Is health literacy an example of construct proliferation? A conceptual and empirical evaluation of its redundancy with general cognitive ability

The conceptualization and development of critical health literacy in children: a scoping review

The cognitive and social practices associated with critical health literacy, such as critical appraisal of health messages and participation in political processes to address wider determinants of health, are of lifelong benefit. Understanding how and where critical health literacy development can be supported early in the life course may improve health outcomes now and in the future. This scoping review focuses on how critical health literacy in children is conceptualized and the supportive environments available for its development. Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines are used in reporting. Evidence retrieved was eligible for inclusion if it contained a substantive conceptual or empirical study of critical health literacy in populations aged 7-11 (middle childhood). From the included 18 peer-reviewed and grey literature sources, schools are identified as the setting most associated with the development of critical health literacy in the target age group. However, the action-oriented dimension of critical health literacy is rarely supported in the school setting. The review concludes that further research is needed to clarify how and where to support children to develop critical health literacy in and outside of school settings.

The association between cognitive ability and body mass index: A sibling-comparison analysis in four longitudinal studies

BACKGROUND

Body mass index (BMI) and obesity rates have increased sharply since the 1980s. While multiple epidemiologic studies have found that higher adolescent cognitive ability is associated with lower adult BMI, residual and unobserved confounding due to family background may explain these associations. We used a sibling design to test this association accounting for confounding factors shared within households.

METHODS AND FINDINGS

We used data from four United States general youth population cohort studies: the National Longitudinal Study of Youth 1979 (NLSY-79), the NLSY-79 Children and Young Adult, the NLSY 1997 (NLSY-97), and the Wisconsin Longitudinal Study (WLS); a total of 12,250 siblings from 5,602 households followed from adolescence up to age 62. We used random effects within-between (REWB) and residualized quantile regression (RQR) models to compare between- and within-family estimates of the association between adolescent cognitive ability and adult BMI (20 to 64 years). In REWB models, moving from the 25th to 75th percentile of adolescent cognitive ability was associated with -0.95 kg/m2 (95% CI = -1.21, -0.69) lower BMI between families. Adjusting for family socioeconomic position reduced the association to -0.61 kg/m2 (-0.90, -0.33). However, within families, the association was just -0.06 kg/m2 (-0.35, 0.23). This pattern of results was found across multiple specifications, including analyses conducted in separate cohorts, models examining age-differences in association, and in RQR models examining the association across the distribution of BMI. Limitations include the possibility that within-family estimates are biased due to measurement error of the exposure, confounding via non-shared factors, and carryover effects.

CONCLUSIONS

The association between high adolescent cognitive ability and low adult BMI was substantially smaller in within-family compared with between-family analysis. The well-replicated associations between cognitive ability and subsequent BMI may largely reflect confounding by family background factors.

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.

Psychological correlates of free colorectal cancer screening uptake in a Scottish sample: a cross-sectional observational study

OBJECTIVES

Colorectal cancer (CRC) screening uptake in Scotland is 56%. This study examined whether psychological factors were associated with CRC screening uptake.

DESIGN

Cross-sectional observational study.

SETTING

This study used data from the Healthy AGeing In Scotland (HAGIS) pilot study, a study designed to be representative of Scottish adults aged 50 years and older.

PARTICIPANTS

908 (505 female) Scottish adults aged 50-80 years (mean age=65.85, SD=8.23), who took part in the HAGIS study (2016-2017).

PRIMARY AND SECONDARY OUTCOME MEASURES

Self-reported participation in CRC screening was the outcome measure. Logistic regression was used to test whether scores on measures of health literacy, cognitive ability, risk aversion, time preference (eg, present oriented or future oriented) and personality were associated with CRC screening when these psychological factors were entered individually and simultaneously in the same model.

RESULTS

Controlling for age, age-squared, sex, living arrangement, and sex*living arrangement, a one-point increase in risk aversion (OR=0.66, 95% CI 0.51 to 0.85) and present orientation (OR=0.86, 95% CI 0.80 to 0.94) was associated with reduced odds of screening. Higher scores on health literacy (OR per one-point increase=1.20, 95% CI 1.09 to 1.31), cognitive ability (OR per SD increase=1.51, 95% CI 1.25 to 1.81) and the intellect personality trait (OR per one-point increase=1.05, 95% CI 1.01 to 1.09) were associated with increased odds of screening. Higher risk aversion was the only psychological variable that was associated with CRC screening participation when all psychological variables were entered in the same model and remained associated with CRC screening when additionally adjusting for deprivation and education. A backward elimination model retained two psychological variables as correlates of CRC screening: risk aversion and cognitive ability.

