This study utilized baseline and 1-year follow-up data from an observational cohort, the “Pause and Play” study, which aimed to assess state policy changes on Louisiana ECE centers before and after implementation of the regulation. The study was designed to occur in ten ECE centers for adequate power to compare differences before and after implementation based on previous research [11]. The Louisiana state licensure changes were enacted in late 2015 for implementation during the 2016–17 school year. The minimum standard was to post the state policies in the ECE center for viewing, such as on a bulletin board, but there were no requirements to update handbooks. Data collection for baseline occurred at the beginning of the implementation period (April 2016–June 2017). Researchers conducted follow-up measures approximately 1 year after each center’s respective baseline assessment (May 2017–May 2018). The Louisiana Department of Education conducts regular unannounced licensure inspections in ECE centers, with inspections no more than 1 year apart. Thus, the ECE centers were inspected at least once after baseline and before follow-up measures to maintain licensure. The full purpose of the study was not disclosed to directors or parents until after data were collected. The Pennington Biomedical Research Center Institutional Review Board approved the study. This study follows the STROBE guidelines for reporting of observational studies (Supplementary Table 1).
As a part of this study, a community-based partnership was formed to evaluate the influence of the policy changes [12]. A prior published investigation revealed that baseline measures of observed and director reported screen-time were related to baseline child physical activity [13]. This investigation focuses on the longitudinal measures of the study.
Participants
Information on licensed ECE centers within a specific parish (county) of Louisiana were obtained from the state’s Department of Education. ECE centers were stratified by federal funding status, then randomized and contacted in order of randomization. Eligibility criteria included being a licensed ECE center in the specific parish, enrollment of at least 18 children between the ages of 3-to-4 years in their ECE center, and willing to participate. One hundred and forty six ECE centers were contacted, though 41 ECE centers did not respond, and 12 ECE centers were not licensed. Ninety three ECE centers participated in phone screen, though only fifteen ECE centers were eligible and five ECE centers did not participate due to changing their mind (n = 1), closed due to natural disaster (n = 1), or the study was filled before they finished enrolling (n = 3). The ECE director provided written informed consent for the ECE center to participate during a pre-observation visit. ECE directors selected one classroom within the age range (ages 3-to-4 years) for observation, and this same classroom was observed one-year later, thus different children might have been present in that particular classroom during the follow-up year. ECE centers received $200 in office and school supplies after both baseline and follow-up visits, and these supplies were not related to physical activity or screen-time.
Parents were recruited through an email or letter from the child’s ECE director or during in-person informational sessions at the ECE centers. Parents were given the opportunity to withdraw their child from participating in the classroom observation, though no parent refused participation. Parents were also invited to provide written informed consent that allowed their child to wear the accelerometer and participate in height and weight assessments. Children were eligible if they were 3–4 years of age, attended the ECE center full time (at least 6 h/day and 5 days/week), and planned to attend the same ECE center the following school year. Researchers invited children to participate in the study using developmental appropriate language and offered the children the opportunity to refuse to participate. Children received a small toy for each day if they wore the accelerometer (totaling less than one U.S. dollar per child overall). Parents completed a demographic form that included the child’s date of birth, sex, race/ethnicity; parental marital status, education level, and employment status; and household income.
ECE center policy engagement
At baseline, the ECE director completed a survey about their participation in Louisiana Department of Education events related to state policy and licensure changes. These events included attending a roundtable discussion, viewing a recorded presentation, or attending a webinar. Policy engagement was categorized into no engagement (did not participate any event), some engagement (participated in 1 event), and high engagement (participated in 2 or more events).
ECE center practices, environment, staff behavior, and policies
The physical activity component of the validated Environmental and Policy Assessment and Observation (EPAO) tool [14, 15] was used to measure each ECE center’s practices, environment, staff behavior, and policies related to physical activity and screen-time.
During a full day of observation of one classroom at each center, trained research specialists documented time children spent in active play, sedentary opportunities, and screen-time; environmental characteristics; and staff behavior. Trained research specialists completed over 20 h of training and obtained over ≥95% agreement during two practice observations prior to data collection. The trained research specialists EPAO domain and total scores were in complete agreement (100% intra-class correlation) for both practice observations. The current study used all eight physical activity domains of the EPAO, including: Active Opportunities, Sedentary Opportunities, Sedentary Environment, Portable Play Environment, Fixed Play Environment, Staff Behaviors, Physical Activity Training and Education, and Physical Activity Policy. Each EPAO domain assesses meeting physical activity standards on a 3 point scale (0 points when the action is not present, 1 points for meeting half the standard, and 2 points for meeting standard), these individual scores are summed and averaged, and then multiplied by 10 to create an EPAO domain score. Domains of the EPAO were calculated with a maximum possible score of 20 points per domain, with a higher score indicating a more supportive environment for physical activity. An overall score (“total EPAO score”), which was a sum of all domains (maximum score 160), was calculated. The following sections (ECE center practices, ECE Center Environment, ECE Center Staff Behavior, and ECE Center Policies) describe the EPAO domains further.
