Comparing individual- and area-based socioeconomic measures for the surveillance of health disparities: A multilevel analysis of Massachusetts births, 1989-1991

The geography of recreational open space: influence of neighborhood racial composition and neighborhood poverty

The geography of recreational open space might be inequitable in terms of minority neighborhood racial/ethnic composition and neighborhood poverty, perhaps due in part to residential segregation. This study evaluated the association between minority neighborhood racial/ethnic composition, neighborhood poverty, and recreational open space in Boston, Massachusetts (US). Across Boston census tracts, we computed percent non-Hispanic Black, percent Hispanic, and percent families in poverty as well as recreational open space density. We evaluated spatial autocorrelation in study variables and in the ordinary least squares (OLS) regression residuals via the Global Moran's I. We then computed Spearman correlations between the census tract socio-demographic characteristics and recreational open space density, including correlations adjusted for spatial autocorrelation. After this, we computed OLS regressions or spatial regressions as appropriate. Significant positive spatial autocorrelation was found for neighborhood socio-demographic characteristics (all p value = 0.001). We found marginally significant positive spatial autocorrelation in recreational open space (Global Moran's I = 0.082; p value = 0.053). However, we found no spatial autocorrelation in the OLS regression residuals, which indicated that spatial models were not appropriate. There was a negative correlation between census tract percent non-Hispanic Black and recreational open space density (r S = -0.22; conventional p value = 0.005; spatially adjusted p value = 0.019) as well as a negative correlation between predominantly non-Hispanic Black census tracts (>60 % non-Hispanic Black in a census tract) and recreational open space density (r S = -0.23; conventional p value = 0.003; spatially adjusted p value = 0.007). In bivariate and multivariate OLS models, percent non-Hispanic Black in a census tract and predominantly Black census tracts were associated with decreased density of recreational open space (p value < 0.001). Consistent with several previous studies in other geographic locales, we found that Black neighborhoods in Boston were less likely to have recreational open spaces, indicating the need for policy interventions promoting equitable access. Such interventions may contribute to reductions and disparities in obesity.

Ethical and practical challenges to studying patients who opt out of large-scale biorepository research

Large-scale biorepositories that couple biologic specimens with electronic health records containing documentation of phenotypic expression can accelerate scientific research and discovery. However, differences between those subjects who participate in biorepository-based research and the population from which they are drawn may influence research validity. While an opt-out approach to biorepository-based research enhances inclusiveness, empirical research evaluating voluntariness, risk, and the feasibility of an opt-out approach is sparse, and factors influencing patients' decisions to opt out are understudied. Determining why patients choose to opt out may help to improve voluntariness, however there may be ethical and logistical challenges to studying those who opt out. In this perspective paper, the authors explore what is known about research based on the opt-out model, describe a large-scale biorepository that leverages the opt-out model, and review specific ethical and logistical challenges to bridging the research gaps that remain.

Disparities in receipt of screening tests for cancer, diabetes and high cholesterol in Ontario, Canada: a population-based study using area-based methods

OBJECTIVES

Few have compared socio-economic disparities in screening tests for cancer with recommended tests for other chronic diseases. We examined whether receipt of testing for colorectal, cervical and breast cancer, as well as diabetes and high cholesterol, differs by neighbourhood-level socio-economic and recent immigrant status.

METHODS

We conducted a population-based retrospective cohort study of patients identified as screen-eligible in 2009 living in Ontario, Canada. Postal codes were used to assign residents to a dissemination area (DA). Using Canadian census data, DAs were stratified by income quintile and proportion of recent immigrants. Prevalence of screening for cancer (colorectal, cervical, breast), diabetes, and high cholesterol, using administrative data, and prevalence ratios (least/most advantaged) were calculated.

RESULTS

The cohort comprised 7,652,592 people. Receipt of screening for colorectal cancer (women 61.6%; men 55.1%) and breast cancer (59.9%) were the lowest and diabetes (women 72.9%; men 61.4%) and high cholesterol (women 82.4%; men 70.3%) were the highest. We found disparities in the receipt of all tests, with the lowest uptake and largest disparities for cancer screening among those living in both low-income and high-immigration DAs: colorectal - women 48.6%; RR 0.77; 95% CI (0.74-0.79) and men 40.6%; RR 0.71 (0.68-0.74); cervical - 52.0%; RR 0.80 (0.78-0.81) and breast - 45.7%; RR 0.74 (0.72-0.77).

CONCLUSION

People living in low-income and high-immigration DAs had the lowest screening participation for all tests, although disparities were highest for cancer. An organized integrated chronic disease screening strategy leveraging the higher diabetes and high cholesterol screening participation may increase screening for cancer and other chronic diseases in never- and underscreened populations.

Factors associated with maternal healthcare services utilization in nine high focus states in India: a multilevel analysis based on 14 385 communities in 292 districts

BACKGROUND

Studies have often ignored examining the role of community- and district-level factors in the utilization of maternity healthcare services, particularly in Indian contexts. The Social Determinants of Health framework emphasizes the role of governance and government policies, the measures for which are rarely incorporated in single-level individual analysis. This study examines factors associated with maternal healthcare utilization in nine high focus states in India, which shares more than half of the total maternal deaths in the country; accounting for individual-, household-, community- and district-level characteristics.

METHODS

The required data are extracted from the third round of the nationally representative District Level Household and Facility Survey conducted during 2007-08. Multilevel analyses were applied to three maternity outcomes, namely, four or more antenatal care visits, skilled birth attendance and post-natal care after birth.

FINDINGS

Results show that along with individual-/household-level factors, community and district-level factors influence the pattern of utilization of maternal healthcare services significantly. At the community level, the odds of maternal healthcare utilization were lower in rural areas and in communities with a high concentration of poor and illiterate women. Moreover, the average population coverage of primary health centres (PHCs), availability of labour room in PHC and percentage of registered pregnancies were significant factors at the district level that influenced the use of maternity care services. The study also found a strong association between the extent of previous use of maternal healthcare and its effect on subsequent usage patterns.

CONCLUSION

This study highlights the role of strengthening public health infrastructure at district level in the study area, and promoting awareness about available healthcare services and subsidized schemes in the community. To reach out to rural and underprivileged communities and to apply a participatory approach from the programme officials are issues to delve into.

The social determinants of infant mortality and birth outcomes in Western developed nations: a cross-country systematic review

Infant mortality (IM) and birth outcomes, key population health indicators, have lifelong implications for individuals, and are unequally distributed globally. Even among western industrialized nations, striking cross-country and within-country patterns are evident. We sought to better understand these variations across and within the United States of America (USA) and Western Europe (WE), by conceptualizing a social determinants of IM/birth outcomes framework, and systematically reviewing the empirical literature on hypothesized social determinants (e.g., social policies, neighbourhood deprivation, individual socioeconomic status (SES)) and intermediary determinants (e.g., health behaviours). To date, the evidence suggests that income inequality and social policies (e.g., maternal leave policies) may help to explain cross-country variations in IM/birth outcomes. Within countries, the evidence also supports neighbourhood SES (USA, WE) and income inequality (USA) as social determinants. By contrast, within-country social cohesion/social capital has been underexplored. At the individual level, mixed associations have been found between individual SES, race/ethnicity, and selected intermediary factors (e.g., psychosocial factors) with IM/birth outcomes. Meanwhile, this review identifies several methodological gaps, including the underuse of prospective designs and the presence of residual confounding in a number of studies. Ultimately, addressing such gaps including through novel approaches to strengthen causal inference and implementing both health and non-health policies may reduce inequities in IM/birth outcomes across the western developed world.