CONCLUSION

Individuals who are more risk averse are less likely to participate in free, home CRC screening.

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.

Intelligence, health and death

The field of cognitive epidemiology studies the prospective associations between cognitive abilities and health outcomes. We review research in this field over the past decade and describe how our understanding of the association between intelligence and all-cause mortality has consolidated with the appearance of new, population-scale data. To try to understand the association better, we discuss how intelligence relates to specific causes of death, diseases/diagnoses and biomarkers of health through the adult life course. We examine the extent to which mortality and health associations with intelligence might be attributable to people's differences in education, other indicators of socioeconomic status, health literacy and adult environments and behaviours. Finally, we discuss whether genetic data provide new tools to understand parts of the intelligence-health associations. Social epidemiologists, differential psychologists and behavioural and statistical geneticists, among others, contribute to cognitive epidemiology; advances will occur by building on a common cross-disciplinary knowledge base.

Pre-pandemic cognitive function and COVID-19 mortality: prospective cohort study

Background

Poorer performance on standard tests of cognitive function is related to an elevated risk of death from lower respiratory tract infections. Whether pre-pandemic measures of cognition are related to COVID-19 mortality is untested.

Methods

UK Biobank, a prospective cohort study, comprises around half a million people who were aged 40 to 69 years at study induction between 2006 and 2010 when a reaction time test was administered to the full sample, and verbal-numeric reasoning assessed in a subgroup. Death from COVID-19 was ascertained from participant linkage to a UK-wide national registry.

Results

Between April 1st and September 23rd 2020, there were 388 deaths (138 women) ascribed to COVID-19 in the 494,932 individuals (269,602 women) with a reaction time test result, and 125 such deaths (38 women) in the 180,198 (97,794 women) for whom there were data on verbal-numeric reasoning. In analyses adjusted for age, sex, and ethnicity, a one standard deviation (118.2 msec) slower reaction time was related to a higher rate of death from COVID-19 (hazard ratio; 95% confidence interval: 1.18; 1.09, 1.28). A one standard deviation disadvantage (2.16 point) on the verbal-numeric reasoning test was also associated with an elevated risk of death (1.32; 1.09, 1.59). Attenuation after adjustment for additional covariates followed a similar pattern for both measures of cognition. For verbal-numeric reasoning, for instance, the hazard ratios were 1.22 (0.98, 1.51) after control for socioeconomic status, 1.16 (0.96, 1.41) after lifestyle factors, 1.25 (1.04, 1.52) after co-morbidity, and 1.29 (1.01, 1.64) after physiological indices.

Conclusions

In the present study, poorer performance on two pre-pandemic indicators of cognitive function, including reaction time, a knowledge-reduced measure, was related to death ascribed to COVID-19.

Psychosocial factors and hospitalisations for COVID-19: Prospective cohort study based on a community sample

BACKGROUND

While certain infectious diseases have been linked to socioeconomic disadvantage, mental health problems, and lower cognitive function, relationships with COVID-19 are either uncertain or untested. Our objective was to examine the association of a range of psychosocial factors with hospitalisation for COVID-19.

METHODS

UK Biobank, a prospective cohort study, comprises around half a million people who were aged 40-69 years at study induction between 2006 and 2010 when information on psychosocial factors and covariates were captured. Hospitalisations for COVID-19 were ascertained between 16th March and 26th April 2020.

