At the present, there is a paucity of research examining the health literacy of young children. Accordingly, the study described here constitutes an important contribution to the evidence base on the health literacy of this under-researched target group. We were able to explore the relative importance of several factors associated with health literacy among fourth grade schoolchildren.
4.1. The Health Literacy of Children
First, we would like to align our results with other relevant findings related to children’s health literacy or health-related attitudes and knowledge. The diversity in conceptualization and operationalization, however, makes comparison difficult and, thus, rather speculative.
The results presented reveal that, on average, the subjective health literacy of children in our sample is rather high, with eight out of ten participants (82.2%) reporting dealing with health-related information as “rather easy” or “very easy”. Similarly, Brown [27
] assessed whether nine- to 13-year-olds consider understanding most health-related information easy or difficult. The self-report indicated that 78.1% of the children indicated it to be “very easy” or “sort of easy,” which is in line with our findings.
Compared to a study aimed at investigating the comprehensive health literacy of nine to 13-year-old children [30
], the findings seem conflicting at first glance. The study investigated knowledge, communication, attitudes, behavior, and self-efficacy as separate dimensions of health literacy. The scores on health attitudes were found to be rather high (mean = 14.5; SD = 2.48; range 3–16), similar to our findings. However, the results diverged when considering the health knowledge dimension, which appeared to be rather limited (50.8% had one out of four correct, 38.0% had two out of four) [30
]. This difference might be based on the measurements used but could also stem from differences between samples. Thus, even though both studies had a similar understanding of health literacy, the results are difficult to compare, given the differences in operationalization. The lack of unanimity in defining and measuring health literacy continues to impede comparability [9
When trying to put the results into a life course perspective, an attempt to draw comparisons to the subjective health literacy of older age groups should be made. It has previously been observed that subjective health literacy declines with old age [16
]. This can be interpreted as an indicator of an increasingly better—i.e., a more realistic—judgement of the challenges that individuals face when dealing with their own health and the healthcare system. Thus, the comparatively lower burden of disease in younger people and their accordingly more limited experience navigating the health care system or handling disease may prompt them to think that it is easy to do so.
4.2. The Associated Factors of Health Literacy in Children
Second, we would like to discuss and interpret the associated factors identified in relation to subjective health literacy. In the first regression model, the sociodemographic indicators age, gender, home language, and family affluence were tested. Although differences in health literacy with regard to gender, age, and family background of migration have been observed [16
], this was not the case in our study. In the case of the participants’ age, this is not surprising, as the age range was small (nine-year-olds and younger vs. ten-year-olds and older). Thus, further studies with broader age ranges are needed to investigate whether and to what extent there are differences in subjective health literacy in different phases of childhood and adolescence, as has been indicated by other studies [27
Regarding gender, it might be plausible that in our sample there had not yet been any differential development of health literacy among the boys and girls surveyed at that point in time. Some studies [27
] have, however, observed a significant difference in the health literacy of boys and girls in similar age groups. Accordingly, it is worthwhile to investigate at which age, under which circumstances, and regarding which components of health literacy (e.g., subjective, knowledge, etc.) gender-related differences emerge.
The indicator of a family background of migration used in this study (home language) identified 33.6% of the sample as having a family background of migration, compared to 43.6% of all students attending primary school in the federal state of North Rhine-Westphalia (94.2% of which with a parent not having been born in Germany) [40
]. Accordingly, it is possible that the indicator home language underestimates the number of children with a migration background, which could be reasonably explained by their parents speaking exclusively German at home (false negative). No significant differences in health literacy related to home language were found in our study. This indicates that migration background, as assessed by this proxy measure, may not—at least not yet in this age group—affect the development of health literacy.
In this study, we found that children with higher family affluence perceived dealing with health information to be significantly easier than their less well-off peers did. Thus, there is evidence suggesting that a social gradient of (subjective) health literacy is present in children as young as nine to ten years and that these differences may even emerge earlier in the course of their life. This social gradient has also been observed by Yu [28
] among children as well as in adolescents. In contrast, Schmidt and colleagues [30
], in their study with children, have not found evidence of a social gradient of health literacy related to income. Although there seems to be evidence indicating the presence of a social gradient of health literacy among young people, it may be worthwhile to further investigate this subject matter in different samples, also considering potential differences between indicators such as family affluence and income. Overall, gender, age, home language, and family affluence were able to explain no more than about 2% of variance in health literacy scores.
The second regression model, in contrast, revealed that significantly more variance in subjective health literacy scores (14.4%) could be explained by the combination of functional health literacy, self-efficacy, and motivation. While these factors have been discussed as being related to or part of health literacy [10
], to our knowledge, this is the first study to concurrently investigate these factors and quantify their relative importance in explaining variance in children’s subjective health literacy. It is plausible that functional health literacy is associated with subjective health literacy, as a low level of functional health literacy may be a significant barrier when children try to access, understand, appraise, and apply health-related information.
Self-efficacy had been hypothesized to be related to the measure of health literacy that we employed, which is supported by our data. This indicates that self-efficacy, on the one hand, might be a source of bias—i.e., part of what is measured by subjective health literacy may be equivalent to self-efficacy—and/or, on the other hand, might be a powerful facilitator in dealing with health information. Empirical evidence in adults supports the latter assumption [41
]. Based on these considerations, the role of self-efficacy needs to be further investigated. If being ruled out as a confounder, self-efficacy could pose a promising and feasible approach to empowering people to successfully deal with health information.
