government databases, this study measured the built environment variables for the 546 administrative areas of Gyeonggi province. A Bayesian spatial multilevel model was performed independently in two age groups (i.e., 40–59 years or ≥60 years). After adjusting for statistical significant individual- and community-level factors with the spatial associations, living far from public transit was associated with an increase in the odds of MI or angina in middle-aged adults, while living in neighborhoods in which fast-food restaurants were concentrated was associated with a decrease in the odds of hypertension and stroke. For adults 60 or older, living farther from public physical-activity (PA) facilities was associated with a 15% increased odds for dyslipidemia, compared with living in neighborhoods nearer to PA facilities. These findings suggest that creating a built environment that provides more opportunities to engage in PA in everyday life should be considered a strategy to reduce the prevalence of CVD.

A critical realist evaluation of an integrated care project for vulnerable families in Sydney, Australia

BACKGROUND

Healthy Homes and Neighbourhoods (HHAN) Integrated Care Initiative was established to improve the care of families with complex health and social needs who reside in Sydney Local Health District. HHAN seeks to provide long-term multi-disciplinary care coordination as well as enhance capacity building and promote integrated care. The critical realist study reported here is part of the longitudinal development and evaluation of complex integrated health and social care interventions in Sydney, Australia.

METHODS

We describe the qualitative component of a critical realist pilot case study aimed at exploring, explaining and refining emerging HHAN programme theories in relation to care coordination. Qualitative interviews were undertaken with HHAN clients (n = 12), staff and other stakeholders (n = 21). Interviews and coding used a context (C), mechanism (M) and outcome (O) framework. Inductive, deductive, retroductive and abductive modes of reasoning were used with the CMO heuristic tool to inform the developing programme theory.

RESULTS

The mechanisms underpinning effective engagement of clients by care coordinators included: building trust, leveraging other family, social and organisational relationships, meeting clients on their own terms, demonstrating staff effectiveness as quickly as possible, and client empowerment. Mechanisms for enhancing care integration included knowledge transfer activities and shared learning among collaborators, structural and cultural changes, enhancing mutual respect, co-location of multidisciplinary and/or interagency staff and cultivating faith in positive change among staff.

CONCLUSIONS

Use of a critical realism case study approach served to elucidate the varied influences of contexts and mechanisms on programme outcomes, to highlight what works for whom and in what context. Findings supported the initial programme theory that engagement and trust building with clients, alongside enhanced collaboration and integration of services, improved outcomes for vulnerable families with complex needs. Further research is needed to explore the cost-effectiveness of integrated care initiatives, in view of the long term nature of service provision and the risk of staff burnout.

Refining Program Theory for a Place-Based Integrated Care Initiative in Sydney, Australia

Introduction

The Healthy Homes and Neighbourhoods (HHAN) Integrated Care Program seeks to enhance vulnerable family engagement with health and social services through a care coordination model. Besides servicing families in Sydney, HHAN has also established place-based initiatives (PBIs) in areas of disadvantage such as Redfern. The Redfern PBI co-locates HHAN with housing, drug and alcohol services, and financial and legal services. This integration aims to facilitate service access and multi-agency support for vulnerable families in Redfern. Hence, this study aims to evaluate for whom, when and why HHAN's PBI at Redfern works, or not, and what are its outcomes.

Methods

The project utilises critical realist methodology to undertake a qualitative evaluation of the impact of the PBI on clients, services and the community. Purposive sampling was used to identify 21 participants including HHAN clients, HHAN staff and stakeholders (HHAN partners). In-depth, semi-structured interviews were audio-recorded, transcribed, coded and analysed using a context (C), intervention (I), mechanism (M) outcome (O) (CIMO) approach to abductive analysis.

Results

Five key CIMO configurations of the Redfern PBI emerged - whole-of-family involvement, flexibility, trust, building connections and co-location. Whilst each theory had specific outcomes, overall client outcomes included improved access to services, better outlook, empowerment and engagement with services. Service outcomes included increased collaboration and foundation for integration between HHAN and other services. Negative outcomes included lack of full integration, the risk associated with integration and difficulty evaluating impact.