RESULTS

There were 908 hospitalisations for COVID-19 in an analytical sample of 431,051 England-based study members. In age- and sex-adjusted analyses, an elevated risk of COVID-19 was related to disadvantaged levels of education (odds ratio; 95% confidence interval: 2.05; 1.70, 2.47), income (2.00; 1.63, 2,47), area deprivation (2.20; 1.86, 2.59), occupation (1.39; 1.14, 1.69), psychological distress (1.58; 1.32, 1.89), mental health (1.50; 1.25, 1.79), neuroticism (1.19; 1.00, 1.42), and performance on two tests of cognitive function - verbal and numerical reasoning (2.66; 2.06, 3.34) and reaction speed (1.27; 1.08, 1.51). These associations were graded (p-value for trend ≤ 0.038) such that effects were apparent across the full psychosocial continua. After mutual adjustment for these characteristics plus ethnicity, comorbidity, and lifestyle factors, only the relationship between lower cognitive function as measured using the reasoning test and risk of the infection remained (1.98; 1.38, 2.85).

CONCLUSIONS

A range of psychosocial factors revealed associations with hospitalisation for COVID-19 of which the relation with cognitive function, a marker of health literacy, was most robust.

Erkenne dich selbst!

Zusammenfassung. Die eigenständige Suche sowie das adäquate Verständnis von Gesundheitsinformationen bilden eine wichtige Grundlage für die fundierte Entscheidungsfindung bei gesundheitlichen Problemen. Die hierfür zentralen Fähigkeiten sind die Gesundheitsinformationskompetenz (Health Information Literacy, HIL) und die allgemeine kognitive Fähigkeit (IQ). Die Konsequenzen einer adäquaten oder weniger adäquaten Einschätzung der eigenen Fähigkeiten für alltägliche Entscheidungen können erheblich sein, wurden jedoch im Kontext der Suche nach Gesundheitsinformationen noch nicht untersucht. In dieser Studie wurde zunächst überprüft, inwiefern HIL und IQ einen differenzierbaren Vorhersagebeitrag hinsichtlich der Präferenz bestimmter Eigenschaften von Gesundheitsinformationsquellen (Expertise, Interaktion, Zugänglichkeit) aufweisen. In einer explorativen Analyse wurden anschließend Unterschiede im Vorhersagebeitrag von Selbsteinschätzungs- und Leistungsmaßen von HIL und IQ untersucht. Dabei wurden Auswirkungen einer Über- oder Unterschätzung der eigenen Fähigkeiten im Hinblick auf die Präferenz bestimmter Quelleneigenschaften betrachtet. N = 286 Personen nahmen an der Untersuchung teil. Mit Hilfe von Response Surface Analysen wurde ein differenzierbarer Einfluss von HIL und IQ ermittelt. Spezifische Effekte der selbst eingeschätzten und objektiv gemessenen Fähigkeiten sowie der Interaktion dieser Maße wurden in Form einer Über- oder Unterschätzung identifiziert. Neben der tatsächlichen Fähigkeit spielen somit auch die eigene Einschätzung dieser Fähigkeit sowie eine daraus resultierende Unter- oder Überschätzung eine wichtige Rolle. In Forschung und Praxis Tätige sollten dies bei der Entwicklung und Durchführung von Maßnahmen zur Förderung der fundierten Entscheidungsfindung bei Patientinnen und Patienten berücksichtigen. Eine englische Übersetzung als Rohfassung dieses Artikels finden Sie als Elektronisches Supplement 1.

Social insurance literacy: a scoping review on how to define and measure it

PURPOSE

Sickness insurance and workers' compensation systems decide on peoples' eligibility for benefits, and are commonly based on medical certificates and assessments of work ability. Systems differ in the extent to which they preserve clients' dignity and right to fair assessments. In this article, we define a new concept for studying interactions between individuals and systems: social insurance literacy, which concerns how well people understand the different procedures and regulations in social insurance systems, and how well systems communicate with clients in order to help them understand the system.

METHODS

The concept was defined through a scoping literature review of related concepts, a conceptual re-analysis in relation to the social insurance field, and a following workshop.

RESULTS

Five related concepts were reviewed for definitions and operationalizations: health literacy, financial/economic literacy, legal capability/ability, social security literacy, and insurance literacy.

