Population-representative Cohort Research Articles

How do potentially inappropriate medications and polypharmacy affect mortality in frail and non-frail cognitively impaired older adults? A cohort study

ObjectivesTo test whether the use of potentially inappropriate central nervous system acting medications, proton pump inhibitors (PPIs) or polypharmacy are associated with mortality in cognitively impaired older adults and whether...

Prevalence of Hymenoptera venom allergy and sensitization in the population-representative German KORA cohort

Allergic reactions to Hymenoptera venoms represent potentially life-threatening conditions. However, studies on their prevalence in Germany and their relation to specific IgE sensitization are rare. The aim of this study was to evaluate the prevalence of Hymenoptera venom allergy as well as the frequency of venom-specific IgE sensitization in a large population-based adult German cohort. Questionnaire data were collected from the participants of the German population-based KORA (Cooperative Health Research in the Region of Augsburg) S4 baseline study population (n = 4,261) and the follow-up F4 study population (n = 3,074), which was conducted seven years later. Moreover, sIgE antibodies to honeybee (HBV) and yellow jacket venom (HJV) as well as to common aeroallergens were measured in the S4 study population. The prevalence of systemic sting reactions ranged between 2.3 % and 2.6 %. sIgE sensitization (≥ 0.35 kUA/L) to HBV and YJV was demonstrated in 23.1 % and 31.7 % of the population, respectively (41.6 % to HBV and/or YJV). Double-sensitization to both venoms occurred in 13.2 % of the individuals. Approximately 53 % and 77 % of the individuals who reported shock symptoms after honeybee and yellow jacket stings, respectively, exhibited sIgE ≥ 0.35 kUA/L to the culprit venom. In contrast, only 2.8 % of the venom-sensitized individuals reported symptoms exceeding local reactions. Local reactions were reported by 4.4 to 4.8 % of the population. Self-reported Hymenoptera sting reactions and venom sensitization are frequent in the general German population. In many cases, sensitization and clinically relevant allergy are not observed in the same individual, indicating that comprehensive diagnostic approaches are a prerequisite for the identification of patients at risk for severe reactions.

Associations between sleep and obesity indices in older adults: results from the HELIAD study.

Short sleep duration and low sleep quality are negatively associated with obesity in young adults, but in older people the results are inconsistent. The aim of the present study was to examine the associations between sleep duration and quality with both body mass index (BMI) and waist circumference (WC) and to investigate sex- and age-specific associations in a population-representative cohort of older adults. 1781 participants ≥ 65years old from the HELIAD study were included. Sleep duration and quality were based on self-report, whereas BMΙ and WC were evaluated clinically. Sleep duration was inversely related to WC, only in women, even after adjustment for age, sex, years of education, total energy intake and level of physical activity. Furthermore, sleep quality was negatively related to both BMI and WC in women. In men, however, no significant relationships were observed between these variables. Associations between sleep and weight did not differ between those aged < 73 and ≥ 73years old. To the best of our knowledge, this is the first study examining both sleep duration and quality with BMI and WC in older adults, performing by-sex analysis. Although additional studies are needed, improvements in sleep habits should be considered in weight management of older individuals. Our results suggest that poor sleep is associated to adverse weight effects in older women, but not men.

White matter hyperintensities are common in midlife and already associated with cognitive decline.

White matter hyperintensities proliferate as the brain ages and are associated with increased risk for cognitive decline as well as Alzheimer’s disease and related dementias. As such, white matter hyperintensities have been targeted as a surrogate biomarker in intervention trials with older adults. However, it is unclear at what stage of aging white matter hyperintensities begin to relate to cognition and if they may be a viable target for early prevention. In the Dunedin Study, a population-representative cohort followed since birth, we measured white matter hyperintensities in 843 45-year-old participants using T2-weighted magnetic resonance imaging and we assessed cognitive decline from childhood to midlife. We found that white matter hyperintensities were common at age 45 and that white matter hyperintensity volume was modestly associated with both lower childhood (ß = −0.08, P = 0.013) and adult IQ (ß=−0.15, P < 0.001). Moreover, white matter hyperintensity volume was associated with greater cognitive decline from childhood to midlife (ß=−0.09, P < 0.001). Our results demonstrate that a link between white matter hyperintensities and early signs of cognitive decline is detectable decades before clinical symptoms of dementia emerge. Thus, white matter hyperintensities may be a useful surrogate biomarker for identifying individuals in midlife at risk for future accelerated cognitive decline and selecting participants for dementia prevention trials.