Income inequality, parental socioeconomic status, and birth outcomes in Japan

The purpose of this study was to investigate the impact of income inequality and parental socioeconomic status on several birth outcomes in Japan. Data were collected on birth outcomes and parental socioeconomic status by questionnaire from Japanese parents nationwide (n = 41,499) and then linked to Gini coefficients at the prefectural level in 2001. In multilevel analysis, z scores of birth weight for gestational age decreased by 0.018 (95% confidence interval (CI): -0.029, -0.006) per 1-standard-deviation (0.018-unit) increase in the Gini coefficient, while gestational age at delivery was not associated with the Gini coefficient. For dichotomous outcomes, mothers living in prefectures with middle and high Gini coefficients were 1.24 (95% CI: 1.05, 1.47) and 1.23 (95% CI: 1.02, 1.48) times more likely, respectively, to deliver a small-for-gestational-age infant than mothers living in more egalitarian prefectures (low Gini coefficients), although preterm births were not significantly associated with income distribution. Parental educational level, but not household income, was significantly associated with the z score of birth weight for gestational age and small-for-gestational-age status. Higher income inequality at the prefectural level and parental educational level, rather than household income, were associated with intrauterine growth but not with shorter gestational age at delivery.

Factors associated with hospitalisations for ambulatory care-sensitive conditions among persons with an intellectual disability: a publicly insured population perspective

BACKGROUND

Hospitalisations for ambulatory care-sensitive (ACS) conditions are used as an indicator of access to, and the quality of, primary care. The objective was to identify factors associated with hospitalisations for ACS conditions among adults with an intellectual disability (ID) in the context of a publicly insured healthcare system.

METHODS

This study examined adults with an ID living in a Canadian province between 1999 and 2003 identified from administrative databases. Using 5 years of data for the study population, characteristics of persons hospitalised or not hospitalised for ACS conditions were compared. Using a conceptual model, independent variables were selected and an analysis performed to identify which were associated with hospitalisations for ACS conditions. The correlated nature of the observations was accounted for statistically.

RESULTS

Living in a rural area [odds ratio (OR) 1.3; 95% confidence intervals (CI) = 1.0, 1.8], living in an area with a high proportion of First Nations people (OR 2.3; 95% CI = 1.3, 4.1), and experiencing higher levels of comorbidity (OR 25.2; 95% CI = 11.9, 53.0) were all associated with a higher likelihood of being hospitalised for an ACS condition. Residing in higher income areas had a protective effect (OR 0.56; 95% CI = 0.37, 0.85). None of the health service resource variables showed statistically significant associations.

CONCLUSIONS

Persons with an ID experience inequity in hospitalisations for ACS conditions according to rurality, income and proportion who are First Nations in a geographic area. This suggests that addressing the socio-economic problems of poorer areas and specifically areas densely populated by First Nations people may have an impact on the number of hospitalisations for ACS conditions. Study strengths and limitations and areas for potential future research are discussed.

Administrative data linkage as a tool for child maltreatment research

Linking administrative data records for the same individuals across services and over time offers a powerful, population-wide resource for child maltreatment research that can be used to identify risk and protective factors and to examine outcomes. Multistage de-identification processes have been developed to protect privacy and maintain confidentiality of the datasets. Lack of information on those not coming to the attention of child protection agencies, and limited information on certain variables, such as individual-level SES and parenting practices, is outweighed by strengths that include large and unbiased samples, objective measures, comprehensive long-term follow-up, continuous data collection, and relatively low expense. Ever emerging methodologies and expanded holdings ensure that research using linked population-wide databases will make important contributions to the study of child maltreatment.

Comparison of individual-level versus area-level socioeconomic measures in assessing health outcomes of children in Olmsted County, Minnesota

BACKGROUND

Socioeconomic status (SES) is an important determinant of health, but SES measures are frequently unavailable in commonly used datasets. Area-level SES measures are used as proxy measures of individual SES when the individual measures are lacking. Little is known about the agreement between individual-level versus area-level SES measures in mixed urban-rural settings.

METHODS

We identified SES agreement by comparing information from telephone self-reported SES levels and SES calculated from area-level SES measures. We assessed the impact of this agreement on reported associations between SES and rates of childhood obesity, low birth weight <2500 g and smoking within the household in a mixed urban-rural setting.

RESULTS

750 households were surveyed with a response rate of 62%: 51% male, 89% Caucasian; mean child age 9.5 years. Individual-level self-reported income was more strongly associated with all three childhood health outcomes compared to area-level SES. We found significant disagreement rates of 22-31%. The weighted Cohen's κ indices ranged from 0.15 to 0.22, suggesting poor agreement between individual-level and area-level measures.

CONCLUSION

In a mixed urban-rural setting comprised of both rural and urbanised areas, area-level SES proxy measures significantly disagree with individual SES measures, and have different patterns of association with health outcomes from individual-level SES measures. Area-level SES may be an unsuitable proxy for SES when individual rather than community characteristics are of primary concern.

Geomedicine: area-based socioeconomic measures for assessing risk of hospital reutilization among children admitted for asthma

OBJECTIVES

We assessed whether geographic information available at the time of asthma admission predicts time to reutilization (readmission or emergency department revisit).

METHODS

For a prospective cohort of children hospitalized with asthma in 2008 and 2009 in Cincinnati, Ohio, we constructed a geographic social risk index from geocoded home addresses linked to census tract extreme poverty and high school graduation rates and median home values. We examined geographic risk associations with reutilization and caregiver report of hardship.

RESULTS

Thirty-nine percent of patients reutilized within 12 months. Compared with those in the lowest geographic risk stratum, those at medium and high risk had 1.3 (95% confidence interval [CI] = 0.9, 1.9) and 1.8 (95% CI = 1.4, 2.4) the risk of reutilization, respectively. Caregivers of children at highest geographic risk were 5 times as likely to report more than 2 financial hardships (P < .001) and 3 times as likely to report psychological distress (P = .001).

CONCLUSIONS

A geographic social risk index may help identify asthmatic children likely to return to the hospital. Targeting social risk assessments and interventions through geographic information may help to improve outcomes and reduce disparities.

Housing data-based socioeconomic index and risk of invasive pneumococcal disease: an exploratory study

We previously developed and validated an index of socioeconomic status (SES) termed HOUSES (housing-based index of socioeconomic status) based on real property data. In this study, we assessed whether HOUSES overcomes the absence of SES measures in medical records and is associated with risk of invasive pneumococcal disease (IPD) in children. We conducted a population-based case-control study of children in Olmsted County, MN, diagnosed with IPD (1995-2005). Each case was age- and gender-matched to two controls. HOUSES was derived using a previously reported algorithm from publicly available housing attributes (the higher HOUSES, the higher the SES). HOUSES was available for 92·3% (n = 97) and maternal education level for 43% (n = 45). HOUSES was inversely associated with risk of IPD in unmatched analysis [odds ratio (OR) 0·22, 95% confidence interval (CI) 0·05-0·89, P = 0·034], whereas maternal education was not (OR 0·77, 95% CI 0·50-1·19, P = 0·24). HOUSES may be useful for overcoming a paucity of conventional SES measures in commonly used datasets in epidemiological research.