CONCLUSIONS

Social insurance literacy is defined as the extent to which individuals can obtain, understand and act on information in a social insurance system, related to the comprehensibility of the information provided by the system. This definition is rooted in theories from sociology, social medicine and public health. In the next step, a measure for the concept will be developed based on this review.Implications for rehabilitationSocial insurance literacy is a new concept that is based on theories in sociology, social medicine and public health.It provides conceptual orientation for analyzing factors that may influence different outcomes of peoples' contacts with social insurance systems.The concept is of relevance for rehabilitation professionals since it focuses on how interactions between individuals and systems can influence the rehabilitation process.The study will in the next step develop a measure of social insurance literacy which will have practical applications for rehabilitation professionals.

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.

Functional health literacy in a population-based sample in Florence: a cross-sectional study using the Newest Vital Sign

OBJECTIVES

To assess the level of functional health literacy (HL) and its antecedents and consequences in an adult population-based sample, using the Italian version of Newest Vital Sign (NVS-IT).

DESIGN

Cross-sectional study.

SETTING

General population.

PARTICIPANTS

984 people were randomly selected from the resident registers of 11 general practitioners; a total of 452 (46.2%) of the selected people completed the study. Inclusion criteria were the following: 18-69 years of age and Italian speaking. Exclusion criteria included cognitive impairment, severe psychiatric diseases and end-stage diseases.

OUTCOME MEASURES

HL levels as assessed by the NVS-IT and the following potential HL predictors and consequences were assessed using logistic regression models: sociodemographic characteristics, body mass index, presence of long-term illnesses, self-reported health status, health services use in the last 12 months.

RESULTS

High likelihood of limited HL, possibility of limited HL and adequate HL were found in 11.5%, 24.6% and 63.9% of the sample, respectively. The results of the multivariate logistic model for the antecedents showed that the risk of having high likelihood or possibility of limited HL levels increases with age (OR 1.07, 95% CI 1.05 to 1.09), lower educational level (OR 4.03; 95% CI 3.41 to 7.49) and with worse financial situation (OR 1.64; 95% CI 1.17 to 2.63). As far as health outcomes are concerned, HL resulted to be positively associated with self-reported health status (OR 2.25, 95% CI 1.75 to 2.75).

CONCLUSIONS

Findings show a good level of functional HL in the population. However, older, less educated and poorer population groups showed to have a higher likelihood of suffering from limited or inadequate HL. Efforts should be made to design and implement public health policies and interventions tailored to different HL levels.

TRIAL REGISTRATION NUMBER

CEAVC:10113.

Non-familial paid caregivers as potential flu carriers and cause of spread: the primary prevention of flu measured through their adhesion to flu vaccination campaigns-A Florentine experience

Introduction: Influenza vaccination is recommended for caregivers of elderly people. In a study aimed at assessing the level of health literacy (HL) in a sample non-familial caregivers in the Florence Health District (Tuscany), data were collected regarding access and adherence to the flu vaccination campaigns.

Methods: The sample consists of 47 non-familial paid caregivers.

We collected information regarding socio-demographic characteristics, services provided and daily work time, whether or not influenza vaccination was administered for the 2016/2017 season and in the previous three years. The level of HL was assessed through the Newest Vital Sign.

Results: 63.8% of non-familial caregivers have not joined the flu campaigns over the last four years, 14.9% have been vaccinated only sometimes (in some epidemic seasons), and 21.3% have received a flu shot in all the seasons investigated. Most of the non-familial caregivers who do not get vaccinated (27.7%) do not perceive that they are in direct contact with a person at-risk; those who get the vaccine regularly (12.8%) reported they want to protect the assisted person as motivation for vaccine uptake. Vaccination was not associated with HL.

Conclusion: Adhesion to anti-flu vaccination campaigns for these homecare workers has been resulted rather poor. Coverage does not seem to be related with HL level. It seems appropriate to promote extensively flu vaccination among family carers by actively offering the vaccination in appropriate forms, places and times, to avoid serious consequences on elderly people with higher risk of comorbidity and frailty.