Caries-related risk factors of obesity among 18-year-old adolescents in Hong Kong: a cross-sectional study nested in a cohort study

BackgroundSocio-economic status, health awareness, and dietary habits have been reported as common risk factors of dental caries and obesity. The present study aimed to explore shared mediators between caries and obesity and to estimate the effects of caries-related factors on adiposity.MethodsThis was a cross-sectional study among adolescents aged 18 years. The study was nested in a population-representative cohort of Chinese in Hong Kong. The number of decayed, missing, and filled permanent teeth (DMFT) was recorded during the oral examinations. Body Mass Index (BMI), Waist Circumference (WC), Waist-Hip-Ratio (WHR), Waist-Height-Ratio (WHtR), and Triceps Skinfold Thickness (TRSKF) were used as adiposity indices. Data on socio-economic status, oral health behavior (tooth brushing habit, use of fluoride toothpaste, dental flossing habit, and mouth rinse habit), and dietary record (frequency and amount of different food) were collected through self-completed questionnaires. Chi-square tests and binary logistic regressions were used for analysis.ResultsThree hundred eighty-three participants were included. The mean (standard deviation, SD) of BMI, WC, WHR, WHtR, TRSKF, and DMFT were 21.26 (3.72), 69.11 (9.25), 0.77 (0.06), 0.42 (0.05), 15.72 (6.33), and 2.06 (2.43), respectively. Males were more likely to be overweight/obese than females. Various factors including gender, parental employment status, mouth rinse habit, frequency and amount of meat intake, frequency of oil intake, use of fluoride toothpaste, and DMFT were found significant (p < 0.05) in different final models of adiposity status.ConclusionsMore mediators should be included in future research to elucidate mechanism of the association between caries and obesity.

Migraine increases the proportion of sudden sensorineural hearing loss: A longitudinal follow-up study

ObjectiveThe aim of the present study was to investigate the proportion of sudden sensorineural hearing loss (SSNHL) patients in a representative population cohort with migraine. MethodsThe Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. A total of 45,114 migraine participants (the migraine group) were matched according to age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 180,456 controls (the control group). The migraine group included participants diagnosed with migraine (International Classification of Disease [ICD]-10: G43) who underwent treatment ≥2 times. The SSNHL was investigated based on the ICD-10 (H912) code and confirmed by an audiometry exam and steroid treatment. Histories of hypertension, diabetes, dyslipidemia, ischemic heart disease, stroke, depression, Meniere’s disease, and tinnitus were evaluated using ICD-10 codes. Crude (simple) and adjusted hazard ratios (HRs) of SSNHL associated with migraine were analyzed using the Cox proportional hazards model. Subgroup analyses were conducted according to age and sex. ResultsIn total, 0.9% (399/44,714) of the migraine patients and 0.6% (1,169/179,287) of the controls were diagnosed with SSNHL (P<0.001). The adjusted HR of migraine for SSNHL was 1.34 (95% confidence interval [CI]=1.19–1.50, P<0.001). Both patient age subgroups (20–59years old and ≥60years old) showed high adjusted HRs for SSNHL. Both the men and women presented an elevated proportion of SSNHL cases. ConclusionMigraine patients had a higher likelihood of SSNHL. All age and sex migraine subgroups showed an elevated proportion of SSNHL cases.

Ethnic Minority Health in Ireland—Co-creating knowledge (EMH-IC): a participatory health research protocol

IntroductionInternational policy recommends continuous, cost-effective monitoring of health data to enable health services to identify and respond to health inequities as experienced by different ethnic groups. However, there is a...