Conclusion

This study successfully refined the program theory for subsequent use in later implementation of critical realist evaluation studies.

Reducing loneliness among migrant and ethnic minority people: a participatory evidence synthesis

Background

To date, there has been little research into the causes of, and solutions to, loneliness among migrant and ethnic minority people.

Objectives

The objectives were to synthesise available evidence and produce new insights relating to initiatives that aim to address loneliness among these populations, plus the logic, functioning and effects of such initiatives.

Data sources

Electronic database searches (MEDLINE, Applied Social Sciences Index and Abstracts and Social Science Citation Index via Web of Science – no date restrictions were applied), grey literature searches, and citation and reference searching were conducted. Data were generated via nine workshops with three consultation panels involving 34 public contributors, and one practitioner workshop involving 50 participants.

Review methods

Guided by ‘systems thinking’, a theory-driven synthesis was combined with an effectiveness review to integrate evidence on the nature and causes of loneliness, interventional types and programme theory, and intervention implementation and effectiveness.

Results

The theory review indicated that common conceptualisations of ‘loneliness’ can be usefully extended to recognise four proximate determinants when focusing on migrant and ethnic minority populations: positive social ties and interactions, negative social ties and interactions, self-worth, and appraisal of existing ties. A total of 170 interventions were included. A typology of eight interventions was developed. Detailed logic models were developed for three common types of intervention: befriending, shared-identity social support groups and intercultural encounters. The models for the first two types were generally well supported by empirical data; the third was more tentative. Evaluation of intervention processes and outcomes was limited by study content and quality. Evidence from 19 qualitative and six quantitative studies suggested that social support groups have a positive impact on dimensions of loneliness for participants. Evidence from nine qualitative and three quantitative studies suggested that befriending can have positive impacts on loneliness. However, inconsistent achievements of the befriending model meant that some initiatives were ineffective. Few studies on intercultural encounters reported relevant outcomes, although four provided some qualitative evidence and three provided quantitative evidence of improvement. Looking across intervention types, evidence suggests that initiatives targeting the proximate determinants – particularly boosting self-worth – are more effective than those that do not. No evidence was available on the long-term effects of any initiatives. UK intervention (n = 41) and non-intervention (n = 65) studies, together with consultation panel workshop data, contributed to a narrative synthesis of system processes. Interlocking factors operating at individual, family, community, organisational and wider societal levels increase risk of loneliness, and undermine access to, and the impact of, interventions. Racism operates in various ways throughout the system to increase risk of loneliness.

Limitations

There was a lack of high-quality quantitative studies, and there were no studies with longer-term follow-up. UK evidence was very limited. Studies addressing upstream determinants operating at the community and societal levels did not link through to individual outcome measures. Some elements of the search approach may mean that relevant literature was overlooked.

Conclusions

Theory regarding the causes of loneliness, and functioning of interventions, among migrant and ethnic minority populations was usefully developed. Evidence of positive impact on loneliness was strongest for shared-identity social support groups. Quantitative evidence was inadequate. The UK evidence base was extremely limited.

Future work

UK research in this area is desperately needed. Co-production of interventional approaches with migrant and ethnic minority people and evaluation of existing community-based initiatives are priorities.

Study registration

This study is registered as PROSPERO CRD42017077378.

Funding

This project was funded by the National Institute for Health Research Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 10. See the NIHR Journals Library website for further project information.

Promoting the health of mothers of young children in Australia: A review of face-to-face and online support

ISSUE ADDRESSED

Social support is essential during early motherhood. Societal changes have altered the support networks of mothers of young children, placing them at greater risk of social isolation. The aim of this review was to explore the research related to the experience of social support for mothers of young children to understand how to best promote social connections for the current generation of mothers.

