2.1 Study design
ACTIve BEhaviour in School Education project (ACTIBESE) is a project funded by the National Agency for Research and Development (ANID) of the Chilean government (Code Nº: 1230801), which seeks to investigate and propose useful tools to increase levels of PA in schools. The project will consist of two parts: a cross-sectional study (first and second years) and an intervention study (third year), for three years. The intervention was registered at https://clinicaltrials.gov/study/NCT06362655, Identifier: NCT06362655 on April 8, 2024.
2.2 Recruitment
An invitation to participate will be sent to the principals of the participating schools. Once the schools agree to take part and are selected, a meeting will be held with both the representatives of the administrative management authorities and the schoolteachers to explain in detail the aims and stages of the project.
Subsequently, an informative meeting will be held with parents and schoolchildren using the same terms. The groups will be divided by age: children from grades 3–6 of primary school (8–11 years old) and adolescents from grade 7 of primary school to grade 2 of secondary school (12–16 years old).
2.3 Cross-sectional study
This study will determine the school factors associated with AB in schoolchildren. These include teaching styles, teaching training, teacher perception of PE, and characteristics of the school and curriculum (school-environmental, spaces to play, infrastructure, recess, time dedicated and weekly frequency of PE, contents, topics, etc.). This information will be obtained through qualitative questionnaires administered to schoolteachers (see Appendix 1). Additionally, the association between social factors and AB in schoolchildren will be studied. This will be determined through standardized questionnaires for parents. In addition, personal factors (i.e., motivation for PE, perception of PE, built-environment perception, and barriers to PA) will be evaluated using qualitative instruments (questionnaires). The outcomes of AB in schoolchildren will be evaluated using device-based methods (accelerometers and pedometers). Figure 1 shows the variables, factor incomes, and outcomes of this cross-sectional study. This will be performed in the first year of the project according to the earlier description.
***Figure 1 here***
2.4 Intervention study
The intervention will have three phases (Fig. 2):
a. Assessment: This consists of applying the evaluation instruments to schoolteachers (NSTSS, interviews, and focus group) and schoolchildren (YAP questionnaire, PACO questionnaire, accelerometry, pedometry, and barriers), both in the pre-test and post-test, to the intervention and control groups. In addition, instruments for parents (regarding interpersonal factors) will be used. The pre-test and post-test 1 correspond to the evaluation of the intervention process. Post-test 2 will evaluate the effect of the intervention through a follow-up process.
b. Intervention: The “teaching training” program consists of weekly class sessions addressed to teachers, where topics will be discussed to improve educational practices in PEaH classes, such as teaching strategies, teaching styles (productive style), recommendations for PA for children and the inclusion of the socioecological model, incorporating all the actors of the school educational environment. In addition, strategies are incorporated to stimulate the self-determination theory (SDT). This activity will be conducted in person; however, it will be changed to an online format according to the circumstances of the distance between cities. The “application of learning” will be carried out, where the teachers must apply the knowledge acquired in the teaching training to courses selected with a weekly frequency of one or two days. The application will take place over a semester (four months). To assess this implementation, pre-and post-tests will be carried out as defined in the methodology. Additionally, the teachers will keep a “field notebook” consisting of a record of the activities that go wrong or of complex situations that require a solution when the Teaching Training is applied in the chosen courses. Parallel to the problem, a solution or activity must be proposed to solve the difficulties that have arisen. Additionally, in the Teaching Training classes, teachers will be asked to attend various “workshops” on topics associated with AB and PEaH to diversify learning. To strengthen the process of applying these lessons, at least two mentoring sessions will be presented to the PEaH classes to resolve doubts, see the implementation of the changes, and understand the reality that schoolteachers face.
