Self-rated health literacy is associated with exercise frequency among adults aged 50+ in Ireland

Abstract

Background

The aim of this study was to investigate the relationship between self-rated health literacy and self-reported exercise frequency among people aged 50+ in Ireland.

Methods

Data were from the European Health Literacy Survey (2011) a nationally representative, cross-sectional survey of adults aged 15+ from eight countries. Health literacy was measured using composite indices (0–50, low to high) in three domains: healthcare, disease prevention and health promotion. Participants reported how often they exercised for 30 min or longer in the month prior to survey. Multivariate logistic regression analysis was used to examine the association between exercise frequency (almost daily activity vs. weekly or less) and health literacy among participants aged 50+ in Ireland (n = 389). All models were fully adjusted for age, gender, employment status, marital status, social status, education, financial deprivation and having a physically limiting illness.

Results

An increased odds of exercising almost daily was associated with understanding disease prevention (OR = 1.18, 95% CI 1.03–1.35) and health promotion information (OR = 1.15, 95% CI 1.01–1.32) and accessing (OR = 1.13, 95% CI 1.00–1.29) and evaluating health promotion information (OR = 1.12, 95% CI 1.00–1.26) with ease.

Conclusions

Public health approaches to promoting exercise often include providing information about the benefits of regular exercise, promoting affordable options and enhancing the accessibility of the built environment. Public health policy should also consider measures to improve interactive health literacy skills in order to achieve positive behavioural change.

Introduction

Physical activity has been described as the ‘best preventive medicine for old age’.¹ Regular, moderate physical activity and exercise significantly reduces the risk of disability² cardiovascular disease, diabetes, colon and breast cancer,³ overweight/obesity,⁴ falls⁵ and dependency at older ages.⁶ Although there are many ways to keep physically active, exercising regularly can help maintain physical and mental health,⁷ promote social engagement and increase quality of life.⁶ Adults aged 18–65 should undertake at least 30 min a day of moderate intensity activity, 5 days a week and adults aged 65+ should focus on aerobic activity, muscle-strengthening and balance 2–3 days per week to reduce their risk of falls.⁸ Despite extensive evidence for the benefits of being active and exercising regularly, physical inactivity is the fourth leading risk factor for global mortality³ and one-in-three adults aged 50+ in Ireland have low physical activity levels.⁹ For these reasons, in this study, we investigate the relationship between self-rated health literacy and exercise among this age group.

In Ireland, the Positive Ageing Strategy¹⁰ aims to prevent and reduce disability, chronic disease and premature mortality through policies to modify harmful lifestyle factors, such as physical inactivity. A specific focus on early intervention and health promotion among those aged 50+ ¹⁰ is supported by evidence of improvements in physical activity from The Irish Longitudinal Study on Ageing (TILDA).¹¹ Between 2011 and 2013, 43% of adults aged 50+ who reported low levels of physical transitioned from low to moderate or high levels of activity, and only adults aged 75+ were more likely to transition to low levels of activity during this time.¹¹ We reiterate this focus on adults aged 50+ in this study of health literacy and exercise to provide policy-relevant information on the modifiable factors that are associated with regular exercise.

Health literacy has been defined as the ability to access, understand, evaluate and apply health information¹² and describes a range of intermediate outcomes associated with health education and health communication.¹³ In this study, we employ a measure of interactive health literacy which is characterized by advanced cognitive and literacy skills which, together with social skills, enable individuals to actively participate in everyday activities, extract information, derive meaning from different forms of health information and apply new health information to changing circumstances.¹³ This differs from functional health literacy; fluid cognitive abilities (reading, writing and numeracy) applied to everyday health tasks.¹⁴

Low health literacy has been associated with all-cause mortality¹⁵ and lower psychological well-being¹⁶ among older adults, and with lower use of preventive health services,¹⁷ poor disease knowledge and poor medication adherence.¹⁸ While studies have identified the role of psychological factors,¹⁹ social expectations^20–22 and environmental factors^23–27 in either promoting or discouraging physical activity among older persons, at present there are a limited number of studies that have focused on the role of health literacy. In the USA, limited health literacy has been identified as an independent risk factor for health disparities among older community-dwelling adults²⁸ and a mediator among ethnicity, education and preventive health behaviour.²⁹ In Britain, sufficient health literacy was independently associated with positive health behaviours such as non-smoking and decreased with age.³⁰ Conversely, among older adults in the USA, limited health literacy was not independently associated with risky health behaviours such as sedentary lifestyle and smoking.³¹ A recent study in Japan found a positive association among functional, interactive and critical health literacy, and exercise; however, adults aged 65+ were excluded from the study.³² Much of the current health literacy literature is dominated by studies of functional health literacy and healthcare, which may have limited applicability to public health and health promotion. Currently, there is no study that has investigated the association between interactive health literacy and exercise among older adults.

