Are the health messages in schoolbooks based on scientific evidence? A descriptive study.

BACKGROUND Most textbooks contains messages relating to health. This profuse information requires analysis with regards to the quality of such information. The objective was to identify the scientific evidence on which the health messages in textbooks are based. METHODS The degree of evidence on which such messages are based was identified and the messages were subsequently classified into three categories: Messages with high, medium or low levels of evidence; Messages with an unknown level of evidence; and Messages with no known evidence. RESULTS 844 messages were studied. Of this total, 61% were classified as messages with an unknown level of evidence. Less than 15% fell into the category where the level of evidence was known and less than 6% were classified as possessing high levels of evidence. More than 70% of the messages relating to "Balanced Diets and Malnutrition", "Food Hygiene", "Tobacco", "Sexual behaviour and AIDS" and "Rest and ergonomics" are based on an unknown level of evidence. "Oral health" registered the highest percentage of messages based on a high level of evidence (37.5%), followed by "Pregnancy and newly born infants" (35%). Of the total, 24.6% are not based on any known evidence. Two of the messages appeared to contravene known evidence. CONCLUSION Many of the messages included in school textbooks are not based on scientific evidence. Standards must be established to facilitate the production of texts that include messages that are based on the best available evidence and which can improve children's health more effectively.

Appropriate therapy for fistulizing and fibrostenotic Crohn's disease: results of a multidisciplinary expert panel - EPACT II

Introduction: Many therapeutic decisions in the management of fistulizing and fibrostenotic Crohn's disease (CD) have to be taken without the benefit of strong scientific evidence. For this reason, explicit appropriateness criteria for CD fistula and stenosis treatment were developed by a multidisciplinary European expert panel in 2004 with the aim of making them easily available on the Internet and thus allowing individual case scenario evaluation; these criteria were updated in 2007. Methods: Twelve international experts convened in Geneva, Switzerland in December 2007. Explicit clinical scenarios, corresponding to real daily practice, were rated on a 9-point scale based on evidence from the published literature and panelists' own expertise. Median ratings were stratified into three categories: appropriate (7-9), uncertain (4-6) and inappropriate (1-3). Results: Overall, panelists rated 60 indications pertaining to fistulas. Antibiotics, azathioprine/6-mercaptopurine and conservative surgery are the mainstay of therapy for simple and complex fistulas. In the event of previous failure of azathioprine/6-mercaptopurine therapy, methotrexate and infliximab were considered appropriate for complex fistulas. The panel also rated 72 indications related to the management of fibrostenotic CD. The experts considered balloon dilation, if the stricture was endoscopically accessible, stricturoplasty and bowel resection to be appropriate for small bowel fibrostenotic Crohn's disease, and balloon dilation and bowel resection appropriate for fibrostenotic colonic disease. In the presence of an ileocolonic or ileorectal anastomotic stricture of <7 cm, endoscopic balloon dilation, and bowel resection were considered appropriate. Conclusion: Antibiotics, azathioprine/6-mercaptopurine, and conservative surgery are the mainstay of therapy for fistulizing Crohn's disease. Infliximab is a therapeutic option in patients without prior response to immunosuppressant therapy. In fibrostenotic Crohn's disease, endoscopic balloon dilation, if feasible, or surgical therapy should be considered. These expert recommendations are available online (www.epact.ch). Prospective evaluation is now needed to test the validity of these appropriateness criteria in clinical practice. (C) 2009 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Update on basic and clinical aspects of eosinophilic oesophagitis.

The identification of a distinct syndrome, designated eosinophilic oesophagitis (EoE), with its own clinical and histopathological characteristics, was first described in the early 1990s. Meanwhile intense research has uncovered many molecular, immunological and clinical aspects of this chronic-inflammatory disorder. This article focuses exclusively on basic and clinical insights of EoE gathered during the last few years. Regarding aetiopathogenesis it has become clear that EoE is a food-triggered disease with milk and wheat as the dominant culprit food categories. However, it is still debated whether a disturbed mucosal integrity allowing allergens to cross the mucosal barrier, or changes in wheat and milk manufacturing might induce these inflammatory responses. Furthermore, basic science and clinical studies have accordingly confirmed that a chronic eosinophilic inflammation leads to a remodelling of the oesophagus with micro- and macro-morphological alterations, ending in a strictured oesophagus with impaired function. Fortunately, long-term therapeutic trials, using either topical corticosteroids or dietary allergen avoidance, have demonstrated that this sequela can be prevented or even reversed. This finding is of clinical relevance as it supports the initiation of a consistent anti-inflammatory therapy. Nevertheless, EoE is still an enigmatic disease and the long list of unanswered questions will certainly stimulate further research.

