Research Article: Long term effect of a school based intervention to prevent chronic diseases in Tunisia, 2009–2015

Date Published: December , 2017

Publisher: Makerere Medical School

Author(s): Rim Ghammam, Jihen Maatoug, Nawel Zammit, Raoudha Kebaili, Lamia Boughammoura, Mustafa Al’Absi, Harry Lando, Hassen Ghannem.


We aimed to evaluate the long term effect of school based intervention to prevent non- communicable disease risk factors.

It was a quasi experimental study conducted during the period of 2009–2015. We involved school children aged from 11 to 16 years old. For the assessment of the program’s effectiveness, subjects in both groups were examined at baseline, at the end of the 3-year intervention period and at the follow-up, one year after program’s cessation.

In the intervention group, the prevalence of school children who reported to be eating 5 fruits and vegetable sdaily increased significantly from 30.0% at pre-assessment to 33.2% at post-assessment, one year after (p=0.02, p=0.41 respectively). For the control group, this prevalence had significantly decreased from 40.2% at baseline to 35.0% at post-intervention, at the follow up, this proportion increased to 44.5%(p=0.001, p<10−3 respectively). Concerning smoking habits, we observed a decreasing trend in the intervention group from 5.7% at pre-assessment, to 4.8% at post-assessment and to 3.4% at the follow-up (p=0.19 and p=0.25 respectively). There was also a significant decrease in school children who did recommended physical activity in the same group. The present work showed that interventions promoting healthy lifestyles should be maintained. Developing countries should be encouraged and supported to design, conduct, and evaluate robust preventive interventions.

Partial Text

With non-communicable disease (NCDs) conditions accounting for nearly two-thirds of deaths worldwide, the emergence of chronic diseases as the predominant challenge to global health is undisputed1. NCDs are one of the major health and development challenges of the 21st century2. As the leading cause of death globally, NCDs were responsible for 38 million (68%) of the world’s 56 million deaths in 2012. More than 40% of them (16 million) were premature deaths under age 70 years. Almost three quarters of all NCDs deaths (28 million), and the majority of premature deaths (82%), occur in low and middle-income countries (LMIC)2. Unhealthy dietary behaviors, physical inactivity, and tobacco use contribute to NCDs and other health conditions, including obesity, diabetes and asthma3. These behaviors often established during childhood and adolescence, extend into adulthood, are interrelated, and preventable3.

The characteristics of the studied population from baseline to one year follow-up are presented in Table 1.

The baseline results indicate an important proportion of low physical activity, tobacco use, overweight and obesity. The effectiveness of the three years’ intervention program in students of Sousse Tunisia has been evaluated in previous studies15–18. Tracking the effects of the intervention in schools a year after its achievement has shown that it still has some positive effects. In fact, we have a stability of the positive effect in recommended serving of fruits and vegetables (30%, 33.2% and 31% respectively in the 3 times of measurement), (p= 0.02 and 0.4) particularly among girls and children under 14 years of age. The same positive effect was observed on smoking habit. Our program also kept a benefic effect on obesity and overweight especially among boys (27%, 23% and 20% respectively in the 3 times of measurement) and older than 14 years old school children (25%, 23.6% and 22.8% respectively in the 3 times of measurement). For recommended physical activity, the intervention didn’t have a positive effect. In the control group, we observed positive effects on physical activity, fruits and vegetables consumption one year after the end of the program. This effect may be explained by the short term effect of the differed intervention that was made for the control group before the follow-up evaluation.

First, there wasn’t randomization between the two groups, that’s why we are not able to confirm that all observed changes were due to the intervention program. Second, we used self-reported data to evaluate lifestyle risk factors. Self reported data is potentially subject to information bias34–36. Nevertheless, the possible subjectivity is the same at pre- and post-assessment and didn’t affect the evolution due to the intervention. The follow-up was realized on sub-samples of the intervention and the control groups. This may be a limit when tracking the real effect of the intervention. Furthermore, it is possible that the control group was contaminated by the intervention effect since the two cities (Sousse and M’saken) are not very distant.

The present work showed that interventions promoting healthy life style should be maintained. A short intervention wasn’t sufficient to reduce cardiovascular risk factors. Although evidence for the effectiveness of school-based interventions was inconclusive, evidence for the effectiveness of community-based and multisectorial interventions was somewhat stronger. More research is needed to examine in more depth, and for longer follow-up periods, the effectiveness of interventions promoting healthy lifestyles. Developing countries should be encouraged and supported to design, conduct, and evaluate robust preventive interventions. Evaluation should be included as part of the project plan.




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