Frailty on the island of Ireland: evidence from the NICOLA and TILDA studies.

BACKGROUND: Aimed to compare the prevalence, characteristics, and associated mortality risk of frailty in Northern Ireland (NI) and the Republic of Ireland (ROI). METHODS: Secondary analysis of the first wave of two nationally representative cohorts, the Northern Ireland Cohort for the Longitudinal Study of Ageing or NICOLA study (N = 8504) and the Irish Longitudinal Study on Ageing or TILDA study (N = 8504). Frailty was assessed using a harmonized accumulation deficits frailty index (FI) containing 30 items. FI scores classified individuals as non-frail (<0.10), pre-frail (0.10-0.24) and frail (≥0.25). Linkage to respective administrative data sources provided mortality information with a follow-up time of 8 years. RESULTS: The prevalence of frailty was considerably higher in NI compared with the ROI (29.0% compared with 15.0%), though pre-frailty was slightly lower (35.8% and 37.3%, respectively). Age, female sex, and lower socio-economic status were consistently associated with a higher likelihood of both pre-frailty and frailty. In the pooled analysis, both frailty and pre-frailty were higher in NI (RR = 2.68, 95% CIs 2.45, 2.94 and RR = 1.30, 95% CIs 1.21, 1.40, respectively). Frailty was associated with an increased mortality risk in both cohorts, even after full adjustment for all other characteristics, being marginally higher in TILDA than in NICOLA (HR = 2.43, 95% CIs 2.03, 2.91 vs. HR = 2.31, 95% CIs 1.90, 2.79). CONCLUSIONS: Frailty is a major public health concern for both jurisdictions. Further research and monitoring are required to elucidate why there is a higher prevalence in NI and to identify factors in early life that may be driving these differences.

Differential methylation in CD44 and SEC23A is associated with time preference in older individuals.

Time preference is a measure used to ascertain the level of which individuals prefer smaller, immediate rewards over larger, delayed rewards. We explored how an individual's time preference associates with their epigenetic profile. Time preferences were ascertained by asking participants of the Northern Ireland COhort for the Longitudinal study of Ageing to make a series of choices between two hypothetical income scenarios. From these, eight 'time preference' categories were derived, ranging from "patient" to "impatient" on an ordinal scale. The Infinium High Density Methylation Assay, MethylationEPIC (Illumina) was used to evaluate the status of 862,927 CpGs. Time preference and DNA methylation data were obtained for 1648 individuals. Four analyses were conducted, assessing the methylation patterns at single site resolution between patient and impatient individuals using two adjustment models. In this discovery cohort analysis, two CpG sites were identified with significantly different levels of methylation (p < 9 × 10-8) between the individuals allocated to the patient group and the remaining population following adjustment for covariates; cg08845621 within CD44 and cg18127619 within SEC23A. Neither of these genes have previously been linked to time preference. Epigenetic modifications have not previously been linked to time preference using a population cohort but they may represent important biomarkers of accumulated, complex determinants of this trait. Further analysis is warranted of both the top-ranked results and of DNA methylation as an important link between measurable biomarkers and health behaviours.

Prevalence and risk factors for age-related macular degeneration in a population-based cohort study of older adults in Northern Ireland using multimodal imaging: NICOLA Study.

PURPOSE: To report prevalence and risk factor associations for age-related macular degeneration (AMD) and AMD features from multimodal retinal grading in a multidisciplinary longitudinal population-based study of aging in Northern Ireland. STUDY DESIGN: Population-based longitudinal cohort study. METHODS: Retinal imaging at the Norther Ireland Cohort for the Longitudinal Aging Study health assessment included stereo Colour Fundus Photography (CFP) (Canon CX-1, Tokyo, Japan) and Spectral-Domain Optical Coherence Tomography (SD-OCT) ((Heidelberg Retinal Angopgraph (HRA)+OCT; Heidelberg Engineering, Heidelberg, Germany). Medical history and demographic information was obtained during a home interview. Descriptive statistics were used to describe the prevalence of AMD and individual AMD features. Multiple imputation followed by multiple regression modelling was used to explore risk factor associations including relationships with AMD genetic risk score. RESULTS: Retinal images from 3386 participants were available for analysis. Mean age of the sample was 63.4 (SD 9.01, range: 36-99). Population weighted prevalence of AMD using colour grading in those over 55 years was: no drusen: 6 0.4%; drusen <63 µm: 15.9%; drusen 63-125 µm: 13.7%; drusen >125 µm or pigmentary changes: 8.3%; late AMD: 1.6%. Prevalence of AMD features in those over 55 years was: OCT drusen 27.5%, complete outer retinal pigment epithelium and outer retinal atrophy (cRORA) on OCT was 4.3%, reticular drusen 3.2% and subretinal drusenoid deposits 25.7%. The genetic risk score was significantly associated with drusen and cRORA but less so for SDD alone and non-significant for hyperpigmentation or vitelliform lesions. CONCLUSIONS: Multimodal imaging-based classification has provided evidence of some divergence of genetic risk associations between classical drusen and SDD. Our findings support an urgent review of current AMD severity classification systems.

