Design and Participants
A school-based education programme was performed from September, 2019 to January, 2021 (a cluster randomised controlled study). Four primary schools in Beijing were selected by using convenience sampling, two schools from Fengtai District and two schools from Shunyi District and were randomly allocated into the intervention and control groups, the randomization implementation were accomplished by an investigator with no involvement in the trial, using an wechat mini program called randomtools. All of the schools are regular public primary schools with similar school size. The randomization implementation were accomplished by an investigator with no involvement in the trial. The students and their head teachers were blinded to the group allocation of participants.
In primary school in Beijing, there are six grades in total, with age ranging from 7 to 12 years. All of the students from 5th grade in the selected schools were eligible and had been invited to participate in this study. All of the participants were involved in a baseline survey (September, 2019), a health programme respectively in different group, a post-intervention survey (January, 2020) and an 1-year follow-up survey (January, 2021). Students who haven’t attended the health education curriculum (IG) or accepted a lecture about health topic (CG), and those being lost to follow-up on baseline, post-intervention or 1-year follow-up survey were finally excluded (Fig. 1 Flowchart of the participation). The study is registered with the Medical Ethics Board of Capital Medical University (Z2019SY063) and informed consent was obtained from each student and their parents.
Sample Size
The estimation of the minimum required sample size was calculated using the PASS 15.0. We took Pc=56% according to the awareness rate of health knowledge in a previous study based on a primary school in 2017 [4] and Pe = 80%. With a power of 85% and α = 0.05, intracluster correlation coefficient = 0.02. The dropout-inflated sample size was finally calculated to be more than 80 students from each school in total 4 schools. In practice, the intervention group included a school with 141 children and the other with 121 children (262 in total), and control group included a school with 80 children and the other with 85 children (165 in total).
Intervention
IG involved a one-semester HECS. The course was taught by the designers once a week in the first semester of 2019–2020 from week 2 to week 17 (2019.9-2020.1).
Development of HECS was launched 5 years ago and designed following the procedures of needs assessment [4], structure established, materials developed, teaching experiment, revise and improvement (Fig. 2). Referring to the guidelines of government including “Guidelines of Health Education for Primary and Secondary Schools” [], “Core Information and Interpretation of Chinese Adolescent Health Education” [], and “Health Literacy of Chinese Citizens –Basic Knowledge and Skills(2015)”[], in combination of the results of needs assessment[,], the curriculum contained 16 lessons with 6 modules and 14 themes (Table 1). Each lesson has a resources bag consisted of Power Point, teaching plan, and other materials (e.g., leaflet, video or teaching aids) that were designed by professional researchers according to uniform standards.
Table 1
Outline of the Health Education Curriculum System (HECS)
Module | Lesson | Theme | Content |
Introduction | 1 | Introduction-Be the master of your health | concepts of health, health and happiness, how to be healthy |
Development and Adolescence | 2 | Human Development | basic composition of the human body, cells, tissue |
3 | Human Development | organs: eyes, teeth, and other important organs |
4 | Human Development | body systems: respiratory system and digestive system |
5 | Puberty | different periods of human growth, characteristics of adolescence and going through puberty |
Prevention of Common Diseases | 6 | Prevention of influenza | causes of influenza, differences between influenza and a cold, hazards of influenza, prevention of influenza |
7 | Prevention of obesity-1 | type of food, diet and exercise, unhealthy diet habits |
8 | Prevention of obesity-2 | causes of obesity, hazards of obesity, evaluation of obesity, and prevention of obesity |
9 | Prevention of saprodontia | causes of saprodontia, symptoms of saprodontia, prevention of saprodontia |
10 | Prevention of myopia | causes of myopia, symptoms of myopia, prevention of myopia |
| 11 | Mid-term test | |
Environment and Health | 12 | Prevention of smog | concept of smog, hazards of smog, identification of smog and prevention of smog |
Prevention of Accidental Injuries | 13 | Prevention of rabies | causes of rabies and its epidemiological features, hazards of rabies and prevention of rabies |
14 | Prevention of falls | concept of falls, hazards of falls, first aid after falls and their prevention |
Mental health | 15 | Self-liking | concepts of self-liking, how to evaluate yourself positively |
| 16 | Final test | post-intervention questionnaire |
Control
In CG, participants were given a 1-hour lecture by one of the curriculum teachers, which was performed in December, 2019. The content of the lecture was extracted from the health education curriculum applied to the IG.