Prevalence, treatment and control of dyslipidaemia in Switzerland: still a long way to go.

BACKGROUND: There is little information regarding the prevalence and management of dyslipidaemia in Switzerland. DESIGN: Cross-sectional population-based study of 3238 women and 2846 men aged 35-75. METHODS: Dyslipidaemia prevalence, treatment and control were defined according to PROCAM guidelines adapted to Switzerland. RESULTS: About 29% of the overall sample presented with dyslipidaemia, of which 39% were treated and 58% of those treated were controlled. Among the 710 patients with personal history of cardiovascular disease (CVD) and/or diabetes, 632 (89%) presented with dyslipidaemia, of which 278 (44%) and 134 (21%) patients were treated and adequately controlled, respectively. On multivariate analysis, hypolipidaemic drug treatment was positively related with age and body mass index (P for trend <0.001), and negatively related with smoking status (P for trend <0.002), whereas personal history of CVD and/or diabetes had no effect [odds ratio (OR)=1.12, 95% confidence interval (CI): 0.90-1.38]. Adequate control of lipid levels was negatively related with female sex (OR=0.65, 95% CI: 0.45-0.94) and personal history of CVD and/or diabetes (OR=0.42, 95% CI: 0.30-0.59). When personal history of CVD and/or diabetes was replaced by PROCAM risk categories, patients in the highest risk were also less well controlled. CONCLUSION: In this population-based study, one-third of the participants was dyslipidaemic, but less than half was treated and only one-fifth was adequately controlled. The low treatment and control levels among individuals at high risk for CVD calls for a better application of recommendations regarding personal preventive measures.

Appropriateness of therapy for active Crohn's disease: results of a multidisciplinary international Expert Panel (EPACT II)

INTRODUCTION: The development of novel therapies and the increasing number of trials testing management strategies for luminal Crohn's disease (CD) have not filled all the gaps in our knowledge. Thus, in clinical practice, many decisions for CD patients need to be taken without high quality evidence. For this reason, a multidisciplinary European expert panel followed the RAND method to develop explicit criteria for the management of individual patients with active, steroid-dependent (ST-D) and steroid-refractory (ST-R) CD. AIMS & METHODS: Twelve international experts convened in Geneva, Switzerland in December 2007, to rate explicit clinical scenarios, corresponding to real daily practice, on a 9-point scale according to the literature evidence and their own expertise. Median ratings were stratified into three categories: appropriate (7-9), uncertain (4-6) and inappropriate (1-3). RESULTS: Overall, panelists rated 296 indications pertaining to mild-to-moderate, severe, ST-D, and ST-R CD. In anti-TNF naïve patients, budesonide and prednisone were found appropriate for mild-moderate CD, and infliximab (IFX) when those had previously failed or had not been tolerated. In patients with prior success with IFX, this drug with or without co-administration of a thiopurine analog was favored. Other anti-TNFs were appropriate in case of intolerance or resistance to IFX. High doses steroids, IFX or adalimumab were appropriate in severe active CD. Among 105 indications for ST-D or ST-R disease, the panel considered appropriate the thiopurine analogs, methotrexate, IFX, adalimumab and surgery for limited resection, depending on the outcome of prior therapies. Anti-TNFs were generally considered appropriate in ST-R. CONCLUSION: Steroids, including budesonide for mild-to-moderate CD, remain first-line therapies in active luminal CD. Anti-TNFs, in particular IFX with respect to the amount of available evidence, remain second-line for most indications. Thiopurine analogs are preferred to anti-TNFs when steroids are not appropriate, except when anti-TNFs were previously successful. These recommendations are available online (www.epact.ch). A prospective evaluation of these criteria in a large database in Switzerland in underway to validate these criteria.

