Pregnancy in teenagers diagnosed with type 1 diabetes mellitus in childhood: a national population-based e-cohort study.

AIMS/HYPOTHESIS: The aim of this study was to describe the characteristics and outcomes of pregnancies in a national cohort of teenage (<20 years) and young adult women (≥20 years) with and without childhood-onset (<15 years) type 1 diabetes. We hypothesised that, owing to poor glycaemic control during the teenage years, pregnancy outcomes would be poorer in teenage mothers with type 1 diabetes than young adult mothers with type 1 diabetes and mothers without diabetes. METHODS: The Brecon Register of childhood-onset type 1 diabetes diagnosed in Wales since 1995 was linked to population-based datasets in the Secure Anonymised Information Linkage (SAIL) Databank, creating an electronic cohort (e-cohort) of legal births (live or stillbirths beyond 24 weeks' gestation) to women aged less than 35 years between 1995 and 2013 in Wales. Teenage pregnancy rates were calculated based on the number of females in the same birth cohort in Wales. Pregnancy outcomes, including pre-eclampsia, preterm birth, low birthweight, macrosomia, congenital malformations, stillbirths and hospital admissions during the first year of life, were obtained from electronic records for the whole Welsh population. We used logistic and negative binomial regression to compare outcomes among teenage and young adult mothers with and without type 1 diabetes. RESULTS: A total of 197,796 births were eligible for inclusion, including 330 to girls and women with childhood-onset type 1 diabetes, of whom 68 were teenagers (age 14-19 years, mean 17.9 years) and 262 were young adults (age 20-32 years, mean 24.0 years). The mean duration of diabetes was 14.3 years (9.7 years for teenagers; 15.5 years for young adults). Pregnancy rates were lower in teenagers with type 1 diabetes than in teenagers without diabetes (mean annual teenage pregnancy rate between 1999 and 2013: 8.6 vs 18.0 per 1000 teenage girls, respectively; p < 0.001). In the background population, teenage pregnancy was associated with deprivation (p < 0.001), but this was not the case for individuals with type 1 diabetes (p = 0.85). Glycaemic control was poor in teenage and young adult mothers with type 1 diabetes (mean HbA1c based on closest value to conception: 81.3 and 80.2 mmol/mol [9.6% and 9.5%], respectively, p = 0.78). Glycaemic control improved during pregnancy in both groups but to a greater degree in young adults, who had significantly better glycaemic control than teenagers by the third trimester (mean HbA1c: 54.0 vs 67.4 mmol/mol [7.1% vs 8.3%], p = 0.01). All adverse outcomes were more common among mothers with type 1 diabetes than mothers without diabetes. Among those with type 1 diabetes, hospital admissions during the first year of life were more common among babies of teenage vs young adult mothers (adjusted OR 5.91 [95% CI 2.63, 13.25]). Other outcomes were no worse among teenage mothers with type 1 diabetes than among young adult mothers with diabetes. CONCLUSIONS/INTERPRETATION: Teenage girls with childhood-onset type 1 diabetes in Wales are less likely to have children than teenage girls without diabetes. Teenage pregnancy in girls with type 1 diabetes, unlike in the background population, is not associated with social deprivation. In our cohort, glycaemic control was poor in both teenage and young adult mothers with type 1 diabetes. Pregnancy outcomes were comparable between teenage and young adult mothers with type 1 diabetes, but hospital admissions during the first year of life were five times more common among babies of teenage mothers with type 1 diabetes than those of young adult mothers with diabetes.

Measuring the impact of spatial network layout on community social cohesion: a cross-sectional study.

