Over the last decade, the field of adolescent health literacy has gained momentum globally [1
]. As a personal asset, it highlights the empowerment of adolescents and their own rights of citizenship in society [5
]. Low health literacy in adolescents is associated with a range of adverse health outcomes including health-compromising behaviours, poor health status and overweight/obesity [6
]. Adolescent health literacy is an important and modifiable determinant of health; promoting health literacy at an early age is a key intervention strategy to reduce disease burden and health disparities [9
Compared to adult health literacy, adolescent health literacy is under-researched, particularly from a cultural and societal perspective [10
]. The seminal health literacy framework proposed by the Institute of Medicine (IOM) highlights three settings (healthcare; education; culture and society) where health literacy can be developed and enhanced at both individual and population levels [11
]. However, most current research focuses on health literacy in either the healthcare context or educational settings [12
Cultural and social contexts shape an individual’s beliefs and languages and, therefore, influence health literacy [11
]. The relationship between health literacy and an individual’s cultural beliefs and language backgrounds has been well documented, with immigrants and ethnic minority groups having a higher risk of low health literacy [10
]. In the present study, we focused on the broad cultural and social environment, rather than an individual’s cultural beliefs and language backgrounds. Culture provides a context through which meaning is gained from health information, and provides the purpose by which people come to understand their health needs and take actions in healthcare, disease prevention and health promotion to maintain good health [11
]. Similarly, the social environment (e.g., schools, families, communities) is well documented regarding the conditions over which an individual has little control but that affects his or her health literacy [1
]. Understanding the role of the cultural and social environment in health literacy is important because this will inform strategic directions for health literacy interventions in this multi-cultural and globalized world, particularly in a diverse multicultural population.
International health literacy studies revealed that the distribution of health literacy levels differed substantially across cultural groups [17
]. For instance, the European Health Literacy Survey conducted in eight countries (Austria, Bulgaria, Germany, Greece, Ireland, the Netherlands, Poland and Spain) revealed that around half (47.6%) of respondents aged over 15 had low health literacy, with the prevalence ranging from 28.7% in the Netherlands to 62.1% in Bulgaria [17
]. While these comparison studies provide an overall picture of health literacy between different cultural groups, they mostly focus on adult health literacy. The comparison of adolescent health literacy remains unclear.
Using multiple measures of health literacy in a single study allows researchers to learn about how each measure performs, to compare results between different measures and to enhance the rigor of findings [20
]. Pleasant et al. [21
] recommended seven principles to advance the field of health literacy measurement. These principles include: (1) explicitly built on a conceptual framework; (2) multi-dimensionality in content and methodology; (3) measure health literacy on a continuous basis; (4) treat health literacy as a latent construct; (5) honour the principle of compatibility; (6) allow comparison across different contexts including across cultures; and (7) prioritize public health applications versus clinical screening. However, little is known about the utility of these principles in practice.
Given that health literacy is a broad concept with a wide range of assessment tools [3
], it is essential to consider it within a specific context for a specific content [22
]. In this present study, we defined adolescent health literacy as “an individual’s ability to find, understand and use health information and services to promote and maintain good health” [23
] and applied it into school settings. Schools were chosen because they are critical venues for improving adolescent health literacy through school-based programs [13
]. Additionally, schools are the most common places where adolescents spend most of their daytime. It was therefore feasible and achievable to recruit large samples in a short time. We targeted two cultural groups of school-aged adolescents in China and Australia due to two reasons. One reason is that low health literacy in adolescents is prevalent in both countries (93.7% in China [24
]; 67.6% in Australia [25
]). However, health literacy measurement is inequivalent and making its results incomparable. Using consistent measurement tools will enable researchers and policymakers to understand the status of health literacy across cultures and identify unique and/or common health literacy needs and influencing factors within each culture, thus contributing to directional strategies about next-step health literacy interventions. The second is an opportunistic reason because of the research team’s background and partnership networks in China and Australia.
