Deprivation, low birth weight, and children's height: a comparison between rural and urban areas

Age and sex differences in the association between neighborhood socioeconomic environment and incident diabetes: Results from the diabetes location, environmental attributes and disparities (LEAD) network

Objective

Worse neighborhood socioeconomic environment (NSEE) may contribute to an increased risk of type 2 diabetes (T2D). We examined whether the relationship between NSEE and T2D differs by sex and age in three study populations.

Research design and methods

We conducted a harmonized analysis using data from three independent longitudinal study samples in the US: 1) the Veteran Administration Diabetes Risk (VADR) cohort, 2) the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, and 3) a case-control study of Geisinger electronic health records in Pennsylvania. We measured NSEE with a z-score sum of six census tract indicators within strata of community type (higher density urban, lower density urban, suburban/small town, and rural). Community type-stratified models evaluated the likelihood of new diagnoses of T2D in each study sample using restricted cubic splines and quartiles of NSEE.

Results

Across study samples, worse NSEE was associated with higher risk of T2D. We observed significant effect modification by sex and age, though evidence of effect modification varied by site and community type. Largely, stronger associations between worse NSEE and diabetes risk were found among women relative to men and among those less than age 45 in the VADR cohort. Similar modification by age group results were observed in the Geisinger sample in small town/suburban communities only and similar modification by sex was observed in REGARDS in lower density urban communities.

Conclusions

The impact of NSEE on T2D risk may differ for males and females and by age group within different community types.

Mapping underweight in children using data from the five Ethiopia Demographic and Health Survey data conducted between 2000 and 2019: A geospatial analysis using the Bayesian framework

Background and aims

The Sustainable Development Goal is targeted to end all types of malnutrition including underweight by 2030. However, the reduction rate is not as expected to meet the target. Thus, we aimed to investigate the spatiotemporal distributions and drivers of underweight among children aged below 5 years in Ethiopia.

Methods

Geostatistical analysis using the Bayesian framework was conducted to map the spatial and Spatiotemporal distributions of underweight. Data for the primary outcome was obtained from the Ethiopian Demographic and Health Survey 2000–2019. Covariate data were accessed from different credible online sources at high resolutions. Spatial binomial regression was fitted to identify drivers of underweight using the Bayesian approach.

Results

The overall national prevalence of underweight was 44.7, 37.7, 35.4, 25.5, and 23.8% in 2000, 2005, 2011, 2016, and 2019, respectively, with a total reduction rate of 46.8%. Significant spatial clustering of underweight was observed in Northern, Northwestern, Southeastern, Eastern borders, and the border between Oromia and SNNPR regions. Mean annual temperature (mean regression coefficient (β): −0.39; 95% credible interval (95% CrI): −0.63, −0.14), altitude (β:−0.30; 95% CrI: 0.57, −0.05), population density (β:−0.03; 95% CrI: −0.03, −0.02), and distance to water bodies (β:−0.03; 95% CrI: −0.05, −0.004) were negatively associated with being underweight. However, travel time to the nearest cities in minutes (β: 0.09; 95% CrI: 0.03, 0.14) was positively associated with being underweight.

Conclusion

The national prevalence of underweight is reduced slower than expected in Ethiopia, with significant spatial variations across subnational and local levels. Temperature, altitude, population density, and distance to water bodies were negatively associated with underweight, whereas travel time to the nearest cities was positively associated with underweight in Ethiopia. Improving child nutrition through creating awareness and providing clean water should be strengthened.

The association between neighborhood social and economic environment and prevalent diabetes in urban and rural communities: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

Objective

The association between neighborhood disadvantage and health is well-documented. However, whether these associations may differ across rural and urban areas is unclear. This study examines the association between a multi-item neighborhood social and economic environment (NSEE) measure and diabetes prevalence across urban and rural communities in the US.

Methods

This study included 27,159 Black and White participants aged ≥45 years at baseline (2003-2007) from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Each participant's residential address was geocoded. NSEE was calculated as the sum of z-scores for six US Census tract variables (% of adults with less than high school education; % of adults unemployed; % of households earning <$30,000 per year; % of households in poverty; % of households on public assistance; and % of households with no car) and within strata of community type (higher density urban, lower density urban, suburban/small town, and rural). NSEE was categorized as quartiles, with higher NSEE quartiles reflecting more disadvantage. Prevalent diabetes was defined as fasting blood glucose ≥126 mg/dL or random blood glucose ≥200 mg/dL or use of diabetes medication at baseline. Multivariable adjusted Poisson regression models were used to estimate prevalence ratios (PR) and 95% confidence intervals (CI) for the association between NSEE and prevalent diabetes across community types.

Results

The mean age was 64.8 (SD=9.4) years, 55% were women, 40.7% were non-Hispanic Black adults. The overall prevalence of diabetes was 21% at baseline and was greatest for participants living in higher density urban areas (24.5%) and lowest for those in suburban/small town areas (18.5%). Compared with participants living in the most advantaged neighborhood (NSEE quartile 1, reference group), those living in the most disadvantaged neighborhoods (NSEE quartile 4) had higher diabetes prevalence in crude models. After adjustment for sociodemographic factors, the association remained statistically significant for moderate density community types (lower density urban quartile 4 PR=1.50, 95% CI=1.29, 1.75; suburban/small town quartile 4 PR=1.54, 95% CI=1.24, 1.92). These associations were also attenuated and of smaller magnitude for those living in higher density urban and rural communities.