Associations between the mediterranean diet and sleep in older adults: Results from the hellenic longitudinal investigation of aging and diet study.

Although there is some evidence of the relationships between sleep duration/quality and nutrient and/or food intake, the associations between sleep and dietary patterns have been poorly explored. The aim of the present study was to evaluate sleep duration and quality in relation to adherence to the Mediterranean diet (MeDi), and to investigate the sex- and age-specific associations in a population-representative cohort of older adults. Participants from the Hellenic Longitudinal Investigation of Aging and Diet were included. The sample consisted of 1639 adults aged ≥65 years. Sleep duration and quality were assessed through a self-report questionnaire, whereas adherence to the MeDi was evaluated by an a priori score. Sleep quality was positively associated with the MeDi in the unadjusted and the adjusted model (age, sex, depression, years of education, body mass index, level of physical activity and total energy intake were added as covariates). In contrast, sleep duration was not associated with MeDi adherence either in the unadjusted or the adjusted models. In relation to the age-related associations, sleep quality was positively associated with MeDi adherence in those aged ≤75 years, and not in those aged >75 years. Associations between sleep and MeDi did not differ between men and women. The present results suggest that sleep quality is associated with MeDi adherence in older adults; there are also age-specific associations between sleep quality and the MeDi. Although additional studies are required, improvements in diet quality should be considered in the context of sleep management interventions in older individuals. Geriatr Gerontol Int 2018; 18: 1543-1548.

Metallothionein-I/II expression associates with the astrocyte DNA damage response and not Alzheimer-type pathology in the aging brain.

Oxidative stress and oxidative DNA damage are early features of mild cognitive impairment and Alzheimer's disease (AD), occurring before the formation of classical AD neuropathology, and resulting from an imbalance between pro- and anti-oxidants. Astrocytes play a major neuroprotective role, producing high levels of anti-oxidants including metallothionein-I and -II (MT-I/II). In the present study we characterized the immunoreactive profile of MT-I/II in the temporal cortex of the Cognitive Function and Ageing Study (CFAS) aging population-representative neuropathology cohort, and examined H2 O2 -modulation of MT transcription by human astrocytes. MT-I/II is primarily expressed by astrocytes in the aging brain, but is also associated with pyramidal neurons in a small proportion of cases. Astrocyte expression of MT-I/II does not correlate with Alzheimer-type pathology (Aβ plaques and neurofibrillary tangles) but does relate to astrocyte oxidative DNA damage (rs = .312, p = .006) and the astrocyte response to oxidative DNA damage in vivo (rs = .238, p = .04), and MT gene expression is significantly induced in human astrocytes response to oxidative stress in vitro (p = .01). In contrast, neuronal MT-I/II does not relate to oxidative DNA damage or the neuronal DNA damage response, but is significantly higher in cases with high levels of local tangle pathology (p = .007). As MT-I/II is neuroprotective against oxidative stress, modulation of MT-I/II expression is a potential therapeutic target to treat the onset and progression of cognitive impairment.

Sa1071 - Statin Use at the Time of Intra-Abdominal Surgery Reduces the Risk of Post-Operative Small Bowel Obstruction and Adhesion-Related Complications: A Populationrepresentative Cohort Study

Sa1071 - Statin Use at the Time of Intra-Abdominal Surgery Reduces the Risk of Post-Operative Small Bowel Obstruction and Adhesion-Related Complications: A Populationrepresentative Cohort Study

Prevalence of age-related macular degeneration associated genetic risk factors and 4-year progression data in the Irish population

Background/aimsAge-related macular degeneration (AMD) is estimated to affect 196 million people >50 years old globally. Prevalence of AMD-associated genetic risk factors and rate of disease progression are unknown in Ireland.MethodsPrevalence...

