Jane Biddulph

Cohort Profile: The Health Survey for England

To monitor the health of the public in England, UK, the Central Health Monitoring Unit within the UK Department of Health commissioned an annual health examination survey, which became known as the Health Survey for England (HSE). The first survey was completed in 1991. The HSE covers all of England and is a nationally representative sample of those residing at private residential addresses. Each survey year consists of a new sample of private residential addresses and people. The HSE collects detailed information on mental and physical health, health-related behaviour, and objective physical and biological measures in relation to demographic and socio-economic characteristics of people aged 16 years and over at private residential addresses. There are two parts to the HSE; an interviewer visit, to conduct an interview and measure height and weight, then a nurse visit, to carry out further measurements and take biological samples. Since 1994, survey participants aged 16 years and over have been asked for consent to follow-up through linkage to mortality and cancer registration data, and from 2003, to the Hospital Episode Statistics database, thus converting annual cross-sectional survey data into a longitudinal study. Annual survey data (1994-2009) are available through the UK Data Archive.

All cause mortality and the case for age specific alcohol consumption guidelines: pooled analyses of up to 10 population based cohorts

Objectives To examine the suitability of age specific limits for alcohol consumption and to explore the association between alcohol consumption and mortality in different age groups. Design Population based data from Health Survey for England 1998-2008, linked to national mortality registration data and pooled for analysis using proportional hazards regression. Analyses were stratified by sex and age group (50-64 and ≥65 years). Setting Up to 10 waves of the Health Survey for England, which samples the non-institutionalised general population resident in England. Participants The derivation of two analytical samples was based on the availability of comparable alcohol consumption data, covariate data, and linked mortality data among adults aged 50 years or more. Two samples were used, each utilising a different variable for alcohol usage: self reported average weekly consumption over the past year and self reported consumption on the heaviest day in the past week. In fully adjusted analyses, the former sample comprised Health Survey for England years 1998-2002, 18 368 participants, and 4102 deaths over a median follow-up of 9.7 years, whereas the latter comprised Health Survey for England years 1999-2008, 34 523 participants, and 4220 deaths over a median follow-up of 6.5 years. Main outcome measure All cause mortality, defined as any death recorded between the date of interview and the end of data linkage on 31 March 2011. Results In unadjusted models, protective effects were identified across a broad range of alcohol usage in all age-sex groups. These effects were attenuated across most use categories on adjustment for a range of personal, socioeconomic, and lifestyle factors. After the exclusion of former drinkers, these effects were further attenuated. Compared with self reported never drinkers, significant protective associations were limited to younger men (50-64 years) and older women (≥65 years). Among younger men, the range of protective effects was minimal, with a significant reduction in hazards present only among those who reported consuming 15.1-20.0 units/average week (hazard ratio 0.49, 95% confidence interval 0.26 to 0.91) or 0.1-1.5 units on the heaviest day (0.43, 0.21 to 0.87). The range of protective effects was broader but lower among older women, with significant reductions in hazards present ≤10.0 units/average week and across all levels of heaviest day use. Supplementary analyses found that most protective effects disappeared where calculated in comparison with various definitions of occasional drinkers. Conclusions Beneficial associations between low intensity alcohol consumption and all cause mortality may in part be attributable to inappropriate selection of a referent group and weak adjustment for confounders. Compared with never drinkers, age stratified analyses suggest that beneficial dose-response relations between alcohol consumption and all cause mortality may be largely specific to women drinkers aged 65 years or more, with little to no protection present in other age-sex groups. These protective associations may, however, be explained by the effect of selection biases across age-sex strata.

Wealth and mortality at older ages: a prospective cohort study

Background Despite the importance of socioeconomic position for survival, total wealth, which is a measure of accumulation of assets over the life course, has been underinvestigated as a predictor of mortality. We investigated the association between total wealth and mortality at older ages. Methods We estimated Cox proportional hazards models using a sample of 10 305 community-dwelling individuals aged ≥50 years from the English Longitudinal Study of Ageing. Results 2401 deaths were observed over a mean follow-up of 9.4 years. Among participants aged 50–64 years, the fully adjusted HRs for mortality were 1.21 (95% CI 0.92 to 1.59) and 1.77 (1.35 to 2.33) for those in the intermediate and lowest wealth tertiles, respectively, compared with those in the highest wealth tertile. The respective HRs were 2.54 (1.27 to 5.09) and 3.73 (1.86 to 7.45) for cardiovascular mortality and 1.36 (0.76 to 2.42) and 2.53 (1.45 to 4.41) for other non-cancer mortality. Wealth was not associated with cancer mortality in the fully adjusted model. Similar but less strong associations were observed among participants aged ≥65 years. The use of repeated measurements of wealth and covariates brought about only minor changes, except for the association between wealth and cardiovascular mortality, which became less strong in the younger participants. Wealth explained the associations between paternal occupation at age 14 years, education, occupational class, and income and mortality. Conclusions There are persisting wealth inequalities in mortality at older ages, which only partially are explained by established risk factors. Wealth appears to be more strongly associated with mortality than other socioeconomic position measures.