Conclusion

Participants living in the most disadvantaged neighborhoods had a higher diabetes prevalence in each urban/rural community type and these associations were only partly explained by individual-level sociodemographic factors. In addition to addressing individual-level factors, identifying neighborhood characteristics and how they operate across urban and rural settings may be helpful for informing interventions that target chronic health conditions.

The strong impact of maternal marital status on birth body size before and during the Second World War in Poznań district, Poland

OBJECTIVES

The study aims to examine whether maternal socio-economic status, represented by marital status and the place of residence, affected birth body size (BBS) of babies in the pre-war period and during the WWII.

METHODS

The dataset consisted of 8934 unique individual information items on mothers and deliveries collected for two birth cohorts: born before (1934, 1935, 1936, and 1937) and during the WWII (1941, 1942, 1943 and 1944). BBS (weight, length, BMI) was compared according to mother's marital status and her place of residence in two cohorts separately. (ART)ANOVA was applied to test the effect of a child's sex, maternal marital status (MMS), and maternal place of residence (MPR) on birth weight/length/BMI of babies born alive before and during the WWII.

RESULTS

Babies with greater BBS were born to married mothers than to single ones. This pattern applied to pre-war and to the WWII cohort. In both pre-war and the WWII cohorts the MMS had the strongest impact on BBS. The effect of mother's place of residence on BBS was observed in the pre-war cohort only.

CONCLUSIONS

Marital status could have acted through economic and social factors, level of psychosocial stress and support, social (in)stability. In the pre-war period, the place of residence much more reflected socio-economic differences between localities. Marginal economic, health and nutritional conditions associated with the WWII affected mothers regardless of the size of their place of residence.

The Diabetes Location, Environmental Attributes, and Disparities Network: Protocol for Nested Case Control and Cohort Studies, Rationale, and Baseline Characteristics

BACKGROUND

Diabetes prevalence and incidence vary by neighborhood socioeconomic environment (NSEE) and geographic region in the United States. Identifying modifiable community factors driving type 2 diabetes disparities is essential to inform policy interventions that reduce the risk of type 2 diabetes.

OBJECTIVE

This paper aims to describe the Diabetes Location, Environmental Attributes, and Disparities (LEAD) Network, a group funded by the Centers for Disease Control and Prevention to apply harmonized epidemiologic approaches across unique and geographically expansive data to identify community factors that contribute to type 2 diabetes risk.

METHODS

The Diabetes LEAD Network is a collaboration of 3 study sites and a data coordinating center (Drexel University). The Geisinger and Johns Hopkins University study population includes 578,485 individuals receiving primary care at Geisinger, a health system serving a population representative of 37 counties in Pennsylvania. The New York University School of Medicine study population is a baseline cohort of 6,082,146 veterans who do not have diabetes and are receiving primary care through Veterans Affairs from every US county. The University of Alabama at Birmingham study population includes 11,199 participants who did not have diabetes at baseline from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a cohort study with oversampling of participants from the Stroke Belt region.

RESULTS

The Network has established a shared set of aims: evaluate mediation of the association of the NSEE with type 2 diabetes onset, evaluate effect modification of the association of NSEE with type 2 diabetes onset, assess the differential item functioning of community measures by geographic region and community type, and evaluate the impact of the spatial scale used to measure community factors. The Network has developed standardized approaches for measurement.

CONCLUSIONS

The Network will provide insight into the community factors driving geographical disparities in type 2 diabetes risk and disseminate findings to stakeholders, providing guidance on policies to ameliorate geographic disparities in type 2 diabetes in the United States.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/21377.

Seasonality of births in affective disorder in an Irish population

Seasonal variation in the births of patients with schizophrenia is a consistently replicated epidemiological finding. Few studies have investigated this phenomenon among patients with a diagnosis of affective disorder. The majority of season of birth studies have employed the chi square test for statistical analysis, a method that has been subject to some criticism. Using a Kolgomorov-Smirnov type statistic, the quarterly birth distribution of 6,646 patients with an ICD 9/10 diagnosis of affective disorder were compared to the general population. Only the births of those individuals with unipolar forms of affective disorder (n = 4,393) differed significantly from the general population, with significant excesses and deficits in the second quarter and fourth quarter respectively. These results were not altered by application of the displacement test. © 1998 Elsevier, Paris

Socioeconomic gradients of adverse birth outcomes and related maternal factors in rural and urban Alberta, Canada: a concentration index approach

OBJECTIVE

Using a summary measure of health inequalities, this study evaluated the distribution of adverse birth outcomes (ABO) and related maternal risk factors across area-level socioeconomic status (SES) gradients in urban and rural Alberta, Canada.

DESIGN

Cross-sectional study using a validated perinatal clinical registry and an area-level SES.

