New statistical model for misreported data with application to current public health challenges.

The main goal of this work is to present a new model able to deal with potentially misreported continuous time series. The proposed model is able to handle the autocorrelation structure in continuous time series data, which might be partially or totally underreported or overreported. Its performance is illustrated through a comprehensive simulation study considering several autocorrelation structures and three real data applications on human papillomavirus incidence in Girona (Catalonia, Spain) and Covid-19 incidence in two regions with very different circumstances: the early days of the epidemic in the Chinese region of Heilongjiang and the most current data from Catalonia.

Quantifying the under-reporting of uncorrelated longitudal data: the genital warts example.

BACKGROUND: Genital warts are a common and highly contagious sexually transmitted disease. They have a large economic burden and affect several aspects of quality of life. Incidence data underestimate the real occurrence of genital warts because this infection is often under-reported, mostly due to their specific characteristics such as the asymptomatic course. METHODS: Genital warts cases for the analysis were obtained from the Catalan public health system database (SIDIAP) for the period 2009-2016. People under 15 and over 94 years old were excluded from the analysis as the incidence of genital warts in this population is negligible. This work introduces a time series model based on a mixture of two distributions, capable of detecting the presence of under-reporting in the data. In order to identify potential differences in the magnitude of the under-reporting issue depending on sex and age, these covariates were included in the model. RESULTS: This work shows that only about 80% in average of genital warts incidence in Catalunya in the period 2009-2016 was registered, although the frequency of under-reporting has been decreasing over the study period. It can also be seen that this issue has a deeper impact on women over 30 years old. CONCLUSIONS: Although this study shows that the quality of the registered data has improved over the considered period of time, the Catalan public health system is underestimating genital warts real burden in almost 10,000 cases, around 23% of the registered cases. The total annual cost is underestimated in about 10 million Euros respect the 54 million Euros annually devoted to genital warts in Catalunya, representing 0.4% of the total budget.

Online Cost-Effectiveness ANalysis (OCEAN): a user-friendly interface to conduct cost-effectiveness analyses for cervical cancer.

BACKGROUND: Most cost-effectiveness analyses in the context of cervical cancer prevention involve the use of mathematical models to simulate HPV infection, cervical disease and prevention strategies. However, it is common for professionals who would need to perform these analyses to not be familiar with the models. This work introduces the Online Cost-Effectiveness ANalysis tool, featuring an easy-to-use web interface providing health professionals, researchers and decision makers involved in cervical cancer prevention programmes with a useful instrument to conduct complex cost-effectiveness analyses, which are becoming an essential tool as an approach for supporting decision-making that involves important trade-offs. RESULTS: The users can run cost-effectiveness evaluations of cervical cancer prevention strategies without deep knowledge of the underlying mathematical model or any programming language, obtaining the most relevant costs and health outcomes in a user-friendly format. The results provided by the tool are consistent with the existing literature. CONCLUSIONS: Having such a tool will be an asset to the cervical cancer prevention community, providing researchers with an easy-to-use instrument to conduct cost-effectiveness analyses.

Cervical cancer prevention in Morocco: a model-based cost-effectiveness analysis.

Objective: Cervical cancer is a huge public health issue in Morocco which represents the second most frequent and fatal cancer among women. Countries that have not yet introduced the HPV vaccine could benefit greatly, but before implementation it is necessary to perform country-specific economic assessments that include current screening practices. Methods: A Markov model was developed to simulate the natural history of HPV and cervical cancer so as to calculate the long-term health benefits and costs of HPV vaccination and current screening by visual inspection with acetic acid (VIA). Starting from a previous transition probability matrix used for a model from Spain, the present model was calibrated to cervical cancer incidence from Morocco. Cost survey data was used to estimate the cost of screening and clinical procedures from the public healthcare perspective. Incremental cost-effectiveness ratios were calculated as 2018US$ per additional year of life saved (YLS) and both costs and health outcomes were discounted at 3%. Results: The expected reduction in lifetime risk of cervical cancer for current screening would be 14% at a cost of US$551/YLS compared with no intervention, assuming VIA every 3 years in women aged 30-49 at 10% coverage. HPV vaccination of pre-adolescent girls at 70% coverage would reduce the lifetime risk of cervical cancer by 62% at a cost of US$1,150/YLS, compared with no intervention. When implementing HPV vaccination in combination with current screening, vaccination would be dominated, and the combined strategy would provide a 69% reduction at a cost of US$2,843/YLS, compared with screening alone. Current screening would be dominated by vaccination when screening coverage is higher than 15%, whereas the combined strategy rapidly exceeds US$4,000/YLS. Conclusions: HPV vaccination could be highly effective and cost-effective in Morocco. Current screening would be good value for money compared with no intervention, but scaling-up screening coverage would make it inefficient compared with vaccination.