Psychiatric Status across Body Mass Index in a Mediterranean Spanish Population.

BACKGROUND Mental and body weight disorders are among the major global health challenges, and their comorbidity may play an important role in treatment and prevention of both pathologies. A growing number of studies have examined the relationship between psychiatric status and body weight, but our knowledge is still limited. OBJECTIVE The present study aims to investigate the cross-sectional relationships of psychiatric status and body mass index (BMI) in Málaga, a Mediterranean city in the South of Spain. MATERIALS AND METHODS A total of 563 participants were recruited from those who came to his primary care physician, using a systematic random sampling, non-proportional stratified by BMI categories. Structured clinical interviews were used to assess current Axes-I and II mental disorders according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). BMI was calculated as weight (Kg) divided by square of height in meters (m2). Logistic regression was used to investigate the association between BMI and the presence of any mental disorder. BMI was introduced in the models using restricted cubic splines. RESULTS We found that high BMI values were directly associated with mood and adjustment disorders, and low BMI values were directly associated with avoidant and dependent personality disorders (PDs). We observed an inverse relationship between low BMI values and cluster A PDs. There were not significant relationships between anxiety or substance-related disorders and BMI. CONCLUSION Psychiatric status and BMI are related in a Mediterranean Spanish population. A multidisciplinary approach to both pathologies becomes increasingly more necessary.

A Lower Olfactory Capacity Is Related to Higher Circulating Concentrations of Endocannabinoid 2-Arachidonoylglycerol and Higher Body Mass Index in Women.

The endocannabinoid (eCB) system can promote food intake by increasing odor detection in mice. The eCB system is over-active in human obesity. Our aim is to measure circulating eCB concentrations and olfactory capacity in a human sample that includes people with obesity and explore the possible interaction between olfaction, obesity and the eCB system. The study sample was made up of 161 females with five groups of body mass index sub-categories ranging from under-weight to morbidly obese. We assessed olfactory capacity with the "Sniffin´Sticks" test, which measures olfactory threshold-discrimination-identification (TDI) capacity. We measured plasma concentrations of the eCBs 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine or anandamide (AEA), and several eCB-related compounds, 2-acylglycerols and N-acylethanolamines. 2-AG and other 2-acylglycerols fasting plasma circulating plasma concentrations were higher in obese and morbidly obese subjects. AEA and other N-acylethanolamine circulating concentrations were lower in under-weight subjects. Olfactory TDI scores were lower in obese and morbidly obese subjects. Lower TDI scores were independently associated with higher 2-AG fasting plasma circulating concentrations, higher %body fat, and higher body mass index, after controlling for age, smoking, menstruation, and use of contraceptives. Our results show that obese subjects have a lower olfactory capacity than non-obese ones and that elevated fasting plasma circulating 2-AG concentrations in obesity are linked to a lower olfactory capacity. In agreement with previous studies we show that eCBs AEA and 2-AG, and their respective congeners have a distinct profile in relation to body mass index. The present report is the first study in humans in which olfactory capacity and circulating eCB concentrations have been measured in the same subjects.

A Nested Case-Control Study of Metabolically Defined Body Size Phenotypes and Risk of Colorectal Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC).

