Interrelations between three proxies of health care need at the small area level: an urban/rural comparison

Study objective: To examine the relations between geographical variations in mortality, morbidity, and deprivation at the small area level in the south west of England and to assess whether these relations vary between urban and rural areas.

Design: A geographically based cross sectional study using 1991 census data on premature limiting long term illness (LLTI) and socioeconomic characteristics, and 1991–1996 data on all cause premature mortality. The interrelations between the three widely used proxies of health care need are examined using correlation coefficients and scatterplots. The distribution of standardised LLTI residuals from a regression analysis on mortality are mapped and compared with the distribution of urban and rural areas. Multilevel Poisson modelling investigates whether customised deprivation profiles improve upon a generic deprivation index in explaining the spatial variation in morbidity and mortality after controlling for age and sex. These relations are examined separately for urban, fringe, and rural areas.

Setting: Nine counties in the south west of England.

Participants: Those aged between 0–64 who reported having a LLTI in the 1991 census, and those who died during 1991–1996 aged 0–74.

Main results: Relations between both health outcomes and generic deprivation indices are stronger in urban than rural areas. The replacement of generic with customised indices is an improvement in all area types, especially for LLTI in rural areas. The relation between mortality and morbidity is stronger in urban than rural areas, with levels of LLTI appearing to be greater in rural areas than would be predicted from mortality rates. Despite the weak direct relations between mortality and morbidity, there are strong relations between the customised deprivation indices computed to predict these outcomes in all area types.

Conclusions: The improvement of the customised deprivation indices over the generic indices, and the similarity between the mortality and morbidity customised indices within area types highlights the importance of modelling urban and rural areas separately. Stronger relations between mortality and morbidity have been revealed at the local authority level in previous research providing empirical evidence that the inadequacy of mortality as a proxy for morbidity becomes more marked at lower levels of aggregation, especially in rural areas. Higher levels of LLTI than expected in rural areas may reflect different perceptions or differing patterns of illness. The stronger relations between the three proxies in urban than rural areas suggests that the choice of indicator will have less impact in urban than rural areas and strengthens the argument to develop better measures of health care need in rural areas.

     

The Index of Multiple Deprivation 2000 and accessibility effects on health

STUDY OBJECTIVE: To investigate whether the Index of Multiple Deprivation 2000 (IMD) is more strongly related to inequalities in health in rural areas than traditional deprivation indices. To explore the contribution of the IMD domain "geographical access to services" to understanding rural health variations. DESIGN: A geographically based cross sectional study. SETTING: Nine counties in the south west region of England. PARTICIPANTS: All those aged below 65 who reported a limiting long term illness in the 1991 census, and all those who died during 1991-96, aged less than 65 years. MAIN RESULTS: The IMD is comparable with the Townsend score in its overall correlation with premature mortality (r(2) = 0.44 v 0.53) and morbidity (r(2) = 0.79 v 0.76). Correlation between the Townsend score and population health is weak in rural areas but the IMD maintains a strong correlation with rates of morbidity (r(2) = 0.70). The "geographical access to services" domain of the IMD is not strongly correlated with rates of morbidity in rural areas (r(2) = 0.04), and in urban areas displays a negative correlation (r(2) = -0.47). CONCLUSIONS: The IMD has a strong relation with health in both rural and urban areas. This is likely to be the result of the inclusion of data in the IMD on the numbers of people claiming benefits related to ill health and disability. The domain "geographical access to services" is not associated with health in rural areas, although it displays some association in urban areas. This domain is potentially important but, as yet, inadequately specified in the IMD for the purposes of health research.     

Health underachievement and overachievement in English local authorities

OBJECTIVE: To identify English local authorities that "overachieve" and "underachieve" in health terms, given their level of deprivation, sociodemographic context, and region. DESIGN: Cross sectional study using data from the 1991 UK census and mortality data from 2000-2. SETTING: England. PARTICIPANTS: 354 local authorities (total population 49 558 000). MAIN OUTCOME MEASURES: Life expectancy. Residual life expectancy after regression analysis. RESULTS: In general, the more materially deprived the population of a local authority was in 1991, the lower its life expectancy a decade later, with men being more sensitive to the effects of deprivation than women. Many local authorities, however, did not follow this general trend, and these shared common characteristics. Mining, Manufacturing and Industry, and Urban Fringe authorities collectively had lower life expectancies than predicted by their level of deprivation, as did authorities located in the north west. Outer London and Education Centres and Inner London authorities had much higher life expectancies than predicted, as did authorities located in the east, south east, and south west. Given their level of deprivation, sociodemographic context, and region, 11 local authorities significantly overachieved for male life expectancy and 10 underachieved, while 12 overachieved for female life expectancy and three underachieved. CONCLUSIONS: Life expectancy in English local authorities is strongly associated not only with material deprivation, but with the local sociodemographic context and the region where the authority is located. Some authorities defy their contexts, however, and overachieve in health terms, while others, including some in affluent areas, underachieve.     