Based on Pleasant’s health literacy measurement principles [21
], we aimed to examine and compare health literacy between Chinese and Australian school-aged adolescents, in order to understand the effect of cultural and social environment on adolescent health literacy and identify areas for improvement across different cultural contexts. A secondary aim was to advance the practice of health literacy measurement.
2. Materials and Methods
2.1. Study Population and Sampling Design
A cross-sectional study was designed to recruit adolescents from five secondary schools in two cities: four schools in Beijing, China, and one school in Melbourne, Australia, using cluster and convenience sampling. Utilizing existing partnerships with Beijing secondary schools, we selected two public government schools in a high socioeconomic district and two in a low socioeconomic district. At each school, two whole classes in each year level (Years 7, 8 and 9) were chosen, with the number of students in each class ranging from 20 to 35. In Melbourne, one public government school in high socioeconomic district was recruited and all students (n = 918) in Years 7–9 were invited to participate in the field survey. Ethics approval to conduct this study was obtained from The University of Melbourne (Ethics number: 1442884) and Peking University Institutional Review Board (Ethics number: IRB00001052-15024). To ensure the reporting and methodological quality of this study, the STROBE statement [26
] and Pleasant’s health literacy measurement principles [21
] were employed. Further details are presented in Appendix A
and Appendix B
2.2. Data Collection
The field survey in Beijing was conducted between November and December 2015. Passive and opt-out consent was obtained from both parents and students. Prior to data collection, the principal researcher gave a brief training to ten investigators (i.e., Master students in public health from Peking University) to ensure consistency of the administration. All secondary students were then asked to complete a self-administered print version questionnaire during class or a class break.
The field survey in Melbourne was conducted between July and September 2016. Active and opt-in consent was obtained from both parents and students. With school representatives’ support, a web link of our questionnaire was sent to all students who had parental consent in Years 7–9 by class email. Students were invited to complete an online questionnaire when participating in the first health and physical education class in the third school term.
The English version questionnaire was developed first based on Manganello’s health literacy framework [1
], which included students’ health literacy, key upstream factors (i.e., intrapersonal, interpersonal, and environmental factors) and health outcomes. Then it was translated into Chinese using a translation and back translation technique [27
]. Given that some measurement scales (i.e., self-efficacy, social support, health literacy, health behaviours, patient-provider communication, and health status) have been translated and validated in Chinese adolescents, we only translated those without a Chinese version (e.g., school environment, community environment).
2.3.1. Intrapersonal Factors
Intrapersonal factors included socio-demographics and self-efficacy. Socio-demographics included age, gender (male or female), year level (Years 7, 8 or 9), family composition (living with two parents or other living arrangement), and family affluence level (low, medium or high) [28
]. Personal self-efficacy was measured by the General Self-Efficacy Scale (GSES) [29
], a 10-item scale that assessed personal belief in the ability to cope with a variety of challenges in life. Respondents indicated their level of agreement on a 4-point scale (1 = not at all true, 4 = exactly true). The GSES total score range was 10–40, with higher scores indicating higher levels of self-efficacy. In the present study, Cronbach’s α for the GSES was 0.89.
2.3.2. Interpersonal Factors
Interpersonal factors were assessed using the Multidimensional Scale of Perceived Social Support (MSPSS) [30
], a 12-item scale that measured an individual’s perceived support from family, friends and significant others. Respondents answered each item on a seven-point Likert scale (1 = very strongly disagree, 7 = very strongly agree). The MSPSS total score range was 12–84, with higher scores reflecting higher levels of social support. Cronbach’s α for the MSPSS was 0.93 for our sample.
2.3.3. Environmental Factors
School environment was assessed by the School Environment Scale (SES), which was derived from the Communities That Care Youth Survey [31
]. The SES comprised 10 items measuring students’ subjective feelings about opportunities and rewards for prosocial involvement at school. Respondents indicated their level of agreement with each statement on a four-point Likert scale (1 = strongly disagree, 4 = strongly agree). The SES total score range was 10–40, with higher scores suggesting stronger bonds of attachment to school. Cronbach’s α for the SES was 0.88 in this study.