A health impact assessment model for environmental changes attributable to development projects

Study objective: European Union legislation requires large industrial and civil development projects to undergo environmental impact assessment. The study objective was to identify environmental health risk estimates for these developments from the epidemiological literature and to develop, and apply these within, a mathematical health impact assessment model. Design and results: In the UK, good practice guidelines have set out environmental issues to be considered in development projects, but little attention is given to direct health effects. Broad quantifiable risks were identified for four—air, chemicals, noise, and road traffic—of 14 standard environmental effects. A mathematical model was constructed that is based on people moving between different health states over their lifetime. Age related hazard functions are applied to cause specific measures of mortality and morbidity. A hypothetical example for a development creating air and chemical pollutants is given. Conclusions: A mathematical model applying epidemiological risks to an exposed population can provide quantification of environmental health effects. The approach may in future find application during project development, and by public health regulatory authorities for environmental health impact assessment.

English Longitudinal Study of Aging: Can Internet/E-mail Use Reduce Cognitive Decline?

BACKGROUND Cognitive decline is a major risk factor for disability, dementia, and death. The use of Internet/E-mail, also known as digital literacy, might decrease dementia incidence among the older population. The aim was to investigate whether digital literacy might be associated with decreased cognitive decline in older adulthood. METHODS Data from the English Longitudinal Study of Aging cohort with 6,442 participants aged 50-89 years, followed for 8 years, with baseline cognitive testing and four additional time points. The main outcome variable was the relative percentage change in delayed recall from a 10-word-list learning task across five separate measurement points. In addition to digital literacy, socioeconomic variables, including wealth and education, comorbidities, and baseline cognitive function were included in predictive models. The analysis used Generalized Estimating Equations. RESULTS Higher education, no functional impairment, fewer depressive symptoms, no diabetes, and Internet/E-mail use predicted better performance in delayed recall. CONCLUSIONS Digital literacy may help reduce cognitive decline among persons aged between 50 and 89 years.

Improving the use of evidence in health impact assessment

OBJECTIVE Health impact assessment (HIA) has been proposed as one mechanism that can inform decision-making by public policy-makers. However, HIA methodology has been criticized for a lack of rigour in its use of evidence. The aim of this work was to formulate, develop and test a practical guide to reviewing publicly available evidence for use in HIA. The term evidence includes all scientific assessments, whether research studies in peer-reviewed journals or previous HIAs. METHODS The formulation and development of the guide involved substantial background research, qualitative research with the target audience, substantial consultations with potential users and other stakeholders, a pilot study to explore content, format and usability, and peer review. Finally, the guide was tested in practice by invited volunteers who used it to appraise existing HIA evidence reviews. FINDINGS During development, a wealth of data was generated on how the guide might be applied in practice, on terminology, on ensuring clarity of the text and on additional resources needed. The final guide provides advice on reviewing quantitative and qualitative research in plain language and is suitable for those working in public health but who may not have experience in reviewing evidence. During testing, it enabled users to discriminate between satisfactory and unsatisfactory evidence reviews. By late 2009, 1700 printed and 2500 downloaded copies of the guide had been distributed. CONCLUSION Substantive and iterative consultation, though time-consuming, was pivotal to producing a simple, systematic and accessible guide to reviewing publicly available research evidence for use in HIA.

Duration of depressive symptoms and mortality risk: the English Longitudinal Study of Ageing (ELSA).

Background The relationship between the duration of depressive symptoms and mortality remains poorly understood. Aims To examine whether the duration of depressive symptoms is associated with mortality risk. Method Data (n = 9560) came from the English Longitudinal Study of Ageing (ELSA). We assessed depressive symptom duration as the sum of examinations with an eight-item Center for Epidemiologic Studies Depression Scale score of ⩾3; we ascertained mortality from linking our data to a national register. Results Relative to those participants who never reported symptoms, the age- and gender-adjusted hazard ratios for elevated depressive symptoms over 1, 2, 3 and 4 examinations were 1.41 (95% CI 1.15–1.74), 1.80 (95% CI 1.44–2.26), 1.97 (95% CI 1.57–2.47) and 2.48 (95% CI 1.90–3.23), respectively (P for trend <0.001). This graded association can be explained largely by differences in physical activity, cognitive function, functional impairments and physical illness. Conclusions In this cohort of older adults, the duration of depressive symptoms was associated with mortality in a dose–response manner.

