Does Health Literacy Affect the Uptake of Annual Physical Check-Up?: The Varying Impact by Age Groups

Introduction Little is known about how health literacy is linked to physical check-ups. This study aimed to examine the levels of physical check-ups by age group and the role of health literacy regarding physical check-ups. Methods Data for the study were obtained from the 2017 Health Information National Trends Survey. The original sample included 3,285 respondents, but only 3,146 surveys were used for this study. Andersen’s Behavioral Model of Health Services Use (Andersen, 1995) guided this study, and a binomial logistic regression model was conducted using Stata 12.0 software package. Results Annual check-ups were reported by 82.0% of the older group and 67.3% of the younger group. Both groups had similar ratios for health literacy-related item reporting. Study results show that annual check-up was positively associated with con�dence in getting health information, having health insurance, and having a primary doctor for both age groups. However, getting a regular check-up was negatively associated with frustration while searching for information among the younger group while it was positively associated with di�culty understanding information for the older group. Conclusions To increase annual physical check-ups, health literacy-related interventions should be developed and address the barriers most associated with health check-ups. One way of addressing this barrier is to improve the line of communication from healthcare professionals to consumers through the use of easy-to-understand explanations appropriate for the consumer.


Introduction
Routine physical check-ups offer multiple health bene ts that can lead to a longer, healthier life.Regular check-ups are used to assess the general health of individuals and prevent future illnesses [1].Check-ups give health care providers an opportunity to get to know their patients better [2], allow for early detection of health problemsat the beginning or early stages, and offer better treatment chances [3,4], and can be cost-saving [4].Despite the positives associated with regular check-ups, some argue there is no clear evidence to support the need of physical check-ups [5] while others believe that annuals increase diagnoses and medications but does not affect ways to decrease morbidity and mortality from diseases such as cardiovascular issues and cancer [2].Contrary to critics' arguments, physicals check-ups are still needed in order to continue to identify and detect diseases and other health issues that individuals experience early [6].By being at the forefront of these diseases and issues, physicians can provide individuals with the appropriate services or refer them to specialists and reduce patients' concerns [1].
Previous studies have reported various barriers and facilitators associated with regular check-ups including socio-demographic characteristics (e.g., age, gender, income) [7,8,9], accessibility to health care services (e.g., health insurance, primary doctor, and living area) [10,11,12,13], personal history of cancer [14,15], and family cancer history [16].For instance, young adults between the ages of 18-26 with a usual source of care were more likely to utilize physical check-ups [17] and having health insurance increased the likelihood of routine check-ups [13].On the other hand, individuals in rural areas were less likely to have physical check-ups because obtaining a primary care doctor was di cult as physicians are typically in cities and more a uent suburbs, and having low income was associated with not seeing a doctor for check-ups because of cost [18].Individuals with a history of cancer were more likely to utilize check-ups than those without a history [14,15], but having a family history of cancer did not increase one's routine check-ups use [16].Another facilitating factor includes having a history of physical check-ups.Labeit and colleagues (2013) concluded that individuals who visited a general physician in the past year were more likely to make an appointment for the coming year, suggesting that once the behavior of annual checkups is initiated, the behavior will continue.
In addition to the literature supporting factors associated with physical check-ups, health literacy could be another critical factor to explain for an individual's physical check-up [19,20].For example, people with limited health literacy tend to have cancer screenings and immunizations less frequently [21].However, little is known about how health literacy is linked to physical check-ups.To our best knowledge, this is the rst study to investigate the contribution of health literacy to the uptake of physical check-up.Hence, this study aimed to examine the levels of physical check-up uptake and factors associated with physical check-up with speci c attention to the role of health literacy on physical check-up uptake in two age groups.In our study, health literacy was de ned as an individuals' ability to obtain, process, and understand basic health information in order to make responsible decisions regarding their health [22,23,24].

Conceptual Framework
Andersen's Behavioral Model of Health Services Use [25] guided this study.The Andersen model is commonly used in studies on a variety of different health services divisions and diseases, such as HIV, dental, and long-term care [26,27,28].In addition, the model has been used to predict variables associated with health literacy [29,30,31].
According to the Andersen model, individuals' access to and use of health services are explained by a function of three components of predisposing, enabling, and need factors [28].Predisposing factors are an individual's social-cultural characteristics (e.g., age, gender, income, and living area).Enabling resources re ect condition making healthcare available to individuals (e.g., health literacy, education, health insurance, and primary doctor).Need factors are an individual's beliefs on their health and access to services such as self-reported health and the number of diseases (e.g., cancer, depression, etc.) and personal and family history of cancer.Figure 1 shows the conceptual model of this study.