This activity will be conducted in person; however, if the circumstances prohibit in-person meetings, it will be changed to an online format. In addition, regular “online meetings” will be established for schoolteachers to resolve questions and establish approaches, share ideas and concerns, and jointly resolve difficulties imposed on schoolwork or how to implement the different strategies learned in teaching training. This activity will take place every two weeks.
c. Follow-up: In this phase, teaching materials will be delivered to teachers to be applied during classes. In addition, there will be an observational follow-up to the process, a field notebook will be used, and two process evaluations will be conducted every six weeks from Post-test 1 through “mentoring.” Additionally, a support web page will be created with help materials, and an app will be created for schoolteachers and schoolchildren to allow us to monitor the intervention.
***Figure 2 here***
2.5 Participants and sample selection
The participants will be from two cities in the Valparaíso Region (Viña del Mar and Los Andes) and one city in the Araucanía Region (Temuco). These cities will be chosen for the convenience of researchers because they are in the region of Chilean institutions conducting the study. Public, subsidized, and private administration schools will be included because, in the Chilean context, schoolchildren are divided into these two groups. The sample includes schoolchildren from rural and urban areas as well as from different social contexts, considering gender equity. A total of 152 schools were identified (Public and Private): 84 in Viña del Mar (n = 25,176), 19 in Los Andes (n = 7,401), and 49 in Temuco (n = 21,647) (https://reportescomunales.bcn.cl/). The representative sample size of the students for the cross-sectional study will be calculated at 95% confidence, 5% error, 50% heterogeneity, and a statistical power of 80%.
As a result, out of the 54,224 students that conform to the population, a representative sample of 382 schoolchildren will be obtained by clustering the city, n = 177 in Viña del Mar, n = 52 in Los Andes, and n = 153 in Temuco. In this cross-sectional study, the participation of three schools in each city (nine schools) will be randomized within each city. Three groups of classes in each school and two teachers from each school will be estimated (men and women equally). In sum, the total sample is expected to reach 405 schoolchildren and 18 schoolteachers, considering a sample loss of 20%. For the intervention study, another randomization of six schools (one intervention and one control per city), 12 schoolteachers, and 180 schoolchildren will be set up. For the follow-up stage, a sample loss of 20% will be considered, and a final sample of five schoolteachers and seventy-two schoolchildren in each group (intervention and control) will be set up for analysis. Specific samples are shown in Fig. 3.
***Figure 3***
The groups will be separated by age: children from grades 3–6 of primary school (8–11 years old) and adolescents from grade 7 of primary school to grade 2 of secondary school (12–16 years old).
The inclusion criterion for schools is that they must have at least two PEaH classes per week, at least in selected grades. Grades between the 4th of primary and the 2nd of secondary will be selected. Each class had to include at least 15 schoolchildren. There must be at least 15 informed consent forms per class for schoolchildren and 15 parents or guardians. Additionally, there must be at least two physical PEaH schoolteachers. Additionally, schoolteachers, schoolchildren, and parents cannot participate in other programs promoting PA.
2.6 Instruments for evaluating school factors
a. For teaching style, the Need-Supportive Teaching Style Scale (NSTSS) will be applied (38), which includes fifteen items that measure task climate support (Items 1 to 5), ego climate support (Items 6 to 8), autonomy support (Items 9 to 12) and relatedness support (Items 12 to 15). Responses will be provided on a 5-point Likert-type scale ranging from 1 (“strongly disagree”) to 5 (“strongly agree”).
b. For teaching training, the evaluation of school physical education (ESPE) will be self-reported. The ESPE has questions regarding the contents of the national PEaH curriculum established by the Chilean Ministry of Education (39). It consists of closed questions in the "Likert scale” (4-point) format, where one is "Disagreeing" and four is "Strongly Agree". The questions are distributed into eight items that consider the practice of sports, the possibility of alternative activities, the development of body expression, the promotion of PA, the development of activities by the school, the development of self-care, the development of active life, and didactics of the PE class. All dimensions consider only PE within the school context and formal or informal activities at school.
c. For teaching training and school characteristics, interviews and focus groups will be applied. Semi-structured interviews will be conducted with teachers taking part in the intervention study (Table 1). This includes feelings about the contents of school PE, perceptions of their practices as teachers, and opportunities and barriers to carrying out classes.