METHODS

A systematic search of eight electronic databases through EBSCOhost was undertaken to identify Australian research published from 2013 onwards. No study design limits were applied. Research which focussed into understanding the social support of mothers with children 0-5 years and had outcomes related to mothers experiences were included.

RESULTS

Fifteen studies were included. Both face-to-face and online support provided benefits to mothers of young children in terms of shared experiences and reciprocity; trust and intimacy; community connectedness and; mental well-being. While online communities offered immediacy of access to social support, contemporary mothers continued to value social support accessed in face-to-face settings. Accessing face-to-face support was a challenge for young mothers and those in new housing areas.

CONCLUSIONS

Face-to-face programs continue to promote the health of contemporary mothers; however, online settings provide avenues for alternative or complimentary support. There is a need to further develop support programs for vulnerable and isolated mothers. SO WHAT?: Social support is essential for mothers of young children and opportunities to enhance social connections are important to boosting mental well-being. While face-to-face programs still need to be provided, services should consider including online options to promote the health of contemporary Australian mothers.

Trajectories of social support in pregnancy and early postpartum: findings from the All Our Families cohort

PURPOSE

Low social support during the perinatal period can increase the risk of postpartum depression and anxiety after giving birth but little is known about women's trajectories of social support during this time. This study will identify trajectories of social support among women from second trimester to 4-month postpartum, and the characteristics associated with different trajectories.

METHODS

Data from the All Our Families longitudinal birth cohort was used to assess women's perceived social support during their second trimester, third trimester, and at 4-month postpartum (n = 3387). Group-based trajectory modeling was used to determine the number of groups, shape of trajectories, and proportion of women with differing trajectories. Multinomial regression was used to compare probability of group membership.

RESULTS

Six distinct trajectory groups were identified, with the majority of participants belonging to groups with stable, high social support (60.6%). Only 2.7% of women had consistently low levels of social support, and 2.3% had rising levels. Membership in groups with lower levels of social support was associated with lower incomes and minority ethnicity. Women whose support improved over time may be more likely to be employed in pregnancy than those whose support remained low.

CONCLUSION

Trajectories of social support are relatively stable in pregnancy and early postpartum. Socio-demographic indicators of vulnerability predict initial levels of support, and participating in the workforce may help improve perception of support over time.

Indian migrant women's experiences of motherhood and postnatal support in Australia: A qualitative study

BACKGROUND

The postpartum period can be challenging for many women. For migrant women, the arrival of a new baby brings unique issues. This study aimed to explore the experiences of motherhood and postpartum support of Indian migrant mothers.

METHODS

A qualitative descriptive naturalist inquiry was adopted, with data collected through face-to-face, semi-structured, in-depth interviews with a purposive sample of 11 English speaking Indian migrant women over 18 years old, (6 weeks to 6 months postpartum) in 2016. The data were thematically analysed.

FINDINGS

Four themes were found in this study: the role of social support in postpartum care, support from health services, a psycho-emotional journey with socio-cultural expectations and struggling to bridge two cultures. Many of the women felt alone and were distressed with undertaking household duties and caring for older children, as this would not have happened in India. The women expressed needing practical support until they settled back into their normal lives. Women never sought professional advice for their ongoing mental health concerns. Conflicting advice from health professionals left some women confused about their expectations of traditional and modern postnatal care.

CONCLUSION

This study gives a unique insight into the experiences of Indian migrant women following birth. There is a need for culturally sensitive and appropriate postnatal services that encourage Indian men to support their partners and help women to find alternative sources of culturally appropriate support. It is vital that mental health support is a key component of any such program of care.

Implementation, Mechanisms of Effect and Context of an Integrated Care Intervention for Vulnerable Families in Central Sydney Australia: A Research and Evaluation Protocol

Introduction:

In March 2014, the New South Wales (NSW) Government (Australia) announced the NSW Integrated Care Strategy. In response, a family-centred, population-based, integrated care initiative for vulnerable families and their children in Sydney, Australia was developed. The initiative was called Healthy Homes and Neighbourhoods. A realist translational social epidemiology programme of research and collaborative design is at the foundation of its evaluation.

