The association between cognitive ability across the lifespan and health literacy in old age: The Lothian Birth Cohort 1936

Factors associated with poor health literacy in older adults: A systematic review

OBJECTIVES

To identify factors associated with poor health literacy in older adults.

METHODS

A systematic literature review was conducted, employing the descriptors "Aged" and "Health Literacy".

PROSPERO - CRD

42022350140.

RESULTS

Out of 23,500 articles screened, 176 were selected. Several factors associated with poor health literacy in older adults were identified, such as sociodemographic (e.g., advanced age, low educational level, non-white population, and others), social (e.g., poor family/social support, loneliness, social isolation, few social activities, and others), economic (e.g., lower income and/or lower socioeconomic status) and health aspects (e.g., poor health, chronic conditions, mental health challenges, hospitalizations, frailty, physical inactivity, cognitive impairment, and others).

CONCLUSIONS

The factors associated with poor health literacy in older adults identified in this review could contribute to future research, support interventions to improve health literacy, and assist professionals in planning educational activities and public policies.

Vergleich unterschiedlicher Instrumente zur Messung von Gesundheitskompetenz im Zusammenhang mit Lesekompetenz und kognitiven Fähigkeiten von Jugendlichen

Zusammenfassung. Instrumente zur Messung von Gesundheitskompetenz bei Jugendlichen basieren auf sehr heterogenen Definitionen und Konzepten. Zudem können sie grundsätzlich in subjektive (Selbsteinschätzungs–) und objektive (die Performanz messende) Verfahren unterteilt werden. In der vorliegenden Studie wurden 2 subjektive (eHEALS; Kurzform des HLS-EU-Q16) und ein objektives Messinstrument (Claim) von 471 Jugendlichen der 6. und 7. Klassenstufe (Durchschnittsalter 13.04 Jahre; 49 % Mädchen; 63 % Familiensprache Deutsch) bearbeitet und auf ihren wechselseitigen Zusammenhang, den Zusammenhang mit kognitiven und Lesefähigkeiten, sowie Unterschiede in Bezug auf Geschlecht und Familiensprache untersucht. Das objektive Verfahren korrelierte nicht mit den subjektiven Verfahren. Dies bestätigt die Annahme, dass sie aufgrund der Messperspektive unterschiedliche Indikatorenausprägungen von Gesundheitskompetenz erfassen. Korrelationen mit Lese- und kognitiven Fähigkeiten zeigten sich nur beim objektiven Instrument, wohingegen die Selbsteinschätzungsinstrumente diese Aspekte der Gesundheitskompetenz nicht abbilden. Unterschiede hinsichtlich des Geschlechts und der Familiensprache zeigten sich insbesondere beim objektiven Instrument, allerdings sind Antwortverzerrungen bei Selbsteinschätzungen möglich. Die spezifischen Vor- und Nachteile von subjektiven und objektiven Verfahren sollten bei der Instrumentenauswahl berücksichtigt werden.

Association of functional health literacy and cognitive ability with self-reported diabetes in the English Longitudinal Study of Ageing: a prospective cohort study

OBJECTIVES

We investigated whether functional health literacy and cognitive ability were associated with self-reported diabetes.

DESIGN

Prospective cohort study.

SETTING

Data were from waves 2 (2004-2005) to 7 (2014-2015) of the English Longitudinal Study of Ageing (ELSA), a cohort study designed to be representative of adults aged 50 years and older living in England.

PARTICIPANTS

8669 ELSA participants (mean age=66.7, SD=9.7) who completed a brief functional health literacy test assessing health-related reading comprehension, and 4 cognitive tests assessing declarative memory, processing speed and executive function at wave 2.

PRIMARY OUTCOME MEASURE

Self-reported doctor diagnosis of diabetes.

RESULTS

Logistic regression was used to examine cross-sectional (wave 2) associations of functional health literacy and cognitive ability with diabetes status. Adequate (compared with limited) functional health literacy (OR 0.71, 95% CI 0.61 to 0.84) and higher cognitive ability (OR per 1 SD=0.73, 95% CI 0.67 to 0.80) were associated with lower odds of self-reporting diabetes at wave 2. Cox regression was used to test the associations of functional health literacy and cognitive ability measured at wave 2 with self-reporting diabetes over a median of 9.5 years follow-up (n=6961). Adequate functional health literacy (HR 0.64; 95% CI 0.53 to 0.77) and higher cognitive ability (HR 0.77, 95% CI 0.69 to 0.85) at wave 2 were associated with lower risk of self-reporting diabetes during follow-up. When both functional health literacy and cognitive ability were added to the same model, these associations were slightly attenuated. Additionally adjusting for health behaviours and body mass index fully attenuated cross-sectional associations between functional health literacy and cognitive ability with diabetes status, and partly attenuated associations between functional health literacy and cognitive ability with self-reporting diabetes during follow-up.

CONCLUSIONS

Adequate functional health literacy and better cognitive ability were independently associated with lower likelihood of reporting diabetes.