Community environment was assessed by the Community Environment Scale (CES), which measured respondents’ subjective feelings of their neighbourhood environment such as cleanliness and safety [32
]. Participants answered each item on a five-point scale (1 = strongly disagree, 4 = strongly agree; 0 = do not know). The CES total score range was 0–36, with higher scores indicating a more liveable and supportive community. In this study, Cronbach’s α for the CES was 0.84.
2.3.4. Health Literacy
Three health literacy instruments were used to compare results between different measures and enhance the rigor of findings [20
]: the eight-item Health Literacy Assessment Tool (HLAT-8) [23
], the six-item Newest Vital Sign (NVS) [33
] and the 47-item Health Literacy Study-Asia-Questionnaire (HLS-47) [34
]. The HLAT-8 and the HLS-47 were self-report instruments that measured an individual’s ability to access, understand, evaluate, and communicate health information in everyday life [23
]; whereas the NVS was a performance-based measure for reading comprehension and numeracy [33
]. The total score range was 0–37, 0–6 and 0–50, respectively, with higher scores indicating higher levels of health literacy. Scores of 4 to 6 for the NVS and scores of 33–50 for the HLS-47 indicated “adequate health literacy”. The NVS and the HLS-47 have shown satisfactory internal consistency and structural validity [34
]. The HLAT-8 has been validated in Chinese secondary students [36
], with a Cronbach’s alpha of 0.79.
2.3.5. Health Outcomes
Three health outcomes were assessed including health behaviours, health service use, and health status. Health behaviours were measured by five items (breakfast eating, physical activity, cigarette smoking, alcohol drinking and teeth brushing) derived from previously well-established student health and wellbeing surveys [37
]. The total score for health behaviours is 5–35, with higher scores indicating more health-promoting behaviours. Health service use was assessed by a single item of patient-provider communication (‘How many times have you raised a question during your doctor’s appointment in the last 12 months?’ 1 = 0 time, 4 = 6 times or more) [34
]. Health status was assessed using a widely-used general self-report health question (‘In general, would you say your health is?’ 1 = poor, 5 = excellent) [38
2.4. Statistical Analysis
All statistical analyses were conducted using STATA 15.1 (StataCorp LLC, College Station, TX, USA). Descriptive statistics (frequency/percentage, mean, median) were first used to examine participants’ socio-demographics, both overall and by two locations. Univariate analysis (t-test, ANOVA, nonparametric test) was then conducted to examine the differences in health literacy, its antecedents and health outcomes between Beijing and Melbourne students. Finally, multivariate analysis (linear regression, logistic regression) was used to investigate the association between health literacy and its antecedents, health literacy and health outcomes. The individual mean substitution was conducted for non-response items in self-report scales. Data normality was assessed using skewness and kurtosis values. Results showed that scores on self-efficacy, health literacy and school environment were distributed normally, whereas scores on social support, community environment and health behaviours showed non-normal distribution.
Adolescent health literacy is sensitive to the broad cultural context. While the prevalence of low health literacy varies when using different health literacy assessment tools, low health literacy is common, with at least one-third of adolescents facing challenges of accessing, understanding and using health information in everyday life. Except for the impact of culture on health literacy, there is consistent evidence showing that adolescent health literacy is associated with personal self-efficacy, social support, and perceptions of school environment in both cultural groups. In addition, adolescent health literacy is related to health behaviours, patient-provider communication, and health status. Given the nature of our study design and small samples, we have made a cautious conclusion that adolescent health literacy might be an interactive outcome influenced by an individual’s health skills and the social environment. Particularly, creating a supportive school environment is critical to develop adolescent health literacy that would eventually contribute to better health outcomes.