Association of Childhood Blood Lead Levels With Criminal Offending

ImportanceLead is a neurotoxin with well-documented effects on health. Research suggests that lead may be associated with criminal behavior. This association is difficult to disentangle from low socioeconomic status, a factor in both lead exposure and criminal offending.ObjectiveTo test the hypothesis that a higher childhood blood lead level (BLL) is associated with greater risk of criminal conviction, recidivism (repeat conviction), conviction for violent offenses, and variety of self-reported criminal offending in a setting where BLL was not associated with low socioeconomic status.Design, Setting, and ParticipantsA total of 553 individuals participated in a prospective study based on a population-representative cohort born between April 1, 1972, and March 31, 1973, from New Zealand; the Dunedin Multidisciplinary Health and Development Study observed participants to age 38 years (December 2012). Statistical analysis was performed from November 10, 2016, to September 5, 2017.ExposuresBlood lead level measured at age 11 years.Main Outcomes and MeasuresOfficial criminal conviction cumulative to age 38 years (data collected in 2013), single conviction or recidivism, conviction for nonviolent or violent crime, and self-reported variety of crime types at ages 15, 18, 21, 26, 32, and 38 years.ResultsParticipants included 553 individuals (255 female and 298 male participants) who had their blood tested for lead at age 11 years. The mean (SD) BLL at age 11 years was 11.01 (4.62) μg/dL. A total of 154 participants (27.8%) had a criminal conviction, 86 (15.6%) had recidivated, and 53 (9.6%) had a violent offense conviction. Variety scores for self-reported offending ranged from 0 to 10 offense types at each assessment; higher numbers indicated greater crime involvement. Self-reported offending followed the well-established age-crime curve (ie, the mean [SD] variety of self-reported offending increased from 1.99 [2.82] at age 15 years to its peak of 4.24 [3.15] at age 18 years and 4.22 [3.02] at age 21 years and declined thereafter to 1.10 [1.59] at age 38 years). Blood lead level was a poor discriminator between no conviction and conviction (area under the curve, 0.58). Overall, associations between BLL and conviction outcomes were weak. The estimated effect of BLL was lower for recidivism than for single convictions and lower for violent offending than for nonviolent offending. Sex-adjusted associations between BLL reached statistical significance for only 1 of the 6 self-reported offending outcomes at age 15 years (r = 0.10; 95% CI, 0.01-0.18; P = .02).Conclusions and RelevanceThis study overcomes past limitations of studies of BLL and crime by studying the association in a place and time where the correlation was not confounded by childhood socioeconomic status. Findings failed to support a dose-response association between BLL and consequential criminal offending.

Is low cognitive functioning a predictor or consequence of major depressive disorder? A test in two longitudinal birth cohorts.

Cognitive impairment has been identified as an important aspect of major depressive disorder (MDD). We tested two theories regarding the association between MDD and cognitive functioning using data from longitudinal cohort studies. One theory, the cognitive reserve hypothesis, suggests that higher cognitive ability in childhood decreases risk of later MDD. The second, the scarring hypothesis, instead suggests that MDD leads to persistent cognitive deficits following disorder onset. We tested both theories in the Dunedin Study, a population-representative cohort followed from birth to midlife and assessed repeatedly for both cognitive functioning and psychopathology. We also used data from the Environmental Risk Longitudinal Twin Study to test whether childhood cognitive functioning predicts future MDD risk independent of family-wide and genetic risk using a discordant twin design. Contrary to both hypotheses, we found that childhood cognitive functioning did not predict future risk of MDD, nor did study members with a past history of MDD show evidence of greater cognitive decline unless MDD was accompanied by other comorbid psychiatric conditions. Our results thus suggest that low cognitive functioning is related to comorbidity, but is neither an antecedent nor an enduring consequence of MDD. Future research may benefit from considering cognitive deficits that occur during depressive episodes from a transdiagnostic perspective.

Association between Long-Term Exposure to Particulate Matter Air Pollution and Mortality in a South Korean National Cohort: Comparison across Different Exposure Assessment Approaches.

