Mylène Riva

Toward the next generation of research into small area effects on health: a synthesis of multilevel investigations published since July 1998

To map out area effects on health research, this study had the following aims: (1) to inventory multilevel investigations of area effects on self rated health, cardiovascular diseases and risk factors, and mortality among adults; (2) to describe and critically discuss methodological approaches employed and results observed; and (3) to formulate selected recommendations for advancing the study of area effects on health. Overall, 86 studies were inventoried. Although several innovative methodological approaches and analytical designs were found, small areas are most often operationalised using administrative and statistical spatial units. Most studies used indicators of area socioeconomic status derived from censuses, and few provided information on the validity and reliability of measures of exposures. A consistent finding was that a significant portion of the variation in health is associated with area context independently of individual characteristics. Area effects on health, although significant in most studies, often depend on the health outcome studied, the measure of area exposure used, and the spatial scale at which associations are examined.

Comparing alternative approaches to measuring the geographical accessibility of urban health services: Distance types and aggregation-error issues

BackgroundOver the past two decades, geographical accessibility of urban resources for population living in residential areas has received an increased focus in urban health studies. Operationalising and computing geographical accessibility measures depend on a set of four parameters, namely definition of residential areas, a method of aggregation, a measure of accessibility, and a type of distance. Yet, the choice of these parameters may potentially generate different results leading to significant measurement errors.The aim of this paper is to compare discrepancies in results for geographical accessibility of selected health care services for residential areas (i.e. census tracts) computed using different distance types and aggregation methods.ResultsFirst, the comparison of distance types demonstrates that Cartesian distances (Euclidean and Manhattan distances) are strongly correlated with more accurate network distances (shortest network and shortest network time distances) across the metropolitan area (Pearson correlation greater than 0.95). However, important local variations in correlation between Cartesian and network distances were observed notably in suburban areas where Cartesian distances were less precise.Second, the choice of the aggregation method is also important: in comparison to the most accurate aggregation method (population-weighted mean of the accessibility measure for census blocks within census tracts), accessibility measures computed from census tract centroids, though not inaccurate, yield important measurement errors for 5% to 10% of census tracts.ConclusionAlthough errors associated to the choice of distance types and aggregation method are only important for about 10% of census tracts located mainly in suburban areas, we should not avoid using the best estimation method possible for evaluating geographical accessibility. This is especially so if these measures are to be included as a dimension of the built environment in studies investigating residential area effects on health. If these measures are not sufficiently precise, this could lead to errors or lack of precision in the estimation of residential area effects on health.

Association between Neighborhood Active Living Potential and Walking

This paper examines the association between neighborhood active living potential and walking among middle-aged and older adults. A sample of 2,614 (61.1% women) persons aged 45 years or older and living in one of 112 census tracts in Montreal, Canada, were recruited between February and May of 2005 to participate in a 20-minute telephone survey. Data were linked to observational data on neighborhood active living potential in the 112 census tracts and analyzed through multilevel modeling. Greater density of destinations in the census tract was associated with greater likelihoods of walking for any reason at least 5 days per week for at least 30 minutes (odds ratio = 1.53, 95% confidence interval: 1.21, 1.94). Associations were attenuated but remained statistically significant after controlling for socioeconomic, health, lifestyle, and other physical activity characteristics. Sensitivity analyses showed that associations were robust across smaller and larger volumes of walking. No associations were found between dimensions of neighborhood active living potential and walking for recreational reasons. The authors conclude that a larger number and variety of neighborhood destinations in ones residential environment are associated with more walking and possibly more utilitarian walking among middle-aged or older adults.

Health geographies I: complexity theory and human health

This paper is the first of two linked progress reports on the application of ideas from complexity theory to health geography. In this paper we focus especially on research which seeks to explain variations in human health from a geographical perspective. We mainly discuss selected studies of geographies of human health which illustrate how ideas from complexity theory are applied empirically. In order to interpret more effectively the dynamic and recursive networks of relationships anticipated by complexity theory, future research will be required to go further in breaking down the divisions that are often assumed between research using different types of empirical methods. We comment on the potential to do this by means of advanced approaches to statistical and spatial modelling and by giving greater attention to the complementarity between these methods and qualitative techniques. We also discuss the emphasis in these examples on research which adopts an interdisciplinary strategy. Our conclusions refer forward to our companion report, which focuses more on studies of geographies of health care and health policy, emphasizing that complexity theory applied to health systems underlines the connections between health, health care and health policy.