The European Health Literacy Survey (HLS-EU), including the European Health Literacy Questionnaire (HLS-EU-Q), provides a unique opportunity to examine this relationship. The HLS-EU-Q ask respondents to self-report their own difficulty accessing, understanding, evaluating and applying health information in three contexts: healthcare; disease prevention; and health promotion. Furthermore, the HLS-EU-Q measures difficulty understanding information about health activities such as exercise, and difficulty understanding health warnings about low physical activity.¹² Current survey length of the HLS-EU-Q does not predispose it for use in clinical settings, and brief functional health literacy measures such as the Newest Vital Sign (NVS)¹⁴ may be more suited to such contexts. However, the HLS-EU-Q does conform³³ with the essential attributes of a comprehensive public health approach to health literacy measurement.³⁴ As an intermediate outcome of health education, interactive health literacy reflects several dimensions of patient empowerment: perceived meaning and importance of health information; perceived competence to perform healthy behaviours; and, self-determination,³⁵ which is a necessary pre-condition for behaviour change.³⁶ In summary, interactive health literacy is a modifiable intermediate outcome of health promotion and education and in this study we aim to investigate the association between self-rated health literacy and exercise among older adults.

Methods

Data

Data are from the European Health Literacy Survey (HLS-EU), a cross-sectional, survey of adults aged 15 years and older in Austria, Germany (North Rhine-Westphalia), Greece, Netherlands, Poland, Spain, Ireland and Bulgaria. A random sample of approximately 1000 respondents in each country was drawn. The total sample from Ireland comprised 1005 individuals and the survey response rate for Ireland was 69% (A full description of the study design and methodology for the Irish survey is available at http://healthliteracy.trinityseven.biz/wp-content/uploads/2010/11/EU-Health-Literacy-Survey-Full-Report.pdf).

For the purpose of this study, we adopted the definition of health literacy which was developed by the HLS-EU Consortium. This definition (and the associated conceptual model) was operationalized into the 47-item HLS-EU-Q. Data were collected in 2011 by the market research company TNS Opinion. Data were collected face-to-face via Computer Assisted Personal Interview (CAPI) in Austria, Germany (North Rhine-Westphalia), Greece, Netherlands, Poland and Spain) and Paper Assisted Personal Interview (PAPI) in Ireland and Bulgaria.

Sample

The analytical sample (n = 389) for this study was drawn from those aged 50 and older who participated in the HLS-EU in Ireland.

Measures

Exercise was measured by a single question ‘how often during the last month did you exercise for 30 min or longer, e.g. running, walking or cycling?’ Categories included: almost every day; a few times a week; a few times a month; not at all. As we were interested in factors that increase the likelihood of meeting national weekly physical activity guidelines, we focused on two categories of exercise: almost every day; and, less often (a few times a week, a few times a month or not at all).

The HLS-EU-Q comprised 47 survey items each with four response categories for difficulty (very easy-very difficult) accessing, understanding, evaluating and applying health information for healthcare, disease prevention and health promotion. Based on these responses, the following health literacy indices were constructed by the HLS-EU Consortium,³⁷ with a scale of 0–50, poor to good: healthcare (Cronbach’s alpha 0.89), disease prevention (Cronbach’s alpha 0.89) and health promotion (Cronbach’s alpha 0.85). (The alpha levels reported are for the current study.)

The following health information processing sub-indices were also reported on a scale of 0–50: accessing, understanding, evaluating and applying health information. Within each health domain (healthcare (HC), disease prevention (DP) and health promotion (HP)), health information-processing sub-indices were reported on a 0–10 scale. The main scales and sub-indices are summarized in table 1.

Understanding disease prevention sub-scale items included difficulty understanding: why you need vaccinations and health screenings; and health warnings about poor health behaviour. Accessing health promotion information sub-scale items included difficulty accessing information on: healthy activities such as exercise; activities that are good for your mental well-being; how your neighbourhood could be more health-friendly; political changes that may affect health; and efforts to promote your health at work. Understanding health promotion sub-scale items included difficulty understanding: information on food packaging; health-promoting information in the media; and information on how to keep your mind healthy. Evaluating health promotion sub-scale items included difficulty judging: how your life affects your health; how your housing conditions help you to stay healthy; and which everyday behaviour is related to your health.