Maternal exposure to moderate ambient carbon monoxide is associated with decreased risk of preeclampsia

OBJECTIVE

Carbon monoxide (CO) in cigarette smoke may be the mechanism by which tobacco use during pregnancy decreases the risk of the development of preeclampsia. We attempted to test this hypothesis by examining the effect of maternal exposure to ambient CO on preeclampsia.

STUDY DESIGN

Births that occurred between 2004 and 2009 in the Canadian province of Ontario were extracted from the data. Study subjects were divided into 4 groups according to quartiles of CO concentration that were based on maternal residence. Adjusted odds ratio and 95% confidence interval were used to estimate the independent effect of CO on preeclampsia.

RESULTS

Rates of preeclampsia were 2.32%, 1.97%, 1.59%, and 1.26%, respectively, in the first, second, third, and fourth quartile of CO concentration. The inverse association between CO concentration and preeclampsia risk remained the same after adjustment for several important confounding factors.

CONCLUSION

Maternal exposure to moderate ambient CO is associated independently with a decreased risk of preeclampsia.

Using geographical information systems to explore disparities in preterm birth rates among foreign-born and U.S.-born Black mothers

OBJECTIVE

To examine spatial patterns of neighborhood contextual factors of stress with preterm birth (PTB) and nativity (foreign-born and U.S.-born) among Black mothers.

DESIGN

Descriptive geographic-spatial research.

SETTING & PARTICIPANTS

Births to Philadelphia residents during 2003-2005 in the context of Philadelphia residential neighborhoods (N = 350) were studied.

METHODS

All data were aggregated to neighborhood levels (census tracts). Maps were created to assess geographic-spatial patterns. A geographic information system (GIS) database was created that imported geo-coded data on births, crime (assaults with guns and domestic abuse), poverty, race, and nativity (foreign-born vs. U.S.-born).

RESULTS

Clear visual patterns of "bad" neighborhoods emerged and were significantly associated with higher prevalence of PTB for foreign-born Black and U.S.-born Black mothers (p < .0001).

CONCLUSIONS

This study demonstrated how GIS visually clarified important spatial patterns of adverse living conditions and PTB prevalence. Nurses can use GIS to better understand living environments of mothers and their families and to target interventions in geographical areas with the greatest service needs. Further research on individual and contextual factors is warranted to address the observed health disparities among the heterogeneous groups of foreign-born Black mothers. Despite limitations of aggregate data, it is clear that where mothers live matters. This has important implications for nursing practice and policy.

Space, race, and poverty: Spatial inequalities in walkable neighborhood amenities?

BACKGROUND

Multiple and varied benefits have been suggested for increased neighborhood walkability. However, spatial inequalities in neighborhood walkability likely exist and may be attributable, in part, to residential segregation.

OBJECTIVE

Utilizing a spatial demographic perspective, we evaluated potential spatial inequalities in walkable neighborhood amenities across census tracts in Boston, MA (US).

METHODS

The independent variables included minority racial/ethnic population percentages and percent of families in poverty. Walkable neighborhood amenities were assessed with a composite measure. Spatial autocorrelation in key study variables were first calculated with the Global Moran’s I statistic. Then, Spearman correlations between neighborhood socio-demographic characteristics and walkable neighborhood amenities were calculated as well as Spearman correlations accounting for spatial autocorrelation. We fit ordinary least squares (OLS) regression and spatial autoregressive models, when appropriate, as a final step.

RESULTS

Significant positive spatial autocorrelation was found in neighborhood socio-demographic characteristics (e.g. census tract percent Black), but not walkable neighborhood amenities or in the OLS regression residuals. Spearman correlations between neighborhood socio-demographic characteristics and walkable neighborhood amenities were not statistically significant, nor were neighborhood socio-demographic characteristics significantly associated with walkable neighborhood amenities in OLS regression models.

CONCLUSIONS

Our results suggest that there is residential segregation in Boston and that spatial inequalities do not necessarily show up using a composite measure.

COMMENTS

Future research in other geographic areas (including international contexts) and using different definitions of neighborhoods (including small-area definitions) should evaluate if spatial inequalities are found using composite measures but also should use measures of specific neighborhood amenities.

Race, socioeconomic status, and the use of bariatric surgery in Michigan

Studies examining the characteristics of patients undergoing bariatric surgery in the USA have concluded that the procedure is not being used equitably. We used population-based data from Michigan to explore disparities in the use of bariatric surgery by gender, race, and socioeconomic status. We constructed a summary measure of socioeconomic status (SES) for Michigan postal ZIP codes using data from the 2000 census and divided the population into quintiles according to SES. We then used data from the state drivers' license list and 2004-2005 state inpatient and ambulatory surgery databases to examine population-based rates of morbid obesity and bariatric surgery in adults according to gender, race, and socioeconomic status. There is an inverse linear relationship between SES and morbid obesity. In the lowest SES quintile, 13% of females and 7% of males have a body mass index >40 compared to 4% of females and males in the highest SES quintile. Overall rates of bariatric surgery were highest for black females (29.4/10,000), followed by white (21.3/10,000), and other racial minority (8.6/10,000) females. Rates of bariatric surgery were low (<6/10,000) for males of all racial groups. An inverse linear relationship was observed between SES and rates of bariatric surgery among whites. However, for racial minorities, rates of surgery are lower in the lowest SES quintiles with the highest rates of bariatric surgery in the medium or highest SES quintiles. In contrast with prior studies, we do not find evidence of wide disparities in the use of bariatric surgery.

Do physician organizations located in lower socioeconomic status areas score lower on pay-for-performance measures?

BACKGROUND

Physician organizations (POs)--independent practice associations and medical groups--located in lower socioeconomic status (SES) areas may score poorly in pay-for-performance (P4P) programs.

OBJECTIVE

To examine the association between PO location and P4P performance.

DESIGN

Cross-sectional study; Integrated Healthcare Association's (IHA's) P4P Program, the largest non-governmental, multi-payer program for POs in the U.S.

PARTICIPANTS

160 POs participating in 2009.

MAIN MEASURES

We measured PO SES using established methods that involved geo-coding 11,718 practice sites within 160 POs to their respective census tracts and weighting tract-specific SES according to the number of primary care physicians at each site. P4P performance was defined by IHA's program and was a composite mainly representing clinical quality, but also including measures of patient experience, information technology and registry use.

KEY RESULTS

The area-based PO SES measure ranged from -11 to +11 (mean 0, SD 5), and the IHA P4P performance score ranged from 23 to 86 (mean 69, SD 15). In bivariate analysis, there was a significant positive relationship between PO SES and P4P performance (p < 0.001). In multivariate analysis, a one standard deviation increase in PO SES was associated with a 44% increase (relative risk 1.44, 95%CI, 1.22-1.71) in the likelihood of a PO being ranked in the top two quintiles of performance (p < 0.001).