Correction: Development of a source-exposure matrix for occupational exposure assessment of electromagnetic fields in the INTEROCC study.

Corrigendum: This work was also funded by the European Commission grant 603794 (GERoNiMO project).

Hepatic accumulation of S-adenosylmethionine in hamsters with non-alcoholic fatty liver disease associated with metabolic syndrome under selenium and vitamin E deficiency.

Progression of non-alcoholic fatty liver disease (NAFLD) in the context of metabolic syndrome (MetS) is only partially explored due to the lack of preclinical models. In order to study the alterations in hepatic metabolism that accompany this condition, we developed a model of MetS accompanied by the onset of steatohepatitis (NASH) by challenging golden hamsters with a high-fat diet low in vitamin E and selenium (HFD), since combined deficiency results in hepatic necroinflammation in rodents. Metabolomics and transcriptomics integrated analyses of livers revealed an unexpected accumulation of hepatic S-Adenosylmethionine (SAM) when compared with healthy livers likely due to diminished methylation reactions and repression of GNMT. SAM plays a key role in the maintenance of cellular homeostasis and cell cycle control. In agreement, analysis of over-represented transcription factors revealed a central role of c-myc and c-Jun pathways accompanied by negative correlations between SAM concentration, MYC expression and AMPK phosphorylation. These findings point to a drift of cell cycle control toward senescence in livers of HFD animals, which could explain the onset of NASH in this model. In contrast, hamsters with NAFLD induced by a conventional high-fat diet did not show SAM accumulation, suggesting a key role of selenium and vitamin E in SAM homeostasis. In conclusion, our results suggest that progression of NAFLD in the context of MetS can take place even in a situation of hepatic SAM excess and that selenium and vitamin E status might be considered in current therapies against NASH based on SAM supplementation.

Subtle excess in lifetime cancer risk related to CT scanning in Spanish young people.

BACKGROUND: CT scan is a life-saving medical diagnostic tool, entailing higher levels of ionising radiation exposure than conventional radiography, which may result in an increase in cancer risk, particularly in children. Information about the use and potential health effects of CT scan imaging among young people in Spain is scarce. OBJECTIVE: This paper aims to estimate the number of radiation-related cancer cases which can be expected due to the use of CT scanning in Spanish children and young adults in a single year (2013). METHODS: The 2013 distribution of number and types of CT scans performed in young people was obtained for Catalonia and extrapolated to the whole Spain. Organ doses were estimated based on the technical characteristics of 17,406 CT examinations extracted from radiology records. Age and sex-specific data on cancer incidence and life tables were obtained for the Spanish population. Age and sex-specific risk models developed by the Committee on Health Risks of Exposure to Low Levels of Ionizing Radiations (BEIR VII) and Berrington de Gonzalez were used, together, with the dose estimates to derive the lifetime attributable risks of cancer in Spain due to one year of CT scanning and project the number of future cancer cases to be expected. RESULTS: In 2013, 105,802 CT scans were estimated to have been performed in people younger than age 21. It was estimated that a total of 168.6 cancer cases (95% CrI: 30.1-421.1) will arise over life due to the ionising radiation exposure received during these CTs. Lifetime attributable risks per 100,000 exposed patients were highest for breast and lung cancer. The largest proportion of CTs was to the head and neck and hence the highest numbers of projected cancer cases were of thyroid and oral cavity/pharynx. CONCLUSIONS: Despite the undeniable medical effectiveness of CT scans, this risk assessment suggests a small excess in cancer cases which underlines the need for justification and optimisation in paediatric scanning. Given the intrinsic uncertainties of these risk projection exercises, care should be taken when interpreting the predicted risks.

Moving towards an organized cervical cancer screening: costs and impact.