BACKGROUND: There is now a substantial body of research suggesting that social cohesion, a collective characteristic measured by the levels of trust, reciprocity and formation of strong social bonds within communities, is an important factor in determining health. Of particular interest is the extent to which factors in the built environment facilitate, or impede, the development of social bonds. Severance is a characteristic of physical environments which is hypothesized to inhibit cohesion. In the current study we test a number of characteristics of spatial networks which could be hypothesized to relate either to severance, or directly to community cohesion. Particular focus is given to our most promising variable for further analysis (Convex Hull Maximum Radius 600 m). METHODS: In the current study we analysed social cohesion as measured at Enumeration District level, aggregated from a survey of 10,892 individuals aged 18 to 74 years in the Caerphilly Health and Social Needs Cohort Study, 2001. In a data mining process we test 16 network variables on multiple scales. The variable showing the most promise is validated in a test on an independent data set. We then conduct a multivariate regression also including Townsend deprivation scores and urban/rural status as predictor variables for social cohesion. RESULTS: We find convex hull maximum radius at a 600 m scale to have a small but highly significant correlation with social cohesion on both data sets. Deprivation has a stronger effect. Splitting the analysis by tertile of deprivation, we find that the effect of severance as measured by this variable is strongest in the most deprived areas. A range of spatial scales are tested, with the strongest effects being observed at scales that match typical walking distances. CONCLUSION: We conclude that physical connectivity as measured in this paper has a significant effect on social cohesion, and that our measure is unlikely to proxy either deprivation or the urban/rural status of communities. Possible mechanisms for the effect include intrinsic navigability of areas, and the existence of a focal route on which people can meet on foot. Further investigation may lead to much stronger predictive models of social cohesion.

The role of health and social factors in education outcome: A record-linked electronic birth cohort analysis.

BACKGROUND AND OBJECTIVE: Health status in childhood is correlated with educational outcomes. Emergency hospital admissions during childhood are common but it is not known how these unplanned breaks from schooling impact on education outcomes. We hypothesised that children who had emergency hospital admissions had an increased risk of lower educational attainment, in addition to the increased risks associated with other health, social and school factors. METHODS: This record-linked electronic birth cohort, included children born in Wales between 1 January 1998 and 31 August 2001. We fitted multilevel logistic regression models grouped by schools, to determine whether emergency hospital inpatient admission before age 7 years was associated with the educational outcome of not attaining the expected level in a teacher-based assessment at age 7 years (KS1). We adjusted for pregnancy, perinatal, socio-economic, neighbourhood, pupil mobility and school-level factors. RESULTS: The cohort comprised 64 934 children. Overall, 4680 (7.2%) did not attain the expected educational level. Emergency admission to hospital was associated with poor educational attainment (OR 1.12 95% Credible Interval (CI) 1.05, 1.20 for all causes during childhood, OR 1.19 95%CI 1.07, 1.32 for injuries and external causes and OR 1.31 95%CI 1.04, 1.22 for admissions during infancy), after adjusting for known determinants of education outcomes such as extreme prematurity, being small for gestational age and socio-economic indicators, such as eligibility for free school meals. CONCLUSION: Emergency inpatient hospital admission during childhood, particularly during infancy or for injuries and external causes was associated with an increased risk of lower education attainment at age 7 years, in addition to the effects of pregnancy factors (gestational age, birthweight) and social deprivation. These findings support the need for injury prevention measures and additional support in school for affected children to help them to achieve their potential.

Evaluating cutpoints for the MHI-5 and MCS using the GHQ-12: a comparison of five different methods.

BACKGROUND: The Mental Health Inventory (MHI-5) and the Mental Health Component Summary score (MCS) derived from the Short Form 36 (SF-36) instrument are well validated and reliable scales. A drawback of their construction is that neither has a clinically validated cutpoint to define a case of common mental disorder (CMD). This paper aims to produce cutpoints for the MHI-5 and MCS by comparison with the General Health Questionnaire (GHQ-12). METHODS: Data were analysed from wave 9 of the British Household Panel Survey (2000), providing a sample size of 14,669 individuals. Receiver Operating Characteristic (ROC) curves were used to compare the scales and define cutpoints for the MHI-5 and MCS, using the following optimisation criteria: the Youden Index, the point closest to (0,1) on the ROC curve, minimising the misclassification rate, the minimax method, and prevalence matching. RESULTS: For the MHI-5, the Youden Index and the (0,1) methods both gave a cutpoint of 76, minimising the misclassification rate gave a cutpoint of 60 and the minimax method and prevalence matching gave a cutpoint of 68. For the MCS, the Youden Index and the (0,1) methods gave cutpoints of 51.7 and 52.1 respectively, minimising the error rate gave a cutpoint of 44.8 and both the minimax method and prevalence matching gave a cutpoint of 48.9. The correlation between the MHI-5 and the MCS was 0.88. CONCLUSION: The Youden Index and (0,1) methods are most suitable for determining a cutpoint for the MHI-5, since they are least dependent on population prevalence. The choice of method is dependent on the intended application. The MHI-5 performs remarkably well against the longer MCS.