Measures
The study tool used in this research was a self-designed questionnaire. Before the survey, experts from public health fields (e.g., children and adolescent health, health education, and epidemiology) were invited to assess the content of the questionnaire. Experts from the fields of primary education including head teachers and school doctors were invited to assess the adaptability and feasibility of the questionnaire. A pilot study with 40 fifth grade student was conducted in May, 2019, and the questionnaire was revised according to results of the pilot study and experts’ suggestions. The baseline questionnaire consisted of two parts, socio-demographic characteristics and the KAP section.
Socio-demographic section
Socio-demographic information involved gender, number of siblings, family structure, parental employment, and whether the parents were working in hospital. Family structure was measured through the question “who do you usually live with” and answers were categorized into core family (only lived with parents), stem family (lived with both parents and grandparents), single-parent family, and other family type.
KAP section
The KAP section consisted of 34 items: 20 items on knowledge, 7 items on health-related attitudes (A1-A7) and 7 items on practice or behavior (B1-B7). Knowledge items were created according to “Core Information and Interpretation of Chinese Adolescent Health Education” and panel members’ suggestions [14]. 10 true-false questions and 10 multiple-choice questions with a maximum score of 20 were set to evaluate the cognition status of participants. The topics of questions were: what is health; the basic structure of a cell and a lung; types of food; how to estimate obesity; how to protect against myopia; the proper duration of teeth brushing; healthy physical activity duration; prevention of influenza; how to choose a mask on smoggy days; prevention of dog bites; what to do after a fall; and accepting yourself.
Attitude and practice sections focused on some health-related issues. These were: duration of teeth brushing, more than 2min; total duration of sleep, 10 hour for children; screen duration per session, less than 15min for children; moderate-to-high-intensity physical activity (MVPA) time on weekends, 1 hour for children [,,]. In terms of other behaviors, there were suggestions for those in which students should engage. For example “don’t drink sugared beverages” [], “accept influenza vaccination []”, and “wear a mask on smoggy day” []. Individuals showed the levels of their intentions with each issue in terms of a 3-point scale: very willingness, unsure, and very unwillingness.
All participants completed the baseline questionnaire in the first week of the semester in September 2019 and post-intervention questionnaire at the last lesson of the curriculum. Additionally, participants in the IG completed a survey on curriculum satisfaction. The researchers inspected each class in case any question proposed by teachers or students. All completed questionnaires were collected and checked by the on-site researchers.
In January 2021, students in both groups were organized in their classrooms to complete 1 year-follow-up questionnaire with the same KAP section in the baseline and post-intervention survey.
Quality Control
Intervention and control schools matched in basic conditions as much as possible. The health education curriculum was carried out in a regular teaching arrangement so that period assignments and attendance of students were guaranteed. The teachers were required to submit a lesson observation report (including students’ attendance, disciplinary situations, classroom questions and answers, and questions raised by students after class) for each lesson. The questionnaires were examined by professional experts in related fields before survey and were implemented by head teachers and researchers and checked on site.
Statistical Analysis
Data were double-entered into Epidata3.0, and analyzed with SPSS20.0. Descriptive statistics of categorized variables were represented as proportions (%), and compared using Chi-square tests. Quantitative variables were represented as mean and standard deviation. For the invention group and control group, score changes to post-intervention and follow-up were examined using ACNOVA. Adjusted means and 95% confidence intervals (CIs) were reported as effect sizes. A two-tailed p-value was considered to indicate a statistically significant test result.