SETTING

The study was conducted in Alberta, Canada. Data about ABO and related maternal risk factors were obtained from the Alberta Perinatal Health Program between 2006 and 2012. An area-level SES index derived from census data (2006) was linked to the postal code at delivery.

PARTICIPANTS

Women (n=3 30 957) having singleton live births with gestational age ≥22 weeks.

PRIMARY AND SECONDARY OUTCOME MEASURES

We estimated concentration indexes to assess inequalities across SES gradients in both rural and urban areas (CIdx_R and CIdx_U, respectively) for spontaneous preterm birth (PTB), small for gestational age (SGA), large for gestational age (LGA), gestational hypertension, gestational diabetes, smoking and substance use during pregnancy and pre-pregnancy weight >91 kg.

RESULTS

The highest health inequalities disfavouring low SES groups were identified for substance abuse and smoking in rural areas (CIdx_R-0.38 and -0.23, respectively). Medium inequalities were identified for LGA (CIdx_R-0.08), pre-pregnancy weight >91 kg (CIdx_R-0.07), substance use (CIdx_U-0.15), smoking (CIdx_U-0.14), gestational diabetes (CIdx_U-0.10) and SGA (CIdx_U-0.07). Low inequalities were identified for PTB (CIdx_R-0.05; CIdx_U-0.05) and gestational diabetes (CIdx_R-0.04). Inequalities disfavouring high SES groups were identified for gestational hypertension (CIdx_R+0.04), SGA (CIdx_R+0.03) and LGA (CIdx_U+0.03).

CONCLUSIONS

ABO and related maternal risk factors were unequally distributed across the socioeconomic gradient in urban-rural settings, with the greatest concentrations in lower SES groups of rural areas. Future research is needed on underlying mechanisms driving SES gradients in perinatal health across the rural-urban spectrum.

Trends in perinatal mortality and its risk factors in Japan: Analysis of vital registration data, 1979-2010

As Japan has achieved one of the lowest perinatal mortality rates (PMR), our study aims to estimate trends in and risk factors for perinatal mortality among singleton births in Japan. We used Japanese vital registration data to assess trends in and risk factors for perinatal outcomes between 1979 and 2010. Birth and death registration data were merged. An autoregressive integrated moving average model was fitted separately by sex to the PMR and the proportion of stillbirths. A multilevel Poisson regression model was used to estimate risk factors for perinatal mortality. Between 1979 and 2010 there were 40,833,957 pregnancies and 355,193 perinatal deaths, the PMR decreased from 18.86 per 1,000 all births to 3.25 per 1,000 all births, and the proportion of stillbirths increased from 83.6% to 92.1%. Key risk factors for perinatal mortality were low or high birth weight, prematurity and post maturity, and being from poorer or unemployed families. A higher proportion of excess perinatal deaths could be averted by effective policies to prevent stillbirths and improved research into their interventions and risk factors. As the cost and challenge of maintaining perinatal mortality gains increases, policies need to be targeted towards higher risk groups and social determinants of health.

Height, body mass index, and socioeconomic status: mendelian randomisation study in UK Biobank

OBJECTIVE

To determine whether height and body mass index (BMI) have a causal role in five measures of socioeconomic status.

DESIGN

Mendelian randomisation study to test for causal effects of differences in stature and BMI on five measures of socioeconomic status. Mendelian randomisation exploits the fact that genotypes are randomly assigned at conception and thus not confounded by non-genetic factors.

SETTING

UK Biobank.

PARTICIPANTS

119,669 men and women of British ancestry, aged between 37 and 73 years.

MAIN OUTCOME MEASURES

Age completed full time education, degree level education, job class, annual household income, and Townsend deprivation index.

RESULTS

In the UK Biobank study, shorter stature and higher BMI were observationally associated with several measures of lower socioeconomic status. The associations between shorter stature and lower socioeconomic status tended to be stronger in men, and the associations between higher BMI and lower socioeconomic status tended to be stronger in women. For example, a 1 standard deviation (SD) higher BMI was associated with a £210 (€276; $300; 95% confidence interval £84 to £420; P=6 × 10(-3)) lower annual household income in men and a £1890 (£1680 to £2100; P=6 × 10(-15)) lower annual household income in women. Genetic analysis provided evidence that these associations were partly causal. A genetically determined 1 SD (6.3 cm) taller stature caused a 0.06 (0.02 to 0.09) year older age of completing full time education (P=0.01), a 1.12 (1.07 to 1.18) times higher odds of working in a skilled profession (P=6 × 10(-7)), and a £1130 (£680 to £1580) higher annual household income (P=4 × 10(-8)). Associations were stronger in men. A genetically determined 1 SD higher BMI (4.6 kg/m(2)) caused a £2940 (£1680 to £4200; P=1 × 10(-5)) lower annual household income and a 0.10 (0.04 to 0.16) SD (P=0.001) higher level of deprivation in women only.

CONCLUSIONS

These data support evidence that height and BMI play an important partial role in determining several aspects of a person's socioeconomic status, especially women's BMI for income and deprivation and men's height for education, income, and job class. These findings have important social and health implications, supporting evidence that overweight people, especially women, are at a disadvantage and that taller people, especially men, are at an advantage.