Health Literacy of Newly-Admitted Cancer Patients in Vietnam: Difficulties Understanding Treatment Options and Processing Health-Related Information

Having a good understanding of cancer patients' health literacy in the early stage of diagnosis can help to implement strategies to improve the management process and overall health outcomes. The study aims to describe health literacy and its association with socio-demographic characteristics among newly admitted cancer patients. A cross-sectional study was conducted on 262 newly admitted patients of a cancer hospital in Vietnam using the Vietnamese version of the HLS-SF12 questionnaire. Descriptive analytics and regression analysis were used to describe health literacy and examine associated factors. Older age, lower level of education, and living in rural areas were associated with lower health literacy while there was no significant relationship between gender and health literacy among newly admitted cancer patients. Many newly admitted patients, especially the older patients have difficulties understanding the different treatment options (54%) and evaluating the reliability of health information on the internet (43%). During the early stage of treatment, strategies should be implemented with regards to patients' health literacy, to properly educate patients and their caregivers to improve communication, adherence to medication, lifestyle, and overall better quality of life and treatment outcome.

Early life predictors of late life cerebral small vessel disease in four prospective cohort studies

Development of cerebral small vessel disease, a major cause of stroke and dementia, may be influenced by early life factors. It is unclear whether these relationships are independent of each other, of adult socio-economic status or of vascular risk factor exposures. We examined associations between factors from birth (ponderal index, birth weight), childhood (IQ, education, socio-economic status), adult small vessel disease, and brain volumes, using data from four prospective cohort studies: STratifying Resilience And Depression Longitudinally (STRADL) (n = 1080; mean age = 59 years); the Dutch Famine Birth Cohort (n = 118; mean age = 68 years); the Lothian Birth Cohort 1936 (LBC1936; n = 617; mean age = 73 years), and the Simpson's cohort (n = 110; mean age = 78 years). We analysed each small vessel disease feature individually and summed to give a total small vessel disease score (range 1-4) in each cohort separately, then in meta-analysis, adjusted for vascular risk factors and adult socio-economic status. Higher birth weight was associated with fewer lacunes [odds ratio (OR) per 100 g = 0.93, 95% confidence interval (CI) = 0.88 to 0.99], fewer infarcts (OR = 0.94, 95% CI = 0.89 to 0.99), and fewer perivascular spaces (OR = 0.95, 95% CI = 0.91 to 0.99). Higher childhood IQ was associated with lower white matter hyperintensity burden (OR per IQ point = 0.99, 95% CI 0.98 to 0.998), fewer infarcts (OR = 0.98, 95% CI = 0.97 to 0.998), fewer lacunes (OR = 0.98, 95% CI = 0.97 to 0.999), and lower total small vessel disease burden (OR = 0.98, 95% CI = 0.96 to 0.999). Low education was associated with more microbleeds (OR = 1.90, 95% CI = 1.33 to 2.72) and lower total brain volume (mean difference = -178.86 cm3, 95% CI = -325.07 to -32.66). Low childhood socio-economic status was associated with fewer lacunes (OR = 0.62, 95% CI = 0.40 to 0.95). Early life factors are associated with worse small vessel disease in later life, independent of each other, vascular risk factors and adult socio-economic status. Risk for small vessel disease may originate in early life and provide a mechanistic link between early life factors and risk of stroke and dementia. Policies investing in early child development may improve lifelong brain health and contribute to the prevention of dementia and stroke in older age.

Associations Between Hearing and Cognitive Abilities From Childhood to Middle Age: The National Child Development Study 1958

Previous cross-sectional findings indicate that hearing and cognitive abilities are positively correlated in childhood, adulthood, and older age. We used an unusually valuable longitudinal dataset from a single-year birth cohort study, the National Child Development Study 1958, to test how hearing and cognitive abilities relate to one another across the life course from childhood to middle age. Cognitive ability was assessed with a single test of general cognitive ability at age 11 years and again with multiple tests at age 50. Hearing ability was assessed, using a pure tone audiogram, in childhood at ages 11 and 16 and again at age 44. Associations between childhood and middle-age hearing and cognitive abilities were investigated using structural equation modelling. We found that higher cognitive ability was associated with better hearing (indicated by a lower score on the hearing ability variables); this association was apparent in childhood (r  =  -0.120, p <0.001) and middle age (r  =  -0.208, p <0.001). There was a reciprocal relationship between hearing and cognitive abilities over time: better hearing in childhood was weakly associated with a higher cognitive ability in middle age (β  =  -0.076, p  =  0.001), and a higher cognitive ability in childhood was associated with better hearing in middle age (β  =  -0.163, p <0.001). This latter, stronger effect was mediated by occupational and health variables in adulthood. Our results point to the discovery of a potentially life-long relationship between hearing and cognitive abilities and demonstrate how these variables may influence one another over time.