Neighbourhood deprivation and self-rated health: the role of perceptions of the neighbourhood and of housing problems.

It has been known for a long time that people living in socially and economically deprived neighbourhoods generally experience poorer health. However, it is often not clear what processes underlie the relationship between neighbourhood deprivation and individual health. In this study we explore the association between neighbourhood socio-economic status and self-rated health using the Caerphilly Health and Social Needs Survey (n=10,892). We found that the association between neighbourhood deprivation and self-rated health was substantially reduced after adjusting for individual socio-economic status, but remained statistically significant. This suggests that the health effects of neighbourhood deprivation are partly contextual. We also found that the association between neighbourhood deprivation and self-rated health was further attenuated when controlling for perceptions of the neighbourhood and of housing problems, suggesting that these variables may play a role in mediating the health effects of neighbourhood deprivation. The implications of the results are that health policy should target 'places' as well as 'people'; and that policies aimed at improving the quality of housing, access to amenities, neighbourhood safety, and social cohesion may help to reduce health inequalities.

Measuring the neighbourhood using UK benefits data: a multilevel analysis of mental health status.

BACKGROUND: Evidence from multilevel research investigating whether the places where people live influence their mental health remains inconclusive. The objectives of this study are to derive small area-level, or contextual, measures of the local social environment using benefits data from the Department of Work and Pensions (DWP) and to investigate whether (1) the mental health status of individuals is associated with contextual measures of low income, economic inactivity, and disability, after adjusting for personal risk factors for poor mental health, (2) the associations between mental health and context vary significantly between different population sub-groups, and (3) to compare the effect of the contextual benefits measures with the Townsend area deprivation score. METHODS: Data from the Welsh Health Survey 1998 were analysed in Normal response multilevel models of 24,975 individuals aged 17 to 74 years living within 833 wards and 22 unitary authorities in Wales. The mental health outcome measure was the Mental Health Inventory (MHI-5) of the Short Form 36 health status questionnaire. The benefits data available were the means tested Income Support and Income-based Job Seekers Allowance, and the non-means tested Incapacity Benefit, Severe Disablement Allowance, Disability Living Allowance and Attendance Allowance. Indirectly age-standardised census ward ratios were calculated to model as the contextual measures. RESULTS: Each contextual variable was significantly associated with individual mental health after adjusting for individual risk factors, so that living in a ward with high levels of claimants was associated with worse mental health. The non-means tested benefits that were proxy measures of economic inactivity from permanent sickness or disability showed stronger associations with individual mental health than the means tested benefits and the Townsend score. All contextual effects were significantly stronger in people who were economically inactive and unavailable for work. CONCLUSION: This study provides evidence for substantive contextual effects on mental health, and in particular the importance of small-area levels of economic inactivity and disability. DWP benefits data offer a more specific measure of local neighbourhood than generic deprivation indices and offer a starting point to hypothesise possible causal pathways to individual mental health status.

Perceptions of the neighbourhood environment and self rated health: a multilevel analysis of the Caerphilly Health and Social Needs Study.

BACKGROUND: In this study we examined whether (1) the neighbourhood aspects of access to amenities, neighbourhood quality, neighbourhood disorder, and neighbourhood social cohesion are associated with people's self rated health, (2) these health effects reflect differences in socio-demographic composition and/or neighbourhood deprivation, and (3) the associations with the different aspects of the neighbourhood environment vary between men and women. METHODS: Data from the cross-sectional Caerphilly Health and Social Needs Survey were analysed using multilevel modelling, with individuals nested within enumeration districts. In this study we used the responses of people under 75 years of age (n = 10,892). The response rate of this subgroup was 62.3%. All individual responses were geo-referenced to the 325 census enumeration districts of Caerphilly county borough. RESULTS: The neighbourhood attributes of poor access to amenities, poor neighbourhood quality, neighbourhood disorder, lack of social cohesion, and neighbourhood deprivation were associated with the reporting of poor health. These effects were attenuated when controlling for individual and collective socio-economic status. Lack of social cohesion significantly increased the odds of women reporting poor health, but did not increase the odds of men reporting poor health. In contrast, unemployment significantly affected men's health, but not women's health. CONCLUSION: This study shows that different aspects of the neighbourhood environment are associated with people's self rated health, which may partly reflect the health impacts of neighbourhood socio-economic status. The findings further suggest that the social environment is more important for women's health, but that individual socio-economic status is more important for men's health.

