The concept of health literacy was first proposed by Simonds (1974) in Health Education as Social Policy, which emphasized the importance of health literacy on national health and the provision of the most basic health literacy education for students in schools [1]. Further, Baker (2006) proposed that health literacy is an important predictor of health status and outcomes [2]. Health literacy has been considered a key factor for determining the effective use of health information and making choices for promoting health [3]. Individuals with low health literacy have a limited understanding of health information and low health self-management ability, which increases hospitalization and medical expenses and causes high mortality [4]. Good health-promoting behavior and lifestyle habits are developed during adolescence, a vital developmental stage, which involves physical, psychological, and social changes that will affect the adolescents’ quality of life in adulthood [5]. Early health literacy can aid in individuals gaining an understanding of health information and promoting interaction with the healthcare system, thereby providing positive health outcomes in the future [6]. Therefore, understanding the health literacy of adolescents is crucial for personal health. The health behavior of an adolescent plays an important role in developing a healthy lifestyle, which may affect his/her lifelong health. However, several studies of health literacy have focused on elucidating the effects of poor health literacy on adult health and few studies have involved adolescents [4, 7, 8]. A study of adolescents using an online survey in Germany found 8.4% of participants had difficulty understanding the health information and 22.7% of adolescent had a low level of health knowledge [8]. However, in a systemic review of 17 studies on adolescent health literacy, the definitions of health literacy were inconsistent across studies because different conceptual frameworks and assessment tools were used [9]. Adolescence is the good opportunity period for learning and improving health literacy during development. Thus, an understanding of factors related to adolescents’ health literacy, health-promoting lifestyle profile, and health status is essential for promoting adolescent health.
Health literacy
The World Health Organization (WHO) has proposed that health literacy represents the cognitive and social skills that determine the motivation and ability of individuals to access, understand, and use information for promoting and maintaining good health [10]. Sørensen et al. (2012) proposed a comprehensive definition of health literacy as entailing individuals’ knowledge, motivation, and competences to access, understand, appraise, and apply health information for making decisions in everyday life concerning healthcare, disease prevention, and health promotion for better quality of life [3]. Health literacy further affects healthcare and medical expenses, health behavior, and care effectiveness in individuals as well as public participation and empowerment and is associated with the issues of fairness and sustainability [11].
In 2011–2012, the European Consortium Health Literacy Project employed the European Health Literacy Survey Questionnaire (HLS-EU-Q) to conduct a large-scale health literacy survey in eight European countries. The survey results reported that 12% of participants had insufficient health literacy and 47% had limited (insufficient or problematic) health literacy [12]. Duong et al. (2017) conducted a health literacy survey with 10,024 general public participants and found that the mean health literacy of the people in each country was: Indonesia 31.4; Kazakhstan 31.6; Malaysia 32.9; Myanmar 31.3; Taiwan 34.4; and Vietnam 29.6, show that, with the exception of Taiwan, most people in these countries lacked health literacy based on a problematic health literacy score of ≤ 34 [13]. Hence, health literacy was found to be typically insufficient in the general public in different countries. However, there is a lack of research data on health literacy in adolescents.
Studies found that age, gender, education level, family income, and occupation were the demographic variables correlated with adults’ health literacy [12, 14]. Loer et al. (2020) also found that age, gender, education, social support and self-efficacy were associated with adolescents’ health literacy [8]. In addition, health literacy is associated with smoking, alcohol consumption, exercise, and health behavior in the adult population [10, 12, 13]. Studies found that higher health literacy is associated with higher ability to pay for medication, higher self-perceived social status, and higher community involvement in adults [12,13,14,15,16]. Lee, Lee, and Moon (2016) found that health literacy can directly affect self-care activities in diabetics [17]. People with low health literacy have poorer health and lack self-related health knowledge and self-care ability.
Health-promoting lifestyle profile
The WHO organized the first international conference on health promotion in 1986 [18]. In the resulting Ottawa Charter, a definition was proposed for health promotion: “Health promotion is the process of enabling people to increase control over their health and its determinants and thereby improve their health”. Walker, Sechrist, and Pender (1987) defined health-promoting lifestyle profile as a multi-dimensional pattern of self-initiated actions and perceptions that serve to maintain or enhance the level of wellness, self-actualization, and fulfillment of the individual [19]. These dimensions include self-actualization, health responsibility, nutrition, interpersonal support, stress management, and exercise, which is a framework used in several subsequent studies [20].
Factors related to health-promoting lifestyle profile include gender and age [20]. Married individuals have higher health-promoting lifestyle profile than single individuals. With age, the health responsibility score increases, whereas the stress management score decreases [21]. The health-promoting lifestyle profile of university students significantly differs according to their academic major, education level, age, and financial status, and this profile has an important correlation with health status [22]. An individual’s lifestyle profile is developed during whole lifespan. Thus, effective health promotion and disease prevention strategies are crucial for development during adolescence.
Adolescent health
The lifestyle profile of adolescents is inevitably affected by emerging technology and obsession with electronic equipment has become threat to their health and growth. An unhealthy lifestyle characterized by the lack of physical exercise is widespread in adolescents. Bhatti et al. (2020) surveyed adolescents aged 16–18 years and found that 15% of adolescents smoked, 21% were overweight or obese, 80% did not achieve the daily required intake of vegetables and fruits, and 90% did not take enough daily exercise in the UK [23]. Moreover, 55% of adolescents do not have sufficient daily sleep or experience insomnia, 52% do not have an exercise habit, and 3% experience anxiety or depression in Taiwan [24]. Nevertheless, surveys have shown that the amount of physical activity is less in adolescents and most adolescents’ age of 15 years did not follow the WHO recommendations of ≥60 min of moderate-to-vigorous activity daily [25].
Adolescence is a period of intense changes during life expansion, with drastic changes in both physiological and psychological growth, which affects an individual’s lifestyle profile and health behavior, thereby affecting health in adulthood [26]. Therefore, elucidating health literacy of adolescents is crucial for both a healthy lifestyle profile and health. The aim of this study was to explore adolescent health literacy, health-promoting lifestyle profile, health status and related factors. Specifically, the research question guiding the study was: ‘What are the demographic factors related to health literacy, health-promoting lifestyle profile, and health status in adolescents in Taiwan?’