Background: HPV screening has been shown to be more cost-effective than cytology screening under most scenarios. Furthermore, it should be offered only in organized programmes with good quality assurance mechanisms. This study analyses the comparative cost of the current policy of opportunistic cytology screening vs. a hypothetical organized programme based on primary HPV screening. Methods: Total cervical cancer expenditure was defined as the sum of three cost elements: (i) direct (medical and non-medical) costs, obtained from a calibrated Markov model of the natural history of HPV and cervical cancer; (ii) programmatic costs, estimated based on other organized screening programmes; and (iii) indirect costs, extrapolated from previously published data. Results: Organized HPV screening at 5-year intervals costs consistently less across all coverage levels than opportunistic cytology screening at 3-year intervals. The current annual direct medical cost to the public health system of the opportunistic cytology at 40% coverage is estimated at €33.2 per woman screened aged 25-64. Under an organized programme of primary HPV screening at 70% coverage, the cost is estimated to be €18.4 per woman screened aged 25-64. Conclusion: Our study concludes that the economic resources currently devoted to providing opportunistic cytology screening to 40% of the target population at 3-year intervals could be more effectively used to screen 70% of the target population at 5-year intervals by switching to an organized programme based on primary HPV screening. This finding is of relevance to other European countries or regions with similar screening policies and health infrastructures.

Follow-up of a healthy lifestyle education program (the EdAl study): four years after cessation of randomized controlled trial intervention.

BACKGROUND: An important challenge of school-based childhood obesity (OB) intervention programs is understanding the maintenance of the effects after cessation of the intervention to overcome the limitations of follow-up studies. The aim of this study is to verify the sustainability of the benefits achieved at a 4-year follow-up of the post-Educació en Alimentació (EDAl) program intervention cessation by assessing the OB-related outcomes and lifestyles of 13- to 15-year-old adolescents. METHODS: This paper describes a 4-year follow-up study after the cessation of a school-based randomized controlled intervention in adolescents (n = 349, intervention; n = 154, control) with baseline and 4-year follow-up data from high schools in Reus (intervention group), Salou, Cambrils and Vila-seca (control group). The outcomes are body mass index (BMI), BMI z-score, and OB prevalence according to the World Health Organization and International Obesity Task Force criteria and lifestyle data (obtained from questionnaires). RESULTS: Compared with the control girls, the intervention girls showed reduced BMI z-scores (-0.33 units, p < 0.01) from baseline (2007) to the 4-year follow-up post-intervention (2014). Compared with the control boys, the intervention boys showed reduced OB prevalence (-7.7%; p = 0.02). Compared with the control boys, more boys in the intervention group (19% increase; p = 0.059) showed ≥4 h/week after-school physical activity (PA). A decrease in the consumption of dairy products, fruits and fish was observed in both groups. CONCLUSIONS: At the 4-year post-intervention follow-up of the EdAl program, compared with the control groups, girls had lower BMI z-scores and boys had lower OB prevalence from the intervention. The encouragement in after-school PA was long-lasting and maintained after the cessation of the intervention, whereas healthy food habits must be further reinforced in adolescents. TRIAL REGISTRATION: ISRCTN29247645 .

Impact of model calibration on cost-effectiveness analysis of cervical cancer prevention.

Markov chain models are commonly used to simulate the natural history of human papillomavirus infection and subsequent cervical lesions with the aim of predicting future benefits of health interventions. Developing and calibrating these models entails making a number of critical decisions that will influence the ability of the model to reflect real conditions and predict future situations. Accuracy of selected inputs and calibration procedures are two of the crucial aspects for model performance and understanding their influence is essential, especially when involves policy decisions. The aim of this work is to assess the health and economic impact on cervical cancer prevention strategies currently under discussion according to the most common methods of model calibration combined with different accuracy degree of initial inputs. Model results show large differences on the goodness of fit and cost-effectiveness outcomes depending on the calibration approach used, and these variations may affect health policy decisions. Our findings strengthen the importance of obtaining good calibrated probability matrices to get reliable health and cost outcomes, and are directly generalizable to any cost-effectiveness analysis based on Markov chain models.

Development of a source-exposure matrix for occupational exposure assessment of electromagnetic fields in the INTEROCC study.