Association Between Health Literacy, eHealth Literacy, and Health Outcomes Among Patients With Long-Term Conditions

Abstract. The objective of this paper is to synthesize and update findings from systematic review on health literacy and health outcomes among patients with long-term conditions, and extend the review to the digital domain. Health outcomes include clinical outcomes, processes of care, and health service use. Data sources are the following: (1) studies which appeared in two previous systematic reviews in 2004 and 2011 whose participants were people with long-term conditions or elderly ( n = 54); (2) articles on health literacy and health outcomes identified in an updated 2011–2016 search ( n = 26); (3) articles on eHealth literacy and its association with health outcomes ( n = 8). Strength of evidence was determined by a qualitative assessment of risk of bias, consistency, and directness. There was a lack of consistent evidence on the relationship between health literacy and clinical outcomes despite the consistent evidence on the association with mortality. There was low to insufficient evidence on the association between health literacy and self-rated health/function and emotional states of anxiety and depression, alongside high evidence on lack of association with quality of life. There was insufficient to low evidence on the association between health literacy and behavioral outcomes (medication adherence, other health behaviors) and finally also low to moderate evidence on the association between health literacy and use of health services such as hospitalization and emergency department. In the eHealth literacy domain, there were few studies reporting association with health behaviors and self-rated health with inconsistent results. In conclusion, it is advocated to examine performed heath literacy and eHealth literacy in large longitudinal studies.

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.

Intelligence in youth and health behaviours in middle age

OBJECTIVE

We investigated the association between intelligence in youth and a range of health-related behaviours in middle age.

METHOD

Participants were the 5347 men and women who responded to the National Longitudinal Survey of Youth 1979 (NLSY-79) 2012 survey. IQ was recorded with the Armed Forces Qualification Test (AFQT) when participants were aged 15 to 23 years of age. Self-reports on exercise (moderate activity, vigorous activity, and strength training), dietary, smoking, drinking, and oral health behaviours were recorded when participants were in middle age (mean age = 51.7 years). A series of regression analyses tested for an association between IQ in youth and the different health related behaviours in middle age, while adjusting for childhood socio-economic status (SES) and adult SES.

RESULTS

Higher IQ in youth was significantly associated with the following behaviours that are beneficial to health: being more likely to be able to do moderate cardiovascular activity (Odds Ratio, 95% CI) (1.72, 1.35 to 2.20, p < .001) and strength training (1.61, 1.37 to 1.90, p < .001); being less likely to have had a sugary drink in the previous week (0.75, 0.71 to 0.80, p < .001); a lower likelihood of drinking alcohol heavily (0.67, 0.61 to 0.74, p < .001); being less likely to smoke (0.60, 0.56 to 0.65, p < .001); being more likely to floss (1.47, 1.35 to 1.59, p < .001); and being more likely to say they "often" read the nutritional information (1.20, 1.09 to 1.31, p < .001) and ingredients (1.24, 1.12 to 1.36, p < .001) on food packaging compared to always reading them. Higher IQ was also linked with dietary behaviours that may or may not be linked with poorer health outcomes (i.e. being more likely to have skipped a meal (1.10, 1.03 to 1.17, p = .005) and snacked between meals (1.37, 1.26 to 1.50, p < .001) in the previous week). An inverted u-shaped association was also found between IQ and the number of meals skipped per week. Higher IQ was also linked with behaviours that are known to be linked with poorer health (i.e. a higher likelihood of drinking alcohol compared to being abstinent from drinking alcohol (1.58, 1.47 to 1.69, p < .001)). A u-shaped association was found between IQ and the amount of alcohol consumed per week and an inverted u-shaped association was found between IQ and the number of cigarettes smoked a day. Across all outcomes, adjusting for childhood SES tended to attenuate the estimated effect size only slightly. Adjusting for adult SES led to more marked attenuation but statistical significance was maintained in most cases.

CONCLUSION

In the present study, a higher IQ in adolescence was associated with a number of healthier behaviours in middle age. In contrast to these results, a few associations were also identified between higher intelligence and behaviours that may or may not be linked with poor health (i.e. skipping meals and snacking between meals) and with behaviours that are known to be linked with poor health (i.e. drinking alcohol and the number of cigarettes smoked). To explore mechanisms of association, future studies could test for a range of health behaviours as potential mediators between IQ and morbidity or mortality in later life.