BACKGROUND Obesity is positively associated with colorectal cancer. Recently, body size subtypes categorised by the prevalence of hyperinsulinaemia have been defined, and metabolically healthy overweight/obese individuals (without hyperinsulinaemia) have been suggested to be at lower risk of cardiovascular disease than their metabolically unhealthy (hyperinsulinaemic) overweight/obese counterparts. Whether similarly variable relationships exist for metabolically defined body size phenotypes and colorectal cancer risk is unknown. METHODS AND FINDINGS The association of metabolically defined body size phenotypes with colorectal cancer was investigated in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Metabolic health/body size phenotypes were defined according to hyperinsulinaemia status using serum concentrations of C-peptide, a marker of insulin secretion. A total of 737 incident colorectal cancer cases and 737 matched controls were divided into tertiles based on the distribution of C-peptide concentration amongst the control population, and participants were classified as metabolically healthy if below the first tertile of C-peptide and metabolically unhealthy if above the first tertile. These metabolic health definitions were then combined with body mass index (BMI) measurements to create four metabolic health/body size phenotype categories: (1) metabolically healthy/normal weight (BMI < 25 kg/m2), (2) metabolically healthy/overweight (BMI ≥ 25 kg/m2), (3) metabolically unhealthy/normal weight (BMI < 25 kg/m2), and (4) metabolically unhealthy/overweight (BMI ≥ 25 kg/m2). Additionally, in separate models, waist circumference measurements (using the International Diabetes Federation cut-points [≥80 cm for women and ≥94 cm for men]) were used (instead of BMI) to create the four metabolic health/body size phenotype categories. Statistical tests used in the analysis were all two-sided, and a p-value of <0.05 was considered statistically significant. In multivariable-adjusted conditional logistic regression models with BMI used to define adiposity, compared with metabolically healthy/normal weight individuals, we observed a higher colorectal cancer risk among metabolically unhealthy/normal weight (odds ratio [OR] = 1.59, 95% CI 1.10-2.28) and metabolically unhealthy/overweight (OR = 1.40, 95% CI 1.01-1.94) participants, but not among metabolically healthy/overweight individuals (OR = 0.96, 95% CI 0.65-1.42). Among the overweight individuals, lower colorectal cancer risk was observed for metabolically healthy/overweight individuals compared with metabolically unhealthy/overweight individuals (OR = 0.69, 95% CI 0.49-0.96). These associations were generally consistent when waist circumference was used as the measure of adiposity. To our knowledge, there is no universally accepted clinical definition for using C-peptide level as an indication of hyperinsulinaemia. Therefore, a possible limitation of our analysis was that the classification of individuals as being hyperinsulinaemic-based on their C-peptide level-was arbitrary. However, when we used quartiles or the median of C-peptide, instead of tertiles, as the cut-point of hyperinsulinaemia, a similar pattern of associations was observed. CONCLUSIONS These results support the idea that individuals with the metabolically healthy/overweight phenotype (with normal insulin levels) are at lower colorectal cancer risk than those with hyperinsulinaemia. The combination of anthropometric measures with metabolic parameters, such as C-peptide, may be useful for defining strata of the population at greater risk of colorectal cancer.

Development of a retrospective job exposure matrix for PCB-exposed workers in capacitor manufacturing

Objectives: Polychlorinated biphenyls (PCBs) are considered probable human carcinogens by the International Agency for Research on Cancer and one congener, PCB126, has been rated as a known human carcinogen. A period-specific job exposure matrix (JEM) was developed for former PCB-exposed capacitor manufacturing workers (n=12,605) (1938-1977). Methods: A detailed exposure assessment for this plant was based on a number of exposure determinants (proximity, degree of contact with PCBs, temperature, ventilation, process control, job mobility). The intensity and frequency of PCB exposures by job for both inhalation and dermal exposures, and additional chemical exposures were reviewed. The JEM was developed in nine steps: (1) all unique jobs (n=1,684) were assessed using (2) defined PCB exposure determinants; (3) the exposure determinants were used to develop exposure profiles; (4) similar exposure profiles were combined into categories having similar PCB exposures; (5) qualitative intensity (high-medium-low-baseline) and frequency (continuous-intermittent) ratings were developed, and (6) used to qualitatively rate inhalation and dermal exposure separately for each category; (7) quantitative intensity ratings based on available air concentrations were developed for inhalation and dermal exposures based on equal importance of both routes of exposure; (8) adjustments were made for overall exposure, and (9) for each category the product of intensity and frequency was calculated, and exposure in the earlier era was weighted. Results: A period-specific JEM modified for two eras of stable PCB exposure conditions. Conclusions: These exposure estimates, derived from a systematic and rigorous use of the exposure determinant data, lead to cumulative PCB exposure-response relationships in the epidemiological cancer mortality and incidence studies of this cohort. [Authors]

Mediterranium

Aplicació web en J2EE que permet inserir receptes i consultar-les mitjançant cerques per categories, nacionalitat i/o ingredients. L'aplicació també permet la gestió de favorits i la planificació d'una setmana de menjars.