An ecometric analysis of neighbourhood cohesion.

BACKGROUND: It is widely believed that the social environment has an important influence on health, but there is less certainty about how to measure specific factors within the social environment that could link the neighbourhood of residence to a health outcome. The objectives of the study were to examine the underlying constructs captured by an adapted version of Buckner's neighbourhood cohesion scale, and to assess the reliability of the scale at the small-area-level by combining ecometric methodology with ordinal modelling of a five-point scale. METHODS: Data were analysed from 11,078 participants in the Caerphilly Health and Social Needs Study, who were sampled from within 325 UK census enumeration districts in Caerphilly county borough, Wales, UK. The responses of interest came from 15 question items designed to capture different facets of neighbourhood cohesion. Factor analysis was used to identify constructs underlying the neighbourhood cohesion item responses. Using a multilevel ecometric model, the variability present in these ordinal responses was decomposed into contextual, compositional, item-level and residual components. RESULTS: Two constructs labelled neighbourhood belonging and social cohesion were identified, and variability in both constructs was modelled at each level of the multilevel structure. The intra-neighbourhood correlations were 6.4% and 1.0% for the neighbourhood belonging and social cohesion subscales, respectively. Given the large sample size, contextual neighbourhood cohesion scores can be estimated reliably. The wide variation in the observed frequency of occurence of the scale item activities suggests that the two subscales have desirable ecometric properties. Further, the majority of between-neighbourhood variation is not explained by the socio-demographic characteristics of the individual respondents. CONCLUSION: Assessment of the properties of the adapted neighbourhood cohesion scale using factor analysis and ecometric analysis extended to an ordinal scale has shown that the items allow fine discrimination between individuals. However, large sample sizes are needed in order to accurately estimate contextual neighbourhood cohesion. The scale is therefore appropriate for use in the measurement of neighbourhood cohesion at small-area-level in future studies of neighbourhoods and health.

Comparison of perceived and modelled geographical access to accident and emergency departments: a cross-sectional analysis from the Caerphilly Health and Social Needs Study.

BACKGROUND: Assessment of the spatial accessibility of hospital accident and emergency departments as perceived by local residents has not previously been investigated. Perceived accessibility may affect where, when, and whether potential patients attend for treatment. Using data on 11,853 respondents to a population survey in Caerphilly county borough, Wales, UK, we present an analysis comparing the accessibility of accident and emergency departments as reported by local residents and drive-time to the nearest accident and emergency department modelled using a geographical information system (GIS). RESULTS: Median drive-times were significantly shorter in the lowest perceived access category and longer in the best perceived access category (p < 0.001). The perceived access and GIS modelled drive-time variables were positively correlated (Spearman's rank correlation coefficient, r = 0.38, p < 0.01). The strongest correlation was found for respondents living in areas in which nearly all households had a car or van (r = 0.47, p < 0.01). Correlations were stronger among respondents reporting good access to public transport and among those reporting a recent accident and emergency attendance for injury treatment compared to other respondents. Correlation coefficients did not vary substantially by levels of household income. Drive-time, road distance and straight-line distance were highly inter-correlated and substituting road distance or straight-line distance as the GIS modelled spatial accessibility measure only marginally decreased the magnitude of the correlations between perceived and GIS modelled access. CONCLUSION: This study provides evidence that the accessibility of hospital-based health care services as perceived by local residents is related to measures of spatial accessibility modelled using GIS. For studies that aim to model geographical separation in a way that correlates well with the perception of local residents, there may be minimal advantage in using sophisticated measures. Straight-line distance, which can be calculated without GIS, may be as good as GIS-modelled drive-time or distance for this purpose. These findings will be of importance to health policy makers and local planners who seek to obtain local information on access to services through focussed assessments of residents' concerns over accessibility and GIS modelling.

Council tax valuation bands, socio-economic status and health outcome: a cross-sectional analysis from the Caerphilly Health and Social Needs Study.