Covariates

Age was measured in years (range 50–91). Gender was measured as male or female. Perceived social status was reported on a 10-point social ladder: one indicating the lowest level in society and 10 indicating the highest level in society.³⁷

Educational attainment was reported using five International Standard Classification of Education (ISCED) categories, ranging from pre-primary/primary education to tertiary or higher. Marital status was reported as not married, married, separated/divorced or widowed.

A measure of perceived financial deprivation was based on Principal Components Analysis and regression factor scores and reported in tertiles (low–high).³⁷

A limiting illness was a binary variable (yes or no). The ‘yes’ category included those limited in activity by a long-term illness or health problem, for at least the last 6 months. The ‘no’ category included all respondents who did not have a long-term illness, and/or were not limited by their illness.

Employment status was reported as employed (full or part-time), unemployed, retired and other (including home duties).

Analysis

Descriptive statistics are presented in table 1. We used Chi-squared (difference in proportions) tests to explore differences in exercise frequency by key sample characteristics and one-way analysis of variance (ANOVA) to explore differences in mean health literacy scores by exercise and all covariates.

We used logistic regression models to estimate the likelihood of exercising almost every day compared with a few times a week or less often (combined). We used each domain-specific health literacy index (healthcare, disease prevention and health promotion) in place of a single index of health literacy in order to identify any dimensionality in the association between health literacy and exercise.

Models were fully adjusted for age, gender, employment status, marital status, education, perceived financial deprivation and having a physically limiting illness. Models were estimated using complete cases; therefore, n values ranged from 278 to 323. For individual variables, the number of missing values was less than 5%. Results were reported as odds ratios (OR), with 95% confidence intervals (95% CI).

Results

Demographic characteristics

Just over half the respondents aged 50 + were female (52.2%, n = 203), 60.0% (n = 236) were married and 64.3% (n = 248) were living together/living in a shared household.

Socio-economic characteristics

Over one quarter (27.5%, n = 106) of respondents had ‘lower secondary education’ and 26.2% (n = 101) had ‘upper secondary education’. One quarter (25.3%, n = 91) reported a high level of financial deprivation and 16.9% (n = 35) reported ‘low’ or ‘very low’ social status.

Health status, behaviour and literacy

Over two-thirds (67.4%, n = 262) of respondents reported being in ‘very good’ or ‘good’ health. Almost half (48%, n = 187) reported one (or more) long-term illness or health problem. Over one third (35.6%, n = 138) reported exercising for 30 min or longer almost every day. On a scale of zero to 50 (low to high), mean health literacy scores were 36.1 (SD 7.9) for healthcare, 35.0 (SD 8.4) for disease prevention and 33.3 (SD 10.1) for health promotion.

The association between socio-demographic characteristics and exercise frequency is profiled in table 2. The results in table 2 show preliminary evidence that low self-perceived financial deprivation is associated with almost daily exercise, and having a limiting health condition is associated with exercising weekly or less often.

The difference in each health literacy index and sub-index scores by frequency of exercise is displayed in table 3. Adults aged 50+ who exercised almost daily had significantly higher health literacy scores for health promotion (total score), understanding disease prevention, accessing health promotion and applying health promotion information.

Table 4 presents the set of significant results from a series of logistic regressions of exercise on each health literacy index and sub-index. High (vs. low) financial deprivation predicted lower odds of exercising daily in each model. Similarly, having a limiting illness and older age significantly predicted lower odds of almost daily exercise.

In the fully adjusted models, an increased odds of exercising almost daily was associated with less difficulty understanding disease prevention information (OR = 1.18, 95% CI 1.03–1.35), less difficulty accessing health promotion information (OR = 1.13, 95% CI 1.00–1.29), less difficulty understanding health promotion information (OR = 1.15, 95% CI 1.01–1.32) and less difficulty evaluating health promotion information (OR = 1.12, 95% CI 1.00–1.26). We found no significant association between any of the healthcare health literacy measures and the odds of exercising almost daily. (The results are as follows: HC-finding (OR = 1.08, 95% CI 0.95–1.23); HC-understanding (OR = 1.05, 95% CI 0.91–1.22); HC-evaluating (OR = 0.98, 95% CI 0.86–1.12); and HC-applying (OR = 0.97, 95% CI 0.82–1.15). Full models are not shown but are available upon request).