Socioeconomic Disparities in Adverse Birth Outcomes in Urban and Rural Contexts: a French Mother-Child Cohort

BACKGROUND

Although adverse birth outcomes have been associated with neighbourhood deprivation in urban areas, few studies have addressed this issue in rural zones. This study examines whether associations between neighbourhood deprivation and adverse birth outcomes differ in urban and rural contexts, while taking individual characteristics and spatial accessibility of prenatal care (SAPC) into account.

METHODS

Pregnant women from a French mother-child cohort were recruited from 2002 to 2006 in Brittany. Their residential addresses were geocoded into their census blocks (the finest geographical resolution available). Deprivation was assessed at the same neighbourhood level. Models to assess the associations of deprivation, stratified by urban/rural status, with preterm delivery (PTD), with small for gestational age birth weight (SGA) and with small for gestational age head circumference at birth (SHC), estimated odds ratios (ORs), adjusted for maternal socioeconomic characteristics and SAPC.

RESULTS

This study considered 2929 liveborn singleton pregnancies from 780 census blocks. Neighbourhood deprivation was associated with increased risks of SGA and SHC (P trend < 0.01 and 0.03 respectively), only among mothers residing in rural areas. Neighbourhood deprivation had statistically significantly heterogeneous effects on SGA and SHC according to the urban/rural status of maternal residence.

CONCLUSION

These findings suggest that neighbourhood deprivation affects fetal growth differentially in urban and rural areas and that SAPC does not seem to be responsible for this difference. Comparison of these findings with the literature requires caution in the conceptualisation of urban and rural settings.

Physical growth during the first year of life. A longitudinal study in rural and urban areas of Hanoi, Vietnam

Background

Good infant growth is important for future health. Assessing growth is common in pediatric care all over the world, both at the population and individual level. There are few studies of birth weight and growth studies comparing urban and rural communities in Vietnam. The first aim is to describe and compare the birth weight distributions and physical growth (weight and length) of children during their first year in one rural and one urban area of Hanoi Vietnam. The second aim is to study associations between the anthropometric outcomes and indicators of the economic and educational situations.

Methods

Totally 1,466 children, born from 1^st March, 2009 to June 2010, were followed monthly from birth to 12 months of age in two Health and Demographic Surveillance Sites; one rural and one urban. In all, 14,199 measurements each of weight and length were made. Birth weight was recorded separately. Information about demographic conditions, education, occupation and economic conditions of persons and households was obtained from household surveys. Fractional Polynomial models and standard statistical methods were used for description and analysis.

Results

Urban infants have higher birth weight and gain weight faster than rural infants. The mean birth weight for urban boys and girls were 3,298 grams and 3,203 grams as compared to 3,105 grams and 3,057 grams for rural children. At 90 days, the urban boys were estimated to be 4.1% heavier than rural boys. This difference increased to 7.2% at 360 days. The corresponding difference for girls was 3.4% and 10.5%. The differences for length were comparatively smaller. Both birth weight and growth were statistically significantly and positively associated with economic conditions and mother education.

Conclusion

Birth weight was lower and the growth, weight and length, considerably slower in the rural area, for boys as well as for girls. The results support the hypothesis that the rather drastic differences in maternal education and economic conditions lead to poor nutrition for mothers and children in turn causing inferior birth weight and growth.

Socio-occupational status and congenital anomalies

BACKGROUND

The aim of this study is to investigate the association between socio-occupational status and the frequency of major congenital anomalies in offspring.

METHODS

The study population comprised 81,435 live singletons born to mothers enrolled in the Danish National Birth Cohort between 1996 and 2002. A total of 3352 cases of major congenital anomalies (EUROCAT criteria) were identified by linkage to the National Hospital Discharge Register. Malformations were recorded at birth or in the first year of life. Information about maternal and paternal socio-occupational status was collected prospectively using telephone interviews in the second trimester of pregnancy and was categorized as high, middle or low. Associations were measured as relative prevalence ratios using the highest socio-occupational status within the couple as the reference group.

RESULTS

The prevalence of all recorded major congenital anomalies was similar, about 4%, in all the socio-occupational categories. Low social status of the couple did, however, correlate with a higher prevalence of congenital anomalies of the 'respiratory system'. No association was substantially attenuated when we adjusted for maternal and paternal age, smoking status, maternal alcohol habits, folic acid intake and body mass index. When malformations of the heart and the cardiovascular system were grouped together, they were more frequent in families where both parents presented a low socio-occupational status.

CONCLUSION

We detected an association between low socio-occupational status and congenital anomalies of the respiratory system, the heart and the circulatory system. These malformations are good candidates for a large study on occupational, environmental and social determinants.