To estimate occupational exposures to electromagnetic fields (EMF) for the INTEROCC study, a database of source-based measurements extracted from published and unpublished literature resources had been previously constructed. The aim of the current work was to summarize these measurements into a source-exposure matrix (SEM), accounting for their quality and relevance. A novel methodology for combining available measurements was developed, based on order statistics and log-normal distribution characteristics. Arithmetic and geometric means, and estimates of variability and maximum exposure were calculated by EMF source, frequency band and dosimetry type. The mean estimates were weighted by our confidence in the pooled measurements. The SEM contains confidence-weighted mean and maximum estimates for 312 EMF exposure sources (from 0 Hz to 300 GHz). Operator position geometric mean electric field levels for radiofrequency (RF) sources ranged between 0.8 V/m (plasma etcher) and 320 V/m (RF sealer), while magnetic fields ranged from 0.02 A/m (speed radar) to 0.6 A/m (microwave heating). For extremely low frequency sources, electric fields ranged between 0.2 V/m (electric forklift) and 11,700 V/m (high-voltage transmission line-hotsticks), whereas magnetic fields ranged between 0.14 µT (visual display terminals) and 17 µT (tungsten inert gas welding). The methodology developed allowed the construction of the first EMF-SEM and may be used to summarize similar exposure data for other physical or chemical agents.

InterCardioRisk: a novel online tool for estimating doses of ionising radiation to occupationally-exposed medical staff and their associated health risks.

Those working in interventional cardiology and related medical procedures are potentially subject to considerable exposure to x-rays. Two types of tissue of particular concern that may receive considerable doses during such procedures are the lens of the eye and the brain. Ocular radiation exposure results in lens changes that, with time, may progress to partial or total lens opacification (cataracts). In the early stages, such opacities do not result in visual disability; the severity of such changes tends to increase progressively with dose and time until vision is impaired and cataract surgery is required. Scattered radiation doses to the eye lens of an interventional cardiologist in typical working conditions can exceed 34 µGy min-1 in high-dose fluoroscopy modes and 3 µGy per image during image acquisition (instantaneous rate values) when radiation protection tools are not used. A causal relation between exposure to ionising radiation and increased risk of brain and central nervous system tumours has been shown in a number of studies. Although absorbed doses to the brain in interventional cardiology procedures are lower than those to the eye lens by a factor between 3.40 and 8.08 according to our simulations, doses to both tissues are among the highest occupational radiation doses documented for medical staff whose work involves exposures to x-rays. We present InterCardioRisk, a tool featuring an easy-to-use web interface that provides a general estimation of both cumulated absorbed doses experienced by medical staff exposed in the interventional cardiology setting and their estimated associated health risks. The tool is available at http://intercardiorisk.creal.cat.

EdAl-2 (Educació en Alimentació) programme: reproducibility of a cluster randomised, interventional, primary-school-based study to induce healthier lifestyle activities in children.

OBJECTIVES: To assess the reproducibility of an educational intervention EdAl-2 (Educació en Alimentació) programme in 'Terres de l'Ebre' (Spain), over 22 months, to improve lifestyles, including diet and physical activity (PA). DESIGN: Reproduction of a cluster randomised controlled trial. SETTING: Two semi-rural town-group primary-school clusters were randomly assigned to the intervention or control group. PARTICIPANTS: Pupils (n=690) of whom 320 constituted the intervention group (1 cluster) and 370 constituted the control group (1 cluster). Ethnicity was 78% Western European. The mean age (±SD) was 8.04±0.6 years (47.7% females) at baseline. Inclusion criteria for clusters were towns from the southern part of Catalonia having a minimum of 500 children aged 7-8 year; complete data for participants, including name, gender, date and place of birth, and written informed consent from parents or guardians. INTERVENTION: The intervention focused on eight lifestyle topics covered in 12 activities (1 h/activity/session) implemented by health promoting agents in the primary school over three academic years. PRIMARY AND SECONDARY OUTCOMES: The primary outcome was obesity (OB) prevalence and the secondary outcomes were body mass index (BMI) collected every year and dietary habits and lifestyles collected by questionnaires filled in by parents at baseline and end-of-study. RESULTS: At 22 months, the OB prevalence and BMI values were similar in intervention and control groups. Relative to children in control schools, the percentage of boys in the intervention group who performed ≥4 after-school PA h/week was 15% higher (p=0.027), whereas the percentage of girls in both groups remained similar. Also, 16.6% more boys in the intervention group watched ≤2 television (TV) h/day (p=0.009), compared to controls; and no changes were observed in girls in both groups. CONCLUSIONS: Our school-based intervention is feasible and reproducible by increasing after-school PA (to ≥4 h/week) in boys. Despite this improvement, there was no change in BMI and prevalence of OB. TRIAL REGISTRATION NUMBER: Clinical Trials NCT01362023.