UNLABELLED: Council tax valuation bands (CTVBs) are a categorisation of household property value in Great Britain. The aim of the study was to assess the CTVB as a measure of socio-economic status by comparing the strength of the associations between selected health and lifestyle outcomes and CTVBs with two measures of socio-economic status: the National Statistics Socio-Economic Classification (NS-SEC) and the 2001 UK census-based Townsend deprivation index. METHODS: Cross-sectional analysis of data on 12,092 respondents (adjusted response 62.7%) to the Caerphilly Health and Social Needs Study, a postal questionnaire survey undertaken in Caerphilly county borough, south-east Wales, UK. The CTVB was assigned to each individual by matching the sampling frame to the local authority council tax register. Crude and age-gender adjusted odds ratios for each category of CTVB, NS-SEC and fifth of the ward distribution of Townsend scores were estimated for smoking, poor diet, obesity, and limiting long-term illness using logistic regression. Mean mental (MCS) and physical (PCS) component summary scores of the Short-Form SF-36 health status questionnaire were estimated in general linear models. RESULTS: There were significant trends in odds ratios across the CTVB categories for all outcomes, most marked for smoking and mental and physical health status. The adjusted odds ratio for being a smoker in the lowest versus highest CTVB category was 3.80 (95% CI: 3.06, 4.71), compared to 3.00 (95% CI: 2.30, 3.90) for the NS-SEC 'never worked and long-term unemployed' versus 'higher managerial and professional' categories, and 1.61 (95% CI: 1.42, 1.83) for the most deprived versus the least deprived Townsend fifth. The difference in adjusted mean MCS scores was 5.9 points on the scale for CTVB, 9.2 for NS-SEC and 3.2 for the Townsend score. The values for the adjusted mean PCS scores were 6.3 points for CTVB, 11.3 for NS-SEC, and 2.5 for the Townsend score. CONCLUSION: CTVBs assigned to individuals were strongly associated with the health and lifestyle outcomes modelled in this study. CTVBs are readily available for all residential properties and deserve further consideration as a proxy for socio-economic status in epidemiological studies in Great Britain.

Mental health, places and people: a multilevel analysis of economic inactivity and social deprivation.

Using data on 24,975 respondents to the Welsh Health Survey 1998 aged 17-74 years, we investigated associations between individual mental health status measured using the SF-36 instrument, social class, economic inactivity and the electoral division Townsend deprivation score. In a multilevel modelling analysis, we found mental health was significantly associated with the Townsend score after adjusting for composition, and this effect was strongest in respondents who were economically inactive. Further contextual effects were shown by significant random variability in the slopes of the relation between mental health and economic inactivity at the electoral division level. Our results suggest that the places in which people live affect their mental health, supporting NHS policy that multi-agency planning to reduce inequalities in mental health status should address the wider determinants of health, as well as services for individual patients.

Risk of congenital anomalies after the opening of landfill sites.

Concern that living near a particular landfill site in Wales caused increased risk of births with congenital malformations led us to examine whether residents living close to 24 landfill sites in Wales experienced increased rates of congenital anomalies after the landfills opened compared with before they opened. We carried out a small-area study in which expected rates of congenital anomalies in births to mothers living within 2 km of the sites, before and after opening of the sites, were estimated from a logistic regression model fitted to all births in residents living at least 4 km away from these sites and hence not likely to be subject to contamination from a landfill, adjusting for hospital catchment area, year of birth, sex, maternal age, and socioeconomic deprivation score. We investigated all births from 1983 through 1997 with at least one recorded congenital anomaly [International Classification of Diseases, Ninth Revision (ICD-9), codes 7400-7599; International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10), codes Q000-Q999]. The ratio of the observed to expected rates of congenital anomalies before landfills opened was 0.87 [95% confidence interval (CI), 0.75-1.00], and this increased to 1.21 (95% CI, 1.04-1.40) after opening, giving a standardized risk ratio of 1.39 (95% CI, 1.12-1.72). Enhanced congenital malformation surveillance data collected from 1998 through 2000 showed a standardized risk ratio of 1.04 (95% CI, 0.88-1.21). Causal inferences are difficult because of possible biases from incomplete case ascertainment, lack of data on individual-level exposures, and other socioeconomic and lifestyle factors that may confound a relationship with area of residence. However, the increase in risk after the sites opened requires continued enhanced surveillance of congenital anomalies, and site-specific chemical exposure studies. Key words: congenital malformations, epidemiology, landfill, small-area health statistics.

Objectively measured residential environment and self-reported health: a multilevel analysis of UK census data.