Discussion

In this study, we investigated the association between perception-based, interactive health literacy and exercise among older adults in Ireland. The results of this study show the specific health literacy difficulties that adults who do not exercise regularly face, independent of educational attainment. A one-point increase in self-reported ability to understand disease prevention information was associated with an 18% increased odds of exercising almost daily. Similarly, a one-point decrease in difficulty understanding health promotion information was associated with a 15% increase in the odds of exercising a few times a week or less often. Less difficulty accessing and evaluating health promotion information also had significant positive effects on the odds of exercising almost daily (13% and 12%, respectively).

High (vs. low) financial deprivation was associated with lower odds of exercising almost daily in all regression models. Cost is likely to be a significant barrier to accessing opportunities to exercise such as sports clubs and gym membership. Increasing frailty and chronic illness can reduce an individual’s capacity to maintain an active lifestyle as they age. In the fully adjusted models, having a limiting health condition was a greater predictor of exercise than age, financial deprivation and health literacy.

Although advice on staying active forms an important part of healthcare, we did not observe a significant association between healthcare health literacy and exercise. This could be due to the focus on healthcare utilization in the measure, such as understanding labels on medication, whereas the disease prevention and health promotion measures contain questions about everyday health behaviours in community settings. Additionally, the complete, general health literacy measure showed no significant association with exercise (results available on request) and, therefore, obscures the association between domain-specific health literacy and exercise.

Despite the multitude of health behaviour studies that have used functional health literacy measures,^28–31 results are mixed. Functional health literacy and education are highly correlated, and measures of interactive health literacy such as those contained in the HLS-EU-Q, may be more suited to public health research, given the emphasis on cognitive and social skills relating to health promotion and disease prevention in such measures.

These findings build on existing research about the factors that predict lower rates of physical activity and exercise among older people in Ireland: being female; older age; poorer health; being in employment; low social engagement; and living in a built up area.²⁶ These findings are comparable with those of a study of the adult population in Japan which showed a positive association between three forms of health literacy (functional, interactive and critical) and exercise,³² and the direct association between health literacy and health behaviours observed among adults in Britain.³⁰

There are several limitations to the current study which warrant discussion and provide directions for future research. Although low health literacy has previously been linked to low self-efficacy and low self-esteem,³⁸ measures of personality and psychological well-being were not included in this study. Information on chronic conditions was also not asked about in the survey. While age-related threshold and transition (e.g. retirement) effects are likely to be present, stratifying the analysis by age group was not possible due to the small study sample. Information on household income can be important when considering cost as a barrier to certain types of opportunities to exercise, such as gyms or sports clubs; however, as there was a high refusal rate for the single question on net monthly household income in the survey across all eight countries, we were unable to include the measure in the analysis (35.7%, n = 139). Instead, we included an indicator of self-perceived financial deprivation which had less than 5% missing data.

Exercise was measured using a single question about the month prior to survey. This approach may be susceptible to social desirability bias in responding, as well as recall bias associating with averaging. A measure such as the International Physical Activity Questionnaire (IPAQ) which comprises exercise as well as health-promoting activities would be a more robust measure for future studies. Finally, low levels of physical activity in early adulthood can track into later life, and life-course factors such as socio-economic status and personal upward social mobility are all related to participation in exercise and sport as a person ages.³⁹ Therefore, activity levels and exercise patterns which are established and change overtime cannot be fully explained by cross-sectional, observational data.

Nevertheless, this study shows a direct association between interactive health literacy and exercising regularly among older adults. In terms of public health practice, community-based programmes to increase exercise and physical activity need not be complex, indeed brisk walking for 150 min per week is sufficient to meet recommended activity guidelines.⁴⁰ Affordable opportunities to exercise (e.g. subsidized leisure centres) and health-focused urban planning can also maximize opportunities for activity. In addition, there are several behaviour-related questions within the HLS-EU-Q that could be used to screen participants engaging in health promotion interventions and to inform the development of tailored interventions. These include difficulty understanding information about health activities such as exercise, and difficulty understanding health warnings about low physical activity.

To conclude, measuring people’s health literacy in relation to behavioural risk factors is an important goal in the prevention of chronic disease³⁶ and for healthy ageing. These findings add to a growing body of knowledge about the association between health literacy and exercise in this regard.

Acknowledgements

The authors acknowledge the European Health Literacy Consortium for granting access to the HLS-EU data. The authors gratefully acknowledge the Ludwig Boltzmann Institute for Health Promotion and Professor Jürgan Pelikan (LBIHP) as research hosts for the analysis phase of this study.

Conflicts of interest: None declared.

Funding

This research was supported by a Postdoctoral Mobility Grant awarded by the Royal Irish Academy.

References