Increasing numbers of cohort studies have reported that long-term exposure to ambient particulate matter is associated with mortality. However, there has been little evidence from Asian countries. We aimed to explore the association between long-term exposure to particulate matter with a diameter ≤10 µm (PM10) and mortality in South Korea, using a nationwide population-based cohort and an improved exposure assessment (EA) incorporating time-varying concentrations and residential addresses (EA1). We also compared the association across different EA approaches. We used information from 275,337 people who underwent health screening from 2002 to 2006 and who had follow-up data for 12 years in the National Health Insurance Service-National Sample Cohort. Individual exposures were computed as 5-year averages using predicted residential district-specific annual-average PM10 concentrations for 2002–2006. We estimated hazard ratios (HRs) of non-accidental and five cause-specific mortalities per 10 µg/m3 increase in PM10 using the Cox proportional hazards model. Then, we compared the association of EA1 with three other approaches based on time-varying concentrations and/or addresses: predictions in each year and addresses at baseline (EA2); predictions at baseline and addresses in each year (EA3); and predictions and addresses at baseline (EA4). We found a marginal association between long-term PM10 and non-accidental mortality. The HRs of five cause-specific mortalities were mostly higher than that of non-accidental mortality, but statistically insignificant. In the comparison between EA approaches, the HRs of EA1 were similar to those of EA2 but higher than EA3 and EA4. Our findings confirmed the association between long-term exposure to PM10 and mortality based on a population-representative cohort in South Korea, and suggested the importance of assessing individual exposure incorporating air pollution changes over time.

Association between obesity and risk of chronic kidney disease: A nationwide Cohort study in Taiwan

Background and aimsIncreased body fat relates to enhanced inflammatory cytokine production, which, in turn, activates the renin-angiotensin-aldosterone system and increases the risk of chronic kidney disease (CKD). Herein, we aimed to examine the association between obesity and the risk of CKD in a population-representative cohort in Taiwan. Methods and resultsA multistage systematic sampling process was applied in the National Health Interview Survey (NHIS) 2000, 2005, and 2009. Participants were interviewed by a standardized face-to-face questionnaire to obtain information on their demographics, socioeconomic status, lifestyle factors, and body mass index (BMI). The BMI values were classified as follows: underweight (<18.5 kg/m2), normal (18.5–23.9 kg/m2), overweight (24–26.9 kg/m2), and obesity (≥27 kg/m2). The NHIS dataset was linked to National Health Insurance claims data to identify the incidence of CKD. Univariate and multivariate Cox proportional hazard models with competing risks were used to investigate the association between BMI and CKD incidence. We analyzed 45,012 subjects (mean age, 42.03 years; 50.09% males). During 374,254 person-years of follow-up, a total of 1913 new-onset CKD cases were identified. Kaplan–Meier curves comparing the four BMI groups revealed a significant difference (p < 0.01, log-rank test). After controlling for confounding factors, the relative risk of incident CKD was significantly higher in the obese group compared to the normal-weight group (adjusted hazard ratio = 1.32; 95% confidence interval: 1.17–1.49), with a significant linear trend (p < 0.01). ConclusionObesity was suggested as an independent risk factor for CKD. Further studies focusing on the effect of losing weight on CKD prevention are warranted.

What is the Longitudinal Relationship between Gait Abnormalities and Depression in a Cohort of Community-Dwelling Older People? Data From the Irish Longitudinal Study on Ageing (TILDA)