Urban-rural differences in self-reported limiting long-term illness in Scotland

BACKGROUND: Previous research suggests that there are significant differences in health between urban and rural areas. The aim of this study is to describe the pattern and magnitude of urban-rural variation in health in Scotland and to examine the factors associated with health inequalities in urban and rural areas. METHODS: The data used in this study were limiting long-term illness (LLTI) and socio-economic data collected by the 1991 Census. A rurality indicator was created using Scottish Household Survey rurality classifications. Multilevel Poisson regression modelling was carried out with LLTI as a health indicator for each type of rurality within Scotland. A variety of socio-economic factors were investigated for each rurality. RESULTS: Areas with the highest Standardized Illness Ratios (SIRs) (>125) are predominantly urban whereas the lowest SIRs (<75) are found in both urban and rural areas. Rural communities are more heterogeneous than urban areas in terms of their social make-up with relation to health; however, when these areas are split according to minor road length and different socio-economic factors are added, the model fit for each new model is improved and the reduction in total variation is comparable with that of the urban models. CONCLUSION: These findings suggest that rural areas should not be treated as a homogeneous group but should be subdivided into rural types.     

The combined impact of rural residence and socio-economic status on premature mortality

The health of rural and urban populations differs, with rural areas appearing healthier. However, it is unknown whether the benefit of living in rural areas is felt by individuals in all levels of deprivation, or whether some suffer a disadvantage of rural residence. For England and Wales 2001–2003 premature mortality rates were calculated, subdivided by individual deprivation and gender, for areas with differing rurality characteristics. Premature mortality data (age 50-retirement) and a measure of the individual's deprivation (National Statistics Socio-economic Classification 1–7) was obtained from death certificates. Overall premature mortality was examined as well as premature mortality subdivided by major cause. Male premature mortality rates (age 50–64) fell with increasing rurality for individuals in all socio-economic status classifications. The most deprived individuals benefitted most from residence in increasingly rural areas. Similar trends were observed when premature mortality was subdivided by the major causes of death. Female premature mortality rates (age 50–59) demonstrated similar trends but the differences between urban and rural areas were less marked.     

Changes in socioeconomic inequalities in census measures of health in England and Wales, 1991-2001

STUDY OBJECTIVES: To investigate changes in socioeconomic inequalities in census measures of health in England and Wales between 1991 and 2001. DESIGN: Indirect standardisation was used to calculate age standardised rates of limiting long term illness and permanent sickness in men and women in all residential wards in England and Wales in 1991 and 2001. The socioeconomic position of each ward was determined using Townsend deprivation scores. SETTING: All residential wards in England and Wales in 1991 and 2001. PARTICIPANTS: All people aged 16-65 who provided census information in the 1991 or 2001 censuses. MAIN RESULTS: There was strong evidence that Townsend deprivation score quintile could predict both logged standardised permanent sickness rate and logged standardised limiting long term illness rate. There was evidence that socioeconomic inequalities in standardised limiting long term illness rates decreased between 1991 and 2001 in both men and women and that socioeconomic inequalities in standardised permanent sickness rates decreased in women but increased in men between 1991 and 2001. CONCLUSIONS: As permanent sickness rates seem to reflect labour market accessibility, this study may have found evidence that socioeconomic inequalities in self reported morbidity decreased but inequalities in labour market participation in men increased between 1991 and 2001.     

Geographical and social variations in mortality due to childhood accidents in England and Wales 1975–1984

An analysis was made of the death rates from accidents in children aged 0-14 by health districts in England and Wales during the five year periods 1974-79 and 1980-84. Death rates were generally higher in the north and west of England and lower in the south and east. Rates were higher in urban areas than in rural areas. There was a more than five-fold difference between the highest and lowest rates by districts during both periods. There was a very strong correlation with social deprivation. Greater efforts are required to reduce unnecessary deaths and disability from childhood accidents. The lessons already learned in many parts of the world must now be put into much wider use and practice in the United Kingdom.     