Table 1
Factors, instruments, participants, and stages of application that will be used throughout the project.
Factors
|
Variable
|
Instrument
|
Participants
|
Stage application
|
School factors
|
Teaching Scale
|
NSTSS (38)
|
Teachers
|
Intervention
|
Teaching training
|
ESPE (39)
|
Teachers
|
Intervention
|
Characteristics of school
|
ESPE (39)
|
Teachers / Schoolchildren
|
Intervention
|
|
|
Focus group/Interviews
|
Teachers / Schoolchildren
|
Intervention
|
Interpersonal factors
|
Parents sociodemographic
|
ACTIBESE questionnaire; FAS (40)
|
Parents
|
Cross-sectional / Intervention
|
Parents active behaviour
|
GPAQ (WHO, 2004)
|
Parents
|
Cross-sectional / Intervention
|
|
PACO (45)
|
Parents
|
Cross-sectional / Intervention
|
|
Accelerometer (Axivity AX3) / Pedometer (Yamax EX510 3D)
|
Parents
|
Intervention
|
Parents support
|
Perceived paternal and maternal support (46)
|
Parents / Schoolchildren
|
Cross-sectional / Intervention
|
Peer support
|
Peer Support (36)
|
Schoolchildren
|
Cross-sectional / Intervention
|
Personal factors
|
Physical activity
|
YAP (47)
|
Schoolchildren
|
Cross-sectional / Intervention
|
|
|
PACO (45)
|
Schoolchildren
|
Cross-sectional / Intervention
|
|
|
Accelerometer (Axivity AX3) / Pedometer (Yamax EX510 3D)
|
Parents / Schoolchildren
|
Intervention
|
|
For built-environmental and perception PE
|
ESPE (39)
|
Schoolchildren
|
Intervention
|
|
Barriers to PA
|
Barrier Scale for PA (53)
|
Schoolchildren
|
Intervention
|
2.7 Instruments for evaluating interpersonal factors
a. The multicomponent ACTIBESE questionnaire was used to obtain sociodemographic and PA variables. Sociodemographic data included sex, age, course, and socioeconomic level using the Family Affluence Scale (FAS III), with questions such as the number of vehicles, household appliances, electronic devices, bathrooms, whether they have their room, and if they travel abroad for vacation (40). According to the score obtained, it is classified as low level (1–4 points), medium level (5–8 points), or high level (9–12 points).
b. The Global Physical Activity Questionnaire (GPAQ) will be used for parents’ AB. Having performed an analysis of the validity of the IPAQ (International Physical Activity Questionnaire) and the GPAQ, the latter was chosen as the best option, since it covers more aspects and has similar validity to the IPAQ (41,42). The GPAQ was developed by the World Health Organization (43) to collect information on PA and sedentary behaviour at work, activity on the move, and activity in leisure time through 16 closed and open questions (mixed).
According to the GPAQ developers’ instructions and standards, physical activities of moderate intensity are considered expenditures of 4 METs, and those of vigorous intensity are considered expenditures of 8 METs. The equation for calculating METs/min/week is [(P2 × P3 × 8) + (P5 × P6 × 4) + (P8 × P9 × 4) + (P11 × P12 × 8) + (P14 × P15 × 4)], where P is the question, and the attached number is the question corresponding to work, transportation, or recreation. Question 16 (Q16) corresponds to the time spent on sedentary activities.
Parents will be classified as physically active when they have completed ≥ 150 min/week, meeting the recommendations, and physically inactive when they have not reached 150 min/week, not meeting the recommendations (43).