Motivation regarding the acquisition of health information, namely the item “I like learning something new about health” proved to be the most potent independent variable in our analysis. This finding can certainly inform further studies and interventions, as it shifts the focus to motivational aspects of dealing with health information instead of a person’s cognitive capability. Thus, specifically in the educational setting, the transmission of knowledge might not be enough when questions like “do students want to learn?” and “what do they want to learn about?” are neglected. As our data indicate, motivation could contribute to the perceived manageability of health-related tasks. Nevertheless, promoting reading and writing capabilities, as well as the transmission of factual knowledge around the topic of health (i.e., functional health literacy), still remains a core responsibility within the school context and might have an independent impact when it comes to promoting the health literacy of children.
In the last regression model, perceived parental health orientation is included as a contextual factor of health literacy. Through this, the explained variance in health literacy scores can be increased to 19.3%. This highlights the need for future studies to consider novel indicators of participants’ proximal social surroundings, because, as our data shows, one contextual factor as simple as perceived parental health orientation was able to explain as much variance in the outcome variable as the standard indicators age, gender, home language, and family affluence combined. While this observation may differ in other samples (e.g., in a sample with a wider age group), it will still be interesting to investigate the effect that different contextual indicators—parental education, income, or occupation, but also parental attitudes, habits, or health literacy—have on the development of children’s health literacy in different stages of youth.
4.3. The Social Gradient
Third, we would like to focus on structural inequalities when interpreting our findings.
Family affluence was the only significant variable in the first model and remained significant even when controlling for functional health literacy, self-efficacy, and health-related motivation in the last model. While material living conditions and socio-economic status have manifold implications for healthy child development [42
] and seem to play a role in shaping health literacy of children at the same time [44
], it is crucial to tackle the problem at its roots. Structural inequities affecting parenting and living conditions should be addressed at the policy level in order to mitigate such effects. However, this recommendation is beyond the scope of this publication and likely applies to the greater number of findings in health inequity research.
In this sample, the social gradient in health literacy is not only conspicuous with regard to material living situations, but also in more discrete, complex structures of social reality—e.g., parental health orientation. While family affluence was able to explain 2% of variance in health literacy, parental health orientation explained 2.9% of variance. Parental health orientation was also the second strongest associated factor of health literacy, indicating that family support and encouragement of healthy behaviors, such as practicing sports and eating healthily, may foster health literacy. However, parental attitudes, cultural values, their orientations and further resources vary along a social gradient and are, of course, affected by their socioeconomic status, making it likely that parental health orientation is affected by the family’s social position [45
While parents may be important actors fostering a positive orientation towards health in children’s lives, it can be argued that other actors and settings that children are part of play a similar role. For example, results from a Finnish study show that higher health literacy is significantly associated to membership in a sports club [46
]. Alongside practicing physical activity, sports clubs may promote positive attitudes and self-determined motivation for physical activity [47
]. Future studies should investigate whether and how positive attitudes towards health (e.g., healthy eating or practicing physical activity) promoted within a particular setting (e.g., family, school, or sport clubs) facilitate or mediate the development of children’s health literacy.
Given that, on average, the sample in question had high subjective health literacy, displayed a rather high family affluence, good functional health literacy, and generally tended to select positive answer options, it is possible that selection bias may have affected the survey. Selection bias may have had an influence at various levels—at the school, class, and individual levels. Given the response rate of 16%, it could be that more schools interested in the topic of health participated. At the same time, due to social desirability, it is possible that school principals assigned the survey to classes known for having students with higher educational attainment. At the class level, another selection process may have taken place, insofar as only those children that were willing and had a letter of consent from their parents participated in the survey. Since the letter of consent was only provided in German, it represents a potential barrier for parents who do not speak German (proficiently). This may have especially hindered the participation of children who only speak a language other than German.
Moreover, given that the sample is not a representative one, it remains unclear whether these findings can be generalized to other samples. Although the quota sampling procedure aimed for a certain amount of variability in terms of school location (areas with high vs. low migration background as well as rural and urban areas), many responses were rather skewed in a positive direction. It is unclear whether this issue arose in this particular sample, or whether the discriminatory power of the items was insufficient. Thus, replicating the study findings in a representative sample of schoolchildren is necessary.
Further, all data is solely based on children’s self-reports. While it is crucial to include the perspectives and opinions of children in research, a comparison with “objective”, i.e., performance-based, data would potentially provide a more comprehensive understanding on the issue at hand. It would be relevant to determine how perceived vs. objective measures influence each other and what relative importance they have in explaining differences in health literacy. Therefore, an objective measurement of parental socio-economic status and migration background, as well as the self-reported health orientation of parents could be included to clarify this.
In terms of measurement, another potential shortfall must be mentioned. For the variables self-efficacy and motivation, we used single-item indicators, and for parental health orientation, we used two combined items instead of a validated scale. There may be a risk that single items do not assess the underlying construct as well as scales. However, at least in the case of self-efficacy, a single-item measure is not unheard of and has proven to be a reliable alternative to a 20-item scale, even displaying a better predictive value at follow-up than the scale as a whole [48
]. This indicates that it might be feasible using single-item instruments. However, in general, it seems desirable to use validated scales, at least until more economic measures have proven to be as reliable.
Finally, given the cross-sectional nature of this study, no inferences regarding causality can be drawn. Therefore, the recommendations for practice, e.g., fostering interest and motivation towards health-related behaviors at home or at school in order to increase health literacy, need to be regarded as hints and suggestions which will have to be verified or falsified through further research. Longitudinal and intervention research is needed to verify the assumptions drawn.