Health geographies II: complexity and health care systems and policy

In this second of two progress reports on geographies of health, we continue a discussion framed from the perspective of complexity theory to consider research which is more particularly focused on health care and health policy. Using selected examples, we discuss how health care and policy have been influenced by ideas from complexity theory and consider the scope for more integrated health geography in future research. These studies illustrate changing perspectives in health geography on the integration of different parts of health systems and the implications for those who plan, deliver and receive health-related care and interventions. They show an increasingly sophisticated theorization of the ways in which understandings of ‘therapeutic’ settings are individually and socially constructed, and how to tackle issues of health inequality and achieve health improvement. These studies emphasize research which takes into account the dynamics of health care and health policy in time as well as space. A consideration of complexity theory raises questions about the potential for re-evaluating other theoretical frameworks and treating different theoretical perspectives as complementary rather than competing discourses.

Promoting active living among people with physical disabilities evidence for neighborhood-level buoys.

BACKGROUND People with physical disabilities are more likely to be sedentary than the general population, possibly because they have an accrued sensitivity to environmental features. OBJECTIVES This paper describes the relationship between neighborhood-level active living buoys and the active living practices of adults with physical disabilities living in a large urban area. METHODS A sample of 205 people with physical disabilities was recruited via a local rehabilitation center and its adapted fitness center. Telephone interviews were administered by senior occupational therapy students. The interview included a modified version of the Physical Activity and Disability Survey, a validated instrument that includes questions on physical activity, active transportation, and other activities of daily living. Individuals were geocoded within their census tract of residence (n=114) using their postal codes. Data on neighborhood active living potential were gleaned from systematic social observation. RESULTS Multilevel logistic regression analyses showed that the association between the presence of environmental buoys and leisure activity was significant (OR=4.0, 95% CI=1.1-13.8) despite adjustments for individual difference variables while the association with active transportation became nonsignificant (OR=2.9, 95% CI=0.7-7.7) following adjustment for these variables. CONCLUSIONS People with physical disabilities who live in neighborhoods with more environmental buoys are more likely to report involvement in leisure-time physical activity.

Household crowding is associated with higher allostatic load among the Inuit

Background Household crowding is an important problem in some aboriginal communities that is reaching particularly high levels among the circumpolar Inuit. Living in overcrowded conditions may endanger health via stress pathophysiology. This study examines whether higher household crowding is associated with stress-related physiological dysregulations among the Inuit. Methods Cross-sectional data on 822 Inuit adults were taken from the 2004 Qanuippitaa? How are we? Nunavik Inuit Health Survey. Chronic stress was measured using the concept of allostatic load (AL) representing the multisystemic biological ‘wear and tear’ of chronic stress. A summary index of AL was constructed using 14 physiological indicators compiled into a traditional count-based index and a binary variable that contrasted people at risk on at least seven physiological indicators. Household crowding was measured using indicators of household size (total number of people and number of children per house) and overcrowding defined as more than one person per room. Data were analysed using weighted Generalised Estimating Equations controlling for participants’ age, sex, income, diet and involvement in traditional activities. Results Higher household crowding was significantly associated with elevated AL levels and with greater odds of being at risk on at least seven physiological indicators, especially among women and independently of individuals’ characteristics. Conclusions This study demonstrates that household crowding is a source of chronic stress among the Inuit of Nunavik. Differential housing conditions are shown to be a marker of health inequalities among this population. Housing conditions are a critical public health issue in many aboriginal communities that must be investigated further to inform healthy and sustainable housing strategies.

Hard times or good times? Inequalities in the health effects of economic change.