CONCLUSIONS

Physician organizations' performance scores in a major P4P program vary by the SES of the areas in which their practice sites are located. P4P programs that do not account for this are likely to pay higher bonuses to POs in higher SES areas, thus increasing the resource gap between these POs and POs in lower SES areas, which may increase disparities in the care they provide.

Sociodemographic characteristics of members of a large, integrated health care system: comparison with US Census Bureau data

BACKGROUND

Data from the memberships of large, integrated health care systems can be valuable for clinical, epidemiologic, and health services research, but a potential selection bias may threaten the inference to the population of interest.

METHODS

We reviewed administrative records of members of Kaiser Permanente Southern California (KPSC) in 2000 and 2010, and we compared their sociodemographic characteristics with those of the underlying population in the coverage area on the basis of US Census Bureau data.

RESULTS

We identified 3,328,579 KPSC members in 2000 and 3,357,959 KPSC members in 2010, representing approximately 16% of the population in the coverage area. The distribution of sex and age of KPSC members appeared to be similar to the census reference population in 2000 and 2010 except with a slightly higher proportion of 40 to 64 year olds. The proportion of Hispanics/Latinos was comparable between KPSC and the census reference population (37.5% vs 38.2%, respectively, in 2000 and 45.2% vs 43.3% in 2010). However, KPSC members included more blacks (14.9% vs 7.0% in 2000 and 10.8% vs 6.5% in 2010). Neighborhood educational levels and neighborhood household incomes were generally similar between KPSC members and the census reference population, but with a marginal underrepresentation of individuals with extremely low income and high education.

CONCLUSIONS

The membership of KPSC reflects the socioeconomic diversity of the Southern California census population, suggesting that findings from this setting may provide valid inference for clinical, epidemiologic, and health services research.

Chlamydia positivity in women screened in family planning clinics: racial/ethnic differences and trends in the northwest U.S., 1997-2006

OBJECTIVES

We assessed chlamydia trends, individual-level risk factors, and population-level area-based socioeconomic measures (ABSMs) associated with chlamydia infection in women attending U.S. Public Health Service (PHS) Region X Infertility Prevention Project (IPP) family planning (FP) clinics from 1997-2006. We then explored these measures within racial/ethnic subpopulations.

METHODS

Using data from 667,223 chlamydia tests obtained from women aged 15-24 years screened in 201 FP clinics, we employed a generalized mixed model with logistic link, incorporating clinic and ZIP code as random effects to adjust for risk of chlamydia associated with individual- and population-level (areal) measures for the overall population and for each racial/ethnic subpopulation.

RESULTS

Significant racial/ethnic differences in chlamydia persisted after adjusting for individual and aggregate factors. Relatively steep chlamydia gradients were found across racial/ethnic ABSM levels. Compared with white women, infection risk was significantly higher for black (adjusted odds ratio [AOR] = 1.93), American Indian/Alaska Native (AOR=1.62), Asian/Pacific Islander (AOR=1.42), and Hispanic (AOR=1.28) women. The impact of population-level ABSMs on chlamydia varied across racial/ethnic groups and was generally modest. Among white women, there was a significant 4% relative annual increase in predicted chlamydia during the 10-year period 1997-2006. Chlamydia positivity over time did not change for racial/ethnic minority groups after adjusting for individual- and population-level factors.

CONCLUSIONS

Racial/ethnic differences in chlamydia persisted over time and were not mitigated by adjustment for aggregate socioeconomic position or areal racial/ethnic measures. Changes in project strategies will be needed to address racial/ethnic disparities for chlamydial infection among young female FP clinic clients.

Identifying at-risk communities for action on cancer prevention: a case study in new brunswick (Canada) communities

Health statistics reported by large geographic area such as province, state, county or health region offer little insight into disease conditions at the community level where people live and work, where occupational and environmental exposures occur, and where industrial emissions are often concentrated. This study investigated overall patterns of cancer incidence and socioeconomic status (SES) among 14 communities in the province of New Brunswick (Canada). A multivariate ordination technique, hierarchical clustering, and permutation procedures were used to identify and test significance of community clusters and whether the overall pattern of SES was correlated with patterns of cancer among communities. Communities with significantly high or significantly low overall rates of cancers were identified, patterns that were not related to SES. The potential influence of age, small populations, diagnostic screening, smoking and environmental risk factors contributing to locally elevated cancer rates are discussed. Cancer incidence reported at smaller spatial scales provides health officials and researchers with a basis for identifying communities potentially at-risk and aids in the development of appropriate community-based risk reduction actions and cancer prevention.

Factors affecting the likelihood of presentation to the emergency department of trauma patients after discharge

STUDY OBJECTIVE

We determine the rate at which trauma patients re-present to the emergency department (ED) after discharge from the hospital and determine whether re-presentation is related to race, insurance, and socioeconomic factors such as neighborhood income level.

METHODS

Trauma patients admitted to a Level I trauma center between January 1, 1997, and December 31, 2007, were identified with the hospital's trauma registry. These patients were linked to administrative data to obtain information about re-presentation to the hospital. Neighborhood income was obtained with census block data; multiple imputation was implemented to account for missing income data. Logistic regression analysis was used to determine the predictors of re-presentation.

RESULTS

There were 6,675 patients who were included in the study. A total of 886 patients (13.3%) returned to the ED within 30 days of discharge from the hospital. Uninsured patients (odds ratio [OR]=1.64; 95% confidence interval [CI] 1.30 to 2.06) and publicly insured patients (OR=1.60; 95% CI 1.20 to 2.14) were more likely to re-present to the ED than those with commercial insurance. Residing in a neighborhood with a median household income less than $20,000 was associated with a higher odds of re-presentation (OR=1.77; 95% CI 1.37 to 2.29). Only 13.2% of patients who came to the ED were readmitted to the hospital.

CONCLUSION

A substantial number of trauma patients return to the ED within 30 days of being discharged, but only a small proportion of these patients required readmission. Re-presentation is associated with being uninsured or underinsured and with lower neighborhood income level.

The neighborhood contribution to black-white perinatal disparities: an example from two north Carolina counties, 1999-2001

Previous studies of black-white disparities in perinatal outcomes have generally not controlled for both observed and unobserved neighborhood inequalities with models that compare only black and white women living in the same neighborhoods. Using 1999-2001 birth certificate data from 2 counties in North Carolina, the authors employed a hybrid fixed-effects approach to assess the total contribution of neighborhood factors to both absolute and relative racial disparities in low birth weight, preterm birth (PTB), and smallness for gestational age at term. Neighborhood factors made a notable contribution to racial disparities for PTB only, accounting for an additional 15% reduction in crude disparities beyond individual sociodemographic characteristics, which accounted for approximately 40% of racial disparities. The neighborhood contribution was greater for moderate PTB (32-36 weeks' gestation) than for very PTB (<32 weeks' gestation). A neighborhood deprivation index accounted for a smaller percentage of PTB disparities than the hybrid fixed-effects estimates, which suggests that measured socioeconomic deprivation does not account for all health-relevant neighborhood inequalities. Contemporaneous individual-level sociodemographic and neighborhood factors together explained one- to two-thirds of perinatal disparities. To fully explain racial disparities in perinatal outcomes, evaluation of other differential exposures (e.g., racism or wealth) and neighborhood factors across the life course may be necessary.