In addition, an active commute-to-work questionnaire will be used (Table 1). The instrument used to assess the mode of parents’ commutes will be a questionnaire from the PACO Study (44). The questions will be “How do you usually get to work?” and “How do you usually get home from work?”. The possible answers are walking, cycling, car, motorcycle, public bus, metro/train, and others (the mode description is required). The mode of commuting will be categorized as “active” (walking and cycling) or “passive” (car, motorcycle, bus, metro/train). Additionally, “passive” commuting will be divided into a private mode of commuting (car, motorcycle) and a public mode of commuting (public bus, metro, train). In addition, the participant will complete the information about the distance and time spent commuting to work.
c. Parental support. Perceived paternal and maternal support will be assessed separately using a 5-item scale based on the following question format: “How often does your mother/father do these things?”. Responses were based on a 4-point Likert scale ranging from “very frequently” to “never”. This relates to encouragement to be physically active and to support PA (i.e., providing transport, watching, and praising PA) and being physically active with their child (46).
d. Peer support. Peer support will be measured using two items: encouragement to be physically active and being physically active with peers using the following question format: “How often do your friends do these things?”. Answers will be based on a Likert Scale ranging (4-point) from “very frequently” to “never.” Peer socializing will also be measured and quantified using the amount of time spent with friends “after school” and “in the evenings” during the school week.
Participants will be asked “How many Days a week do you usually spend with friends after school?” and “How many evenings during the school week do you usually spend time with friends?” (36).
2.8 Instruments for evaluating personal factors
a. Three instruments will be used to evaluate PA. First, the Youth Activity Profile (YAP) questionnaire, which provides a simple and low-cost method that has already been calibrated and validated to accurately estimate children’s moderate-to-vigorous physical activity (MVPA) and sedentary behaviour at the group level (47). A Spanish version of the YAP questionnaire was devised using a back-translation process, which is a feasible and reliable questionnaire for Spanish-speaking adolescents. The YAP includes a total of 19 items, including four general items and 15 specific items divided into three sections: 1) Activity at School, 2) Out-of-School Activity, and 3) Sedentary Habits. The final variables to analyse will be an average score ranging from 1 to 5 (lowest to highest) for PA at school and PA out of school, respectively. In addition, PA in children and adolescents will be established by transforming the YAP score to minutes/day in MVPA using the Fairclough equations (48). The min/day of MVPA at school, out-of-school MVPA, and weekend MVPA will be obtained separately for children, adolescents, boys, and girls. The cut-off points to be "physically active" will be > 60 min/day MVPA (49), which is classified as meeting MVPA recommendations. Those children who did not comply will be considered "physically inactive.”
An active commuting to school questionnaire will also be applied. The questions will be the same as those in the PACO Study (45). The questionnaire has been validated in the Chilean population (50). In children and adolescents, the questions included in the questionnaire will be “How do you usually get to school?” and “How do you usually get home from school?”. The possible answers are walking, cycling, car, motorcycle, school bus, public bus, metro/train, and others (the mode description will be needed). The mode of commuting for schoolchildren will be categorized as “active” (walking and cycling) or “passive” (car, motorcycle, school bus, public bus, metro/train). Additionally, “passive” commuting will be divided into private modes of commuting (car, motorcycle, school bus) and public modes of commuting (public bus, metro/train). In addition, participants will complete questions on distance, time spent commuting to school, and accompaniment.
Accelerometry and pedometry. PA will be measured objectively with a triaxial accelerometer (Axivity AX3 puck, Newcastle Helix, UK) for ten consecutive days. Schoolchildren will be instructed to use an accelerometer attached to their waist on the right side of the belt. Students will be instructed on how to care for the device, which will be removed during water activities and sleeping hours at night. Schoolchildren will also complete an accelerometry diary to record when it is removed. Actilife software (OMGUI software) will be used for both the initial configuration before the evaluations and for the data dump registered during the evaluation week. In addition, the GGIR R package (Almere, Netherlands) for accelerometer data processing will be used (51). According to recommendations, accelerometers should be programmed at a frequency of 100 Hz and an EPOCH of 15 s (52). The final variables to be analysed will be the daily minutes of light, moderate, vigorous, moderate-vigorous, total PA, and Bouts. In addition, accelerometer data will also be extracted from specific times of the day for each participant, calculating the PA during active commuting, in school (physical education lesson, recess, and free time), and out-of-school hours (afternoon and weekend) to identify when changes in PA may have occurred. To obtain time data, participants will carry a pedometer (Yamax EX510 3D Power-Walker Pedometer, UK) on the left side of the belt together with the accelerometer. The device will be removed during water activities and at night. It records up to 30 consecutive days by measuring the number of steps, calories, distance, and time. They will be kept in the custody of their parents during the intervention to stimulate the practice of PA throughout the follow-up period.