Low Health Literacy Is Associated With Frailty and Reduced Likelihood of Liver Transplant Listing: A Prospective Cohort Study

The effect of low health literacy (HL) on outcomes in end-stage liver disease (ESLD) is largely unknown. The association of low HL on clinical outcomes was investigated in a prospective cohort of outpatients with ESLD undergoing liver transplantation (LT) evaluation. From 2014 to 2017, 276 patients underwent LT evaluation with assessments of liver disease severity, medical and psychosocial comorbidities, physical frailty, and malnutrition. Literacy was measured with the Newest Vital Sign, a brief validated assessment. Multivariate models assessed relationships between HL and clinical outcomes adjusting for clinical and psychosocial variables. The median Model for End-Stage Liver Disease-sodium score of the study sample was 15 (interquartile range, 11-19), 71 (25.7%) of candidates were frail, 117 (42.4%) had malnutrition, 151 (54.7%) had hepatic encephalopathy, 104 (37.7%) had low HL, and 85 (39.2%) had marginal or poor social support. Adjusting for education level, socioeconomic factors, and severity of illness, low HL was independently associated with physical frailty (adjusted odds ratio [aOR], 3.59; 95% confidence interval [CI], 1.50-8.59; P = 0.004) and not being wait-listed (aOR 1.96; 95% CI, 1.03-3.75; P = 0.04). Strong social support attenuated the relationship between low HL and not being wait-listed (aOR, 1.58; 95% CI, 0.74-3.36; P = 0.24). Low HL is common and a largely unrecognized risk factor for poor health outcomes among patients with ESLD. Patient-oriented infrastructure and support are needed at the health system level to ensure all patients can successfully navigate the complex process of LT evaluation and wait-listing.

Which Aspects of Education Matter for Early Adult Mortality? Evidence from the High School and Beyond Cohort

What dimensions of education matter for people's chances of surviving young adulthood? Do cognitive skills, non-cognitive skills, course taking patterns, and school social contexts matter for young adult mortality, even net of educational attainment? We analyze data from High School & Beyond-a nationally representative cohort of ~25,000 high school students first interviewed in 1980. Many dimensions of education are associated with young adult mortality, and high school students' math course taking retain their associations with mortality net of educational attainment. Our work draws on theories and measures from sociological and educational research and enriches public health, economic, and demographic research on educational gradients in mortality that has almost exclusively relied on ideas of human capital accumulation and measures of degree attainment. Our findings also call on social and education researchers to engage together in research on the life-long consequences of educational processes, school structures, and inequalities in opportunities to learn.

Cognitive aptitude, peers, and trajectories of marijuana use from adolescence through young adulthood

BACKGROUND

Using a nationally representative longitudinal cohort, we examine how cognitive aptitude in early adolescence is associated with heterogeneous pathways of marijuana use from age sixteen through young adulthood. We also examine whether this relationship can be explained by the role of cognitive aptitude in the social organization of peer group deviance.

METHODS

Using the National Longitudinal Survey of Youth 1997, we identified 5 latent trajectories of frequency of marijuana use between ages 16 and 26: abstainers, dabblers, early heavy quitters, consistent users, and persistent heavy users. Multinomial regression assessed the relationship of cognitive aptitude in early adolescence with these latent trajectories, including the role of peer group substance use in this relationship.

RESULTS

A one decile increase in cognitive aptitude in early adolescence is associated with greater relative risk of the dabbler trajectory (RR = 1.048; p < .001) and consistent user trajectory (RR = 1.126; p < .001), but lower relative risk of the early heavy quitter trajectory (RR = 0.917; p < .05) in comparison with the abstainer trajectory. There was no effect for the persistent heavy user trajectory. The inclusion of peer group substance use-either via illegal drugs or smoking-had no effect on these relationships.

CONCLUSIONS

Adolescents who rate higher in cognitive aptitude during early adolescence may be more likely to enter into consistent but not extreme trajectories of marijuana use as they age into young adulthood. Cognition may not influence patterns of marijuana use over time via the organization of peer groups.

Genetic Contributions to Health Literacy

Higher health literacy is associated with higher cognitive function and better health. Despite its wide use in medical research, no study has investigated the genetic contributions to health literacy. Using 5783 English Longitudinal Study of Ageing (ELSA) participants (mean age = 65.49, SD = 9.55) who had genotyping data and had completed a health literacy test at wave 2 (2004-2005), we carried out a genome-wide association study (GWAS) of health literacy. We estimated the proportion of variance in health literacy explained by all common single nucleotide polymorphisms (SNPs). Polygenic profile scores were calculated using summary statistics from GWAS of 21 cognitive and health measures. Logistic regression was used to test whether polygenic scores for cognitive and health-related traits were associated with having adequate, compared to limited, health literacy. No SNPs achieved genome-wide significance for association with health literacy. The proportion of variance in health literacy accounted for by common SNPs was 8.5% (SE = 7.2%). Greater odds of having adequate health literacy were associated with a 1 standard deviation higher polygenic score for general cognitive ability [OR = 1.34, 95% CI (1.26, 1.42)], verbal-numerical reasoning [OR = 1.30, 95% CI (1.23, 1.39)], and years of schooling [OR = 1.29, 95% CI (1.21, 1.36)]. Reduced odds of having adequate health literacy were associated with higher polygenic profiles for poorer self-rated health [OR = 0.92, 95% CI (0.87, 0.98)] and schizophrenia [OR = 0.91, 95% CI (0.85, 0.96)). The well-documented associations between health literacy, cognitive function and health may partly be due to shared genetic etiology. Larger studies are required to obtain accurate estimates of SNP-based heritability and to discover specific health literacy-associated genetic variants.