Investigating urban-rural disparities in tuberculosis treatment outcome in England and Wales

The purpose of this study was to compare the occurrence of tuberculosis (TB) and the outcome of treatment between TB patients living in urban and rural areas. Cases of TB reported from 2001 to 2003 in England and Wales were assigned to a rural or urban area classification. The outcome of interest, non-completion of treatment, was investigated to determine the odds ratio for urban vs. rural residence. The effects of age, sex, ethnicity, place of birth, time since arrival in the United Kingdom, disease site, isoniazid resistance and previous diagnosis were adjusted for by multivariable logistic regression. Crude odds ratios showed a significantly higher level of treatment non-completion in rural areas. These results became non-significant (OR 1.02, 95% CI 0.83-1.26, P=0.82) after adjusting for the confounding effects of ethnic group and age. In England and Wales residence in a rural location is not an independent determinant of TB treatment outcome failure.

Perceived neighborhood problems and quality of life, physical functioning, and depressive symptoms among adults with asthma

OBJECTIVES

We investigated associations between perceived neighborhood problems and quality of life (QOL), physical functioning, and depressive symptoms among adults with asthma.

METHODS

Using cross-sectional data from adults with asthma in northern California (n=435), we examined associations between 5 types of perceived neighborhood problems (traffic, noise, trash, smells, and fires) and asthma-specific QOL (Marks instrument), physical functioning (Short Form-12 physical component summary), and depressive symptoms (Center for Epidemiological Studies-Depression). We used multivariate regression analysis.

RESULTS

When asthma severity and sociodemographics were taken into account, people reporting a score of 8 or higher on a scale of 0 to 25 for serious problems (the top quartile of seriousness) in their neighborhoods had significantly poorer QOL scores (mean difference=5.91; standard error [SE]=1.63), poorer physical functioning (mean difference=-3.04; SE=1.27), and almost a fivefold increase in depressive symptoms (odds ratio=4.79; 95% confidence interval=2.41, 9.52).

CONCLUSIONS

A high level of perceived neighborhood problems was associated with poorer QOL, poorer physical functioning, and increased depressive symptoms among people with asthma when disease severity and sociodemographic factors were taken into account.

Socioeconomic factors and the risk of anencephaly in a Mexican population: a case-control study

OBJECTIVE

The study was designed to evaluate the association between socioeconomic level (as measured by maternal education, maternal occupation, and monthly family income) and anencephaly.

METHODS

The authors conducted a case-control study using data from the Epidemiological Surveillance System Register for Neural Tube Defects for three states of the Mexican Republic: Puebla, Guerrero and the State of Mexico. Mothers of 151 cases of infants born with anencephaly and mothers of 151 control infants born during the period March 2000 to February 2001 were interviewed about their socioeconomic characteristics and other factors including reproductive history, use of prenatal care, use of tobacco and alcohol, fever during pregnancy, and folic acid supplementation.

RESULTS

After adjustment for potential confounders, a risk gradient was seen with decreasing maternal education. Women with less than a primary school education (adjusted odds ratio [OR]=3.0; 95% confidence interval [CI] 1.2, 7.6) and women who had completed primary school but had not completed junior high school (adjusted OR=2.2; 95% CI 0.9, 5.7) had higher risks of giving birth to an infant with anencephaly, compared to women with a higher educational level. A monthly income < or = 1,000 pesos (approximately dollars 100 U.S.) was also associated with a higher risk of anencephaly (OR=2.5; 95% CI 1.2, 5.1). Women employed in industry or agriculture during the acute risk period (three months prior to conception to one month after conception) had a risk 6.5 times (95% CI 1.4, 29.6) that of professional and business women.

CONCLUSIONS

This study helps to identify groups that may be especially vulnerable to this type of congenital malformation so that primary and secondary preventive strategies can be targeted to these groups.

Endocrine profile and physical stature of children with Perthes disease

Children with Perthes disease have been thought to be of smaller stature than their peers. No reproducible evidence exists to demonstrate an endocrinopathy as the cause. This study reviewed 139 children with Perthes disease. Height and weight were recorded and compared with standardized growth charts. A blood sample was analyzed for thyroid stimulating hormone (TSH), thyroxin (T4), and insulin-like growth factor 1 (IGF1). Two urine samples were collected at 8 am and 8 pm within 24 hours. From these a cortisol/creatinine ratio was calculated. The results were compared with those from 40 healthy matched controls. No significant differences were found between the study or control children for levels of TSH, T4, IGF1, or cortisol. Review of the height and weight results revealed that the study children were of normal body habitus compared with the general pediatric population and do not undergo a period of growth acceleration following the active stages of the disease.

Statistical and Substantive Inferences in Public Health: Issues in the Application of Multilevel Models

Multilevel statistical models have become increasingly popular among public health researchers over the past decade. Yet the enthusiasm with which these models are being adopted may obscure rather than solve some problems of statistical and substantive inference. We discuss the three most common applications of multilevel models in public health: (a) cluster-randomized trials, (b) observational studies of the multilevel etiology of health and disease, and (c) assessments of health care provider performance. In each area of investigation, we describe how multilevel models are being applied, comment on the validity of the statistical and substantive inferences being drawn, and suggest ways in which the strengths of multilevel models might be more fully exploited. We conclude with a call for more careful thinking about multilevel causal inference.