Association between quality of care and the sociodemographic composition of physicians' patient panels: a repeat cross-sectional analysis

BACKGROUND

Pay-for-performance programs could worsen health disparities if providers who care for disadvantaged patients face systematic barriers to providing high-quality care. Risk adjustment that includes sociodemographic factors could mitigate the financial incentive to avoid disadvantaged patients.

OBJECTIVE

To test for associations between quality of care and the composition of a physician's patient panel.

DESIGN

Repeat cross-sectional analysis

PARTICIPANTS

Nationally representative sample of US primary care physicians responding to a panel telephone survey in 2000-2001 and 2004-2005

MAIN MEASURES

Quality of primary care as measured by provision of eight recommended preventive services (diabetic monitoring [hemoglobin A1c testing, eye examinations, cholesterol testing and urine protein analysis], cancer screening [screening colonoscopy/sigmoidoscopy and mammography], and vaccinations against influenza and pneumococcus) documented in Medicare claims data and the association between quality and the sociodemographic composition of physicians' patient panels.

KEY RESULTS

Across eight quality measures, physicians' quality of care was not consistently associated with the composition of their patient panel either in a single year or between time periods. For example, a substantial number (seven) of the eighteen significant associations seen between sociodemographic characteristics and the delivery of preventive services in the first time period were no longer seen in the second time period. Among sociodemographic characteristics, panel Medicaid eligibility was most consistently associated with differences in the delivery of preventive services between time points; among preventive services, the delivery of influenza vaccine was most likely to demonstrate disparities in both time points.

CONCLUSIONS

In a Medicare pay-for-performance program, a better understanding of the effect of effect of patient panel composition on physicians' quality of care may be necessary before implementing routine statistical adjustment, since the association of quality and sociodemographic composition is small and inconsistent. In addition, we observed improvements between time periods among physicians with varying panel composition.

Neighborhood socioeconomic context and cognitive decline among older Mexican Americans: results from the Sacramento Area Latino Study on Aging

In 1 previous study, it was shown that neighborhood socioeconomic disadvantage is associated with cognitive decline among Latinos. No studies have explored whether and to what extent individual-level socioeconomic factors account for the relation between neighborhood disadvantage and cognitive decline. The purpose of the present study was to assess the influence of neighborhood socioeconomic position (SEP) on cognitive decline and examine how individual-level SEP factors (educational level, annual income, and occupation) influenced neighborhood associations over the course of 10 years. Participants (n = 1,789) were community-dwelling older Mexican Americans from the Sacramento Area Latino Study on Aging. Neighborhood SEP was derived by linking the participant's individual data to the 2000 decennial census. The authors assessed cognitive function with the Modified Mini-Mental State Examination. Analyses used 3-level hierarchical linear mixed models of time within individuals within neighborhoods. After adjustment for individual-level sociodemographic characteristics, higher neighborhood SEP was significantly associated with cognitive function (β = -0.033; P < 0.05) and rates of decline (β = -0.0009; P < 0.10). After adjustment for individual educational level, neighborhood SEP remained associated with baseline cognition but not with rates of decline. Differences in individual educational levels explained most of the intra- and interneighborhood variance. These results suggest that the effect of neighborhood SEP on cognitive decline among Latinos is primarily accounted for by education.

Prevalence of congenital hydrocephalus in California, 1991-2000

In a population-based retrospective cohort of 5,353,022 California births from 1991 to 2000, 3,152 newborns were diagnosed with congenital hydrocephalus during the birth hospitalization. We compared demographic and clinical characteristics of infants with and without congenital hydrocephalus, and examined in-hospital fatality rates. The prevalence of congenital hydrocephalus was 5.9 per 10,000. During the study period, there was a decline in congenital hydrocephalus due to spina bifida (1.4 to 0.9 per 10,000), and an increase in congenital hydrocephalus due to obstructive hydrocephalus (0.5 to 1.0 per 10,000). Independent risk factors for congenital hydrocephalus were birth weight <1,500 g (odds ratio [OR] 51.6, 95% confidence interval [CI] 47.7-55.8) and birth weight 1,500-2,000 g (OR 14.1, 95% CI 12.4-16) compared to birth weight greater than 2,000 g, low socioeconomic status (OR 1.5, 95% CI 1.4-1.6), and male sex (OR 1.2, 95% CI 1.1-1.3). Asians had a decreased risk for congenital hydrocephalus (OR 0.7, 95% CI 0.6-0.8) when compared to whites. Thirteen percent of affected neonates died before hospital discharge.

Socioeconomic factors and diagnosis of uveal melanoma in the mid-southern United States

PURPOSE

To establish the base incidence of uveal melanoma in the mid-southern United States and to explore the regional frequency of uveal melanoma diagnosis as a function of area-based socioeconomic measures (ABSM) aggregated at the level of small geographic units delimited by Zoning Improvement Plan (ZIP) codes.

METHODS

Based on a retrospective chart review (1996-2007) of patients seen at our institutions with the diagnosis of uveal melanoma, the number of uveal melanoma cases was calculated for each ZIP-code in Arkansas, Mississippi, western Tennessee and Louisiana. The base incidence of uveal melanoma was calculated using the population size reported in the 2000 census as the population at risk for each geographic area. Data on the average house value and average household income reported in the 2000 census were used in a Poisson regression analysis to examine their effect on the frequency of uveal melanoma diagnosis.

RESULTS

There were 327 (of 1,669) regional ZIP-codes that were the source of 457 patients with uveal melanoma. Higher ABSM, defined as greater average house value or household income, were positively associated with the number of observed melanoma cases per ZIP-code. The annualized incidence of uveal melanoma was at least 3.5 cases per million in the areas studied.

CONCLUSION

Higher ABSM were associated with the increased frequency of uveal melanoma diagnosis in the regions studied. Extrapolating from similar trends observed with non-ocular cancers, this may signify a need for increased access to ophthalmologic care to ensure timely diagnosis.

Administrative record linkage as a tool for public health research

Linked administrative databases offer a powerful resource for studying important public health issues. Methods developed and implemented in several jurisdictions across the globe have achieved high-quality linkages for conducting health and social research without compromising confidentiality. Key data available for linkage include health services utilization, population registries, place of residence, family ties, educational outcomes, and use of social services. Linking events for large populations of individuals across disparate sources and over time permits a range of research possibilities, including the capacity to study low-prevalence exposure-disease associations, multiple outcome domains within the same cohort of individuals, service utilization and chronic disease patterns, and life course and transgenerational transmission of health. Limited information on variables such as individual-level socioeconomic status (SES) and social supports is outweighed by strengths that include comprehensive follow-up, continuous data collection, objective measures, and relatively low expense. Ever advancing methodologies and data holdings guarantee that research using linked administrative databases will make increasingly important contributions to public health research.