Patient-selected media and knowledge of risk to kidneys of nonsteroidal anti-inflammatory drugs

OBJECTIVES

Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause community-acquired acute kidney injury, especially in high-risk populations. Both the U.S. Food and Drug Administration (FDA) medication guide and over-the-counter labeling vaguely describe kidney risks of NSAIDs and do not provide information for patients to evaluate their risk for kidney problems. The purpose of this study was to use a mobile application to evaluate the impact of patient choice of media delivering NSAID avoidance education on patient knowledge about kidney risks associated with NSAIDs.

DESIGN

Prospective cohort study. The mobile application was used to deliver either a redesigned FDA medication guide or a video focused on NSAID risks (selected by the patient), followed by patient knowledge questions (PKQs) and a kidney risk assessment.

SETTING AND PARTICIPANTS

One hundred fifty adult primary care patients in southeast Michigan.

MAIN OUTCOME MEASURES

The primary outcome was the score on 5 NSAID PKQs between the media selected. Secondary outcomes included characterization of media choice among different demographic and NSAID kidney risk groups. The relationship between kidney risk assessment and self-reported NSAID avoidance behavior also was evaluated.

RESULTS

The majority of participants (72.7%) chose to review print material. Those that chose print had significantly higher PKQ scores (5 total points) compared with participants who selected the video: mean scores 4.2 ± 0.9 with print and 3.8 ± 1.0 with video (P = 0.034). Older patients (>65 years) had significantly lower PKQ scores compared with other age groups. Forty-four percent of individuals (n = 66) reported current NSAID use, and 65% stated that they would avoid NSAIDs after the selected education material.

CONCLUSION

Scores for questions related to NSAID kidney risk knowledge were higher among participants who chose print compared with video education material. Education regarding NSAID kidney risks encouraged patients to limit their use. Targeted education may be beneficial in high-risk (e.g., older) patients and should be further studied.

Dietary glycaemic index and cognitive function: prospective associations in adults of the 1946 British birth cohort

Objective

Evidence suggests that the rate of glucose release following consumption of carbohydrate-containing foods, defined as the glycaemic index (GI), is inversely associated with cognitive function. To date, most of the evidence stems from either single-meal studies or highly heterogeneous cohort studies. We aimed to study the prospective associations of diet GI at age 53 years with outcomes of verbal memory and letter search tests at age 69 years and rate of decline between 53 and 69 years.

Design

Longitudinal population-based birth cohort study.

Setting

MRC National Survey for Health and Development.

Participants

Cohort members (n 1252).

Results

Using multivariable linear and logistic regression, adjusted for potential confounders, associations of higher-GI diet with lower verbal memory, lower letter search speed and lower number of hits in a letter search test were attenuated after adjustments for cognitive ability at age 15 years, educational attainment, further training and occupational social class. No association was observed between diet GI at 53 years and letter search accuracy or speed–accuracy trade-off at 69 years, or between diet GI at 53 years and rate of decline between 53 and 69 years in any cognitive measure.

Conclusions

Diet GI does not appear to predict cognitive function or decline, which was mainly explained by childhood cognitive ability, education and occupational social class. Our findings confirm the need for further research on the association between diet and cognition from a life-course perspective.

Health literacy, cognitive ability and smoking: a cross-sectional analysis of the English Longitudinal Study of Ageing

OBJECTIVES

We used logistic regression to investigate whether health literacy and cognitive ability independently predicted whether participants have ever smoked and, in ever smokers, whether participants still smoked nowadays.

DESIGN

Cross-sectional study.

SETTING

This study used data from Wave 2 (2004-05) of the English Longitudinal Study of Ageing, which is a cohort study of adults who live in England and who, at baseline, were aged 50 years and older.

PARTICIPANTS

8734 (mean age=65.31 years, SD=10.18) English Longitudinal Study of Ageing participants who answered questions about their current and past smoking status, and completed cognitive ability and health literacy tests at Wave 2.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measures were whether participants reported ever smoking at Wave 2 and whether ever smokers reported still smoking at Wave 2.

RESULTS

In models adjusting for age, sex, age left full-time education and occupational social class, limited health literacy (OR=1.096, 95% CI 0.988 to 1.216) and higher general cognitive ability (OR=1.000, 95% CI 0.945 to 1.057) were not associated with reporting ever smoking. In ever smokers, limited compared with adequate health literacy was associated with greater odds of being a current smoker (OR=1.194, 95% CI 1.034 to 1.378) and a 1 SD higher general cognitive ability score was associated with reduced odds of being a current smoker (OR=0.878, 95% CI 0.810 to 0.951), when adjusting for age, sex, age left full-time education and occupational social class.

CONCLUSIONS

When adjusting for education and occupation variables, this study found that health literacy and cognitive ability were independently associated with whether ever smokers continued to smoke nowadays, but not with whether participants had ever smoked.