Exposure to the troubles in Northern Ireland, memory functioning, and social activity engagement: results from NICOLA.

We investigated the potential impact of a cohort traumatic exposure, the Troubles in Northern Ireland, on memory functioning in later life, and the potential moderating effect of social activity engagement. Using data from 6571 participants aged 60 + in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA) cohort, we used a structural equation modelling framework to explore associations between traumatic exposure during the Troubles and memory functioning. As expected, social activity engagement was positively associated with memory functioning, ß = .102. Traumatic exposure was also positively associated with memory functioning, ß = .053. This association was stronger at low levels of social activity engagement; among those with higher levels, there was little association, interaction ß = - 0.054. The positive association between traumatic exposure during the Troubles and memory functioning was not moderated by the age at which the exposures occurred (based on analysis of a subsample with available data), interaction ß = - 0.015. We conclude that superior memory functioning was associated with higher levels of traumatic exposure during the Troubles, particularly among those with lower levels of social activity engagement, and regardless of the age at which the exposures occurred. Future longitudinal analyses are required to build on these results, which potentially have implications for life-course epidemiology, in relation to critical periods for traumatising experiences. Supplementary Information: The online version contains supplementary material available at 10.1007/s10433-022-00683-5.

An investigation into DNA methylation patterns associated with risk preference in older individuals.

Risk preference is a complex trait governed by psycho-social, environmental and genetic determinants. We aimed to examine how an individual's risk preference associates with their epigenetic profile.Risk preferences were ascertained by asking participants of the Northern Ireland COhort for the Longitudinal study of Ageing to make a series of choices between hypothetical income scenarios. From these, four risk preference categories were derived, ranging from risk-averse to risk-seeking. Illumina's Infinium High-Density Methylation Assay was used to evaluate the status of 862,927 CpGs.Risk preference and DNA methylation data were obtained for 1,656 individuals. The distribution of single-site DNA methylation levels between risk-averse and risk-seeking individuals was assessed whilst adjusting for age, sex and peripheral white cell counts. In this discovery cohort, 55 CpGs were identified with significantly different levels of methylation (p≤x10-5) between risk-averse and risk-seeking individuals when adjusting for the maximum number of covariates. No CpGs were significantly differentially methylated in any of the risk preference groups at an epigenome-wide association level (p<9x10-8) following covariate adjustment.Protein-coding genes NWD1 and LRP1 were among the genes in which the top-ranked dmCpGs were located for all analyses conducted. Mutations in these genes have previously been linked to neurological conditions.Epigenetic modifications have not previously been linked to risk-aversion using a population cohort, but may represent important biomarkers of accumulated, complex determinants of this trait. Several striking results from this study support further analysis of DNA methylation as an important link between measurable biomarkers and health behaviours.

Retinal microvascular parameters are not associated with diabetes in the Northern Ireland Cohort for the Longitudinal Study of Ageing.

