健康信息素养是衡量我国民众健康水平的重要指标之一，也是健康素养的核心内容，是指个体为维护和促进自身健康，有意识、有规范、有效地获取、理解、评价和应用健康信息做出合理健康决策所需的综合品质。初中阶段正处于青春期，不仅是身体、心理和社会功能发展的关键期，也是建立健康行为和习惯的重要时期。提升初中生健康信息素养有助于他们养成健康的生活方式，降低不良健康行为发生的风险，从而有效应对复杂的健康问题和挑战，顺利过渡到成年阶段。然而，目前健康信息素养研究分散，多以实践为导向，存在概念不明确、理论支撑不足、测评工具不够规范等问题。尤其是有关中小学生健康信息素养发展规律和影响因素的研究非常有限，影响了相关政策的制定和教育活动开展。因此，开展初中生健康信息素养测评及其影响机制研究具有重要的理论意义和应用价值。

本研究主要以T市七、八年级学生和他们的健康教育教师为研究对象，共开展了四项研究。前三项研究解决初中生健康信息素养科学测评的问题，第四项研究探索影响因素及其作用机制。具体研究内容和方法是：研究一，采用文献法和德尔菲法，经过概念分析、相关研究分析、课标分析，对16位专家开展2轮专家咨询，构建了健康信息素养评价指标体系。研究二，基于健康信息素养评价指标体系，遵循素养导向的测评理念，依据大规模测验的编制程序，对353名学生进行预测试并开展正式测试，通过测量学分析，编制了一套初中生健康信息素养测验，并检验了测验的信度和效度。研究三，采用分层抽样方法，对T市27所学校2732名学生进行计算机测试，采用描述统计、t检验、方差分析、潜在剖面分析等方法揭示整体和不同性别、年级、家庭所在地、学习成绩的学生表现特征，探索初中生健康信息素养的群体类型。研究四，首先采用扎根理论研究方法，以23名初中生及11名教师为研究对象进行半结构化访谈，构建了初中生健康信息素养影响因素模型；然后，采用多水平回归模型分析方法，以2669名学生，50个班级为研究对象，基于相关文献及影响因素模型，探索学生、班级层面影响初中生健康信息素养的关键因素；最后，采用多水平中介效应检验方法，基于关键影响因素，探讨学生和教师因素对初中生健康信息素养的作用机制。

本研究得出的主要结论如下：

1.健康信息素养评价指标体系由三级指标构成，包含健康信息意识、健康信息能力、健康信息规范3个一级指标；健康信息价值认同、健康信息需求意识、健康信息行为意向、健康信息获取能力、健康信息理解能力、健康信息评价能力、健康信息应用能力、保护个人信息安全、负责任使用健康信息9个二级指标，以及21个三级指标。经德尔菲法专家征询，各指标重要性总均值为4.84，满分率均值为85.45%，变异系数均小于0.2，专家意见一致性均值为0.92。

2.初中生健康信息素养测验采用情境化试题和Likert5级评分量表两种题型，由三个分测验组成，分别是健康信息意识测验（31题）、健康信息能力测验（30题）、健康信息规范测验（14题），整套测验共75个题目。经检验，测验具有良好的信度和效度，内部一致性信度分别是0.962、0.836、0.752。验证性因素分析结果分别是CFI=0.958，TLI=0.954，RMSEA=0.049，SRMR=0.056；CFI=0.955，TLI=0.950，RMSEA=0.030，SRMR=0.048；CFI=0.925，TLI=0.905，RMSEA=0.059，SRMR=0.068。以EHIL为效标，测验及各分测验均具有较好的效标关联效度（r=0.425、0.429、0.317、0.194，p均＜0.01）。

3.初中生健康信息素养水平发展不均衡，与健康信息能力和健康信息规范相比，学生健康信息意识表现较好，但主要体现为学生认同健康信息的价值，健康信息需求意识还需提升。不同性别、年级、家庭所在地、学习成绩学生健康信息素养差异显著。从总分看，女生表现显著优于男生（p＜0.01），八年级学生表现显著优于七年级学生（p＜0.001），城镇学生表现显著优于农村学生（p＜0.05），学习成绩较好的学生表现均显著优于学习成绩落后的学生（p＜0.001）。初中生健康信息素养可分为五种类型，分别是低动力低能力组、待提升组、能力缺失组、动力缺失组、主动健康潜力组。多数初中生属于低动力低能力组（31.6%），具备主动健康潜力的学生仅占比10.9%。