Data and Sample
Data used for the current study is derived from the 2017 Health Information National Trends Survey (HINTS).A single-mode mail survey administered in English and Spanish was generated and dispersed in January to May 2017.The original sample included 3,285 respondents, but our study sample included 3,146.To achieve the objectives of the present study, we excluded those aged under 18 years (N=139).
The sample was categorized into two age subgroups: those aged 18-59 years and those aged = ≥ 60 years.Overall, the sample consisted of 1,681 respondents aged 18-59 years and 1,465 respondents aged = ≥ 60 years.

Measures Dependent Variables
The dependent variable measured respondents' self-reported check-up within the last year (1= Yes, 0 = No).

Independent Variables
Three sets of independent variables were included, which represented the predisposing, enabling, and need factors of the Andersen model.concerned about the quality of the information you found, (4) the information you found was hard to understand, and (5) con dence in getting health information.The rst four items are based on a 4point scale ranging from strongly disagree (1), to strongly agree (4).For analysis, all items were dichotomized (0=disagree; 1=agree).The last health literacy item (con dence in getting health information) was measured on a 5-point scale from not con dent at all (1) to completely con dent (5).For analysis, it was dichotomized as not very con dent (0) or very con dent (1).Education was measured by seven categories (1 = less than eight years; 2 = eight through 11 years; 3 = 12 years or completed high school; 4 = post-high school training other than college; 5 = some college; 6 = college graduate; 7 = postgraduate) and the level of education was dichotomized as high school diploma or less (0) or some college and above (1).The two variables of health insurance and primary doctor were measured using a yes (1) or no (0) question.
3. Need Factors.Four need factors consisted of health status, depression, personal history of cancer, and family history of cancer.Health status was measured a single question on a ve-scale from poor (1) to excellent (5).Depression was measured using four items (i.e., little interest or pleasure in doing things; feeling down, depressed, or hopeless; feeling nervous, anxious, or on edge; not being able to stop or control worrying).All the items were on a four scale from not at all (1) to nearly every day (4), with a higher score indicating a high level of depression.The total score of each item was computed by summing all the individual items.Two questions of cancer history were measured if the respondent has cancer (yes=1; no=0) and if their family has cancer (yes=1; no=0).

Data Analysis
Our analytic process involved two steps.In step one, descriptive statistics were calculated to generate frequencies and proportions for sociodemographic characteristics of the sample and the health literacy and check-up variables.These statistics were calculated by younger and older age groups.Differences between younger and older respondents were examined using χ2 tests with an α level of 0.05.In the second step, to examine the role of health literacy on a physical check-up uptake among study samples, we used a binomial logistic regression model with adjustments for predisposing factors, enabling factors, and need factors.All analyses applied jackknife weighting procedures provided by HINTS for analysis of the complex survey design and were conducted using survey procedures in Stata version 12.0 [32].This allowed us to produce a valid variance estimation that eventually led us to produce unbiased estimates.

Sociodemographic Characteristics
Table 1 presents the sociodemographic characteristics by age group.Of the 1,681 in the 18-59 age group, 67.3% had an annual check-up within the past year as well as 82.0% of the 1,465 respondents in the 60 years or older group.The average age was 44 years (SD = 10.737) in the younger group and 70 years (SD = 7.999) in the older group.There were relatively more females than males in both age groups.About 56.41% of the younger group and 72.42% of the older group members earned <$75,000 per year.Most (88.58% and 84.37%, respectively) participants lived in an urban area.Two-fths of the younger group completed some college or higher, and nearly half (41.18%) of the older group had a high school diploma or less.The majority in both groups had health insurance.More than a third in the younger group and most (81%) of the older group had a primary doctor and 86.1% of the younger and 77.79% of the older group reported their health as more than good.The average depression level was higher in the younger group (6.069, SD = 2.923) than the older group (5.747, SD = 2.617).Only 7.74% had ever had cancer in the younger group and 24.16% in the older group.Second, the younger and older groups had similar ratios for health literacy-related item reporting.More than a third put forth a lot of effort to get information and felt frustrated during searches for information.Nearly half reported that understanding the information they found was di cult, yet almost 60% of respondents in both groups reported that they felt con dent getting health information.Lastly, as can be seen by the cross-tabulated frequencies in