BACKGROUND: The retinal microvasculature offers unique non-invasive evaluation of systemic microvascular abnormalities. Previous studies reported associations between retinal microvascular parameters (RMPs) and diabetes. The aim of this study was to assess associations between RMPs and diabetes in a cross-sectional analysis of older persons from the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA). METHODS: RMPs (central retinal arteriolar/venular equivalents, arteriolar to venular ratio, fractal dimension, and tortuosity) were measured from optic disc-centred fundus images using semi-automated software. Associations were assessed between RMPs and diabetes status with adjustment for potential confounders. RESULTS: Data were included for 1762 participants with 209 classified as having diabetes. Participants had a mean age of 62.1 ± 8.5 years, and 54% were female. As expected, participants with diabetes had significantly higher mean glycated haemoglobin A1c compared to participants without diabetes (57.4 ± 17.6 mmol/mol versus 37.0 ± 4.2 mmol/mol, respectively). In unadjusted and minimally adjusted regression, arteriolar to venular ratio, arteriolar tortuosity and venular tortuosity were significantly associated with diabetes (minimally adjusted odds ratio [OR] = 0.85; 95% confidence intervals [CIs] 0.73, 0.99; P = 0.04, OR = 1.18; 95% CI 1.02, 1.37; P = 0.03 and OR = 1.20; 95% CI 1.04, 1.38; P = 0.01, respectively), although all failed to remain significant following adjustment for potential confounders. No additional associations between other RMPs and diabetes were detected. CONCLUSION: Despite previously reported associations between diabetes and RMPs, our study failed to corroborate these associations in an older community-based cohort.

Multimorbidity, activity limitation and self-reported health all predict mortality risk, but better measures were required.

BACKGROUND AND OBJECTIVE: With an ageing population, morbidity and multiple health conditions are an increasing public health concern. This study aimed to investigate how morbidity as measured by the Charlson comorbidity index and two morbidity measures; activity limitation and self-reported health, individually and collectively explain the increased risk of mortality with age. METHODS: We used the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA) wave one, dataset, a national representative sample of people over 50 years of age, with follow-up until May 31, 2020. Cox proportional hazard regression models were used to assess the associations between a modified Charlson comorbidity index (m-Charlson), self-reported health, activity limitation, and mortality in the Northern Irish cohort. RESULTS: m-Charlson showed a steeper relationship with age, the proportion of participants with a Charlson of two or more increase from 15.2% (aged 50-59) to 32.0% (aged 80+). All measures of morbidity exhibited a strong relationship with socio-economic status, though the gradients were more marked for self-reported health than for activity limitation or Charlson index. All three morbidity measures were independently related to mortality risk though the associations attenuated with age. However, even in models with all three measures of morbidity, most of the age-related increase in mortality risk remained unexplained. CONCLUSION: All three morbidity measures carry separate and independent information about the health status of older people and therefore about mortality risk; it is apparent that it is still worth asking patients how they feel and how their health is affecting their activity. Further research should aim to dissect health trajectories in dynamic prediction models in addition to other measures of health status.

Dietary patterns associated with renal impairment in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA).

BACKGROUND: Dietary-based primary prevention guidelines for chronic kidney disease (CKD) treatment are lacking due to limited evidence. Single nutrient intake studies do not account for complex dietary interactions. We assessed associations between dietary patterns and renal function in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA). DESIGN: A cross-sectional observational study used NICOLA baseline dietary data collected between February 2014 and March 2016 via a food frequency questionnaire for 2590 participants aged ≥ 50 years. Principal component analysis identified a posteriori dietary patterns. Renal function was characterised by estimated glomerular filtration rate (eGFR) using serum creatinine and cystatin-C. Associations were assessed according to quintiles of dietary pattern adherence and multivariable regression analysis examined associations with eGFR. RESULTS: Variation in three dietary patterns was significantly associated with eGFR. After adjustment for potential confounders, participants with least adherence to the 'healthy' dietary pattern 1 had a mean eGFR 3.4 ml/min/1.73m2 (95% confidence interval, [CI] - 5.0, - 1.7, p < 0.001) lower than the most adherent. Those with lowest adherence to the 'unhealthy' dietary pattern 2 had a mean eGFR 1.9 ml/min/1.73m2 (CI 0.2, 3.5, p = 0.03) higher than those with highest adherence. Participants with lowest adherence to dietary pattern 3, characterised by a high consumption of alcohol and coffee, had a mean eGFR 1.8 ml/min/1.73m2 (- 3.5, - 0.01, p = 0.05) lower than those with greatest adherence. CONCLUSIONS: Our findings identify independent associations between dietary patterns and eGFR. These findings can inform the development of diet-related primary prevention advice for CKD.

Association of renal impairment with cognitive dysfunction in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA).