Does baseline gait disturbance predict incident depression in a cohort of community-dwelling older people? This is a longitudinal study, embedded within the Irish Longitudinal Study on Ageing (TILDA), examining the association between baseline depression and incident gait abnormalities, as well as between baseline gait abnormalities and incident depression at 2 year follow-up. Depression was defined as a score of ≥16 on the Centre for Epidemiological Studies Depression Scale (CES-D). Gait abnormality was defined as a Timed Up and Go Test (TUG) ≥12 seconds. Assessments were carried out at baseline and at 2 year follow-up. 7% (179/2,638) had baseline depression and 11% (296/2,638) had a gait abnormality at baseline. The incidence of new-onset depression and gait abnormality at Wave 2 was 4% (95/2,364) and 13% (308/2,342) respectively. Logistic regression models demonstrated that baseline gait abnormality was a significant predictor of incident depression with an Incidence Rate Ratio (IRR) of 2.00 (95% CI: 1.18 - 3.40, p =0.010, t =2.57, df =625), which was not attenuated after controlling for covariates. Baseline depression was a predictor of incident gait abnormality at Wave 2 with an IRR of 1.68 (95% CI: 1.16 - 2.43, p =0.006, t =2.75, df =625) but this association was no longer statistically significant when analysis was adjusted for clinical variables. This study demonstrates that baseline gait disturbance, measured by TUG, predicts incident depression, defined by CES-D, in a population-representative cohort of community-dwelling older people. Possible biological mechanisms for this relationship include white matter disease and executive dysfunction.

A Systematic Review of Longitudinal Studies Which Measure Alzheimer's Disease Biomarkers.

Alzheimer’s disease (AD) is a progressive and fatal neurodegenerative disease, with no effective treatment or cure. A gold standard therapy would be treatment to slow or halt disease progression; however, knowledge of causation in the early stages of AD is very limited. In order to determine effective endpoints for possible therapies, a number of quantitative surrogate markers of disease progression have been suggested, including biochemical and imaging biomarkers. The dynamics of these various surrogate markers over time, particularly in relation to disease development, are, however, not well characterized. We reviewed the literature for studies that measured cerebrospinal fluid or plasma amyloid-β and tau, or took magnetic resonance image or fluorodeoxyglucose/Pittsburgh compound B-positron electron tomography scans, in longitudinal cohort studies. We summarized the properties of the major cohort studies in various countries, commonly used diagnosis methods and study designs. We have concluded that additional studies with repeat measures over time in a representative population cohort are needed to address the gap in knowledge of AD progression. Based on our analysis, we suggest directions in which research could move in order to advance our understanding of this complex disease, including repeat biomarker measurements, standardization and increased sample sizes.

Re-employment, job quality, health and allostatic load biomarkers: prospective evidence from the UK Household Longitudinal Study.

BackgroundThere is little evidence on whether becoming re-employed in poor quality work is better for health and well-being than remaining unemployed. We examined associations of job transition with health and chronic stress-related biomarkers among a population-representative cohort of unemployed British adults.MethodsA prospective cohort of 1116 eligible participants aged 35 to 75 years, who were unemployed at wave 1 (2009/10) of the UK Household Longitudinal Study, were followed up at waves 2 (2010/11) and 3 (2011/12) for allostatic load biomarkers and self-reported health. Negative binomial and multiple regression models estimated the association between job adversity and these outcomes.ResultsCompared with adults who remained unemployed, formerly unemployed adults who transitioned into poor quality jobs had higher levels of overall allostatic load (0.51, 0.32–0.71), log HbA1c (0.06, <0.001–0.12), log triglycerides (0.39, 0.22–0.56), log C-reactive protein (0.45, 0.16–0.75), log fibrinogen (0.09, 0.01–0.17) and total cholesterol to high-density lipoprotein (HDL) ratio (1.38, 0.88–1.88). Moreover, physically healthier respondents at wave 1 were more likely to transition into good quality and poor quality jobs after 1 year than those who remained unemployed.ConclusionsFormerly unemployed adults who transitioned into poor quality work had greater adverse levels of biomarkers compared with their peers who remained unemployed. The selection of healthier unemployed adults into these poor quality or stressful jobs was unlikely to explain their elevated levels of chronic stress-related biomarkers. Job quality cannot be disregarded from the employment success of the unemployed, and may have important implications for their health and well-being.

Mediterranean diet and cognitive health: Initial results from the Hellenic Longitudinal Investigation of Ageing and Diet.