Theory and Method:

The UK Medical Research Council (MRC) Framework for evaluating complex health interventions was adapted. This has four components, namely 1) development, 2) feasibility/piloting, 3) evaluation and 4) implementation. We adapted the Framework to include: critical realist, theory driven, and continuous improvement approaches. The modified Framework underpins this research and evaluation protocol for Healthy Homes and Neighbourhoods.

Discussion:

The NSW Health Monitoring and Evaluation Framework did not make provisions for assessment of the programme layers of context, or the effect of programme mechanism at each level. We therefore developed a multilevel approach that uses mixed-method research to examine not only outcomes, but also what is working for whom and why.

A Critical Realist Translational Social Epidemiology Protocol for Concretising and Contextualising a "Theory of Neighbourhood Context, Stress, Depression, and the Developmental Origins of Health and Disease (DOHaD)", Sydney Australia

Background:

We will describe here a translational social epidemiology protocol for confirming a critical realist “Theory of Neighbourhood Context, Stress, Depression, and the Developmental Origins of Health and Disease (DOHaD). The approach will include the concretising and contextualising of the above causal theory into programme theories for child and adolescent interventions that aim to break intergenerational cycles of disadvantage and poor life outcomes. In undertaking this work we seek to advance realist translational methodology within the discipline of applied perinatal and paediatric social epidemiology.

Theory and Methods:

The research settings are in metropolitan Sydney. The design will be a longitudinal, multi-level, mixed method realist evaluation of applied programme interventions that seek to break the intergeneration cycle of social disadvantage and poor child health and developmental outcomes. The programme of research will consist of three components: 1) Operationalisation of the theory and designing of programme initiatives for implementation; 2) Evaluation of the translated programme and implementation theory using Theory of Change and critical realist evaluation; and 3) Theory Testing of realist hypotheses using both intensive and extensive critical realist research methods including realist structural modelling.

Discussion:

The proposed programme of research will assist in translating empirical explanatory theory building to theory driven interventions. The research will be situated in socially disadvantaged regions of Sydney where the local child and family inter-agencies will collaborate to design and implement new initiatives that address significant disparities in childhood development and adolescent outcomes attributed to neighbourhood circumstances, family stress and intergenerational cycles of disadvantage and poor mental health.

Local Residential Segregation Matters: Stronger Association of Census Tract Compared to Conventional City-Level Measures with Fatal and Non-Fatal Assaults (Total and Firearm Related), Using the Index of Concentration at the Extremes (ICE) for Racial, Economic, and Racialized Economic Segregation, Massachusetts (US), 1995-2010

Research on residential segregation and health, primarily conducted in the USA, has chiefly employed city or regional measures of racial segregation. To test our hypothesis that stronger associations would be observed using local measures, especially for racialized economic segregation, we analyzed risk of fatal and non-fatal assault in Massachusetts (1995-2010), since this outcome is strongly associated with residential segregation. The segregation metrics comprised the Index of Concentration at the Extremes (ICE), the Index of Dissimilarity, and poverty rate, with measures computed at both the census tract and city/town level. Key results were that larger associations between fatal and non-fatal assaults and residential segregation occurred for models using the census tract vs. city/town measures, with the greatest associations observed for racialized economic segregation. For fatal assaults, comparing the bottom vs. top quintiles, the incidence rate ratio (and 95% confidence interval (CI)) in models using the census tract measures equaled 3.96 (95% CI 3.10, 5.06) for the ICE for racialized economic segregation, 3.26 (95% CI 2.58, 4.14) for the ICE for income, 3.14 (95% CI 2.47, 3.99) for poverty, 2.90 (95% CI 2.21, 3.81) for the ICE for race/ethnicity, and only 0.93 (95% CI 0.79, 1.11) for the Index of Dissimilarity; in models that included both census tract and city/town ICE measures, this risk ratio for the ICE for racialized economic segregation was higher at the census tract (3.29; 95% CI 2.43, 4.46) vs. city/town level (1.61; 95% CI 1.12, 2.32). These results suggest that, at least in the case of fatal and non-fatal assaults, research on residential segregation should employ local measures, including of racialized economic segregation, to avoid underestimating the adverse impact of segregation on health.