INTRODUCTION: Chronic kidney disease (CKD) is a recognized risk factor for cognitive impairment. Identification of those at greatest risk of cognitive impairment may facilitate earlier therapeutic intervention. This study evaluated associations between estimated glomerular filtration rate (eGFR) and cognitive function in the Northern Ireland Cohort for the Longitudinal Study of Ageing. METHODS: Data were available for 3412 participants ≥50 years of age living in non-institutionalized settings who attended a health assessment between February 2014 and March 2016. Measures of serum creatinine (SCr) and cystatin C (cys-C) were used for eGFR. Cognitive function was measured using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). RESULTS: Following adjustment for potential confounders, a single unit decrease in eGFR was significantly associated with reduced cognitive function defined by an MMSE ≤24/30 {eGFR calculated using serum cys-C [eGFRcys]: ß = -0.01 [95% confidence interval (CI) -0.001 to -0.01], P = 0.01} and MoCA <26/30 [ß = -0.01 (95% CI -0.002 to -0.02), P = 0.02]. Similarly, CKD Stages 3-5 were also associated with a moderate increase in the odds of cognitive impairment (MMSE ≤24) following adjustment for confounders [eGFRcys: odds ratio 2.73 (95% CI 1.38-5.42), P = 0.004]. CONCLUSIONS: Decreased eGFRcys was associated with a significantly increased risk of cognitive impairment in a population-based cohort of older adults. However, there was no evidence of an association between cognitive impairment and the more commonly used eGFR calculated using SCr. eGFRcys may offer improved sensitivity over eGFRcr in the determination of renal function and associated risk of cognitive impairment.

Do interviewer attitudes to data linkage influence respondents' consent to linkage? Analysis of Understanding Society.

BACKGROUND: Variable consent rates threaten the validity of linked datasets. One modifiable element is the interviewer-respondent relationship. We examine interviewer attitudes to consent to linkage and the effect on respondent consent. METHODS: Subjects were 27 380 respondents from the Wave 1 Understanding Society (US) survey in Great Britain and 449 interviewers who completed the US Interviewer Survey. Two types of consent were considered: (i) whether the interviewer would hypothetically agree to having their data linked if he/she was an US respondent and (ii) whether the respondent consented to have their data linked. Factors influencing the interviewer's propensity to link data were examined using logistic regression. The association between interviewer consent and respondent consent to health record linkage was assessed using multi-level logistic regression models. RESULTS: The interviewer's propensity to consent to data linkage was strongly positively associated with its perceived usefulness: those that found it somewhat useful were 57% less likely to consent [adjusted odds ratio (AOR) 0.43, 95% CI: 0.22-0.82] compared to those who thought it was very useful. Positive beliefs about data security and their ability to understand the data linkage information were also associated. Respondents were 17% less likely to consent when interviewed by an interviewer who would not consent to record linkage (AOR 0.83, 95% CI: 0.71-0.97). CONCLUSIONS: The interviewer's propensity to consent was influenced by their beliefs about data linkage, which in turn influenced respondent consent. We recommend using interviewer training to emphasize the usefulness of data linkage and the measures around data security.

Intraocular pressure and circumpapillary retinal nerve fibre layer thickness in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA): distributions and associations.

AIMS: To describe the distributions of and associations with intraocular pressure (IOP) and circumpapillary retinal nerve fibre layer (cRNFL) thickness in a population-based study. METHODS: Northern Ireland Cohort for the Longitudinal Study of Ageing participants underwent a computer-assisted personal interview, a self-completion questionnaire and a health assessment (HA). At the HA, participants underwent IOP measurement using Ocular Response Analyser and spectral-domain optical coherence tomography with Heidelberg Spectralis. Participants also underwent a range of anthropometric, ophthalmic, cardiovascular, cognition and blood tests. Participants who attended the HA and had a vertical cup-to-disc ratio (VCDR) measurement in at least one eye were eligible for the study. Participants without any IOP or cRNFL measurements were excluded from the respective analyses. RESULTS: There were 3221 participants eligible for this study (5753 eyes included in the IOP analysis and 5461 eyes included in the cRNFL analysis). The mean (SD) Goldmann correlated IOP (IOPg) was 15.39 mm Hg (3.55 mm Hg). The mean (SD) average global cRNFL thickness was 94.39 µm (11.18 µm). Increased IOPg was associated with increased age, male sex, hypertension, refractive error (myopic decrease in spherical equivalent) and increased corneal resistance factor, while beta-blocker drug use was associated with lower IOPg in the fully adjusted multivariate analysis. Thinner average global cRNFL was associated with Alzheimer's disease in the age-adjusted and sex-adjusted model. In the fully adjusted multivariate analysis, increased age, male sex, left eyes, hypertension, increased VCDR, refractive error (myopic decrease in spherical equivalent) and increased IOPg were associated with thinner average global cRNFL, while Parkinson's disease and current (vs never) smoking status were associated with thicker average global cRNFL. CONCLUSIONS: Increased IOP and reduced cRNFL were associated with increased age, myopic refractive error, male sex and hypertension. Alzheimer's disease was associated with thinner average global cRNFL, while Parkinson's disease was associated with thicker average global cRNFL.