Knowledge Is Power for Medical Assistants: Crystallized and Fluid Intelligence As Predictors of Vocational Knowledge

Medical education research has focused almost entirely on the education of future physicians. In comparison, findings on other health-related occupations, such as medical assistants, are scarce. With the current study, we wanted to examine the knowledge-is-power hypothesis in a real life educational setting and add to the sparse literature on medical assistants. Acquisition of vocational knowledge in vocational education and training (VET) was examined for medical assistant students (n = 448). Differences in domain-specific vocational knowledge were predicted by crystallized and fluid intelligence in the course of VET. A multiple matrix design with 3 year-specific booklets was used for the vocational knowledge tests of the medical assistants. The unique and joint contributions of the predictors were investigated with structural equation modeling. Crystallized intelligence emerged as the strongest predictor of vocational knowledge at every stage of VET, while fluid intelligence only showed weak effects. The present results support the knowledge-is-power hypothesis, even in a broad and more naturalistic setting. This emphasizes the relevance of general knowledge for occupations, such as medical assistants, which are more focused on learning hands-on skills than the acquisition of academic knowledge.

Maternal and offspring intelligence in relation to BMI across childhood and adolescence

Objective

The present study tested the association between both mothers’ and offspring’s intelligence and offspring’s body mass index (BMI) in youth.

Method

Participants were members of the National Longitudinal Survey of Youth 1979 (NLSY-79) Children and Young Adults cohort (n = 11,512) and their biological mothers who were members of the NLSY-79 (n = 4932). Offspring’s IQ was measured with the Peabody Individual Achievement Test (PIAT). Mothers’ IQ was measured with the Armed Forces Qualification Test (AFQT). A series of regression analyses tested the association between IQ and offspring’s BMI by age group, while adjusting for pre-pregnancy BMI and family SES. The analyses were stratified by sex and ethnicity (non-Black and non-Hispanic, Black, and Hispanic).

Results

The following associations were observed in the fully adjusted analyses. For the non-Blacks and non-Hispanics, a SD increment in mothers’ IQ was negatively associated with daughters’ BMI across all age-groups, ranging from β = −0.12 (95% CI −0.22 to −0.02, p = 0.021) in late childhood, to β = −0.17 (95% C.I. −0.27 to −0.07, p = 0001), in early adolescence and a SD increment in boys’ IQ was positively associated with their BMI in early adolescence β = 0.09 (95% CI 0.01–0.18, p = 0.031). For Blacks, there was a non-linear relationship between mothers’ IQ and daughters’ BMI across childhood and between girls’ IQ and BMI across adolescence. There was a positive association between mothers’ IQ and sons’ BMI in early adolescence (β = 0.17, 95% CI 0.02–0.32, p = 0.030). For Hispanic boys, there was a positive IQ-BMI association in late childhood (β = 0.19, 95% CI 0.05–0.33, p = 0.008) and early adolescence (β = 0.17, 95% CI 0.04–0.31, p = 0.014).

Conclusion

Mothers’ IQ and offspring’s IQ were associated with offspring’s BMI. The relationships varied in direction and strength across ethnicity, age group and sex. Obesity interventions may benefit from acknowledging the heterogeneous influence that intelligence has on childhood BMI.

The evolving relationship between premorbid intelligence and serious depression across the lifespan - A longitudinal study of 43,540 Swedish men

BACKGROUND

An association between higher intelligence and lower probability of serious depression has previously been established. Yet, to our knowledge, no large prospective study has examined the relationship across the lifespan.

METHODS

A cohort of 49,321 Swedish men was followed from conscription in 1969-70 (age 18-20) through to 2008. Odds ratios (OR) for first time hospitalisation for depression (FTHD) were calculated in relation to intelligence for distinct time periods across the lifespan, while controlling for established risk factors for depression.

RESULTS

There was a linear association between higher intelligence in youth and lower odds for FTHD during the entire follow-up period, 1973-2008. The association got progressively weaker across the lifespan. During 1973-80, one step down on the stanine scale was associated with an unadjusted increase in OR of 1.34 [95% confidence interval (CI) 1.26-1.42], adjusted OR 1.23 [1.15-1.32]; while, during 2001-2008, the ORs were less than half of the magnitude of the first period, unadjusted 1.14 [1.07-1.21], and adjusted 1.09 [1.01-1.17].

LIMITATIONS

The study includes men only, and the number of available places for in-patient care decreased during the follow-up period.