Role of cognitive ability in the association between functional health literacy and mortality in the Lothian Birth Cohort 1936: a prospective cohort study

OBJECTIVES

We investigated the role that childhood and old age cognitive ability play in the association between functional health literacy and mortality.

DESIGN

Prospective cohort study.

SETTING

This study used data from the Lothian Birth Cohort 1936 (LBC1936) study, which recruited participants living in the Lothian region of Scotland when aged 70 years, most of whom had completed an intelligence test at age 11 years.

PARTICIPANTS

795 members of the LBC1936 with scores on tests of functional health literacy and cognitive ability in childhood and older adulthood.

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants were followed up for 8 years to determine mortality. Time to death in days was used as the primary outcome measure.

RESULTS

Using Cox regression, higher functional health literacy was associated with lower risk of mortality adjusting for age and sex, using the Shortened Test of Functional Health Literacy in Adults (HR 0.95, 95% CI 0.92 to 0.98), the Newest Vital Sign (HR 0.88, 95% CI 0.80 to 0.97) and a functional health literacy composite measure (HR 0.77, 95% CI 0.65 to 0.92), but not the Rapid Estimate of Adult Literacy in Medicine (HR 0.95, 95% CI 0.90 to 1.01). Adjusting for childhood intelligence did not change these associations. When additionally adjusting for fluid-type cognitive ability in older age, associations between functional health literacy and mortality were attenuated and non-significant.

CONCLUSIONS

Current fluid ability, but not childhood intelligence, attenuated the association between functional health literacy and mortality. Functional health literacy measures may, in part, assess fluid-type cognitive abilities, and this may account for the association between functional health literacy and mortality.

Healthy cognitive ageing in the Lothian Birth Cohort studies: marginal gains not magic bullet

In the face of shifting demographics and an increase in human longevity, it is important to examine carefully what is known about cognitive ageing, and to identify and promote possibly malleable lifestyle and health-related factors that might mitigate age-associated cognitive decline. The Lothian Birth Cohorts of 1921 (LBC1921, n = 550) and 1936 (LBC1936, n = 1091) are longitudinal studies of cognitive and brain ageing based in Scotland. Childhood IQ data are available for these participants, who were recruited in later life and then followed up regularly. This overview summarises some of the main LBC findings to date, illustrating the possible genetic and environmental contributions to cognitive function (level and change) and brain imaging biomarkers in later life. Key associations include genetic variation, health and fitness, psychosocial and lifestyle factors, and aspects of the brain's structure. It addresses some key methodological issues such as confounding by early-life intelligence and social factors and emphasises areas requiring further investigation. Overall, the findings that have emerged from the LBC studies highlight that there are multiple correlates of cognitive ability level in later life, many of which have small effects, that there are as yet few reliable predictors of cognitive change, and that not all of the correlates have independent additive associations. The concept of marginal gains, whereby there might be a cumulative effect of small incremental improvements across a wide range of lifestyle and health-related factors, may offer a useful way to think about and promote a multivariate recipe for healthy cognitive and brain ageing.

A life course approach to health literacy: the role of gender, educational attainment and lifetime cognitive capability

Objective

social inequalities in health are believed to arise in part because individuals make use of social and economic resources in order to improve survival. In recent years, health literacy has received increased attention as a factor that can help explain differences in health outcomes. However, examination of life course predictors of health literacy has been limited.

Methods

life course data from the Wisconsin Longitudinal Study 1957-2011 were used to examine predictors of health literacy in old age (N = 2,122), using the Newest Vital Sign. Generalised structural equation modelling was used to model pathways to health literacy.

Results

predictors of health literacy included educational attainment, and adolescent cognitive and non-cognitive skills, and, in men, rate of cognitive decline from middle to later life.

Discussion

numerous studies have documented health literacy issues among older adults, and recommendations have been made for ways to improve health literacy for this population. This study reports on risk factors across the life course that are associated with health literacy later in life, identifying possible intervention targets to reduce risk of poor health as people age. Our results suggest that a range of life course factors, beginning in early life, predict health literacy. Further research studying health literacy over the life course is warranted.

Mental retirement and health selection: Analyses from the U.S. Health and Retirement Study

BACKGROUND

Research has recently suggested that retirement may decrease cognitive engagement, resulting in cognitive aging. Few studies have systematically documented whether or how selectivity into retirement shapes the relationship between retirement and cognitive aging.

METHODS

We draw on data from the Health and Retirement Study (1998-2012) to examine the relationship between cognition and retirement for 18,575 labor force participants. Longitudinal regression discontinuity modeling was used to examine performance and decline in episodic memory. Models differentiated three forms of selection bias: indirect and direct selection as well as reverse causation. To further interrogate the disuse hypothesis, we adjust for confounding from health and socioeconomic sources.

RESULTS

Results revealed that individuals who retired over the course of the panel were substantially different in terms of health, wealth and cognition when compared to those who remained employed. However, accounting for observed selection biases, significant associations were found linking longer retirement with more rapid cognitive decline.