Little is known about the association between health and the quality of the residential environment. What is known is often based on subjective assessments of the environment rather than on measurements by independent observers. The aim of this study, therefore, was to determine the association between self-reported general health and an objectively assessed measure of the residential environment. We studied over 30,000 residents aged 18 or over living in 777 neighbourhoods in south Wales. Built environment quality was measured by independent observers using a validated tool, the Residential Environment Assessment Tool (REAT), at unit postcode level. UK Census data on each resident, which included responses to a question which assessed self-reported general health, was linked to the REAT score. The Census data also contained detailed information on socio-economic and demographic characteristics of all respondents and was also linked to the Welsh Index of Multiple Deprivation. After adjusting for both the individual characteristics and area deprivation, respondents in the areas of poorest neighbourhood quality were more likely to report poor health compared to those living in areas of highest quality (OR 1.36, 95% confidence interval 1.22-1.49). The particular neighbourhood characteristics associated with poor health were physical incivilities and measures of how well the residents maintained their properties. Measures of green space were not associated with self-reported health. This is the first full population study to examine such associations and the results demonstrate the importance for health of the quality of the neighbourhood area in which people live and particularly the way in which residents behave towards their own and their neighbours' property. A better understanding of causal pathways that allows the development of interventions to improve neighbourhood quality would offer significant potential health gains.

Socioeconomic patterning of excess alcohol consumption and binge drinking: a cross-sectional study of multilevel associations with neighbourhood deprivation.

OBJECTIVES: The influence of neighbourhood deprivation on the risk of harmful alcohol consumption, measured by the separate categories of excess consumption and binge drinking, has not been studied. The study objective was to investigate the effect of neighbourhood deprivation with age, gender and socioeconomic status (SES) on (1) excess alcohol consumption and (2) binge drinking, in a representative population survey. DESIGN: Cross-sectional study: multilevel analysis. SETTING: Wales, UK, adult population ∼2.2 million. PARTICIPANTS: 58 282 respondents aged 18 years and over to four successive annual Welsh Health Surveys (2003/2004-2007), nested within 32 692 households, 1839 census lower super output areas and the 22 unitary authority areas in Wales. PRIMARY OUTCOME MEASURE: Maximal daily alcohol consumption during the past week was categorised using the UK Department of Health definition of 'none/never drinks', 'within guidelines', 'excess consumption but less than binge' and 'binge'. The data were analysed using continuation ratio ordinal multilevel models with multiple imputation for missing covariates. RESULTS: Respondents in the most deprived neighbourhoods were more likely to binge drink than in the least deprived (adjusted estimates: 17.5% vs 10.6%; difference=6.9%, 95% CI 6.0 to 7.8), but were less likely to report excess consumption (17.6% vs 21.3%; difference=3.7%, 95% CI 2.6 to 4.8). The effect of deprivation varied significantly with age and gender, but not with SES. Younger men in deprived neighbourhoods were most likely to binge drink. Men aged 35-64 showed the steepest increase in binge drinking in deprived neighbourhoods, but men aged 18-24 showed a smaller increase with deprivation. CONCLUSIONS: This large-scale population study is the first to show that neighbourhood deprivation acts differentially on the risk of binge drinking between men and women at different age groups. Understanding the socioeconomic patterns of harmful alcohol consumption is important for public health policy development.

Cohort profile: the Caerphilly health and social needs electronic cohort study (E-CATALyST).

The Caerphilly Health and Social Needs study was established to inform and support collaborative multiagency working on reducing inequalities in health and to investigate neighbourhood influences on mental health. Initially, we collated a robust small-area multiagency dataset of contextual health determinants and outcomes from routine sources and sharing of data between the National Health Service and Caerphilly county borough council. These data were widely used in local joint planning to improve health and reduce health inequalities. Secondly, we carried out a baseline population questionnaire survey, collecting data from 10 892 (60.6%) respondents aged 18-74 years on a wide range of socio-economic, lifestyle, health and housing factors and perceptions of the local neighbourhood, including access to services, social cohesion and neighbourhood quality. We carried out wave 2 of the survey after 7 years with responses from 4558 (50.2%) participants to the same range of questions. We developed the study into an electronic cohort, linking all 17 979 sampled participants aged 18-74 years to mortality and hospital admission records with 10-year follow-up and full recording of migration both within and out of the borough. Readers with an interest in collaborative use of the data should contact Professor David Fone, Principal Investigator.

Modelling the risk of visual field loss arising from long-term exposure to the antiepileptic drug vigabatrin: a cross-sectional approach.