The association between neighbourhoods and adverse birth outcomes: a systematic review and meta-analysis of multi-level studies

Many studies have examined the role of neighbourhood environment on birth outcomes but, because of differences in study design and modelling techniques, have found conflicting results. Seven databases were searched (1900-2010) for multi-level observational studies related to neighbourhood and pregnancy/birth. We identified 1502 articles of which 28 met all inclusion criteria. Meta-analysis was used to examine the association between neighbourhood income and low birthweight. Most studies showed a significant association between neighbourhood factors and birth outcomes. A significant pooled association was found for the relationship between neighbourhood income and low birthweight [odds ratio = 1.11, 95% confidence interval: 1.02, 1.20] whereby women who lived in low income neighbourhoods had significantly higher odds of having a low birthweight infant. This body of literature was found to consistently document significant associations between neighbourhood factors and birth outcomes. The consistency of findings from observational studies in this area indicates a need for causal studies to determine the mechanisms by which neighbourhoods influence birth outcomes.

The protective effects of social/contextual factors on psychiatric morbidity in LGB populations

BACKGROUND

Lesbian, gay and bisexual (LGB) populations evidence higher rates of psychiatric disorders than heterosexuals, but most LGB individuals do not have mental-health problems. The present study examined risk modifiers at the social/contextual level that may protect LGB individuals from the development of psychiatric disorders.

METHODS

Data are drawn from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (N = 34,653), a nationally representative study of non-institutionalized US adults. Risk variables included social isolation and economic adversity. High state-level concentration of same-sex couples, obtained from the US Census, was examined as a protective factor.

RESULTS

The past-year prevalence of major depression and generalized anxiety disorder was lower among LGB respondents living in states with higher concentrations of same-sex couples, compared with LGB respondents in states with lower concentrations. Additionally, the increased risk for mood and anxiety disorders among LGB individuals exposed to economic adversity and social isolation was evident only in states with low concentrations of same-sex couples. These interactions between the risk and protective factors were not found among heterosexuals, suggesting specificity of the effects to LGB individuals. Results were not attenuated after controlling for socio-demographic factors, state-level income inequality, state-level policies targeting LGBs and state-level attitudes towards LGB-relevant issues.

CONCLUSIONS

These results provide evidence for the protective effect of social/contextual influences on the prevalence of psychiatric disorders in LGB individuals. Measures of the social environment should be incorporated into future research on the mental health of LGB populations.

The California Neighborhoods Data System: a new resource for examining the impact of neighborhood characteristics on cancer incidence and outcomes in populations

Research on neighborhoods and health has been growing. However, studies have not investigated the association of specific neighborhood measures, including socioeconomic and built environments, with cancer incidence or outcomes. We developed the California Neighborhoods Data System (CNDS), an integrated system of small area-level measures of socioeconomic and built environments for California, which can be readily linked to individual-level geocoded records. The CNDS includes measures such as socioeconomic status, population density, racial residential segregation, ethnic enclaves, distance to hospitals, walkable destinations, and street connectivity. Linking the CNDS to geocoded cancer patient information from the California Cancer Registry, we demonstrate the variability of CNDS measures by neighborhood socioeconomic status and predominant race/ethnicity for the 7,049 California census tracts, as well as by patient race/ethnicity. The CNDS represents an efficient and cost-effective resource for cancer epidemiology and control. It expands our ability to understand the role of neighborhoods with regard to cancer incidence and outcomes. Used in conjunction with cancer registry data, these additional contextual measures enable the type of transdisciplinary, "cells-to-society" research that is now being recognized as necessary for addressing population disparities in cancer incidence and outcomes.

Changing trends in low birth weight rates among non-Hispanic black infants in the United States, 1991-2004

We examined trends in low birth weight (LBW, <2,500 g) rates among US singleton non-Hispanic black infants between 1991 and 2004. We conducted Joinpoint regression analyses, using birth certificate data, to describe trends in LBW, moderately LBW (MLBW, 1,500-2,499 g), and very LBW (VLBW, <1,500 g) rates. We then conducted cross-sectional and binomial regression analyses to relate these trends to changes in maternal or obstetric factors. Non-Hispanic black LBW rates declined -7.35% between 1991 and 2001 and then increased +4.23% through 2004. The LBW trends were not uniform across birth weight subcategories. Among MLBW births, the 1991-2001 decease was -10.20%; the 2001-2004 increase was +5.61%. VLBW did not follow this pattern, increasing +3.84% between 1991 and 1999 and then remaining relatively stable through 2004. In adjusted models, the 1991-2001 MLBW rate decrease was associated with changes in first-trimester prenatal care, cigarette smoking, education levels, maternal foreign-born status, and pregnancy weight gain. The 2001-2004 MLBW rate increase was independent of changes in observed maternal demographic characteristics, prenatal care, and obstetric variables. Between 1991 and 2001, progress occurred in reducing MLBW rates among non-Hispanic black infants. This progress was not maintained between 2001 and 2004 nor did it occur for VLBW infants between 1991 and 2004. Observed population changes in maternal socio-demographic and health-related factors were associated with the 1991-2001 decrease, suggesting multiple risk factors need to be simultaneously addressed to reduce non-Hispanic black LBW rates.

Father's education: an independent marker of risk for preterm birth

To explore the association between paternal education and preterm birth, taking into account maternal social and economic factors. We analyzed data from a population-based cross-sectional postpartum survey, linked with birth certificates, of women who gave birth in California from 1999 through 2005 (n = 21,712). Women whose infants' fathers had not completed college had significantly higher odds of preterm birth than women whose infants' fathers were college graduates, even after adjusting for maternal education and family income [OR (95% CI) = 1.26 (1.01-1.58)]. The effect of paternal education was greater among unmarried women than among married women. Paternal education may represent an important indicator of risk for preterm birth, reflecting social and/or economic factors not measured by maternal education or family income. Researchers and policy makers committed to understanding and reducing socioeconomic disparities in birth outcomes should consider paternal as well as maternal socioeconomic factors in their analyses and policy decisions.

Cervical cancer screening among urban immigrants by region of origin: a population-based cohort study

OBJECTIVES

We compared the prevalence of appropriate cervical cancer screening among screening-eligible immigrant women from major geographic regions of the world and native-born women.

METHODS

We determined the proportion of women who were screened during the three-year period of 2006-2008 among 2.9 million screening-eligible women living in urban centres in Ontario, Canada. In multivariate analyses, we adjusted for numerous variables including age, neighbourhood-level income, and prenatal visits during the study period.

RESULTS

61.3% of women were up-to-date on cervical cancer screening. Screening rates were lowest among women from South Asia when compared to the referent group (Canadian-born women and immigrants who arrived before 1985) (adjusted rate ratio 0.81, 95% CI [0.80-0.82] among women aged 18-49 years, adjusted rate ratio 0.67 [0.65-0.69] among women aged 50-66 years). Of the older South Asian women living in the lowest-income neighbourhoods and not in a primary care enrollment model, 21.9% had been appropriately screened. In contrast, among Canadian-born women living in the highest-income neighbourhoods and in a primary care enrollment model, 79.0% had been appropriately screened.

CONCLUSION

Efforts to reduce cervical cancer screening disparities should focus on women living in the lowest-income neighbourhoods and women from South Asia.

Moving beyond traditional measurement of mortality after injury: evaluation of risks for late death

BACKGROUND

The purpose of this study was to evaluate long-term mortality after trauma, and to determine risk factors and possible disparities related to mortality after hospital discharge.