DISCUSSION

This study examined respondents who were in the labor force at baseline and transitioned into retirement. Analyses suggested that those who retired over the course of the panel had worse overall functioning, but also experienced more rapid declines after retirement that increased the rate of aging by two-fold, resulting in yearly losses of 3.7% (95% CI = [3.5, 4.0]) of one standard deviation in functioning attributable to retirement. Results are supportive of the view that retirement is associated with more rapid cognitive aging.

Does educational attainment shape reactions to genetic risk for Alzheimer's disease? Results from a national survey experiment

While higher education is associated with healthy lifestyles and health literacy, it remains unclear whether education shapes reactions to varying levels of genetic risk for Alzheimer's disease (AD). In this study, participants (N = 701) in the National Genetic Risk Survey Experiment (NGRISE) received a hypothetical genetic risk assessment for AD (ranging from 20 to 80% lifetime risk) and then completed items on their cognitive (perceived threat to health), emotional (general negative affect), and anticipated behavioral (seek information, improve health behaviors, engage in public or private civic action) reactions to this risk. Individuals with a college education showed reactions to increasing genetic risk approximately twice or several times as strong relative to those of individuals with lower (high school, HS) education. In fact, behavioral reactions do not significantly increase with AD risk among those with HS education. Some educational differences in risk response widen at older ages.

Intelligence in youth and mental health at age 50

BACKGROUND

Few cognitive epidemiology studies on mental health have focused on the links between pre-morbid intelligence and self-reports of common mental disorders, such as depression, sleep difficulties, and mental health status. The current study examines these associations in 50-year-old adults.

METHODS

The study uses data from the 5793 participants in the National Longitudinal Survey of Youth 1979 cohort (NLSY-79) who responded to questions on mental health at age 50 and had IQ measured with the Armed Forces Qualification Test (AFQT) when they were aged between 15 and 23 years in 1980. Mental health outcomes were: life-time diagnosis of depression; the mental component score of the 12-item short-form Health Survey (SF-12); the 7-item Center for Epidemiological Studies Depression Scale (CES-D); and a summary measure of sleep difficulty.

RESULTS & CONCLUSION

Higher intelligence in youth is associated with a reduced risk of self-reported mental health problems at age 50, with age-at-first-interview and sex adjusted Bs as follows: CES-depression (B = - 0.16, C.I. - 0.19 to - 0.12, p < 0.001), sleep difficulties (B = - 0.11, C.I. - 0.13 to - 0.08, p < 0.001), and SF-12 mental health status (OR = 0.78, C.I. 0.72 to 0.85, p < 0.001; r = - 0.03 p = 0.075). Conversely, intelligence in youth is linked with an increased risk of receiving a diagnosis of depression by the age of 50 (OR 1.11, C.I. 1.01 to 1.22, p = 0.024; r = 0.03, p = 0.109). No sex differences were observed in the associations. Adjusting for adult SES accounted for most of the association between IQ and the mental health outcomes, except for having reported a diagnosis of depression, in which case adjusting for adult SES led to an increase in the size of the positive association (OR = 1.32, C.I. 1.16 to 1.51, p < 0.001).

Aging and Functional Health Literacy: A Systematic Review and Meta-Analysis

OBJECTIVES

To review the evidence on the association between age and limited health literacy, overall and by health literacy test, and to investigate the mediating role of cognitive function.

METHOD

The Embase, MEDLINE, and PsycINFO databases were searched. Eligible studies were conducted in any country or language, included participants aged ≥50 years, presented a measure of association between age and health literacy, and were published through September 2013.

RESULTS

Seventy analyses in 60 studies were included in the systematic review; 29 of these were included in the meta-analysis. Older age was strongly associated with limited health literacy in analyses that measured health literacy as reading comprehension, reasoning, and numeracy skills (random-effects odds ratio [OR] = 4.20; 95% confidence interval [CI]: 3.13-5.64). By contrast, older age was weakly associated with limited health literacy in studies that measured health literacy as medical vocabulary (random-effects OR = 1.19; 95% CI: 1.03-1.37). Evidence on the mediating role of cognitive function was limited.

DISCUSSION

Health literacy tests that utilize a range of fluid cognitive abilities and mirror everyday health tasks frequently observe skill limitations among older adults. Vocabulary-based health literacy skills appear more stable with age. Researchers should select measurement tests wisely when assessing health literacy of older adults.

Intelligence in youth and health at age 50

Background

The link between intelligence in youth and all-cause mortality in later-life is well established. To better understand this relationship, the current study examines the links between pre-morbid intelligence and a number of specific health outcomes at age 50 using the NLSY-1979 cohort.

Methods

Participants were the 5793 participants in the NLSY-79 who responded to questions about health outcomes at age 50. Sixteen health outcomes were examined: two were summary measures (physical health and functional limitation), 9 were diagnosed illness conditions, 4 were self-reported conditions, and one was a measure of general health status. Linear and logistic regressions were used, as appropriate, to examine the relationship between intelligence in youth and the health outcomes. Age, sex and both childhood and adult SES, and its sub-components – income, education, & occupational prestige – are all adjusted for separately.