b. For built-environmental and perception PE, school physical education (ESPE) will be self-reported for schoolchildren (39), as previously explained (Table 1).
c. Barriers to PA. To obtain data on barriers to PA, schoolchildren will complete the Barrier Scale for PA (53). This is composed of 17 statements that assess which barriers can negatively influence PA, with seven response levels ranging from "I do not have that problem" to "It is a big problem.” Questions related to the barriers that affect the practice of PA will be categorized into barriers related to time, security, material elements, and capacity for enjoyment. Barriers will be classified as major (> 50%), moderate (25–50%), or minor (< 25%).
***Table 1 here***
Data Analysis
Before the analysis, if there is an unintentional random loss of data will be imputed using a nonparametric method using the R package “missForest” (54). This function successfully imputes large and complex mixed-type datasets (continuous or categorical variables), including complex and nonlinear interactions based on observed values that predict missing values. A Q-Q plot (quantile-quantile plot) will be used to visually verify normality.
Additionally, the interaction between sex and age will be explored. Descriptive statistics for the study variables will be calculated using the mean and standard deviation for continuous variables, and frequency and percentages for categorical variables. The T-test and chi-square test will be used for the continuous and categorical variables, respectively. To establish the association between continuous variables (i.e., PA level), several linear regressions using a standardized coefficient (ß) will be used. Associations of dichotomous variables with binary logistic regression models will be performed to obtain the odds ratio (OR) with their respective confidence intervals (95% CI). The results will be analysed according to age (children and adolescents) and sex (girls and boys). To determine the dependence between students within the same school, multilevel logistic regressions that group students will be applied. In addition, network analysis, exploratory factor analysis, confirmatory factor analysis, and structural equation modelling (SEM) will be used to determine the influence of different factors on PA.
The variation between the pre-and post-test results of the interventions will be determined through mixed models, estimating the effect size, analysis of covariance (ANCOVA), and a 2×2×2 factorial ANOVA. Mediation analysis using the PROCESS SPSS script (55) adjusted for age and sex will be performed.
Multicollinearity will be tested before completing the mediation analysis through the tolerance value and variance inflation factors (56). The percentage of the total contribution accounted for by mediation using the standardized coefficients will be calculated. A significant “indirect role” (mediation) will be established when (a) the independent variable is significantly related to the mediator, (b) the independent variable is significantly related to the dependent variable, (c) the mediator is significantly related to the dependent variable and (d) the association between the independent and dependent variable (“direct role”) is attenuated when the mediator is included in the regression model. In both studies, SPSS® v29 (IBM, New York, NY, USA), JASP software (V 0.18.3), and Jamovi version 2.0.0.0 (57) will be used for all analyses. GraphPad Prism software (GraphPad, San Diego, CA, USA) will be used to construct the graphs. Additionally, a p < 0.05 value will be established as statistically significant.
Ethical aspects
Once the authorization of the respective schools has been received, teachers and parents must sign an informed consent form for participation.
Likewise, the students will sign an informed consent form that will describe the characteristics of the study, the aims, and the activities to be conducted. The project will be developed following the Declaration of Helsinki (58) with the approval of the Bioethics Committee of the Pontificia Universidad Católica de Valparaíso (Code: BIOEPUCV-H 638–2023).