A comparison, for older people with diabetes, of health and health care utilisation in two different health systems on the island of Ireland.

BACKGROUND: There are social and economic differences between Northern Ireland (NI) and the Republic of Ireland (ROI). There are also differences in the health care systems in the two jurisdictions. The aims of this study are to compare health (prevalence of diabetes and related complications) and health care utilisation (general practitioner, outpatient or accident and emergency utilisation) among older people with diabetes in the NI and ROI. METHODS: Large scale comparable surveys of people over 50 years of age in Northern Ireland (NICOLA, wave 1) and the Republic of Ireland (TILDA, wave 1) are used to compare people with diabetes (type I and type II) in the two jurisdictions. The combined data set comprises 1536 people with diabetes. A coarsened exact matching approach is used to compare health care utilisation among people with diabetes in NI and ROI with equivalent demographic, lifestyle and illness characteristics (age, gender, education, smoking status and self-related health, number of other chronic diseases and number of diabetic complications). RESULTS: The overall prevalence of diabetes in the 50 to 84 years old age group is 3.4 percentage points higher in NI (11.1% in NI, 7.7% ROI, p-value < 0.01). The diabetic population in NI appear sicker - with more diabetic complications and more chronic illnesses. Comparing people with diabetes in the two jurisdictions with similar levels of illness we find that there are no statistically significant differences in GP, outpatient or A&E utilisation. CONCLUSION: Despite the proximity of NI and ROI there are substantial differences in the prevalence of diabetes and its related complications. Despite differences in the health services in the two jurisdictions the differences in health care utilisation for an equivalent cohort are small.

Assessment of the Vitreomacular Interface Using High-Resolution OCT in a Population-Based Cohort Study of Older Adults.

PURPOSE: To describe the prevalence of vitreomacular interface (VMI) features and their associated risk factors in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA) Study. DESIGN: Cross-sectional population-based study. PARTICIPANTS: Noninstitutionalized Northern Irish adults 40 years of age or older. METHODS: Using geographic stratification, a representative sample of people in Northern Ireland was invited to participate in the NICOLA Study. SD OCT images of participants were graded for vitreomacular traction (VMT), macular hole (MH), and epiretinal membrane (ERM) according to the International Vitreomacular Traction Study Group. A subsample was graded in more detail to estimate the prevalence of VMA and VMA area detailing size and location of VMA. Descriptive analysis and risk factors for each VMI feature were determined using generalized estimating equations. Results were standardized to the Northern Ireland population census (2011). MAIN OUTCOME MEASURES: Cohort profile, standardized prevalence, and risk factor associations of each VMI feature. RESULTS: Three thousand three hundred fifty-one NICOLA participants had gradable SD OCT images available for at least 1 eye. The prevalence of VMT was 0.5% (CI, 0.31%-0.70%), that for MH was 0.3% (CI, 0.23%-0.52%), and that for ERM was 7.6% (CI, 7.0%-8.3%). A detailed VMA analysis was performed on a subsample consisting of the first 1481 participants. The prevalence of VMA was 22.6% (CI, 21.1-24.2), and VMA area ranged from 0.25 to 42.7 mm2 (mean, 12.53 mm2; standard deviation, 6.90 mm2). In multivariate analyses, increased age was associated with an increased odds ratio (OR) of VMT, MH, and ERM. VMA area was positively associated with younger age and normal blood pressure. ERM and MH were present more often in more myopic eyes, associated with an increase in levels of high-density lipoprotein (HDL) cholesterol and triglycerides. CONCLUSIONS: The epidemiologic characteristics of VMI features indicated that VMI interactions throughout life are age dependent. Vitreous separation reduced to a greater extent in the horizontal meridians compared with the vertical, differing from previous studies. Future longitudinal studies of the evolution of these VMI changes over time would be of great interest.

Glaucoma in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA): cohort profile, prevalence, awareness and associations.