Prevalence of visual impairment in El Salvador: inequalities in educational level and occupational status / Prevalencia de deficiencia visual en El Salvador: desigualdades según el nivel educativo y la situación laboral

OBJECTIVE: To examine the prevalence of blindness, visual impairment, and related eye diseases and conditions among adults in El Salvador, and to explore socioeconomic inequalities in their prevalence by education level and occupational status, stratified by sex. METHODS: Based upon the Rapid Assessment of Avoidable Blindness (RAAB) methodology, this nationwide sample comprised 3 800 participants (3 399 examined) ≥ 50 years old from 76 randomly selected clusters of 50 persons each. The prevalence of blindness, visual impairment and related eye diseases and conditions, including uncorrected refractive error (URE), was calculated for categories of education level and occupational status. Multiple logistic regression models were fitted to calculate odds ratios (ORs) and 95% confidence intervals (CIs) and stratified by sex. RESULTS: Age-adjusted prevalence was 2.4% (95% CI: 2.2-2.6) for blindness (men: 2.8% (95% CI: 2.5-3.1); women: 2.2% (95% CI: 1.9-2.5)) and 11.8% (95% CI: 11.6-12.0) for moderate visual impairment (men: 10.8% (95% CI: 10.5-11.1); women: 12.6% (95% CI: 12.4-12.8)). The proportion of visual impairment due to cataract was 43.8% in men and 33.5% in women. Inverse gradients of socioeconomic inequalities were observed in the prevalence of visual impairment. For example, the age-adjusted OR (AOR) was 3.4 (95% CI: 2.0-6.4) for visual impairment and 4.3 (95% CI: 2.1-10.4) for related URE in illiterate women compared to those with secondary education, and 1.9 (95% CI: 1.1-3.1) in cataract in unemployed men. CONCLUSIONS: Blindness and visual impairment prevalence is high in the El Salvador adult population. The main associated conditions are cataract and URE, two treatable conditions. As socioeconomic and gender inequalities in ocular health may herald discrimination and important barriers to accessing affordable, good-quality, and timely health care services, prioritization of public eye health care and disability policies should be put in place, particularly among women, the unemployed, and uneducated people.

OBJETIVO: Analizar la prevalencia de la ceguera, la deficiencia visual, y las enfermedades y afecciones oculares relacionadas en adultos de El Salvador, y explorar las desigualdades socioeconómicas en cuanto a su prevalencia según el nivel educativo y la situación laboral, estratificados por sexos. MÉTODOS: Se adoptó el método de Evaluación Rápida de la Ceguera Evitable, y se escogió una muestra a escala nacional de 3 800 participantes (de ellos se examinaron 3 399) de 50 años de edad o mayores, pertenecientes a 76 agrupamientos seleccionados aleatoriamente y constituidos por 50 personas cada uno. Se calculó la prevalencia de la ceguera, la deficiencia visual y las enfermedades y afecciones oculares relacionadas, incluido el error de refracción no corregido, según las diferentes categorías de nivel educativo y situación laboral. Se emplearon modelos de regresión logística múltiple para calcular las razones de posibilidades (OR) y los intervalos de confianza (IC) de 95%, y se estratificaron por sexos. RESULTADOS: La prevalencia ajustada por edad fue de 2,4% (IC de 95%: 2,2-2,6) para la ceguera (hombres: 2,8% [IC de 95%: 2,5-3,1]; mujeres: 2,2% [IC de 95%: 1,9-2,5]) y de 11,8% (IC de 95%: 11,6-12,0) para la deficiencia visual moderada (hombres: 10,8% [IC de 95%: 10,5-11,1]; mujeres: 12,6% [IC de 95%: 12,4-12,8]). La proporción de deficiencias visuales debidas a catarata fue de 43,8% en los hombres y de 33,5% en las mujeres. En la prevalencia de la deficiencia visual se observaron gradientes inversos de desigualdades socioeconómicas. Por ejemplo, la OR ajustada por edad fue de 3,4 (IC de 95%: 2,0-6,4) para la deficiencia visual y de 4,3 (IC de 95%: 2,1-10,4) para el error de refracción no corregido relacionado en las mujeres analfabetas, en comparación con las que tenían un nivel de educación secundaria, y fue de 1,9 (IC de 95%: 1,1-3,1) para la catarata en los hombres desempleados. CONCLUSIONES: La prevalencia de ceguera y deficiencia visual es alta en la población adulta de El Salvador. Las principales afecciones asociadas son la catarata y el error de refracción no corregido, ambas tratables. Puesto que las desigualdades socioeconómicas y de género en materia de salud ocular pueden ser indicativas de discriminación y de la existencia de barreras importantes para obtener acceso a servicios de atención de salud asequibles, de buena calidad y oportunos, es preciso dar prioridad a la atención oftalmológica pública y a las políticas dirigidas a corregir la discapacidad, en particular en las mujeres y en las personas desempleadas y sin formación.