Portraying innovation in the public service of Brazil: Frameworks, systematization and characterization

ABSTRACT Innovation is essential for improving organizational performance in both the private and public sectors. This article describes and analyzes the 323 innovation experiences of the Brazilian federal public service that received prizes during the 16 annual competitions (from 1995 to 2012) of the Award for Innovation in Federal Public Management held by the Brazilian National School of Public Administration (ENAP). It is a qualitative and quantitative study in which were employed as categories for analysis the four types of innovation defined in the Copenhagen Manual: product, process, organizational and communication. The survey results allow us to affirm that there is innovation in the public sector, in spite of the skepticism of some researchers and the incipient state of theoretical research on the subject. It was possible to observe that organizational innovation was the one with the highest number of award- -winning experience, followed respectively by process, communication and product innovation, with citizen services and improvement of work processes being the main highlights. The results showed that, although the high incidence of innovation occurs at the national level, a significant number of innovations also occur at the local level, probably because many organizations of the federal government have their actions spread only at this level of government. Concerning the innovative area, health and education predominate, with almost 33% of initiatives, which can be explained by capillarity of these areas and the fact that both maintain a strong interaction with the user. The contributions of this work include the use of theoretical model of innovation analysis in the public sector in Brazil still upcoming, and the systematization of knowledge in empirical basis for this innovation. In this sense, it also contributes to the development of the theory with the presentation of evidence that the characteristics, determinants and consequences of innovation in the public sector differ not only from innovation in the industry, but also from innovation in services in the private sector.

Markers of atherosclerosis and of inflammation for prediction of coronary heart disease in older adults

BACKGROUND: Several markers of atherosclerosis and of inflammation have been shown to predict coronary heart disease (CHD) individually. However, the utility of markers of atherosclerosis and of inflammation on prediction of CHD over traditional risk factors has not been well established, especially in the elderly. METHODS: We studied 2202 men and women, aged 70-79, without baseline cardiovascular disease over 6-year follow-up to assess the risk of incident CHD associated with baseline noninvasive measures of atherosclerosis (ankle-arm index [AAI], aortic pulse wave velocity [aPWV]) and inflammatory markers (interleukin-6 [IL-6], C-reactive protein [CRP], tumor necrosis factor-a [TNF-a]). CHD events were studied as either nonfatal myocardial infarction or coronary death ("hard" events), and "hard" events plus hospitalization for angina, or the need for coronary-revascularization procedures (total CHD events). RESULTS: During the 6-year follow-up, 283 participants had CHD events (including 136 "hard" events). IL-6, TNF-a and AAI independently predicted CHD events above Framingham Risk Score (FRS) with hazard ratios [HR] for the highest as compared with the lowest quartile for IL-6 of 1.95 (95%CI: 1.38-2.75, p for trend<0.001), TNF-a of 1.45 (95%CI: 1.04-2.02, p for trend 0.03), of 1.66 (95%CI: 1.19-2.31) for AAI £0.9, as compared to AAI 1.01-1.30. CRP and aPWV were not independently associated with CHD events. Results were similar for "hard" CHD events. Addition of IL-6 and AAI to traditional cardiovascular risk factors yielded the greatest improvement in the prediction of CHD; C-index for "hard"/total CHD events increased from 0.62/0.62 for traditional risk factors to 0.64/0.64 for IL-6 addition, 0.65/0.63 for AAI, and 0.66/0.64 for IL-6 combined with AAI. Being in the highest quartile of IL-6 combined with an AAI £ 0.90 or >1.40 yielded an HR of 2.51 (1.50-4.19) and 4.55 (1.65-12.50) above FRS, respectively. With use of CHD risk categories, risk prediction at 5 years was more accurate in models that included IL-6, AAI or both, with 8.0, 8.3 and 12.1% correctly reclassified respectively. CONCLUSIONS: Among older adults, markers of atherosclerosis and of inflammation, particularly IL-6 and AAI, are independently associated with CHD. However, these markers only modestly improve cardiovascular risk prediction beyond traditional risk factors. Acknowledgments: This study was supported by Contracts NO1-AG-6-2101, NO1-AG-6- 2103, and NO1-AG-6-2106 of the National Institute on Aging. This research was supported in part by the Intramural Research Program of the NIH, National Institute on Aging.