ECE center practices
Trained research specialists directly observed active play, television viewing time, non-television screen-time time, and total screen-time (including both television and screen use on non-television devices) during the day of ECE center observation. Active play was defined as an activity where more than half of the children were participating, and the children were engaged in MVPA. Non-television screen-time included viewing time of a computer, hand-held device, or tablet. A stopwatch and clock were used to record time and summed for the entire day.
ECE center environment
The ECE center Environment components assessed included EPAO scores of Active Opportunities, Sedentary Opportunities, and a revised-Sedentary Opportunities Score. Active Opportunities and Sedentary Opportunities scores are on observed active play and screen viewing time (see ECE Center Practices). Active Opportunities is meeting standards for active play minutes (60 or more minutes), teacher-led active play opportunities (any teacher-led opportunities), outdoor play opportunities (any outdoor play observed), and outdoor play minutes (120 or more minutes). Sedentary Opportunities included meeting standards for sedentary minutes (no more than 30 min sedentary at one time), viewing television (no viewing is the standard), viewing video games (no viewing), and length of viewing television (no viewing) and video games (no viewing). Due to the recent changes in technology, a revised-Sedentary Opportunities score was calculated utilizing screen-time from non-television devices (such as computers, tablets, or electronic toys) along with television. Sedentary Environment, Portable Play Environment, and Fixed Play Environment scores utilized observed equipment and indoor and outdoor areas. Sedentary Environment score was meeting standards for sedentary considerations including presence of TV (not present), computer or electronic device in the room for use by children (not present), and posters, pictures or books about physical activity displayed (present). Portable Environment score included the presence (2 points) or absence (0 points) of seven physical activity specific equipment (ball play, floor play, jumping play, parachute, push/pull toys, riding toys, and twirling equipment). Fixed Environment score included the presence (2 points) or absences (0 points) of having specific fixed environment items (basketball hoop, merry-go-round, see-saw, swinging equipment, and tunnels), outdoor play occurred, and size of outdoor (unobstructed for 2 points) and indoor play space (room for all activities given 2 points).
ECE center staff behavior
Staff Behaviors score from the EPAO was meeting staff behavior standards, including restricting play as punishment (not observed), participating activity (observed), and positive statements made about physical activity (3 or greater for 2 points, and 1 or 2 statements for 1 point, 0 points for no statements).
Physical Activity Training and Education score was a combination of observed (formal physical education lessons, extracurricular activities offered along with active alternatives for children) and director reported physical activity training opportunities (training in physical activity for preschool teachers and a documented physical activity curriculum). Presence of the standard was given 2 points and no points if the action was not observed or rarely observed.
ECE center policies
The EPAO Physical Activity Policy score was based on reviewing the ECE center’s handbook review of specific physical activity and TV viewing related policies, including policies related to active play and inactive play, supporting physical activity, TV use and TV viewing, and physical activity education. If the policy included at least two policies they were given 2 points, and 1 point if there was only one component.
Child physical activity
An ActiGraph GT3X+ accelerometer (Walton Beach, FL) measured child physical activity. A trained research specialist placed the accelerometer on the child’s right hip and secured using an adjustable latex-free elastic waist/hip belt. Parents were asked that the children wear the accelerometer for 8 days continuously (24 h/day) and only to take off the accelerometer for water-based activities.
Researchers used accelerometer data recorded on observation day during the class start and end time was used for analysis. Continuous strings of zeros that exceeded 30 min were removed based on previous literature in this age range [16, 17]. Age appropriate cut-points were applied to determine sedentary behavior (SB; < 200 counts/15 s), light physical activity (200–419 counts/15 s), and MVPA (≥420 counts/15 s) while the child was at the ECE center [18, 19]. Total physical activity (TPA) was the sum of light physical activity and MVPA. All intensities were expressed as minutes/hours worn to account for child wear time. Children who wore the device for at least 4 hours while at the ECE center were included in analysis based on previous research [7, 20].
Child anthropometry
Two measures of height (in in centimeters) and weight (in kilograms) were measured at the ECE center by a trained research specialist in a private setting with the child wearing light clothing and shoes removed. Height was measured to the nearest 0.1 cm on a portable stadiometer, and weight was measured to the nearest 0.1 kg via a high-precision electronic scale. A third measurement was taken if the two measurements differed by more than 0.5 units. Body mass index (BMI) percentile was calculated based on the child’s age and sex [21].
Data analysis
Central tendencies were calculated to describe the sample. Aim 1 was conducted in the sub-group of 49 children who were in the same observed classroom at each center at both baseline and follow-up to assess within-classroom and within-child changes. For these children, mixed models were used to assess the change in ECE center components (random parameters) with change in child physical activity, including the covariates of the center’s baseline ECE center practice in minutes (for ECE center practice models) or EPAO domain score in points (for EPAO domain models); the baseline child age, sex, race, and BMI percentile (fixed parameters); and accounting for clustering within ECE center. For Aim 2, a One-Way analysis of variance (ANOVA) assessed differences in total EPAO score at baseline, follow-up, and overall change by policy engagement category (no engagement, some engagement, high engagement). Paired t-tests assessed the difference between baseline and follow-up ECE center practices, environment, staff behavior, and policies. Cohen’s d for paired t-tests was calculated for effect sizes. SAS statistical software package 9.4 performed all analyses and significance was set at the p < 0.05 level.