A primary-school-based study to reduce the prevalence of childhood obesity--the EdAl (Educació en Alimentació) study: a randomized controlled trial.

BACKGROUND: Obesity is one of the main determinants of avoidable disease burden.To implement a program by university students acting as "health promoting agents" (HPAs) and to evaluate the effects on obesity prevalence of the primary-school-based program that promotes healthy lifestyle, including dietary and physical activity recommendations over 28 months. METHODS: Two school clusters were randomly assigned to intervention (24 schools, 1,222 pupils) or control (14 schools, 717 pupils); 78% of pupils were Western European. Mean age (±SD) was 8.4±0.6 years (49.9% females) at baseline. Generalized linear mixed models were used to analyze differences in primary outcome between both groups. Data collected included body mass index (BMI) every year. Dietary habits and lifestyle questionnaires were filled in by the parents at baseline and at the end of the study. The interventions focused on eight lifestyle topics covered in 12 activities (1 hour/activity/session) implemented by HPAs over 3 school academic years. RESULTS: At 28 months, obesity prevalence in boys was decreased -2.36% in the intervention group (from 9.59% to 7.23%) and increased 2.03% (from 7.40% to 9.43%) in the control group; the difference was 4.39% (95% CI 3.48 to 5.30; P=0.01). The boys in the intervention group had an effective reduction of -0.24 units in the change of BMI z-score (from 0.01 to -0.04), compared to control (from -0.10 to 0.09); 5.1% more intervention pupils undertook physical activity>5 hours/week than control pupils (P=0.02).Fish consumption was a protector (odds ratio 0.39; 95% CI 0.23 to 0.67) while "fast-food" consumption was a risk factor for childhood obesity (odds ratio: 2.27; 95% CI 1.08 to 4.77). CONCLUSIONS: Our school-based program, conducted by HPA students, successfully reduced childhood obesity prevalence in boys. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number: ISRCTN29247645.

A primary-school-based study to reduce prevalence of childhood obesity in Catalunya (Spain)--EDAL-Educació en alimentació: study protocol for a randomised controlled trial.

BACKGROUND: The EdAL (Educació en Alimentació) study is a long-term, nutrition educational, primary-school-based program designed to prevent obesity by promoting a healthy lifestyle that includes dietary recommendations and physical activity.The aims are: 1) to evaluate the effects of a 3-year school-based life-style improvement program on the prevalence of obesity in an area of north-west Mediterranean 2) To design a health-promotion program to be implemented by health-promoter agents (university students) in primary schools. METHODS/DESIGN: 1) The intervention study is a randomised, controlled, school-based program performed by university-student health-promoter agents. Initial pupil enrolment was in 2006 and continued for 3 years. We considered two clusters (designated as cluster A and cluster B) as the units for randomisation. The first cluster involved 24 schools from Reus and the second involved 14 schools from surrounding towns Cambrils, Salou and Vilaseca combined in order to obtain comparable groups. There are very good communications between schools in each town, and to avoid cross influence of the programs resulting from inter-school dialogue, the towns themselves were the unit for randomisation. Data collected included name, gender, date and place of birth at the start of the program and, subsequently, weight, height, body mass index (BMI) and waist circumference every year for 3 years. Questionnaires on eating and physical activity habits are filled-in by the parents at the start and end of the study and, providing that informed consent is given, the data are analysed on the intention-to-treat basis.The interventions are based on 8 nutritional and physical activity objectives. They are implemented by university students as part of the university curriculum in training health-promoter agents. These 8 objectives are developed in 4 educational activities/year for 3 years (a total of 12 activities; 1 h/activity) performed by the health-promoter agents in primary schools. Control pupils follow their usual activities.2) Courses on education and promotion of health, within in the curriculum of medicine and health sciences for university students, are designed to train health-promoter agents to administer these activities in primary schools. DISCUSSION: This controlled school-based intervention will test the possibility of preventing childhood obesity. TRIAL REGISTRATION NUMBER: ISRCTN: ISRCTN29247645.