BACKGROUND/AIMS: This study aimed to describe the cohort profile of the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA) and to report the prevalence of, awareness of and associations with glaucoma. METHODS: Using geographic stratification, a representative sample of non-institutionalised Northern Irish adults aged over 50 years was invited to participate. NICOLA participants underwent a Computer-Assisted Personal Interview (CAPI), a Self-Completion Questionnaire (SCQ) and a health assessment. The CAPI and SCQ collected comprehensive sociodemographic and health-related data. At the health assessment, participants underwent optic disc stereophotography, intraocular pressure (IOP) measurement using ocular response analyser (ORA), autorefraction, spectral domain optical coherence tomography and self-reported history of glaucoma. We invited NICOLA participants suspected of having glaucoma due to optic disc appearance or raised IOP for clinical examination by a glaucoma expert and perimetry. Epidemiological definitions by the International Society Geographical and Epidemiological Ophthalmology were used to define glaucoma. RESULTS: Of 3221 NICOLA participants (mean age 64.4, SD 8.5, female sex 51.7%) who attended the health assessment component of the NICOLA study (and had a vertical cup to disc ratio measurement in at least one eye), 91 participants had glaucoma. Overall, the crude prevalence of glaucoma was 2.83% (95% CI 2.31% to 3.46%) and 67% of affected individuals did not give a self-reported history of glaucoma. CONCLUSIONS: The prevalence of glaucoma in Northern Ireland is comparable with other population-based studies of European populations. Approximately two-thirds of people with glaucoma were undiagnosed.

The Impact of Risk Factors for Coronary Heart Disease on Related Disability in Older Irish Adults.

OBJECTIVE: The aim of this study is to examine the prevalence of coronary heart disease (CHD)-related disability (hereafter also "disability") and the impact of CHD risk factors on disability in older adults in the Republic of Ireland (ROI) and Northern Ireland (NI). METHOD: Population attributable fractions were calculated using risk factor relative risks and disability prevalence derived from The Irish Longitudinal Study on Ageing and the Northern Ireland Health Survey. RESULTS: Disability was significantly lower in ROI (4.1% vs. 8.8%). Smoking and diabetes prevalence rates, and the fraction of disability that could be attributed to smoking (ROI: 6.6%; NI: 6.1%), obesity (ROI: 13.8%; NI: 11.3%), and diabetes (ROI: 6.2%; NI: 7.2%), were comparable in both countries. Physical inactivity (31.3% vs. 54.8%) and depression (10.2% vs. 17.6%) were lower in ROI. Disability attributable to depression (ROI: 16.3%; NI: 25.2%) and physical inactivity (ROI: 27.5%; NI: 39.9%) was lower in ROI. DISCUSSION: Country-specific similarities and differences in the prevalence of disability and associated risk factors will inform public health and social care policy in both countries.

Are the differences in adulthood ill-health across the north-south divide and between Scotland and England also evident in early childhood health indicators?

Regional differences in adult morbidity and mortality within England (i.e., north-south divide or gradient) and between England and Scotland (i.e., Scottish effect) are only partly explained by adult levels of socioeconomic status or risk factors. This suggests variation in early life, and is supported by the foetal origins and life-course literature which posits that birth outcomes and subsequent, cumulative exposures influence adult health. However, no studies have examined the north-south gradient or Scottish effect in health in the earliest years of life. The aims of the study were: i) to examine health indicators in English and Scottish children at birth and age three to establish whether regional differences exist; and ii) to establish whether observed changes in child health at age three were attributable to birth and/or early life environmental exposures. Respondents included 10,639 biological Caucasian mothers of singleton children recruited to the Millennium Cohort Study (MCS) in the year 2000. Outcome variables were: gestational age and birth weight, and height, body mass index (BMI), and externalising behavioural problems at age three. Region/country was categorised as: South (reference), Midlands, North (England), and Scotland. Respondents provided information on child, maternal, household, and socioeconomic characteristics. Results indicated no significant regional variations for gestational age or birth weight. At age three there was a north-south gradient for externalising behaviour and a north-south divide in BMI which attenuated on adjustment. However, a north-south divide in height was not fully explained by adjustment. There was also evidence of a 'Midlands effect', with increased likelihood of shorter stature and behaviour problems. Results showed a Scottish effect for height and BMI in the unadjusted models, and height in the adjusted model, but a decreased likelihood of behaviour problems. Findings indicated no regional differences in health at birth, but some regional variation at age three supports the cumulative life-course model.