CONCLUSION

For the first time, we have shown that the association between lower intelligence and depression decreases over time. The attenuation of the association in the adjusted models suggests a slower accumulation of depressogenic stressors among people with a higher IQ-score. Further exploration of intelligence's role in the etiology of depression across the lifespan is required in order to facilitate adequate diagnoses and ameliorating interventions.

Lower verbal intelligence is associated with diabetic complications and slower walking speed in people with Type 2 diabetes: the Maastricht Study

AIMS

To determine the association of verbal intelligence, a core constituent of health literacy, with diabetic complications and walking speed in people with Type 2 diabetes.

METHODS

This study was performed in 228 people with Type 2 diabetes participating in the Maastricht Study, a population-based cohort study. We examined the cross-sectional associations of score on the vocabulary test of the Groningen Intelligence Test with: 1) determinants of diabetic complications (HbA_1c , blood pressure and lipid level); 2) diabetic complications: chronic kidney disease, neuropathic pain, self-reported history of cardiovascular disease and carotid intima-media thickness; and 3) walking speed. Analyses were performed using linear regression and adjusted in separate models for potential confounders and mediators. Significant age- and sex-adjusted associations were additionally adjusted for educational level in a separate model.

RESULTS

After full adjustment, lower verbal intelligence was associated with the presence of neuropathic pain [odds ratio (OR) 1.18, 95% CI 1.02;1.36], cardiovascular disease (OR 1.14, 95% CI 1.01;1.30), and slower walking speed (regression coefficient -0.011 m/s, 95% CI -0.021; -0.002 m/s). These associations were largely explained by education. Verbal intelligence was not associated with blood pressure, glycaemic control, lipid control, chronic kidney disease or carotid intima-media thickness.

CONCLUSIONS

Lower verbal intelligence was associated with the presence of some diabetic complications and with a slower walking speed, a measure of physical functioning. Educational level largely explained these associations. This implies that clinicians should be aware of the educational level of people with diabetes and should provide information at a level of complexity tailored to the patient.

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).

Verbal memory and search speed in early midlife are associated with mortality over 25 years' follow-up, independently of health status and early life factors: a British birth cohort study

BACKGROUND

Cognitive capabilities in childhood and in late life are inversely associated with mortality rates. However, it is unclear if adult cognition, at a time still relatively free from comorbidity, is associated with subsequent mortality, and whether this explains the associations of early life factors with adult mortality.

METHODS

We used data from the MRC National Survey of Health and Development, a birth cohort study prospectively assessing 5362 participants born in 1946. The present analysis includes participants followed up from age 43 and undergoing cognitive assessment (verbal memory and search speed). Mortality outcomes were notified through linkage with a national register. Cox regression was used to estimate mortality hazards in relation to cognitive performance at age 43, adjusting for early life factors, socioeconomic position and health status.

RESULTS

Data were available on 3192 individuals. Univariable analyses indicated that adult verbal memory and search speed, parental factors, childhood cognition and educational attainment were associated with mortality. However, multivariable models showed that the mortality associations with earlier life factors were explained by adult cognitive capability. A standard deviation increase in verbal memory and search speed scores was associated with lower mortality rates [hazard ratio (HR) = 0.86, 95% confidence interval (CI) 0.77-0.97, P = 0.02; HR = 0.88, 95% CI 0.78-1.00, P = 0.05, respectively), after adjustment for adult health.

CONCLUSIONS

Cognitive capability in early midlife was inversely associated with mortality rates over 25 years and accounted for the associations of family background, childhood cognitive ability and educational attainment with mortality. These findings, in a nationally representative cohort with long-term follow-up, suggest that building cognitive reserve may improve later life health and survival chances.

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.

Association between maternal health literacy and child vaccination in India: a cross-sectional study

Background

Education of mothers may improve child health. We investigated whether maternal health literacy, a rapidly modifiable factor related to mother's education, was associated with children's receipt of vaccines in two underserved Indian communities.

Methods

Cross-sectional surveys in an urban and a rural site. We assessed health literacy using Indian child health promotion materials. The outcome was receipt of three doses of diphtheria-tetanus-pertussis (DTP3) vaccine. We used multivariate logistic regression to investigate the relationship between maternal health literacy and vaccination status independently in each site. For both sites, adjusted models considered maternal age, maternal and paternal education, child sex, birth order, household religion and wealth quintile. Rural analyses used multilevel models adjusted for service delivery characteristics. Urban analyses represented cluster characteristics through fixed effects.