STUDY DESIGN

Level I trauma center registry data from a 6-year period (2000 through 2005) were linked to patient electronic medical records, the National Death Index with cause of death codes, and census data using geographic information science (GIS) methodologies. Census data provided supplemental demographic and socioeconomic information from patient neighborhoods.

RESULTS

The hospital mortality rate for 15,285 patients was 3.3%, and mortality after discharge was 4.8%. Overall mortality for the study period was 8.1% (average follow-up, 2.8 years, 1-year mortality, 5.4%). Mortality after discharge was related to the initial injury in 33%, possibly related in 23%, and unrelated in 44% of patients. Logistic regression analysis demonstrated that independent predictors of hospital mortality were age, Injury Severity Score, gunshot injury, significant head injury, fall, and spinal cord injury. In contrast, independent risk factors for mortality after discharge were age, hospital length of stay, discharge from the hospital to a locale other than home, and the presence of spinal cord injury. Intoxication at hospital admission and injury due to a gunshot wound or motor vehicle collision were protective for late mortality. Bivariate analysis of census data demonstrated that lower socioeconomic status was associated with improved hospital survival, and non-native status was associated with mortality after discharge.

CONCLUSIONS

There is significant mortality attributable to trauma for up to 1 year after hospital discharge. These findings suggest that mortality after trauma needs to be measured beyond hospital discharge in order to assess the complete impact of injury.

Socioeconomic position, not race, is linked to death after cardiac surgery

BACKGROUND

Health disparities have been associated with the prevalence of cardiovascular disease. In cardiac surgery, association has been found between race, sex, and poorer prognosis after surgery. However, there is a complex interplay between race, sex, and socioeconomic position (SEP). In our investigation we sought to identify which of these was the driver of risk-adjusted survival.

METHODS AND RESULTS

From January 1, 1995, and December 30, 2005, 23 330 patients (15 156 white men, 6932 white women, 678 black men, and 564 black women) underwent isolated coronary artery bypass grafting, valve, or combined coronary artery bypass grafting and valve procedures. Median follow-up was 5.8 years (25th and 75th percentiles: 3 and 8.6 years). Effect of race, sex, and SEP on all-cause mortality was examined with 2-phase Cox model and generalized propensity score technique. As expected, blacks and women had lower SEP as compared with whites and men for all 6 SEP indicators. Patients with lower SEP had more atherosclerotic disease burden, more comorbidity, and were more symptomatic. Lower SEP was associated with a risk-adjusted dose-dependent reduction in survival after surgery (men, P<0.0001; women, P=0.0079), but black race, once adjusted for SEP, was not.

CONCLUSIONS

Our large investigation demonstrates that disparities in SEP are present and significantly affect health outcomes. Although race per se was not the driver for reduced survival, patients of low SEP were predominantly represented by blacks and women. Socioeconomically disadvantaged patients had significantly higher risk-adjusted mortality after surgery. Further investigation and targeted intervention should focus specifically on patients of low SEP, their health behaviors, and secondary prevention efforts.

The influence of neighborhood environment on the incidence of childhood asthma: a propensity score approach

BACKGROUND

The propensity score method has been underused in research concerning asthma epidemiology, which is useful for addressing covariate imbalance in observational studies.

OBJECTIVE

To examine the impact of neighborhood environment on asthma incidence by applying the propensity score method.

METHODS

The study was designed as a retrospective cohort study. Study subjects were all children born in Rochester, Minn, between 1976 and 1979. Asthma status was previously determined by applying predetermined criteria. We applied the propensity score method to match children who lived in census tracts facing or not facing intersections with major highways or railroads. The propensity score of children living in a census tract facing intersections was formulated from a logistic regression model with 16 variables that may not be balanced between comparison groups. The Cox proportional hazard models were used in the matched samples to estimate hazard ratios of neighborhood environment and some other variables of interest and their corresponding 95% CIs.

RESULTS

After matching with propensity scores, we found that children who lived in census tracts facing intersections with major highways or railroads had a higher risk of asthma (hazard ratios, 1.385-1.669 depending on the matching methods) compared with the matched counterparts who lived in census tracts not facing intersections with major highways or railroads.

CONCLUSION

Neighborhood environment may be an important risk factor in understanding the development of pediatric asthma. The propensity score method is a useful tool in addressing covariate imbalance and exploring for causal effect in studying asthma epidemiology.

Mapping and measuring disparities in welfare for cats across neighborhoods in a large US city

OBJECTIVE

To determine whether disparities in health and welfare among cats are present within neighborhoods and across census tracts in a large US city, and to compare results with area-level human data.

SAMPLE POPULATION

17,587 cat intake records from 2 animal sheltering organizations serving Boston, and summary data from city animal control authorities for a 5-year period (2004 through 2008).

PROCEDURES

Geocoded addresses (n = 15,285) were spatially joined to neighborhood and census tract polygons. Cat intakes and deaths were calculated per capita and compared with human demographic and death data. Poisson mixed-effects models were used to smooth mortality rates and calculate relative risks.

RESULTS

Data from geocoded records indicated that annual rates of cat intakes and deaths ranged widely (0.85 to 10.3 cats/1,000 persons and 0.27 to 3.9 cats/1,000 persons, respectively) within 16 neighborhoods of Boston. The disparity across 156 census tracts that comprised these neighborhoods was even greater (0.10 to 22.1 cats/1,000 persons and 0.15 to 6.47 cats/1,000 persons for intakes and deaths, respectively). Cat deaths were significantly correlated with human premature deaths at the neighborhood level (R2 = 0.77). Overall, annual per capita city-wide shelter-associated mortality rate for cats (estimated at approx 2.6 cats/1,000 persons) was similar to rates in other progressive communities.

CONCLUSIONS AND CLINICAL RELEVANCE

By use of geospatial techniques, 14- to 40-fold gradients in cat deaths were detected across Boston neighborhoods and census tracts. Cat deaths were associated with human premature deaths and socioeconomic indicators reflecting deprivation. Targeted interventions may be effective in resolving these disparities.

[Social inequalities in premature cardiovascular mortality in a medium-size Brazilian city]

Cardiovascular diseases are the main cause of death in many countries. In Brazil, premature cardiovascular death is more frequent than in wealthy countries. The aim of this study was to analyze the relationship between premature cardiovascular death and socioeconomic conditions in urban areas. The study design was ecological, with the urban areas of a medium-size municipality in Minas Gerais State, Brazil, as the units of analysis. The relationship between standardized mortality ratio and social development index (SDI) was studied with a binomial negative generalized linear model. The urban regions with the best socioeconomic conditions had significantly lower cardiovascular mortality. The reduction of socioeconomic inequalities in medium-size cities could help decrease health inequities.

The impact of socioeconomic conditions on chronic Chagas disease progression

INTRODUCTION AND OBJECTIVES

The extent to which a patient's socioeconomic conditions determine the persistence or control of chronic Chagas disease has not been previously investigated. The aim of this study was to evaluate the effect of socioeconomic conditions on clinical and serologic measures of disease progression.

METHODS

Data on the following socioeconomic variables were obtained by questioning as part of medical history taking at admission: birth in a rural area, time of residence in endemic and urban areas (in years), overcrowding index (i.e. number of inhabitants/number of bedrooms), absence of toilet facilities, years of education, employed or unemployed, and health insurance coverage (i.e. private contributory medical insurance cover). The study endpoints for the Cox regression analysis were: consistently negative results on serologic tests and on tests for markers of cardiomyopathy progression by the end of the study.