Rural/urban differences in the association between deprivation and healthcare utilisation

Whilst associations between inequalities in healthcare utilisation and socio-economic deprivation are well established in the UK it is argued that deprivation indices, such as the Townsend index, remain insensitive to rural/urban differences. This study examines how Townsend and its components differ in their association with healthcare utilisation across the rural/urban spectrum of a large health region. Our research was carried out in the West Midlands National Health Service region (population 5.3 million), comprising of a similar geographical population diversity to that of the United Kingdom (UK) using Hospital Episode Statistics (1994/5-1998/9) and 1991 census socio-demographic data. Retrospective multilevel multivariate models compare three ward-level healthcare utilisation measures (standardised episode-, admission-, and bed-rates) in relation to the Townsend index of material deprivation, its components, and four rural/urban characteristics (population density, population potential, electoral ward area and perimeter size). The associations between outcomes and Townsend were generally not attenuated by the rural/urban characteristics. The constituent component of car-ownership was similarly unperturbed, whereas population potential significantly perturbed the home-ownership model and overcrowding was significantly perturbed by all four rural/urban characteristics considered. A deprivation index may encapsulate different meanings to that of its components when used to assess variations in healthcare utilisation. Constituent components may yield considerable perturbation in relation to healthcare utilisation across the rural/urban spectrum, whilst the composite measure does not. In particular, and contrary to anecdotal opinion, car-ownership and unemployment (as recorded in the 1991 UK census) exhibited a stable relationship across different rural/urban areas with respect to healthcare utilisation.

Social inequalities and children's height in Trinidad and Tobago

OBJECTIVE

The aim of the study was to report the association of socio-economic factors with child's height.

DESIGN

Cross-sectional study based on a representative national sample of government schools.

SETTING

Trinidad and Tobago in 1999.

SUBJECTS

A total of 2608 boys and girls mean age 5.8 y, range 4.38-6.99 y and 3080 mean age 8.6 y, range 7.00-10.44 y olds.

OUTCOME

Measurement of height and a questionnaire completed by parents. In the analysis height was expressed as standard deviation scores (s.d.s.) based on the British height curves (1990) or height below -1.5 s.d.s.

RESULTS

Ethnicity, parental heights, birthweight, maternal age at child's birth and number of children in the family were the main factors associated with children's height. Lack of piped water supply in the home was the only socio-economic factor consistently associated with height (mean difference in s.d.s. adjusted only for age group, gender and ethnicity -0.192, 95% CI -0.257 to -0.127 and in addition adjusted for the variables listed above -0.080, 95% CI -0.141 to -0.019). Parental education, household overcrowding and employment status were weakly associated with height in the partially adjusted model only. Analysis of severe growth failure gave similar results.

CONCLUSION

The impact of socio-economic factors on height is marginal in Trinidad and Tobago. As socio-economic factors may have an impact on a broad range of health indicators, height and rates of undernutrition should not be used as sole criteria for assessing progress in decreasing health differentials caused by social inequalities.

The treatment of parental height as a biological factor in studies of birth weight and childhood growth

Parental height is frequently treated as a biological variable in studies of birth weight and childhood growth. Elimination of social variables from multivariate models including parental height as a biological variable leads researchers to conclude that social factors have no independent effect on the outcome. This paper challenges the treatment of parental height as a biological variable, drawing on extensive evidence for the determination of adult height through a complex interaction of genetic and social factors. The paper firstly seeks to establish the importance of social factors in the determination of height. The methodological problems associated with treatment of parental height as a purely biological variable are then discussed, illustrated by data from published studies and by analysis of data from the 1958 National Childhood Development Study (NCDS). The paper concludes that a framework for studying pathways to pregnancy and childhood outcomes needs to take account of the complexity of the relation between genetic and social factors and be able to account for the effects of multiple risk factors acting cumulatively across time and across generations. Illustrations of these approaches are given using NCDS data.

Urban-rural mortality differentials: controlling for material deprivation

This paper investigates the relationship between premature mortality and material deprivation, and the differences in this relationship between urban and rural areas. We examine, given comparable measures of affluence or deprivation, whether residual differences exist between urban and rural areas for all-causes of death and, separately, for cancers, circulatory and respiratory diseases. Using 1990-92 mortality data for the 908 wards of Wales we apply statistical analyses based on tabular data and parametric Poisson regression models. Contrasts are sought between six urban and rural categories defined in terms of settlement sizes and the employment structure of rural areas. Inequalities in all-cause premature mortality are widest in the cities, narrowest in the deeper rural areas, and of intermediate and comparable value in other areas of Wales. This is largely a reflection of the different distributions of material deprivation in these areas. After controlling for differences in socio-economic characteristics, using deprivation measures, the tendency for lower mortality in deeper rural areas is substantially reduced. Residual mortality differences between urban and rural areas are shown to be dependent on the way deprivation is measured and the disease group under study. For cancers there are no residual mortality differences, while for respiratory and circulatory diseases some of the residual variation can be accounted for by employment variables, particularly previous employment in the coal mining industry.