Metrics for monitoring cancer inequities: residential segregation, the Index of Concentration at the Extremes (ICE), and breast cancer estrogen receptor status (USA, 1992-2012)

PURPOSE

To address the paucity of evidence on residential segregation and cancer, we explored their relationship using a new metric: the Index of Concentration at the Extremes (ICE). We focused on breast cancer estrogen receptor (ER) status, a biomarker associated with survival and, etiologically, with social and economic privilege.

METHODS

We obtained data from the 13 registry group of US Surveillance, Epidemiology, and End Results (SEER) program for 1992-2012 on all women aged 25-84 who were diagnosed with primary invasive breast cancer (n = 516,382). We appended to each case's record her annual county median household income quintile and the quintile for her annual county value for ICE measures for income (≤20th vs. ≥80th household income quintile), race/ethnicity (black vs. white), and income plus race/ethnicity (low-income black vs. high-income white). The odds of being ER+ versus ER- were estimated in relation to the county-level income and ICE measures, adjusting for relevant covariates.

RESULTS

Women in the most privileged versus deprived county quintile for household income and for all three ICE measures had a 1.1- to 1.3-fold increased odds (95 % confidence intervals excluding 1) of having an ER+ tumor. These results were robust to adjustment for age at diagnosis, cancer registry, tumor characteristics (tumor stage, size, histology, grade), and race/ethnicity.

CONCLUSION

A focus on segregation offers news possibilities for understanding how inequitable group relations contribute to cancer inequities. The utility of employing the ICE for monitoring cancer inequities should be investigated in relation to other cancer outcomes.

Realist theory construction for a mixed method multilevel study of neighbourhood context and postnatal depression

BACKGROUND

We have recently described a protocol for a study that aims to build a theory of neighbourhood context and postnatal depression. That protocol proposed a critical realist Explanatory Theory Building Method comprising of an: (1) emergent phase, (2) construction phase, and (3) confirmatory phase. A concurrent triangulated mixed method multilevel cross-sectional study design was described. The protocol also described in detail the Theory Construction Phase which will be presented here.

METHODS

The Theory Construction Phase will include: (1) defining stratified levels; (2) analytic resolution; (3) abductive reasoning; (4) comparative analysis (triangulation); (5) retroduction; (6) postulate and proposition development; (7) comparison and assessment of theories; and (8) conceptual frameworks and model development.

THEORY CONSTRUCTION

The stratified levels of analysis in this study were predominantly social and psychological. The abductive analysis used the theoretical frames of: Stress Process; Social Isolation; Social Exclusion; Social Services; Social Capital, Acculturation Theory and Global-economic level mechanisms. Realist propositions are presented for each analysis of triangulated data. Inference to best explanation is used to assess and compare theories. A conceptual framework of maternal depression, stress and context is presented that includes examples of mechanisms at psychological, social, cultural and global-economic levels. Stress was identified as a necessary mechanism that has the tendency to cause several outcomes including depression, anxiety, and health harming behaviours. The conceptual framework subsequently included conditional mechanisms identified through the retroduction including the stressors of isolation and expectations and buffers of social support and trust.

CONCLUSION

The meta-theory of critical realism is used here to generate and construct social epidemiological theory using stratified ontology and both abductive and retroductive analysis. The findings will be applied to the development of a middle range theory and subsequent programme theory for local perinatal child and family interventions.

Public Health Monitoring of Privilege and Deprivation With the Index of Concentration at the Extremes

OBJECTIVES

We evaluated use of the Index of Concentration at the Extremes (ICE) for public health monitoring.