RESULTS

The study included 801 Argentine patients (mean age 42 years) who were followed up for a mean of 10 years between 1990 and 2005. After adjustment for age and antiparasitic treatment, negative seroconversion was associated with a short time of residence in an endemic area (hazard ratio [HR]=0.97; 95% confidence interval [CI], 0.96-0.99; P=.004), a low overcrowding index (HR=0.82; 95% CI, 0.70-0.97; P=.022) and medical insurance cover (HR=1.46; 95% CI, 1.01-2.09; P=.04). After adjustment for age, sex, ECG abnormalities and antiparasitic treatment, a low rate of cardiomyopathy progression was associated with more years of education (HR=0.88; 95% CI, 0.80-0.97; P=.01) and higher medical insurance cover (HR=0.49; 95% CI, 0.30-0.81; P=.005).

CONCLUSIONS

Socioeconomic conditions had a significant effect on chronic Chagas disease progression which was independent of antiparasitic treatment and clinic characteristics.

Avertable deaths associated with household income in Virginia

OBJECTIVES

We estimated how many deaths would be averted if the entire population of Virginia experienced the mortality rates of the 5 most affluent counties or cities.

METHODS

Using census data and vital statistics for the years 1990 through 2006, we applied the mortality rates of the 5 counties/cities with the highest median household income to the populations of all counties and cities in the state.

RESULTS

If the mortality rates of the reference population had applied to the entire state, 24.3% of deaths in Virginia from 1990 through 2006 (range = 21.8%-28.1%) would not have occurred. An annual mean of 12 954 deaths would have been averted (range = 10 548-14 569), totaling 220 211 deaths from 1990 through 2006. In some of the most disadvantaged areas of the state, nearly half of deaths would have been averted.

CONCLUSIONS

Favorable conditions that exist in areas with high household incomes exert a major influence on mortality rates. The corollary-that health suffers when society is exposed to economic stresses-is especially timely amid the current recession. Further research must clarify the extent to which individual-level factors (e.g., earnings, education, race, health insurance) and community characteristics can improve health outcomes.

Health inequalities in urban and rural Canada: comparing inequalities in survival according to an individual and area-based deprivation index

Social health inequalities are smaller in rural than urban areas because, some argue, people's social conditions are estimated at a small-area level, hiding variability at the individual or household level. This paper compares inequalities in survival according to an individual and area-based version of a deprivation index among a large sample of Canadians living in various urban and rural settings. Results show that survival inequalities in small towns and rural areas are lower than elsewhere when an area-based index is used, except in the remote hinterland, but of equal magnitude when the individual version of this index is considered.

Neighborhood disparities in incident hospitalized myocardial infarction in four U.S. communities: the ARIC surveillance study

PURPOSE

Hospital-based surveillance of myocardial infarction (MI) in the United States (U.S.) typically includes age, gender, and race, but not socioeconomic status (SES). We examined the association between neighborhood median household income (nINC) and incident hospitalized MI in four U.S. communities (1993-2002).

METHODS

Average annual indirect age-standardized MI rates were calculated using community-specific and community-wide nINC tertiles. Poisson generalized linear mixed models were used to calculate MI incidence rate ratios by tertile of census tract nINC (high nINC group referent).

RESULTS

Within community, and among all race-gender groups, those living in low nINC neighborhoods had an increased risk of MI compared to those living in high nINC neighborhoods. This association was present when both community-specific and community-wide nINC cut points were used. Blacks and, to a lesser extent, women, were disproportionately represented in low nINC neighborhoods, resulting in a higher absolute burden of MI in blacks and women living in low compared with high nINC neighborhoods.

CONCLUSIONS

These findings suggest a need for the joint consideration of racial, gender, and social disparities in interventions aimed at preventing coronary heart disease.

Investigating socio-economic disparities in preterm birth: evidence for selective study participation and selection bias

Selective study participation can theoretically lead to selection bias. We explored this issue in the context of a multicentre cohort study of socio-economic disparities in preterm birth. Women with singleton pregnancies were recruited from four large Montreal maternity hospitals and invited to return for an interview, vaginal examination and venepuncture at 24-26 weeks of gestation. We compared the observed preterm birth rate (ultrasound confirmed) among the 5146 cohort women to that expected based on all 108 724 Montreal Census Metropolitan Area (CMA) singleton births for 1998-2000. The observed preterm birth rate in the study cohort was 5.1%, compared with 6.3% in the CMA (P < 0.001) (unadjusted morbidity ratio [95% CI] = 0.80 [0.71, 0.90]). Within each stratum of maternal education and neighbourhood income (the latter based on postal code matched links to the 2001 Canadian census), cohort women had substantially lower rates of preterm birth than women from the CMA. No significant association between socio-economic status (SES) and preterm birth was observed in the study cohort, except among 'indicated' (non-spontaneous) cases. The association between neighbourhood income and preterm birth was biased to the null in the study cohort, with adjusted odds ratios in the poorest vs. richest quintiles of 1.01 [0.63, 1.64] in the cohort vs. 1.28 [1.18, 1.39] in the CMA, although no such bias was observed for the association with maternal education assessed at the individual level. We speculate that the lower-than-expected preterm birth rate and attenuated association between neighbourhood income and preterm birth may be related to selective participation by women more psychologically invested in their pregnancies. Investigators should consider the potential for biased associations in pregnancy/birth cohort studies, especially associations based on SES or race/ethnicity, and carry out sensitivity analyses to gauge their effects.

Identifying infants at increased risk for late initiation of immunizations: maternal and provider characteristics

OBJECTIVE

We identified maternal, provider, and community predictors among infants for late initiation of immunizations.

METHODS

We performed a retrospective cohort study of infants born between January 1, 2002, and December 31, 2004, in Philadelphia, Pennsylvania. Primary outcomes were age in days at first office-based immunization and status as a late starter (i.e., initiating office-based immunizations after 90 days of age). Candidate predictors included sociodemographic and prenatal characteristics, immunization provider practice type and size, and neighborhood factors. We performed hierarchical logistic regression and Cox regression models to identify independent predictors for being a late starter and prolonged time to first immunization.

RESULTS

Of the 65,519 infants from this birth cohort in Philadelphia's immunization registry, 54,429 (88.1%) were included in analysis and 12.6% of these were late starters. Infants whose mothers were younger, received less than five prenatal visits, had less than a high school education, had more than two children, and who smoked cigarettes prenatally were significantly more likely to be late starters. Receiving care at hospital/university-based or public health clinics was also significantly associated with likelihood of being a late starter. Neither distance between infant's residence and practice nor neighborhood socioeconomic indicators was independently associated with the outcomes. Common risk factor profiles based on practice type and four maternal characteristics were found to reliably identify infant risk.

CONCLUSIONS

Maternal receipt of fewer prenatal care visits, younger maternal age, higher birth order, and receiving care at public health clinics were the strongest predictors of being a late starter and time to first immunization. Risk factor profiles based on information already collected at birth can be used to identify higher-risk infants. Early intervention and potentially partnering with prenatal care providers may be key strategies for preventing underimmunization.