The financial crisis in 2007 led to a deepening economic recession with global reductions in economic growth and rising unemployment. This has led to renewed discussions about the effects of economic cycles on population health both in the popular media and in academia. The media coverage tends to speculate on the idea that mortality increases around times of economic downturn, reflecting findings from some research which suggests that mortality trends are ‘counter-cyclical’ to economic trends. However, there appear to be varying views in the academic literature concerning the relationship between macroeconomic fluctuations and population health. A ‘pro-cyclical’ relationship has been reported in several studies; i.e. mortality rates get worse when the economy is growing and improve during periods of economic recession (Gerdtham and Ruhm 2006; Ruhm 2000; Tapia Granados 2005; Tapia Granados and Ionides 2008; Laporte 2004; Neumayer 2004). In other words, economic recession is associated with relatively good population health. Many mechanisms have been put forward to explain this, including an increase in work demands and working hours during periods of growth, heavier traffic generating more accidents, increase in consumption of alcohol (Ruhm and Black 2002) and tobacco (Ruhm 2000), as well as reductions in physical activity levels (Ruhm 2000), leisure time and social interactions. However, in this commentary, we argue that not only do the health effects of the macroeconomic cycle vary in respect to how key factors are measured (i.e. competing measures of the economic cycle, lag effect, variation by health outcome), but they also depend on individuals’ characteristics and place of residence. Probing beneath the surface shows that the relationship between macroeconomic cycles and health is not evenly distributed across the population. Some studies report that men are more affected than women by changes in the economic cycle (Edwards 2008; Gerdtham and Johannesson 2005). For example, a Swedish study observed that mortality increased for men during recession, but this association was not observed among women (Gerdtham and Johannesson 2005). An American study reported that higher unemployment rate at the state level was associated with lower mortality among working age and older men and among older women, but not among women of working age (Edwards 2008). Health inequalities by sex could be explained by differences between men and women according to the type of work and industrial sector of employment. Men are more likely to work in the private sector and in parts of the economy conventionally more vulnerable to economic downturns (such as finance and business services, manufacturing, construction) (Office for National Statistics 2009). There is evidence suggesting that the health impact of economic fluctuations also vary by age groups with, e.g. greater risk of mortality among younger Americans (Ruhm 2000; Tapia Granados 2005) although these studies did not test whether estimates are statistically significant different between age groups (and historically, younger people have had relatively low employment rates compared to ‘prime-age’ workers). In addition, negative impacts of economic contraction appear to extend beyond those of working age to affect the health of older adults M. Riva (&) C. Bambra S. Easton S. Curtis Department of Geography, Durham University, Science Laboratories, South Road, Durham DH1 3LE, UK e-mail: mylene.riva@durham.ac.uk

All in It Together? The Effects of Recession on Population Health and Health Inequalities in England and Sweden, 1991–2010

This article is the first to comparatively examine the effects of two recessions on population health and health inequalities in the two historically contrasting welfare states of England and Sweden. Data from 1991–2010 on self-reported general health, age, gender, and educational status were obtained from the Health Survey for England, the Swedish Survey of Living Conditions, and the European Union Survey of Income and Living Conditions, for individuals aged over 16. Generalized linear models were used to test the effects of recessions on self-reported health and educational inequalities in health. Overall, recessions had a significant positive effect on the health of women—but not men—in both England (4%) and Sweden (7%). In England, this improvement was only enjoyed by the most educated women, with the health of less educated women declining during recession. In contrast, in Sweden, the health of all women improved significantly during recession regardless of their educational status, although the most educated benefitted the most. Relative educational inequalities in self-reported health therefore increased during recessions in both countries by 14 percent (England) and 17 percent (Sweden) but for different reasons. This study suggests that Swedens welfare state protects the health of all during recessions.

Household Crowding and Food Insecurity Among Inuit Families With School-Aged Children in the Canadian Arctic

OBJECTIVES We examined the relation of household crowding to food insecurity among Inuit families with school-aged children in Arctic Quebec. METHODS We analyzed data collected between October 2005 and February 2010 from 292 primary caregiver-child dyads from 14 Inuit communities. We collected information about household conditions, food security, and family socioeconomic characteristics by interviews. We used logistic regression models to examine the association between household crowding and food insecurity. RESULTS Nearly 62% of Inuit families in the Canadian Arctic resided in more crowded households, placing them at risk for food insecurity. About 27% of the families reported reducing the size of their childrens meals because of lack of money. The likelihood of reducing the size of childrens meals was greater in crowded households (odds ratio=3.73; 95% confidence interval=1.96, 7.12). After we adjusted for different socioeconomic characteristics, results remained statistically significant. CONCLUSIONS Interventions operating across different levels (community, regional, national) are needed to ensure food security in the region. Targeting families living in crowded conditions as part of social and public health policies aiming to reduce food insecurity in the Arctic could be beneficial.