Results & conclusion

Higher pre-morbid intelligence is linked with better physical health at age 50, and a lower risk for a number of chronic health conditions. For example, a 1 SD higher score in IQ was significantly associated with increased odds of having good, very good, or excellent health, with an odds ratio of 1.70 (C.I. 1.55–1.86). Thirteen of the illness outcomes were significantly and negatively associated with IQ in youth; the odds ratios ranged from 0.85 for diabetes/high blood sugar to 0.65 for stroke, per one standard deviation higher score in IQ. Adjustment for childhood SES led to little attenuation but adult SES partially mediated the relationship for a number of conditions. Mediation by adult SES was not consistently explained by any one of its components—income, education, and occupation status. The current findings contribute to our understanding of lower intelligence as a risk factor for poor health and how this may contribute to health inequalities.

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We examined links between intelligence in youth and health at age 50 in NLSY-1979.

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Higher intelligence in youth is linked with better physical health at age 50.

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Higher intelligence in youth is linked with lower risk for chronic illnesses.

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Adult but not childhood SES partially mediated the intelligence–health relationship.

Markers of Psychological Differences and Social and Health Inequalities: Possible Genetic and Phenotypic Overlaps

Associations between markers of ostensible psychological characteristics and social and health inequalities are pervasive but difficult to explain. In some cases, there may be causal influence flowing from social and health inequalities to psychological differences, whereas sometimes it may be the other way around. Here, we focus on the possibility that some markers that we often consider as indexing different domains of individual differences may in fact reflect at least partially overlapping genetic and/or phenotypic bases. For example, individual differences in cognitive abilities and educational attainment appear to reflect largely overlapping genetic influences, whereas cognitive abilities and health literacy may be almost identical phenomena at the phenotypic, never mind genetic, level. We make the case for employing molecular genetic data and quantitative genetic techniques to better understand the associations of psychological individual differences with social and health inequalities. We illustrate these arguments by using published findings from the Lothian Birth Cohort and the Generation Scotland studies. We also present novel findings pertaining to longitudinal stability and change in older age personality traits and some correlates of the change, molecular genetic data-based heritability estimates of Neuroticism and Extraversion, and the genetic correlations of these personality traits with markers of social and health inequalities.

The role of cognitive function in the relationship between age and health literacy: a cross-sectional analysis of older adults in Chicago, USA

OBJECTIVES

To investigate how 3 measures of health literacy correlate with age and the explanatory roles of fluid and crystallised cognitive abilities in these relationships among older adults.

DESIGN

Cross-sectional baseline analysis of the 'LitCog' cohort study.

SETTING

1 academic internal medicine clinic and 5 federally qualified health centres in Chicago, USA.

PARTICIPANTS

English-speaking adults (n=828) aged 55-74 years, recruited from August 2008 through October 2011.

OUTCOME MEASURES

Health literacy was measured by the Test of Functional Health Literacy in Adults (TOFHLA) and the Newest Vital Sign (NVS), both of which assess reading comprehension and numeracy in health contexts, and by the Rapid Estimate of Adult Literacy in Medicine (REALM), which assesses medical vocabulary. Fluid cognitive ability was assessed through the cognitive domains of processing speed, inductive reasoning, and working, prospective and long-term memories, and crystallised cognitive ability through the verbal ability domain.

RESULTS

TOFHLA and NVS scores were lower at ages 70-74 years compared with all other age groups (p<0.05 for both tests). The inverse association between age and TOFHLA score was attenuated from β=-0.39 (95% CI -0.55 to -0.22) to β=-0.06 (95% CI -0.20 to 0.08) for ages 70-74 vs 55-59 years when fluid cognitive ability was added to the model (85% attenuation). Similar results were seen with NVS scores (68% attenuation). REALM scores did not differ by age group (p=0.971). Crystallised cognitive ability was stable across age groups, and did not influence the relationships between age and TOFHLA or NVS performance.

CONCLUSIONS

Health literacy skills show differential patterns of age-related change, which may be explained by cognitive ageing. Researchers should select health literacy tests appropriate for their purposes when assessing the health literacy of older adults. Clinicians should be aware of this issue to ensure that health self-management tasks for older patients have appropriate cognitive and literacy demands.

Do dietary patterns influence cognitive function in old age?

BACKGROUND

Evidence from observational studies to date suggests that healthy dietary patterns are associated with better cognitive performance in later life. We examined the extent to which childhood intelligence quotient (IQ) and socioeconomic status account for this association.

METHODS

Analyses were carried out on 882 participants in the Lothian Birth Cohort 1936 Study. Four dietary patterns were extracted using principal components analysis of a food frequency questionnaire, namely "Mediterranean-style," "health aware," "traditional," and "sweet foods." Cognitive function was assessed at the age of 70 years, including general (g) cognitive ability, processing speed, memory, and verbal ability.

RESULTS

Before adjustment for childhood IQ and socioeconomic status, the "Mediterranean-style" dietary pattern was associated with significantly better cognitive performance (effect size as partial eta-square (ηp(2)) range = 0.005 to 0.055), and the "traditional" dietary pattern was associated with poorer performance on all cognitive domains measured in old age (ηp(2) = 0.009 to 0.103). After adjustment for childhood IQ (measured at the age of 11 years) and socioeconomic status, statistical significance was lost for most associations, with the exception of verbal ability and the "Mediterranean-style" pattern (National Adult Reading Test (NART) ηp(2) = 0.006 and Wechsler Test of Adult Reading (WTAR) ηp(2) = 0.013), and the "traditional" pattern (NART ηp(2) = 0.035 and WTAR ηp(2) = 0.027).