METHODS

We used New York City data centered around 2010 to assess cross-sectional associations at the census tract and community district levels, for (1) diverse ICE measures plus the US poverty rate, with (2) infant mortality, premature mortality (before age 65 years), and diabetes mortality.

RESULTS

Point estimates for rate ratios were consistently greatest for the novel ICE that jointly measured extreme concentrations of income and race/ethnicity. For example, the census tract-level rate ratio for infant mortality comparing the bottom versus top quintile for an ICE contrasting low-income Black versus high-income White equaled 2.93 (95% confidence interval [CI] = 2.11, 4.09), but was 2.19 (95% CI = 1.59, 3.02) for low versus high income, 2.77 (95% CI = 2.02, 3.81) for Black versus White, and 1.56 (95% CI = 1.19, 2.04) for census tracts with greater than or equal to 30% versus less than 10% below poverty.

CONCLUSIONS

The ICE may be a useful metric for public health monitoring, as it simultaneously captures extremes of privilege and deprivation and can jointly measure economic and racial/ethnic segregation.

Being alone and expectations lost: a critical realist study of maternal depression in South Western Sydney

The study reported here is part of a critical realist multilevel study. It seeks to identify and explain complex perinatal contextual social and psychosocial mechanisms that may influence the developmental origins of health and disease, with a focus on the role of postnatal depression. The aims of the greater study are to: (1) describe the phenomenon of postnatal depression in South Western Sydney; and (2) identify mechanisms that would add to our understanding of the psycho-social causes of maternal depression. This paper will move beyond our previous quantitative descriptions of individual-level predictors of depressive symptoms by seeking the views of local mothers and practitioners, to explain the mechanisms that might be involved. The study was set in South Western Sydney, New South Wales, Australia. An Explanatory Theory Building Method was used. The previously reported quantitative study was a non-linear principal component analysis and logistic regression study of 15,389 months delivering in 2002 and 2003. This intensive qualitative study used open coding of interviews, of seven practitioners and three naturally occurring mothers groups, to enable maximum emergence. The theoretical concepts identified were: attachment and nurturing, infant temperament, unplanned pregnancy and sole parenthood, support for mothers, access to services, stress, financial hardship, isolation and marginalisation, mothers' "loss of control" and "power", and expectations and dreams. Being alone and expectations lost emerged as possible triggers of stress and depression for mothers. These findings might also apply to others who have their dreams shattered during life's transitions. In these situations social and cultural context can either nurture and support or marginalise and isolate. The challenge for policy and practice is to support mothers and their partners during the transition to parenthood within a challenging social and material context.

Spatial social polarisation: using the Index of Concentration at the Extremes jointly for income and race/ethnicity to analyse risk of hypertension

BACKGROUND

Growing spatial social and economic polarisation may be an important societal determinant of health, but only a few studies have used the recently developed Index of Concentration at the Extremes (ICE) to analyse the impact of joint concentrations of privilege and privation on health outcomes. We explore use of the ICE to investigate risk of hypertension in an urban, multiracial/ethnic, and predominantly working-class study population of US adults.

METHODS

We generated novel ICE measures at the census tract level that jointly assess extreme concentrations of both income and racial/ethnic composition. We then linked the ICE measures to data from two observational, cross-sectional studies conducted in the Boston metropolitan area (2003-2004; 2008-2010; N=2145).

RESULTS

The ICE measure for extreme concentrations of white compared with black residents was independently associated with lower odds of hypertension (OR=0.76; 95% CI 0.62 to 0.93), controlling for race/ethnicity, age, gender, smoking, body mass index, household income, education and self-reported exposure to racial discrimination. Even stronger associations were observed for the ICE measures that compared concentrations of high-income white residents versus low-income residents of colour (OR=0.61; 95% CI 0.40 to 0.96) and high-income white versus low-income black residents (OR=0.48; 95% CI 0.29 to 0.81).