Discussion
Guided by Andersen's Behavioral Model, the current study examined the levels of physical check-ups and factors associated with physical check-ups with a speci c focus on the role of health literacy in the uptake of physical check-up in two age groups.Of the participants in the older group, 82% reported an annual check-up within the last year, while only 67.3% of the younger group reported the same.Our ndings are consistent with previous studies that older group received more physical check-ups than younger adults [7,33,34,35].Among the Korean participants of a similar study, 29.5% of the older age group regularly visited the doctor, and only 8% of the younger group reported regular visits, further proving that older adults utilize regular visits to the doctor more than younger adults [35].It might be a rational assumption that older adults take action as the onset of negative health issues arise rather than waiting like younger adults who are less likely to experience health issues and have a positive perception about their health.
The results from binominal logistic regression analysis indicated that two predisposing factors (age and gender) in the younger group and three enabling factors (health literacy, health insurance, and primary doctor) in both age groups were signi cant factors of an annual check-up.All of the need factors used in the study were not associated with annual health check-ups in both groups.In the younger age group, older and female participants tended to get an annual check-up more than their younger and male counterparts.Previous studies report that women visit their primary care clinic and use preventive care services more often than men [8,36].Such behaviors might be rooted in traditional women's role and responsibility in managing the family's health [37] and men's lack of help-seeking behavior.Men tend to feel weak and vulnerable in help-seeking situations and viewing health symptoms as minor or insigni cant [38,39].
The current study indicated that health literacy is an important enabling factor of annual check-ups.This study found that three different items of health literacy predicted annual check-up in both age groups.For the younger group, feelings of frustration when searching for information negatively in uenced partaking in annual check-ups; however, the majority of older adults indicated that di culty in understanding information was positively associated with partaking in annual check-ups.It seems that when feeling frustrated in searching for information, the younger age group may pursue an annual check-up where they can directly ask health questions to health care professionals.In contrast, for the older age group, when having di culty in understanding health information, they might tend to pursue physical check-up to ask meanings and accuracy of health information to their health care providers.
Although both groups expressed issues with health information, whether obtaining or understanding, study results indicated that annual health check-ups were positively associated with con dence in getting health information for both groups.Con dence in obtaining health information can stem from having reliable sources of information via the web, social media, friends, and a primary care doctor to provide more information, and knowledge allows the transition to improved regular check-up behavior.These reliable sources of information also impacted health literacy levels among participants of the 2003 National Assessment of Adult Literacy [40].Participants with pro cient levels of health literacy relied on the internet or personal contacts, such as health care professionals, to answer health-related questions, those with basic or intermediate health literacy levels relied on newspapers or magazines, and individuals with below basic health literacy, gathered their healthcare information mainly from either the radio or television [40].
Other enabling factors associated with annual check-ups were health insurance and a primary doctor for both groups.Study participants who had health insurance and a primary doctor were more likely to get annual check-ups than those who did not have either.This nding is not surprising given that health insurance and having a primary doctor are key factors in accessing health care and utilizing preventive health care.

Limitations
While the current study ndings provide insight into the association between health literacy and physical check-up, there exist some limitations.First, this is a cross-sectional study, and only correlation could be identi ed.More future longitudinal studies are needed to further explore the causal relationship between health literacy and physical check-up.Second, the explanatory power of the identical model is low.This model could explain only 9.0% and 5.25% of the total variance among respondents aged between 18 and 59 years and over 60 years, respectively.There may exist some other important factors to better explain the variance of health check-up among speci c age groups.Another limitation to add is that outcome measure (physical check-up) was self-reported rather than clinically or behaviorally measured, which might have caused response biases.

Implications for Health Practice and Policy
Several methods to increase annual health check-up are suggested.First, many participants in our study showed frustrations in searching for health information and di culty to understand the meaning of the medical terminologies used by professionals.Health care professionals have the responsibility to share healthcare information to not only their patients but to the larger community as well by using the right communication strategies.Medical information should be translated into easy-to-understand language by healthcare professionals.Additionally, policies should recommend medical facilities or primary doctors to provide routine reminders via call/text/email regarding upcoming appointments as it may instill awareness and enhance health literacy to include health check-ups in the person's agenda [34,41].Moreover, it is critical for health care professionals and policymakers to have different strategies for each age group to enhance health literacy.For younger age groups, providing easily accessible health information and cultivating the capacity to nd health information would be crucial.The ability to obtain accurate medical information quickly and conveniently via online may provide an opportunity for betterinformed decision making.At the same time, for older age groups, providing education to improve understanding of health materials should be provided [42,43].Lastly, it is important to increase preventive medical service utilization such as annual check-ups, ultimately to aid in preventing health deterioration.
The Institute of Medicine [44] states that the individual's efforts alone have limitations in improving health literacy.Therefore, it will be necessary to understand the mutual function between the individual and the medical environment, as well as environmental changes.Moreover, efforts to decrease the barriers in accessibility for regular health check-ups should be accompanied by bringing awareness and service to the community with special efforts from the health care settings. Tables

Figures Figure 1 Conceptual
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Table 1 .
Demographic Characteristics of the Sample by Check-Up