CONCLUSIONS

Our results suggest a pattern of reverse causation or confounding; a higher childhood cognitive ability (and adult socioeconomic status) predicts adherence to a "healthy" diet and better cognitive performance in old age. Our models show no direct link between diet and cognitive performance in old age; instead they are related via the lifelong-stable trait of intelligence.

Cognitive function is a risk for health literacy in older adults with diabetes

AIMS

Cognitive impairment is common in older adults with diabetes, yet it is unclear to what extent cognitive function is associated with health literacy. We hypothesized that cognitive function, independent of education, is associated with health literacy.

METHODS

The sample included 537 African American, American Indian, and White men and women 60 years or older. Measures of cognitive function included the Mini-Mental State Examination (MMSE), Verbal Fluency, Brief Attention, and Digit Span Backward tests. Health literacy was assessed using the S-TOFHLA.

RESULTS

Cognitive function was associated with health literacy, independent of education and other important confounders. Every unit increase in the MMSE, Digit Span Backward, Verbal Fluency or Brief Attention was associated with a 20% (p<.001), 34% (p<.001), 5% (p<.01), and 16% (p<.01) increase in the odds of having adequate health literacy, respectively.

CONCLUSIONS

These results suggest that cognitive function is associated with health literacy in older adults with diabetes. Because poor cognitive function may undermine health literacy, efforts to target older adults on improving health literacy should consider cognitive function as a risk factor.

Health literacy, numeracy, and graphical literacy among veterans in primary care and their effect on shared decision making and trust in physicians

Studies reveal high levels of inadequate health literacy and numeracy in African Americans and older veterans. The authors aimed to investigate the distribution of health literacy, numeracy, and graph literacy in these populations. They conducted a cross-sectional survey of veterans receiving outpatient care and measured health literacy, numeracy, graph literacy, shared decision making, and trust in physicians. In addition, the authors compared subgroups of veterans using analyses of covariance. Participants were 502 veterans (22-82 years). Low, marginal, and adequate health literacy were found in, respectively, 29%, 26%, and 45% of the veterans. The authors found a significant main effect of race qualified by an age and race interaction. Inadequate health literacy was more common in African Americans than in Whites. Younger African Americans had lower health literacy (p <.001), graph literacy (p <.001), and numeracy (p <.001) than did Whites, even after the authors adjusted for covariates. Older and younger participants did not differ in health literacy, objective numeracy, or graph literacy after adjustment. The authors found no health literacy or age-related differences regarding preferences for shared decision making. African Americans expressed dissatisfaction with their current role in decision making (p =.03). Older participants trusted their physicians more than younger participants (p =.01). In conclusion, African Americans may be at a disadvantage when reviewing patient education materials, potentially affecting health care outcomes.

Literacy, cognitive function, and health: results of the LitCog study

BACKGROUND

Emerging evidence suggests the relationship between health literacy and health outcomes could be explained by cognitive abilities.

OBJECTIVE

To investigate to what degree cognitive skills explain associations between health literacy, performance on common health tasks, and functional health status.

DESIGN

Two face-to-face, structured interviews spaced a week apart with three health literacy assessments and a comprehensive cognitive battery measuring 'fluid' abilities necessary to learn and apply new information, and 'crystallized' abilities such as background knowledge.

SETTING

An academic general internal medicine practice and three federally qualified health centers in Chicago, Illinois.

PATIENTS

Eight hundred and eighty-two English-speaking adults ages 55 to 74.

MEASUREMENTS

Health literacy was measured using the Rapid Estimate of Adult Literacy in Medicine (REALM), Test of Functional Health Literacy in Adults (TOFHLA), and Newest Vital Sign (NVS). Performance on common health tasks were globally assessed and categorized as 1) comprehending print information, 2) recalling spoken information, 3) recalling multimedia information, 4) dosing and organizing medication, and 5) healthcare problem-solving.

RESULTS

Health literacy measures were strongly correlated with fluid and crystallized cognitive abilities (range: r=0.57 to 0.77, all p<0.001). Lower health literacy and weaker fluid and crystallized abilities were associated with poorer performance on healthcare tasks. In multivariable analyses, the association between health literacy and task performance was substantially reduced once fluid and crystallized cognitive abilities were entered into models (without cognitive abilities: β= -28.9, 95 % Confidence Interval (CI) -31.4 to -26.4, p; with cognitive abilities: β= -8.5, 95 % CI -10.9 to -6.0).

LIMITATIONS

Cross-sectional analyses, English-speaking, older adults only.

CONCLUSIONS

The most common measures used in health literacy studies are detecting individual differences in cognitive abilities, which may predict one's capacity to engage in self-care and achieve desirable health outcomes. Future interventions should respond to all of the cognitive demands patients face in managing health, beyond reading and numeracy.