4.基于扎根理论构建的初中生健康信息素养影响因素模型由学生因素、家庭因素、学校因素和社会因素四部分构成，包含4个一级指标、15个二级指标、43个三级指标。多水平回归模型分析表明，在学校生态下，对学生健康信息素养具有显著正向预测作用的因素有学习成绩（β=0.708，p<0.001）、健康意识（β=0.120，p<0.001）、自我效能感（β=0.798，p<0.001）、健康理念（β=0.969，p<0.001）；网络使用时间（假期）（β=0.500，p<0.01）、领悟朋友支持（β=0.110，p<0.01）、教师参加健康教育培训次数（γ=0.996，p<0.01）；年级（β=1.661，p<0.05）、自身健康状况（β=0.307，p<0.05）、领悟教师支持（β=0.062，p<0.05）、教师健康教育投入（γ=0.907，p<0.05）。具有显著负向预测作用的因素有学生网络使用时间（上学）（β=-1.294，p<0.001）。

5.多水平中介效应检验共揭示了两条影响路径。第一，教师健康教育投入并不直接影响学生健康信息素养，但可以通过影响学生领悟到的朋友支持产生影响。第二，教师参加健康教育培训次数可以直接影响学生健康信息素养，也可以通过影响学生健康理念产生影响。

本研究的创新主要体现为：从系统观出发，整合多学科研究成果，提出了新的健康信息素养的概念，发展了健康信息素养的相关理论；构建健康信息素养三级评价指标体系，为健康信息素养测评工具的研制提供科学有效的理论框架；运用现代测评理念和技术编制初中生健康信息素养测验，提升了测验的科学性，以计算机为施测手段提升了测评的便捷性，并能应用于初中生的大规模测试；探讨了初中生健康信息素养的发展规律和类型特征，可以为健康信息素养教育实践提供理论参考；健康信息素养的影响因素和作用机制可以为学校健康教育质量提升和学生健康促进提供科学依据。

Health information literacy is a significant indicator of the health status of the population in China. It reflects individuals’ comprehensive ability to consciously, normatively, and effectively acquire, understand, evaluate, and apply health information to make informed decisions regarding their well-being and promote their overall health. Adolescence is a critical period not only for the development of physical, mental, and social functioning but also for establishing healthy behaviors and habits. By enhancing the health information literacy of junior high school students, we can assist them in cultivating a healthy lifestyle and reducing the likelihood of engaging in detrimental health behaviors. However, the research on health information literacy is scattered and predominantly focused on practical aspects, resulting in several issues such as unclear conceptualization, inadequate theoretical foundation, and the absence of standardized evaluation tools. In particular, the research on the development law and influencing factors of primary and secondary school students’ health information literacy is very limited, which affects the formulation of relevant policies and the development of educational activities. Therefore, it is very important to research the evaluation of health information literacy of junior high school students and its influence mechanism.

This research primarily centers on 7th and 8th-grade students and their health education teachers in T city. A total of four studies were conducted.

In the first study, the evaluation index system of health information literacy was constructed by using the literature method and the Delphi method.

In the second study, a set of health information literacy tests for junior high school students was prepared based on the evaluation index system of health information literacy and the large-scale test compilation program. This was accomplished through a pre-test conducted with 353 students, and the tests were subsequently assessed for reliability and validity.

In the third study, 2732 students from 27 schools in T city were tested by computer using a stratified sampling method. Descriptive statistics, t-tests, analysis of variance, potential profile analysis, and other methods were used to reveal the performance characteristics of students with different genders, grades, places of origin, and academic performance, as well as to determine the types of health information literacy of junior high school students.

In the fourth study, firstly, based on the grounded theory, 23 junior high school students and 11 teachers were selected for semi-structured interviews to construct a model of influencing factors on junior high school students' health information literacy. Then, based on the multi-level regression model, 2669 students and 50 classes were selected to explore the key factors affecting health information literacy. Finally, the multilevel mediation effect test was used to explore the mechanism of student and teacher factors on junior high school students’ health information literacy based on key influencing factors.