Geographical patterns of excess mortality in Spain explained by two indices of deprivation

STUDY OBJECTIVE: To analyse the geographical patterns and the magnitude of the association between deprivation and mortality in Spain. To estimate the excess of mortality in more deprived areas of the country by region. DESIGN: Cross sectional ecological study using 1991 census variables and mortality data for 1987-1992. SETTING: 2220 small areas in Spain. MAIN RESULTS: A geographical gradient from north east to south west was shown by both mortality and deprivation levels in Spain. Two dimensions of deprivation (that is, Index 1 and Index 2) obtained by exploratory factor analysis using four census indicators were found to predict mortality: mortality over 65 years of age was more associated with Index 1, while mortality under 65 years of age was more associated with Index 2. Excess mortality in the most deprived areas accounted for about 35,000 deaths. CONCLUSIONS: Two indices of deprivation strongly predict mortality in two age groups. Excess number of deaths in the most deprived geographical areas account for 10% of total number of deaths annually. In Spain there is great potential for reducing mortality if the excess risk in more deprived areas fell to the level of the most affluent areas.     

Urban-rural differences in suicide trends in young adults: England and Wales, 1981-1998

Suicide rates amongst young people, particularly males, have increased in many industrialised countries since the 1960s. There is evidence from some countries that the steepest rises have occurred in rural areas. We have investigated whether similar geographical differences in trends in suicide exist in England and Wales by examining patterns of suicide between 1981 and 1998 in relation to rurality. We used two complementary population-based indices of rurality: (1) population density and (2) population potential (a measure of geographic remoteness from large concentrations of population). We used the electoral ward (n=9264, median population aged 15-44: 1829) as the unit of analysis. To assess whether social and economic factors underlie rural-urban differences in trends we used negative binomial regression models to investigate changes in suicide rates between the years for which detailed national census data were available (1981 and 1991). Over the years studied, the most unfavourable trends in suicide in 15-44-year olds generally occurred in areas remote from the main centres of population; this effect was most marked in 15-24-year-old females. Observed patterns were not explained by changes in age- and sex-specific unemployment, socio-economic deprivation or social fragmentation. The mental health of young adults or other factors influencing suicide risk may have deteriorated more in rural than urban areas in recent years. Explanations for these trends require further investigation.     

Place and personal circumstances in a multilevel account of women's long-term illness

This paper investigates geographical variations in women's reports of limiting long-term illness in terms of individual inequalities and the contribution of area characteristics among wards and county districts. We use multilevel modelling of linked census data from the Office for National Statistics Longitudinal Study for England and Wales. We follow a random sample of 76.374 women aged between 16 and 45 at the time of the 1971 Census for 20 years to observe their reported limiting long-term illness (LLTI) at the 1991 Census. Car and home ownership were useful markers of social and material advantage, apparently protecting against the risk of reporting LLTI. Migration into the South-East region appeared beneficial, but otherwise there was little difference between those who moved home and those who did not. Differences between county districts persist after adjustment for individual circumstances (education and ethnicity), but almost all of these differences are explained by the social profile of wards in these areas. Geographical differences in LLTI are not, therefore, entirely explained by the distribution of individual characteristics: a woman with the same history may face a different risk of illness in different kinds of area. For women, the social composition of the locality (using the ward as a proxy) is more relevant than the broader economic and industrial classification of the surrounding county district, which is more important for health inequalities among men.     

Unravelling the extent of inequalities in health across urban and rural areas: Evidence from a national sample in England

Studies of inequalities in health between rural and urban settings have produced mixed and sometimes conflicting results, depending on the national setting of the study, the level of geographic detail used to define rural areas and the health indicators studied. By focusing on morbidity data from a national sample of individuals, this study aims to examine the extent of inequalities in health between urban and rural areas, as well as inequalities in health across rural areas of England. Multilevel analyses for poor self-rated health, overweight and obesity, and common mental disorders are reported for a sample of 30,776 individuals aged 18 years and older (obtained from the Health Survey for England years 2000–2003 combined) and distributed across 3645 small areas classed in four categories: two groups of urban areas (Greater London area or ‘other cities’) and two types of rural settings (semi-rural areas or villages). Results show that rural dwellers were significantly less likely than residents of urban areas to report their health as being fair or poor and to report common mental disorders, independent of their socio-demographic characteristics. However, as for urban settlements, there were significant variations in health across semi-rural areas and across villages, indicating the presence of health inequalities within rural settings in England. These inequalities were not fully explained by the individual composition of the areas or by the available measures of area socioeconomic conditions, indicating that in rural contexts more specific factors may have significance for health. Different policies and services for health promotion and care may need to be targeted to different types of rural areas.     

