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Social Capital: evidence from large scale surveys. Social capital, place and health: developing and applying small-area indicators of social capital in the investigation of health inequalities. John Mohan 1 , Liz Twigg 2 , 1 University of Southampton, 2 University of Portsmouth
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Social Capital: evidence from large scale surveys Social capital, place and health: developing and applying small-area indicators of social capital in the investigation of health inequalities John Mohan1, Liz Twigg2, 1University of Southampton, 2University of Portsmouth (J.F.Mohan@soton.ac.uk, liz.twigg@port.ac.uk)
1. Introduction • Social capital may have a contextual effect on health outcomes • Much work appears to demonstrate a plausible association BUT is at a large geographical scale (e.g. States in the USA). • When replicated in the UK very little of significance is found. • We wanted to create small-area indicators to investigate whether social capital operated at a different scale of resolution.
2. Direct estimates • Direct observations of community norms (e.g. Chicago neighbourhoods project – systematic social observation BUT difficult to scale up) • Blood donation – relative propensity to engage in altruistic acts • But may say as much about NBS as about social capital • Also likely to reflect health status
3. ‘Multilevel’ synthetic estimates. • Use national survey responses on social capital questions • Model responses using multilevel methods • Probability that individuals will engage in s.c. activities will be a function of: • Individual characteristics (age, gender, SES, etc) • Contextual circumstances (characteristics of place) AND • Interactions between the two
“Modelling nationally, predicting locally” • ML equations are re-worked using census data • Estimates of several possible proxies for social capital at small area level • ‘Value-added’ approach to the analysis of large-scale survey data
Social capital estimates:- • General Household Survey • Volunteering and ‘core volunteering’ • British Household Panel Survey • Active in political/ social/ altruistic activities • ‘Belongs’ to the neighbourhood • Local friends are important • Willing to work with others to improve the neighbourhood • Talks regularly to local friends • Frequently meets local friends and relatives • Voted in ’97 general election • Survey of English Housing • Thinks that the area is friendly
Example:-Altruistic activityNB Active in 2 or more of the following Tenants’ GroupReligious GroupVolunteer GroupOther community groupWomen’s Institute
4. The impact of social capital on health outcome HEALTH AND LIFESTYLE SURVEY (HALS) • 9003 individuals in 1984/5 (surveyed on health, lifestyle, socio-economic characteristics and also aspects of social capital) • 2001 individuals ‘health’ outcome assessed via mortality status (1882 deaths) • ML Binary Logistic Modelling: total of 585 models! (Different combinations of individual/areal social capital, areal deprivation and individual socio-structural measures) • Summary presented here
Initial exploratory sequence STAGE 1 Assess influence of individual SC (HALS derived) after controlling for individual confounders (age, sex, tenure, social class, and HRBs) STAGE 2 Assess influence of areal SC (direct measure and estimates) after controlling for individual confounders (age, sex, tenure, social class, and HRBs) STAGE 3 Importance of areal measures of material deprivation contrasted against the results from above
Initial exploratory sequence designed to:- • Report the overall impact of area social capital once all individual variables have been taken into account • Monitor attenuation of social capital after areal deprivation brought into the equation
Results 1:- • No effect for individual social capital (measured through HALS) • Higher OR reported for areal deprivation (in models without areal social capital) OR = 1.23 for ‘deprived’ • Higher OR for low levels of volunteering; social; altruistic and political activities (in models without areal deprivation). The OR range from 1.27 (low political activity) – 1.36 (low social activity).
Results 1 contd:- • When Carstairs index of deprivation added to the above, social capital coefficients become insignificant. • Deprivation terms remains significant in the political activity models (and some of the other models where SC did not have an impact) • NB None of these ecological measures of social capital or deprivation are as important as the effect for individual tenure (OR around 2.0 in the ecological models) • Blood donation and voter turnout are not significant, neither are dimensions relating to friends, neighbours and feeling part of the neigbourhood
Second phase:- • Summarise the maximum effects of areal social capital Odds of Dying = f(age and sex) + social capital • Determine whether i) individual HRBs and/or ii) individual material circumstances mediate this relationship i) Odds of Dying = f(age,sex, HRBs) + social capital ii) Odds of Dying = f(age,sex, class and tenure) + social capital Third phase:-
Results 2:-‘Maximum effects’ • Clear statistically significant gradient for:- • Volunteering; social activity; altruistic activity; political activity and voting behaviour (e.g. OR = 2.06 for lowest volunteering) ‘Mediating effects’ i) Adding in HRBs • Statistically significant gradients remain for:- • volunteering, social and political activities but now less strong (OR = 1.67) • Most HRBs remain significant and similar in all models.
Results 2 contd:- ‘Mediating effects’ ii) Adding in class and tenure • Statistically significant gradients remain only for volunteering but these are less strong • Impact of class and tenure remains fairly constant across all models.
6. Concluding thoughts • A valid procedure for producing small area estimates of social capital in which we have a degree of confidence • “value-added” • Little evidence for individual effects of social capital • Area effects of social capital on health: • Apparently an ecological effect but social capital indicators (used here) and deprivation are highly collinear so separating out their effects is problematic. • Some evidence to suggest that HRBs and individual material circumstance mediate the relationship between social capital and health
Further information:- Mohan et al, 2004:- “Social capital, place and health: creating,validating and applying small-area indicators in the modelling of health outcomes”. Available at http://www.publichealth.nice.org.uk/