Socioeconomic inequalities in risk of congenital anomaly

AIMS

To investigate socioeconomic inequalities in the risk of congenital anomalies, focusing on risk of specific anomaly subgroups.

METHODS

A total of 858 cases of congenital anomaly and 1764 non-malformed control births were collected between 1986 and 1993 from four UK congenital malformation registers, for the purposes of a European multicentre case control study on congenital anomaly risk near hazardous waste landfill sites. As a measure of socioeconomic status, cases and controls were given a value for the area level Carstairs deprivation index, by linking the postcode of residence at birth to census enumeration districts (areas of approximately 150 households).

RESULTS

Risk of non-chromosomal anomalies increased with increasing socioeconomic deprivation. The risk in the most deprived quintile of the deprivation index was 40% higher than in the most affluent quintile. Some malformation subgroups also showed increasing risk with increasing deprivation: all cardiac defects, malformations of the cardiac septa, malformations of the digestive system, and multiple malformations. No evidence for socioeconomic variation was found for other non-chromosomal malformation groups, including neural tube defects and oral clefts. A decreasing risk with increasing deprivation found for all chromosomal malformations and Down's syndrome in unadjusted analyses, occurred mainly as a result of differences in the maternal age distribution between social classes.

CONCLUSION

Our data, although based on limited numbers of cases and geographical coverage, suggest that more deprived populations have a higher risk of congenital anomalies of non-chromosomal origin and some specific anomalies. Larger studies are needed to confirm these findings and to explore their aetiological implications.

The impact of the environment on height in Europe: conceptual and theoretical considerations

PRIMARY OBJECTIVE

The purpose of this review is to assess whether information available to evaluate the impact of the environment and, more specifically, socio-economic factors on height in European countries is sufficient.

MAIN OUTCOMES AND RESULTS

It is proposed that studies based on measurements taken 25 years ago or more are unsatisfactory for assessing the current situation. There is a widespread assumption that sufficient information is available for assessing the issue. However, on inspection, there are very few environmental factors for which sufficient material on their effects on height has been published. In many studies to evaluate the effect of the environment an ecological design is used and a post hoc interpretation is made. It is concluded that this type of study is helpful only for generating hypotheses. When inspecting analytical studies on the association between socio-economic factors and height it is observed that the reports identified are only the tip of the iceberg of published reports on the subject and include studies from less than half the European countries. In many of these papers the independent variables are not defined in the same manner and a formal comparison is difficult to make.

CONCLUSIONS

Given the current deficiencies, it is worthwhile to discuss in auxological epidemiology whether it is relevant to tackle the issue proposed in this review. If the answer is yes, it is necessary to identify the best course of action. Possible avenues to explore are the potential and the barriers for harmonizing the investigation of socio-economic factors in growth studies, and the organization of a registry of reports on growth and social factors. At a more modest level, a collaborative report examining the availability of information and gaps on this topic among European countries could be helpful.

The social environment and health: a discussion of the epidemiologic literature

The environment can be thought of in terms of physical and social dimensions. The social environment includes the groups to which we belong, the neighborhoods in which we live, the organization of our workplaces, and the policies we create to order our lives. There have been recent reports in the literature that the social environment is associated with disease and mortality risks, independent of individual risk factors. These findings suggest that the social environment influences disease pathways. Yet much remains to be learned about the social environment, including how to understand, define, and measure it. The research that needs to be done could benefit from a long tradition in sociology and sociological research that has examined the urban environment, social areas, social disorganization, and social control. We summarize this sociological literature and discuss its relevance to epidemiologic research.

Poverty area residence and changes in physical activity level: evidence from the Alameda County Study

OBJECTIVES

Evidence from the Alameda County Study indicated that residential area has an independent effect on mortality risk. The current research examined the effect of poverty area residence on change in physical activity (n = 1737).

METHODS

Data were from a longitudinal population-based cohort. Multiple linear regression analyses were used.

RESULTS

Age- and sex-adjusted change scores between 1965 and 1974 for physical activity were 0.67 units lower for people living in poverty areas (P = .0001). Independent of individual income, education, smoking status, body mass index, and alcohol consumption, poverty area residence remained associated with physical activity change.

CONCLUSION

These results further support the hypothesis that place affects health behaviors.

Birth weight and environmental pollution in the county of Telemark, Norway

The possible effect of environmental pollution on fetal growth was examined in 3,231 consecutively liveborn single infants (>/=37 weeks' gestation) of Caucasian parents born between 1986 and 1988. The parents lived in an industrial area or in less polluted urban and rural residential areas. Information about lifestyle, health, and work exposures was collected from the parents. A significantly lower arithmetic mean birth weight was observed for newborns in the industrial residential area (3,517 g, SD, 482), compared with the urban (3,592 g, SD 495) and rural (3,618 g, SD 517) areas (P < 0.05). Even controlling for gestational age, sex, parity, maternal smoking habits, and social class, residential area still had a significant effect on birth weight. Among other factors examined, only maternal psychological stress at work had a significant effect on birth weight. If the observed association reflects a causal relationship, birth weight may represent a potential outcome parameter for surveillance of effects on humans of environmental exposures.