Studying place effects on health by synthesising individual and area-level outcomes

It is well established that there exist substantial area-level socio-demographic variations in population health. However, area-level associations between deprivation and health cannot necessarily be interpreted as place effects on individual health. We demonstrate how recently developed statistical models for combining individual and aggregate data can help to separate the effects of place of residence and personal circumstances. We apply these to two health outcomes: risk of hospitalisation for cardiovascular disease (CVD) and risk of self-reported limiting long-term illness (LLTI). A combination of small-area data from UK hospital episode statistics and the UK census and individual data from the Health Survey for England are analysed, using a new multilevel modelling method termed hierarchical related regression (HRR). The standard multilevel model for place and health explains outcomes from individual data in terms of individual and area-level characteristics. HRR models increase precision by also explaining population aggregate outcomes, in terms of the same predictors. Aggregate outcomes are modelled by averaging the individual-level exposure-outcome relationship over the area, which can alleviate the ecological bias associated with interpreting the relationship between aggregate quantities as an individual-level relationship. We find that there are associations between area-level deprivation indicators and both area-level rates of hospital admission for CVD and area-level rates of LLTI. Multilevel models fitted to the individual data alone had insufficient power to determine whether these associations were due to compositional or contextual effects. Using HRR models which incorporate area-level outcomes in addition to individual outcomes, we found that for CVD, the area-level differences were mostly explained by individual-level effects, in particular the increased risk for individuals from non-white ethnic backgrounds. In contrast, there remained a significant association between LLTI and area-level deprivation even after adjusting for the significant increased risk associated with individual-level ethnicity and income. Our study illustrates that extending multilevel models to incorporate both individual and area-level outcomes increases power to distinguish between contextual and compositional effects.     

Deprivation and poor health in rural areas: inequalities hidden by averages

Poor health and social deprivation scores in 570 wards in East Anglia, UK, were much less associated in rural than in urban areas. The deprivation measure most closely related to poor health in the least accessible rural wards was male unemployment, but use of this measure did not remove the urban-rural gradient of association strength. Neither did replacing wards by smaller enumeration districts as the units of analysis. The differences between urban and rural correlations were removed by restricting the comparison to wards with the same unemployment range and combining pairs of rural wards with similar deprivation values. Apparent differences between rural and urban associations are therefore not due to the choice of deprivation indices or census areas but are artifacts of the greater internal variability, smaller average deprivation range and smaller population size of rural small areas. Deprived people with poor health in rural areas are hidden by favourable averages of health and deprivation measures and do not benefit from resource allocations based on area values.     

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.     

An exploratory spatial data analysis approach to understanding the relationship between deprivation and mortality in Scotland

This paper considers the spatial characteristics of the relationship between deprivation and mortality rates in Scotland. Scotland not only has higher average mortality rates than England and Wales but the greatest spatial concentrations of the poorest health areas in Britain. Recent analysis has suggested that degree of deprivation alone cannot explain the majority of Scotland's 'excess' poor health relative to England and Wales, a finding referred to as the 'Scottish effect'. This analysis considers if the spatial patterning of deprivation could be significant to understanding of high mortality in Scotland. Exploratory spatial data analysis methods are implemented to study the spatial relationships between deprivation and standardised mortality ratios (SMRs) in post-code sectors in Scotland. Deprivation was measured using the 2001 Carstairs score, and the total number of deaths during a 3-year period around the 2001 census was used to calculate SMRs. A strong spatial relationship is observed between deprivation and mortality. Deprivation impacts mortality levels not only within the same areas but also in spatially proximate areas. It is concluded that, further research on the 'Scottish effect' can benefit from new methodological approaches which assess the variation in both the extent and spatial arrangement of deprivation and mortality in small areas.     

Effect of labour market conditions on reporting of limiting long-term illness and permanent sickness in England and Wales.

STUDY OBJECTIVE: To identify any bias in the reporting of limiting long term illness and permanent sickness due to labour market conditions, and show the absence of the effect in mortality rates. DESIGN: A geographically based study using data from the 1991 census. Standardised ratios for mortality and long term illness in people aged 0-64 years and permanent sickness in people of working age were compared with Carstairs deprivation scores in multilevel models which separated the effects operating at three geographical scales: census wards, travel to work areas, and standard regions. Holding ward and regional effects constant, variations between travel to work areas were compared with long term unemployment rates. SETTING: Altogether 8690 wards and 262 travel to work areas in England and Wales. MAIN RESULTS: Variations in mortality, limiting long term illness, and permanent sickness were related to Carstairs deprivation scores and standard region. With these relationships controlled, limiting long term illness and permanent sickness were significantly related to long term unemployment levels in travel to work areas, but mortality was not affected. Self reported morbidity was more sensitive to variations in long term unemployment rates in conditions of high social deprivation than in affluent populations. CONCLUSIONS: Limiting long term illness and permanent sickness measures may reflect a tendency for higher positive response in difficult labour market conditions. For average social deprivation conditions, standardised limiting long term illness for people aged 0-64 years was 20% higher in travel to work areas where employment prospects were relatively poor compared with areas with relatively good employment prospects. This casts doubt on the use of limiting long term illness as an indicator of objective health care needs for resource allocation purposes at national level.     