Large panel-survey data demonstrated country-level and ethnic minority variation in consent for health record linkage.

OBJECTIVES: To investigate individual, household, and country variation in consent to health record linkage. STUDY DESIGN AND SETTING: Data from 50,994 individuals aged 16-74 years recruited to wave 1 of a large UK general purpose household survey (January 2009-December 2010) were analyzed using multilevel logistic regression models. RESULTS: Overall, 70.7% of respondents consented to record linkage. Younger age, marriage, tenure, car ownership, and education were all significantly associated with consent, although there was little deviation from 70% in subgroups defined by these variables. There were small increases in consent rates in individuals with poor health when defined by self-reported long-term limiting illness [adjusted odds ratio (OR) = 1.11; 95% confidence intervals (CIs): 1.06, 1.16], less so when defined by General Health Questionnaire score (adjusted OR = 1.05; 95% CIs: 1.00, 1.10), but the range in absolute consent rates between categories was generally less than 10%. Larger differences were observed for those of nonwhite ethnicity who were 38% less likely to consent (adjusted OR = 0.62; 95% CIs: 0.59, 0.66). Consent was higher in Scotland than England (adjusted OR = 1.17; 95% CIs: 1.06, 1.29) but lower in Northern Ireland (adjusted OR = 0.56; 95% CIs: 0.50, 0.63). CONCLUSION: The modest overall level of systematic bias in consent to record linkage provides reassurance for record linkage potential in general purpose household surveys. However, the low consent rates among nonwhite ethnic minority survey respondents will further compound their low survey participation rates. The reason for the country-level variation requires further study.

The influence of parents, older siblings, and non-parental care on infant development at nine months of age.

BACKGROUND: The majority of research examining the influence of social environment on early child development suggests benefits to two-parent households, but contradictory evidence for the effects of siblings. The aims of the present study were to examine the influence of the child's proximal social environment, and the effects of interactions between socioeconomic status and social environment on developmental outcomes. METHODS: Primary caregivers of a representative sample of 10,748 nine-month-old infants in Ireland completed the Ages and Stages Questionnaire and provided information on social environment. Adjustment was made for infant and maternal characteristics, household income, and area where the child was living at the time of the study. Further analyses tested for interactions between social environment and household income. RESULTS: Binary logistic regressions indicated no effects for number of parents in the household. However, the presence of siblings in the household was a consistent predictor of failing to reach milestones in communication, gross motor, problem-solving, and personal-social development. Furthermore, there was a gradient of increasing likelihood of failing in gross motor, problem-solving, and personal-social development with increasing numbers of siblings. Care by a grandparent decreased the likelihood of failing in communication and personal-social development. CONCLUSIONS: These findings do not support the majority of research that finds positive benefits for two-parent households. Similarly, the findings suggest limited effects for non-parental care. However, the observed negative effects of siblings support both the confluence and resource dilution models of sibling effect. Examination of follow-up data may elucidate current findings.

Prospective clinical audit of chloral hydrate administration practices in a neonatal unit.

AIM: Chloral hydrate is generally considered a safe and effective single dosing procedural sedative for neonates in the clinical setting. However, its safety profile as a repetitive dosing maintenance sedative is largely unknown. This study aimed to document current administration practices of chloral hydrate in the Neonatal Unit, Royal Children's Hospital, Melbourne, Australia, over a 6-month period. METHODS: Patients who had been prescribed chloral hydrate during the specified audit period were recruited into the study and prospectively followed for a period of 28 days, or until they were discharged from the unit. Demographic data were collected on recruitment, and daily documentation of chloral hydrate administration was recorded. RESULTS: A total of 238 doses of chloral hydrate were administered to a cohort of 32 patients during the study period. The majority of the audited doses (84%) were ordered as repeating doses. Doses were more likely to be given at night than during the day, and the median dosage for repetitive dosing was found to be above the study site's recommended dosing range. Pre-dose and/or post-dose assessment of distress/agitation accompanied dosage approximately half of the time. The audit did not reveal any recognisable pattern of sedation maintenance or weaning process for patients who received multiple doses. CONCLUSIONS: Health-care professionals caring for hospitalised infants should be made aware of the potential risks of chloral hydrate as a repetitive dosing sedative, and of the importance of systematically evaluating the appropriateness and effectiveness of utilising such pharmacological intervention for managing and treating distress.