ARMADA - a computer model of the impact of environmental factors on health

Environmental impact assessments are conducted on many developments as part of the planning process. There is currently wide interest in developing tools for assessing the impact on the health of the local population of proposed developments that will cause environmental changes. A computer model called ARMADA (Age Related Morbidity And Death Analysis) is described that provides a framework for investigating such health impacts. ARMADA generates estimates of age-related patterns of morbidity and mortality within the local population. These estimates incorporate the demographic features of the population in question and base-line information about the incidence of the disease classes being considered.

Vitamin D and inflammatory markers: cross-sectional analyses using data from the English Longitudinal Study of Ageing (ELSA)

Recent evidence suggests that low vitamin D concentrations are associated with increased levels of inflammatory markers. However, there are limited studies investigating associations between vitamin D levels and inflammatory markers in the general population and much of this evidence in older adults is inconclusive. Therefore, this study investigates the cross-sectional association of serum 25-hydroxyvitamin D (25(OH)D) levels with inflammatory markers in 5870 older English adults from wave 6 (2012–2013) of the English Longitudinal Study of Ageing (ELSA). ELSA is a large prospective observational study of community-dwelling people aged 50 years and over in England. Serum 25(OH)D levels, C-reactive protein (CRP) levels, plasma fibrinogen levels, white blood cell count (WBC), age, season of blood collection, waist circumference, total non-pension household wealth, measures of health and health behaviours that included depression, number of cardiovascular, non-cardiovascular conditions and difficulties in activities of daily living, smoking, and physical activity were measured. There was a significant negative association between low 25(OH)D levels (≤30 nmol/l) and CRP (OR 1·23, 95 % CI 1·00, 1·51) and WBC (OR 1·35, 95 % CI 1·13, 1·60) that remained after adjustment for a wide range of covariates of clinical significance. However, for fibrinogen, the association did not remain significant when waist circumference was entered in the final model. Our findings showed that 25(OH)D levels were associated with two out the three inflammatory markers investigated. The independent and inverse association between serum 25(OH)D levels and inflammation suggests a potential anti-inflammatory role for vitamin D in older English individuals from the general population.

Associations Between Vitamin D Levels and Depressive Symptoms in Later Life: Evidence From the English Longitudinal Study of Ageing (ELSA)

Abstract Background A possible role of vitamin D in depression has received considerable attention, especially given the significant disability, mortality, and healthcare costs associated to depression and the high prevalence of vitamin D deficiency. Methods We investigated the cross-sectional associations between serum 25-hydroxyvitamin D (25OHD) levels and depressive symptoms (CES-D) in 5,607 older adults from the English Longitudinal Study of Ageing (ELSA). Results Overall, there was a significant association between low 25OHD levels and elevated depressive symptoms (odds ratio [OR] = 1.58, 95% confidence interval [CI] = 1.20–2.07 for the lowest quartile; OR = 1.45, 95% CI = 1.15–1.83 for <30 nmol/L cut-off and OR = 1.34, 95% CI = 1.10–1.62 for the ≤50 nmol/L cut-off) after adjustment for a wide range of covariates of clinical significance. Fully adjusted models showed that women in the lowest (OR = 1.67, 95% CI = 1.20–2.34) and second lowest (OR = 1.68, 95% CI = 1.20–2.35) quartiles of 25OHD as well as those with 25OHD levels <30 nmol/L (OR = 1.40, 95% CI = 1.06–1.86) and ≤50 nmol/L (OR = 1.35, 95% CI = 1.07–1.72) were more likely to report elevated depressive symptoms. For men, however, this association only remained significant for those with 25OHD levels of <30 nmol/L (OR = 1.60, 95% CI = 1.06–2.42) in the fully adjusted models. Conclusions The independent and inverse association found between low 25OHD levels and elevated depressive symptoms suggests that vitamin D deficiency may be a risk factor for late-life depression, particularly among women. Whether our findings have any clinical meaning or not, additional data are needed from well-designed randomized controlled trials of vitamin D for the prevention and treatment of late-life depression.