Living conditions, inequalities in health, human rights and security: a European perspective in a global context

This paper examines the living conditions and inequalities affecting health, human rights and security in developed Western countries. Possible remedies based on experience in Sandwell Health District, West Midlands, are considered and analogies drawn with global initiatives.

The importance of normalisation in the construction of deprivation indices

STUDY OBJECTIVES

Measuring socio-economic deprivation is a major challenge usually addressed through the use of composite indices. This paper aims to clarify the technical details regarding composite index construction. The distribution of some variables, for example unemployment, varies over time, and these variations must be considered when composite indices are periodically re-evaluated. The process of normalisation is examined in detail and particular attention is paid to the importance of symmetry and skewness of the composite variable distributions.

DESIGN

Four different solutions of the Townsend index of socioeconomic deprivation are compared to reveal the effects that differing transformation processes have on the meaning or interpretation of the final index values. Differences in the rank order and the relative separation between values are investigated.

MAIN RESULTS

Constituent variables which have been transformed to yield a more symmetric distribution provide indices that behave similarly, irrespective of the actual transformation methods adopted. Normalisation is seen to be of less importance than the removal of variable skewness. Furthermore, the degree of success of the transformation in removing skewness has a major effect in determining the variation between the individual electoral ward scores. Constituent variables undergoing no transformation produce an index that is distorted by the inherent variable skewness, and this index is not consistent between re-evaluations, either temporally or spatially.

CONCLUSIONS

Effective transformation of constituent variables should always be undertaken when generating a composite index. The most important aspect is the removal of variable skewness. There is no need for the transformed variables to be normally distributed, only symmetrically distributed, before standardisation. Even where additional parameter weights are to be applied, which significantly alter the final index, appropriate transformation procedures should be adopted for the purpose of consistency over time and between different geographical areas.

Genetic and environmental influences on growth

OBJECTIVES

To provide an overview of the factors associated with growth in primary school children in England and Scotland and to provide information about the secular trend of growth in the last 20 years.

SETTING

Representative English and Scottish samples and an English inner city sample.

METHODS

The study had a mixed longitudinal design from 1972 to 1994. Between 8000 and 10,000 children participated in each survey. Height was measured in at least 95% of the children in most surveys, and 75% to 85% of parents provided information about family background. Main results are based on published information. Multiple regression was used for most of the analyses.

RESULTS

Parents' height, child's birth weight, mother's age at child's delivery, ethnic background and, in white children, family size are the only factors markedly associated with height. Variables that have traditionally been used to assess the possible effect of social conditions were generally not associated with height. The height increase was more marked in Scotland than England over the period 1972 to 1990, and the differences in height of children in the two countries is now minimal.

CONCLUSIONS

Most factors cannot be neatly classified as purely genetic or environmental, but seem to indicate that genes are relatively more important. Social factors usually assessed in growth studies do not have an important effect on growth. The marked increase of height over time indicates that the environment and social conditions have allowed children to grow taller. Sibship size is the only factor that was shown to be related to the secular trend in growth.

Deprivation and hospital use in a non-metropolitan region of England

OBJECTIVE

To investigate influences on hospital use in a non-metropolitan region of England (Wessex).

DESIGN

Least-squares regression analysis was used to identify area predictors, at local authority level, of number of consultant episodes and (separately) of bed use. Variables were assigned for deprivation, strength of primary care, private sector provision, and local levels of ill health. Short-stay (less than 30 days) episodes and bed use were examined separately from long stays.

RESULTS

There were substantial differences between the regression models for number of episodes and bed use, and between those for short stays and long stays. Significant predictors of the number of short-stay episodes were: number of general practitioners, standardised mortality ratio and proportion of residents with limiting long-term illness; these variables did not predict bed use in short-stay episodes. None of the variables was significantly associated with long-stay episodes or bed use.

CONCLUSIONS

Analysis of geographic variation in hospital use should distinguish between short-stay and long-stay use, and should defend the choice of number of admissions versus bed use as the dependent variable. Deprivation was not shown to be a factor influencing bed use in Wessex. This finding argues against the use of a single funding formula across the whole of the country.

Confinement of winter birth excess in schizophrenia to the urban-born and its gender specificity

BACKGROUND

The season of birth phenomenon in schizophrenia was reexamined in relation to place of birth, in order to test the hypothesis that a seasonal factor might operate preferentially among those who were urban-born.

METHOD

The seasonal distribution of births was examined among 3253 patients in two case registers having an ICD-9 diagnosis of schizophrenia and compared with the distribution of births among the normal population born in those catchment areas over the same period; those subjects born in population centres greater than 50,000 were defined as urban-born.

RESULTS

Patients who were urban-born showed an excess of winter births relative to controls that was absent among their rural-born counterparts. On comparing patient groups, those who were urban-born were more likely to be born in the winter, while those who were rural-born were more likely to be born in the spring; this urban-rural distinction was confined essentially to female patients.

CONCLUSIONS

These findings might be accommodated most readily in terms of a spatially as well as seasonally varying environmental factor that is associated with urbanicity and to which female offspring are more vulnerable.