Does car ownership reflect socio-economic disadvantage in rural areas? A cross-sectional geographical study in Wales,UK

It is widely believed that area-based deprivation indices that include the car ownership census variable are poor indicators of deprivation in rural areas since car ownership is a necessity of rural life. In this cross-sectional geographical study, we assess whether the relation between lack of car ownership and socio-economic deprivation varies between urban and rural enumeration districts of Wales, UK. We classified the 6376 census enumeration districts in Wales into rural (1636, 26%) and urban (4740, 74%), using the Office for National Statistics' classification based on land use. Rank correlation coefficients between the proportion of households with no car and a range of other proxy deprivation census variables were strongly positive in urban and the most densely populated rural enumeration districts. However, these correlations were weaker in sparsely populated rural enumeration districts, with a declining trend across deciles of population density. Exclusion of the car ownership variable from the Townsend index of deprivation re-categorized rural enumeration districts as more deprived and urban enumeration districts as less deprived compared with the standard Townsend index. Our results suggest that lack of car ownership is a poor proxy for social deprivation in the most sparsely populated rural areas of Wales, and therefore, deprivation indices that include the car ownership variable are less valid for use in rural areas.     

An index of unhealthy lifestyle is associated with coronary heart disease mortality rates for small areas in England after adjustment for deprivation

Indices of socio-economic deprivation are often used as a proxy for differences in the health behaviours of populations within small areas, but these indices are a measure of the economic environment rather than the health environment. Sets of synthetic estimates of the ward-level prevalence of low fruit and vegetable consumption, obesity, raised blood pressure, raised cholesterol and smoking were combined to develop an index of unhealthy lifestyle. Multi-level regression models showed that this index described about 50% of the large-scale geographic variation in CHD mortality rates in England, and substantially adds to the ability of an index of deprivation to explain geographic variations in CHD mortality rates.     

Are health inequalities between differently deprived areas evident at different ages? A longitudinal study of census records in England and Wales, 1991–2001

The notion that mortality inequalities between differently deprived areas vary by age is logical since not all causes of death increase in risk with age and not all causes of death are related to the gradient of deprivation. In addition to the cause-age and cause-deprivation relationships, population migration may redistribute the population such that the health-deprivation relationship varies by age.We calculate cross-sectional all cause mortality and self-reported limiting long-term illness (LLTI) rate ratios of most to least deprived areas to demonstrate inequalities at different ages. We use longitudinal data to investigate whether there are changes in the distribution of cohorts between differently deprived areas over time and whether gradients of LLTI with deprivation also change.We find similar deprivation inequalities by age for all cause mortality and self-reported health with less inequality for young adults and the elderly but the greatest inequalities during mid life. Over time there are systematic movements of cohorts between differently deprived areas and associated increases and decreases in the gradient of LLTI across deprivation. It seems likely that population migration does influence inequalities by age. Further work should investigate whether the situation exists for other morbidities and, to better inform public health policy, whether restricting summary measures of area health to ages between 30 and 60 when inequalities are greatest will highlight between area differences.     

Mortality, long-term illness and deprivation in rural and metropolitan wards of England and Wales

The relationships between mortality, limiting long-term illness and indicators of social deprivation were investigated using regression analysis on data for rural wards, metropolitan wards and the remaining wards in England and Wales. Regional differences were controlled. In rural wards, people had better health than average and slightly better health than would be expected from their deprivation scores. Average levels of health in rural areas were only weakly related to deprivation, which was partly but not fully due to the restricted range of average deprivation values in rural wards. In metropolitan areas, relatively poor levels of health were largely explained by social deprivation, but people in Inner London were healthier than might be expected from measures of deprivation. The relationship between health and social deprivation is therefore not uniform over England and Wales, but varies between geographical types of area. One consequence is that resource allocation on the basis of social deprivation would put the populations of rural areas and Inner London at an advantage.