Results

The rural analysis included 1170 women from 60 villages. The urban analysis included 670 women from nine slum clusters. In each site, crude and adjusted models revealed a positive association between maternal health literacy and DTP3. In the rural site, the adjusted OR was 1.57 (95% CI 1.11 to 2.21, p=0.010) for those with medium health literacy, and OR=1.30 (95% CI 0.89 to 1.91, p=0.172) for those with high health literacy. In the urban site, the adjusted OR was 1.10 (95% CI 0.65 to 1.88, p=0.705) for those with medium health literacy, and OR=2.06 (95% CI 1.06 to 3.99, p=0.032) for those with high health literacy.

Conclusions

In these study settings, maternal health literacy is independently associated with child vaccination. Initiatives targeting health literacy could improve vaccination coverage.

Cognitive ability and personality as predictors of participation in a national colorectal cancer screening programme: the English Longitudinal Study of Ageing

BACKGROUND

The English NHS Bowel Cancer Screening Programme has offered biennial faecal occult blood testing to people aged 60-69 years since 2006, and to those aged 60-74 years since 2010. Analysis of the first 2.6 million screening invitations found that 54% of eligible people took up the invitation. The reasons for this low uptake are unclear. We investigated whether participation in screening varies according to cognitive ability and personality.

METHODS

Participants were members of The English Longitudinal Study of Ageing. In 2010-2011, respondents were asked about participation in bowel cancer screening, and cognitive ability and the 'Big Five' personality traits were assessed. Logistic regression was used to examine the cross-sectional relationships between cognitive ability and personality and screening participation in 2681 people aged 60-75 years who were eligible to have been invited to take part in the UK national screening programme for bowel cancer.

RESULTS

In age-adjusted and sex-adjusted analyses, better cognition and higher conscientiousness were associated with increased participation in cancer screening. ORs (95% CIs) per SD increase were 1.10 (1.03 to 1.18) for cognitive ability and 1.10 (1.01 to 1.19) for conscientiousness. After further adjustment for household wealth and health literacy-shown previously to be associated with participation-these associations were attenuated (ORs were 1.07 (1.00 to 1.15) and 1.07 (0.97 to 1.18), respectively).

CONCLUSIONS

We found some indication that better cognitive function and greater conscientiousness may be linked with a slightly increased likelihood of participation in bowel cancer screening. These relationships need investigation in other cohorts of older people.

Internet use, social engagement and health literacy decline during ageing in a longitudinal cohort of older English adults

Background

Health literacy skills tend to decline during ageing, which is often attributed to age-related cognitive decline. Whether health literacy skills may be influenced by technological and social factors during ageing is unknown.

Methods

We investigated whether internet use and social engagement protect against health literacy decline during ageing, independent of cognitive decline. We used prospective data from 4368 men and women aged ≥52 years in the English Longitudinal Study of Ageing from 2004 to 2011. Health literacy was measured at baseline (2004–2005) and at follow-up (2010–2011) using a reading comprehension test of a fictitious medicine label. The influences of consistent internet use and engagement in each of the civic, leisure and cultural activities on health literacy decline over the follow-up were estimated.

Results

After adjusting for cognitive decline and other covariates, consistent internet use (1379/4368; 32%) was protectively associated with health literacy decline (OR=0.77; 95% CI 0.60 to 0.99), as was consistent engagement in cultural activities (1715/4368; 39%; OR=0.73; 95% CI 0.56 to 0.93). As the number of activities engaged in increased, the likelihood of health literacy decline steadily decreased (p_trend<0.0001), with OR=0.51 (95% CI 0.33 to 0.79) for engaging in all four of the internet use and civic, leisure and cultural activities versus none.

Conclusions

Internet use and social engagement, particularly in cultural activities (eg, attending the cinema, art galleries, museums and the theatre), may help older adults to maintain health literacy during ageing. Support for older adults to maintain socially engaged lives and to access the internet should help promote the maintenance of functional literacy skills during ageing.