CONCLUSIONS

Results suggest public health studies should explore the joint impact of racial/ethnic and economic spatial polarisation on population health.

Black carbon exposure, socioeconomic and racial/ethnic spatial polarization, and the Index of Concentration at the Extremes (ICE)

BACKGROUND

Scant data quantify associations between economic and racial/ethnic spatial polarization and individual's exposure to pollution.

METHODS

We linked data on the socioeconomic position (SEP) of 1757 urban working class white, black, and Latino adults (age 25-64; Boston, MA: 2003-2004; 2008-2010) to: (1) spatiotemporal model-based estimates of cumulative black carbon exposure at their exact residential address, and (2) their census tract values for the Index of Concentration at the Extremes (ICE) for SEP and race/ethnicity.

RESULTS

ICE measures, but not individual- and household-SEP, remained independently associated with black carbon exposure.

CONCLUSIONS

The ICE may be useful for environmental health research.

Bayesian hierarchical spatial regression of maternal depressive symptoms in South Western Sydney, Australia

Background

There is increasing interest in the role played by maternal depression in mediating the effects of adversity during pregnancy and poor infant outcomes. There is also increasing evidence from multilevel regression studies for an association of area-level economic deprivation and poor individual mental health. The purpose of the study reported here is to explore the spatial distribution of postnatal depressive symptoms in South Western Sydney, Australia, and to identify covariate associations that could inform subsequent multilevel studies.

Methods

Mothers (n = 15,389) delivering in 2002 and 2003 were assessed at 2–3 weeks after delivery for risk factors for depressive symptoms. The individual-level binary outcome variables were Edinburgh Depression Scale (EDS) >9 and >12. The association between social, demographic and ecological factors and aggregated outcome variables were investigated using exploratory factor analysis and multivariate hierarchical Bayesian spatial regression. Relative risks from the final EDS >12 regression model were mapped to visualise the contribution from explanatory covariates and residual components.

Results

The exploratory factor analysis identified six factors: neighbourhood adversity, social cohesion, health behaviours, housing quality, social services, and support networks. Variables associated with neighbourhood adversity, social cohesion, social networks, and ethnic diversity were consistently associated with aggregated depressive symptoms. Measures of social disadvantage, lack of social cohesion and lack of social capital were associated with increased depressive symptoms. The association with social disadvantage was not significant when controlling for ethnic diversity and social capital.

Conclusions

The findings support the theoretical proposition that neighbourhood adversity causes maternal psychological distress and depression within the context of social buffers including social networks, social cohesion, and social services. The finding have implications for the distribution of health services including early nurse home visiting which has recently been confirmed to be effective in preventing postnatal depression.

Electronic supplementary material

The online version of this article (doi:10.1186/2193-1801-3-55) contains supplementary material, which is available to authorized users.

Explaining ecological clusters of maternal depression in South Western Sydney

BACKGROUND

The aim of the qualitative study reported here was to: 1) explain the observed clustering of postnatal depressive symptoms in South Western Sydney; and 2) identify group-level mechanisms that would add to our understanding of the social determinants of maternal depression.

METHODS

Critical realism provided the methodological underpinning for the study. The setting was four local government areas in South Western Sydney, Australia. Child and Family practitioners and mothers in naturally occurring mothers groups were interviewed.

RESULTS

Using an open coding approach to maximise emergence of patterns and relationships we have identified seven theoretical concepts that might explain the observed spatial clustering of maternal depression. The theoretical concepts identified were: Community-level social networks; Social Capital and Social Cohesion; "Depressed community"; Access to services at the group level; Ethnic segregation and diversity; Supportive social policy; and Big business.

CONCLUSIONS

We postulate that these regional structural, economic, social and cultural mechanisms partially explain the pattern of maternal depression observed in families and communities within South Western Sydney. We further observe that powerful global economic and political forces are having an impact on the local situation. The challenge for policy and practice is to support mothers and their families within this adverse regional and global-economic context.