BACKGROUND: The antiepileptic drug vigabatrin has been used widely since 1989, but has only been approved for use in the US since 2009. The risk:benefit of vigabatrin is generally predicated upon an assumed frequency of associated visual field loss (VAVFL) of approximately 31 %. This estimate is based upon relatively short-term usage (up to 4-5 years) and it is essential to determine whether the frequency of VAVFL increases with longer-term usage. OBJECTIVE: The aim of this study was to model, from cross-sectional evidence, over greater ranges of treatment duration and cumulative dose than previously evaluated, the risk (frequency) of VAVFL with increasing exposure to vigabatrin. STUDY DESIGN AND SETTING: This was a retrospective cohort study undertaken in a regional hospital epilepsy clinic. PATIENTS: The cohort comprised 147 consecutive patients treated with vigabatrin for refractory complex partial (focal) seizures, who had all undergone ophthalmological examination and who had undertaken perimetry, reliably, according to a standard and robust protocol. The visual field plots were evaluated masked to treatment duration and dose. MAIN OUTCOME MEASURE: The risk (frequency) of VAVFL with increasing exposure to vigabatrin was modelled, from the cross-sectional evidence, by standard and plateau logistic regression. RESULTS: The cohort comprised 80 females and 67 males (mean age 40.3 years, standard deviation 13.7). The median duration of vigabatrin exposure was 7.9 years (interquartile range 3.6-11.0, range 0.2-16.1 years); 46 patients (31 %) had received vigabatrin for over 10 years. Eighty-seven patients (59 %) exhibited VAVFL; the proportion with VAVFL was higher in males (66 %) than females (54 %). The plateau model for duration and for cumulative dose exhibited a better fit than the standard model (both p < 0.001). The modelled frequency of VAVFL increased with increasing exposure up to approximately 6 years duration and 5 kg cumulative dose, and plateaued at approximately 76 % (95 % CI 67-85) and 79 % (95 % CI 70-87), respectively. Severity of VAVFL, classified in terms of the visual field index Mean Deviation, was not significantly associated with either duration or cumulative dose of therapy. CONCLUSION: Clinicians and patients, in enabling informed choice, should be alert to the possible substantial increased risk:benefit for VAVFL with increasing long-term exposure to vigabatrin and the ensuing increased cost:benefit resulting from the necessary additional visual assessments.

Health locus of control beliefs and socio-economic differences in self-rated health.

BACKGROUND: Social inequalities in health are well documented in the social epidemiology literature. However, less is known about the mechanisms linking individual and area-level socio-economic status to health. In this paper we examine whether health locus of control (HLC) beliefs can help to explain socio-economic differences in self-rated health using the multidimensional HLC scale. METHODS: Data for this study come from the Caerphilly Health and Social Needs Survey (n=10,892). Multilevel modelling was used to examine the variation in HLC beliefs across different socio-demographic groups and levels of neighbourhood socio-economic status, and to investigate whether HLC beliefs mediate the health effects of individual and neighbourhood socio-economic position. RESULTS: This study found that the HLC scales were significantly associated with individual and neighbourhood socio-economic status, as well as with self-rated health. HLC beliefs appeared to mediate some of the health effects of individual socio-economic status and to a lesser extent the health effects of neighbourhood socio-economic status. CONCLUSIONS: Some evidence was found that HLC forms part of the pathway between individual and neighbourhood socio-economic status and health. Future research should further explore the psychological consequences of living in economically deprived conditions, alongside material, social and behavioural processes, and examine how this impacts upon people's health and well-being.

Associations between common mental disorders and the Mental Illness Needs Index in community settings. Multilevel analysis.

BACKGROUND: The relationship between the Mental Illness Needs Index (MINI) and the common mental disorders is not known. AIMS: To investigate associations between the small-area MINI score and common mental disorder at individual level. METHOD: Mental health status was measured using the Mental Health Inventory of the Short Form 36 instrument (SF-36). Data from the Caerphilly Health and Social Needs population survey were analysed in multilevel models of 10 653 individuals aged 18-74 years nested within the 2001 UK census geographies of 110 lower super output areas and 33 wards. RESULTS: The MINI score was significantly associated with common mental disorder after adjusting for individual risk factors. This association was stronger at the smaller spatial scale of the lower super output area and for individuals who were permanently sick or disabled. CONCLUSIONS: The MINI is potentially useful for small-area needs assessment and service planning for common mental disorder in community settings.