BackgroundThe Mediterranean dietary pattern has been associated with a decreased risk of many degenerative diseases and cognitive function in particular; however, relevant information from Mediterranean regions, where the prototype Mediterranean diet is typically adhered to, have been very limited. Additionally, predefined Mediterranean diet (MeDi) scores with use of a priori cut-offs have been used very rarely, limiting comparisons between different populations and thus external validity of the associations. Finally, associations between individual components of MeDi (i.e., food groups, macronutrients) and particular aspects of cognitive performance have rarely been explored. We evaluated the association of adherence to an a priori defined Mediterranean dietary pattern and its components with dementia and specific aspects of cognitive function in a representative population cohort in Greece.MethodsParticipants from the Hellenic Longitudinal Investigation of Ageing and Diet (HELIAD), an on-going population-based study, exploring potential associations between diet and cognitive performance in a representative sample from Greek regions, were included in this analysis. Diagnosis of dementia was made by a full clinical and neuropsychological evaluation, while cognitive performance was assessed according to five cognitive domains (memory, language, attention-speed, executive functioning, visuospatial perception) and a composite cognitive score. Adherence to MeDi was evaluated by an a priori score (range 0–55), derived from a detailed food frequency questionnaire.ResultsAmong 1,865 individuals (mean age 73±6 years, 41% male), 90 were diagnosed with dementia and 223 with mild cognitive impairment. Each unit increase in the Mediterranean dietary score (MedDietScore) was associated with a 10% decrease in the odds for dementia. Adherence to the MeDi was also associated with better performance in memory, language, visuospatial perception and the composite cognitive score; the associations were strongest for memory. Fish consumption was negatively associated with dementia and cognitive performance positively associated with non-refined cereal consumption.ConclusionsOur results suggest that adherence to the MeDi is associated with better cognitive performance and lower dementia rates in Greek elders. Thus, the MeDi in its a priori constructed prototype form may have cognitive benefits in traditional Mediterranean populations.

THE PREVALENCE, CAUSES AND CONSEQUENCES OF UNDIAGNOSED DEMENTIA IN ENGLAND: A RECORD LINKAGE STUDY OF THE COGNITIVE FUNCTION AND AGEING STUDY II

It is acknowledged that, whatever criteria are used, a substantial proportion of people with dementia remain undiagnosed. This may vary according to diagnostic methods, the services available and clinical and community perceptions of the value of diagnosis. Research that can examine the characteristics of those who are known to services in relation to an independent and objective assessment of dementia is rare. Here we describe diagnostic status of a population representative cohort of people with dementia, and estimate the prevalence, predictors and outcomes of undiagnosed dementia in England. The Cognitive Function and Ageing Study II (CFAS II) recruited 7500 people aged ≥65 years from three areas of England (2008–11). Baseline and two year follow-up assessments included a cognitive battery, personal interview and an informant interview. For each participant study dementia status, previously validated against DSM-III-R, was established. Primary care records from 598 participants with consent for health service data linkage were sought including 447 people with dementia and a stratified subsample of those without (n=151). Dementia diagnoses, cognitive complaints and referrals to specialist services were extracted. Linking study diagnoses and CFAS II assessments with the records held in primary care enables estimation of: (i) the true relationship between those receiving a formal health service diagnosis and those receiving a study diagnosis; (ii) social and clinical predictors of becoming diagnosed; and, (iii) outcomes among the diagnosed and non-diagnosed populations. We hypothesise that these groups will vary in social circumstances, signs and symptoms, comorbidities and service use outcomes. To date primary care records from 472 patients have been collected. We will present the prevalence of diagnosis among groups stratified by dementia severity, and the proportion of those with no diagnosis but with a record of help seeking or referral to secondary services. We will compare the characteristics and service use history of diagnosed and undiagnosed people with dementia. Epidemiological studies including objective validated dementia diagnoses provide a unique opportunity to estimate the extent and predictors of heath service use among people with dementia. This is important to understanding dementia in populations and improving diagnostic and support services.