The main conclusions drawn from this study are as follows:

1. The health information literacy evaluation index system is composed of three-level indicators, including 3 first-level indicators, health information awareness, health information ability, and health information norms. 9 second-level indicators, and 21 third-level indicators. After experts’ consultation in the Delphi method, the total mean of the importance of each indicator is 4.84, the average full score rate is 85.45%, the coefficient of variation is less than 0.2, and the average agreement of expert opinions is 0.92.

2. The health information literacy test for junior high school students uses two types of questions: situational test questions and Likert 5-level rating scales. It is composed of three sub-tests, namely, the health information awareness test (31 questions), the health information ability test (30 questions), and the health information norms test (14 questions), with a total of 75 questions. The test has good reliability and validity, and the internal consistency reliability is 0.962, 0.836, and 0.752 respectively. The results of confirmatory factor analysis were CFI=0.958, TLI=0.954, RMSEA=0.049, SRMR=0.056; CFI=0.955, TLI=0.950, RMSEA=0.030, SRMR=0.048; CFI=0.925, TLI=0.905, RMSEA=0.059, SRMR=0.068. Taking EHIL as the criterion, the test and its subtests had good criterion-related validity (r=0.425, 0.429, 0.317, 0.194, p<0.01).

3. The development of junior high school students’ health information literacy is uneven. Compared with health information ability and health information norms, students’ health information awareness is better, but mainly because students agree with the value of health information, students’ health information demand awareness needs to be improved. There are significant differences in health information literacy among students of different genders, grades, places of origin, and academic achievement. From the total score, the performance of girls was significantly better than that of boys (p<0.01), the performance of Grade 8 students was significantly better than that of Grade 7 students (p<0.001), the performance of urban students was significantly better than that of rural students (p<0.05), and the performance of students with good grades was significantly better than that of students with poor grades (p<0.001). The health information literacy of junior high school students can be divided into five types, namely, low motivation and low ability group, to be improved group, ability deficiency group, motivation deficiency group, and active health potential group. Most of the junior high school students belong to the low motivation and low ability group (31.6%), and only 10.9% of the students have active health potential.

4. The influencing factor model of junior high school students' health information literacy based on grounded theory consists of four parts: student factor, family factor, school factor, and social factor, including 4 first-level indicators, 15 second-level indicators, and 43 third-level indicators. Under the school ecology, multi-level regression model analysis showed that the factors that had significant positive predictive effect on students’ health information literacy are academic achievement (β=0.708, p<0.001), health awareness (β=0.120, p<0.001), self-efficacy (β=0.798, p<0.001), health concept (β=0.969, p<0.001); network use time (holidays) (β=0.500, p<0.01), understanding friend support (β=0.110, p<0.01), teachers’ participation in health education training times (γ=0.996, p<0.01); Grade (β=1.661, p<0.05), health status (β=0.307, p<0.05), understanding teacher support (β=0.062, p<0.05), teacher health education investment (γ=0.907, p<0.05). The factor with a significant negative predictive effect is network use time (school attendance) (β=-1.294, p<0.001).

5. The multilevel mediation effect test revealed two influence paths. First, teachers’ investment in health education does not directly affect students’ health information literacy, but it can affect students’ health information literacy by influencing their perceived support from friends. Second, the number of times teachers participate in health education training can directly affect students’ health information literacy, and can also affect students’ health information literacy by affecting students’ health concepts.

The innovations of this study are as follows: From the perspective of the system, this study proposes a new definition and conceptual model of health information literacy, which is based on the integration of multidisciplinary research results. The construction of a three-level evaluation index system for health information literacy offers a scientific and effective theoretical framework for the development of assessment tools in this field. The application of modern assessment concepts and technologies in developing the health information literacy test for junior high school students enhances the test’s scientific rigor, and the use of computers for assessment improves its convenience, making it suitable for large-scale testing among junior high school students. The exploration of developmental patterns and typological characteristics in junior high school students’ health information literacy offers theoretical insights for the practice of health information literacy education. The identification of influencing factors and mechanisms in health information literacy provides a scientific foundation for enhancing the quality of school health education and students’ health promotion efforts.