Effects of a school based intervention to promote healthy habits in children 8-11 years old, living in the lowland area of Bologna Local Health Unit. R. Sacchetti* ...
R. Sacchetti et al. Ann Ig 2015; 27: 432-446 doi:10.7416/ai.2015.2030
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Effects of a school based intervention to promote healthy habits in children 8-11 years old, living in the lowland area of Bologna Local Health Unit R. Sacchetti*, L. Dallolio**, M.A. Musti***, E. Guberti****, A. Garulli*****, P. Beltrami***, F. Castellazzi***, E. Centis***, C. Zenesini***, C. Coppini****, C. Rizzoli****, M. Sardocardalano****, E. Leoni** Key words: Health promotion, primary school, physical activity, dietary habits, BMI Parole chiave: Promozione della salute, scuola primaria, attività fisica, abitudini alimentari, BMI
Abstract Background: A school based health promotion intervention was performed with the aim of increasing physical activity and improving the dietary habits of primary school pupils, using integrated educational strategies involving schools, families, public bodies, sports associations and public health operators. Methods: The intervention concerned 11 classes during 3 school years from 2009-10 (231 third-year school children) to 2011-12 (234 fifth-year school children). Information was collected both before and after the intervention about the dietary habits and the physical activities practised by the children, using the questionnaires of the project “OKkio alla Salute” which were administered to both children and parents. At the same time anthropometric measurements were taken (height, weight, BMI) and motor skills were assessed using standardized tests: Sit & Reach, medicine-ball forward throw, standing long jump, 20 m running speed, and forward roll. At the end of the intervention 12 different expected outcomes were assessed (5 about dietary habits, 5 about motor habits, 1 about anthropometric characteristics, 1 about motor skills). Results: At baseline, 35.8% of the children show excess weight (23.4% overweight; 12.4% obese); this percentage falls to 29.3% (25.3% overweight; 4% obese) after the intervention (p 22.2) and 10.5 y (overweight: F >20.3, M >20.4; obese: F >24.8, M >24.6). Assessment of motor skills A limited number of tests were selected from among the numerous motor tests suggested at international and national level to assess the main conditioning and coordinative abilities in young people (31, 32). In accordance with our previous studies, the selected motor tests were suitable for the age group, were easy to perform and able to provide a representative spectrum of the children’s physical abilities (24, 33). The following tests were carried out: The Sit & Reach Test to assess the hip and low-back flexibility; in a seated position
Promotion of healthy habits in primary schools
with the knees extended and the feet placed firmly against a vertical support the pupil reached forward along the measuring line as far as possible with the arms at the same level; the score was recorded to the nearest centimetre as the distance reached by the hands, using the level of the feet as recording zero, so that any measure that did not reach the toes was negative and any measure beyond the toes was positive. The Forward Roll Test to assess the children’s perception of themselves in space and their dynamic total body coordination; from a standing position, the pupil was instructed to place the hands on the ground and roll forward, leaning in succession the head, shoulders, back and pelvis; the results were quantified into three levels: insufficient, sufficient, good. The 2Kg Medicine-ball Forward Throw Test to assess upper limbs power; the pupil was instructed to throw a 2Kg medicineball as far as possible, using both hands and keeping the feet firmly on the ground; the test was scored in cm. The Standing Long Jump Test to assess the lower body and legs explosive strength; the pupil was instructed to jump as far as possible from a standing start, with the feet slightly apart; the test was scored in cm. The 20m Running Speed Test to assess speed and anaerobic power; the children were instructed to cover a 20 meter distance as fast as possible; the test was scored in seconds. All the tests were performed twice and the best result was recorded. To compare the results of the motor tests between pre- and post-intervention and to compensate for any changes due to the growth process, the throw, jump and running tests were standardized using the following formula: Standard score= (mean score - raw score) /σ where: Mean score = Σ scores / N σ2 = Σ (deviation2) / N; σ = square root of σ2 deviation = mean score - raw score
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The standardized scores were divided into the categories Good, Sufficient and Insufficient choosing cut-off values of +1 and -1. In the throw and jump tests the category Good was assigned for a standard score ≥1; Sufficient for a standard score between -1 and +1; Insufficient for a standard score ≤-1. In the speed test the category Good was assigned for a standard score ≤-1; Sufficient for a standard score between -1 and +1; Insufficient for a standard score ≥1. Data analysis The answers given by the pupils and their parents, the values of the anthropometric parameters and the results of the motor tests were all collected in a database and analyzed using the Stata Intercooled statistical analysis package for Windows, version 12.0. Data are reported as means ± standard deviations for the continuous variables and frequency percentages for the categorical variables. The pre-post comparisons between the frequencies of the answers given by the children and parents regarding their alimentary and motor habits, and between the distributions of the BMI and of the standardized scores of the motor tests, were made using the Pearson Chi Squared test, considering only the subjects with data available for both the third and fifth classes. The differences in the children’s performances in the various motor tests were assessed on the basis of gender, using the Pearson Chi Squared test (comparison between standardized scores), and of BMI, using the one-way ANOVA test (comparison between the measurements taken for S&R, throwing, jumping, running). A p value