Activity assessment of eosinophilic esophagitis.

The activity of eosinophilic esophagitis (EoE) can be assessed with patient-reported outcomes and biologic measures. Patient-reported outcomes include symptoms and quality of life, whereas biologic measures refer to endoscopic, histologic, and biochemical activity (e.g. blood biomarkers). So far, a validated tool to assess EoE activity in the above-mentioned dimensions is lacking. Given the lack of a standardized way to assess EoE activity in the various dimensions, the results of different clinical trials may be difficult to compare. For symptom assessment in adult patients, the symptom 'dysphagia' should be evaluated according to different standardized food consistencies. Furthermore, symptom assessment should take into account the following items: avoidance of specific food categories, food modification, and time to eat a regular meal. A distinct symptom recall period (e.g. 2 weeks) has to be defined for symptom assessment. Performing an 'esophageal stress test' with ingestion of a standardized meal to measure symptom severity bears the potential risk of acute food bolus impaction and should therefore be avoided. The description of endoscopic findings in EoE has meanwhile been standardized. Histologic evaluation of EoE activity should report either the size of the high-power field used or count the eosinophils per mm(2). There is a current lack of blood biomarkers demonstrating a good correlation with histologic activity in esophageal biopsies. The development and validation of an adult and pediatric EoE activity index is urgently needed not only for clinical trials and observational studies, but also for daily practice.

Appropriate therapy for fistulizing and fibrostenotic Crohn's disease: results of a multidisciplinary international expert panel (EPACT II)

Introduction Many therapeutic decisions in the management of fistulizing and fibrostenotic Crohn's disease (CD) have to be taken without the benefit of strong scientific evidence. For this reason, explicit appropriateness criteria for CD fistula and stenosis treatment were developed by a multidisciplinary European expert panel in 2004 with the aim of making them easily available on the Internet and thus allowing individual case scenario evaluation; these criteria were updated in 2007. Methods Twelve international experts convened in Geneva, Switzerland in December 2007. Explicit clinical scenarios, corresponding to real daily practice, were rated on a 9-point scale based on evidence from the published literature and panelists' own expertise. Median ratings were stratified into three categories: appropriate (7-9), uncertain (4-6) and inappropriate (1-3). Results Overall, panelists rated 60 indications pertaining to fistulas. Antibiotics, azathioprine/6-mercaptopurine and conservative surgery are the mainstay of therapy for simple and complex fistulas. In the event of previous failure of azathioprine/6-mercaptopurine therapy, methotrexate and infliximab were considered appropriate for complex fistulas. The panel also rated 72 indications related to the management of fibrostenotic CD. The experts considered balloon dilation, if the stricture was endoscopically accessible, stricturoplasty and bowel resection to be appropriate for small bowel fibrostenotic Crohn's disease, and balloon dilation and bowel resection appropriate for fibrostenotic colonic disease. In the presence of an ileocolonic or ileorectal anastomotic stricture of <7 cm, endoscopic balloon dilation, and bowel resection were considered appropriate. Conclusion Antibiotics, azathioprine/6-mercaptopurine, and conservative surgery are the mainstay of therapy for fistulizing Crohn's disease. Infliximab is a therapeutic option in patients without prior response to immunosuppressant therapy. In fibrostenotic Crohn's disease, endoscopic balloon dilation, if feasible, or surgical therapy should be considered. These expert recommendations are available online (www.epact.ch). Prospective evaluation is now needed to test the validity of these appropriateness criteria in clinical practice.

A model for physical activity, bahaviour and energy expenditure assessment in real-life condition

RésuméL'origine de l'obésité, qui atteint des proportions épidémiques, est complexe. Elle est liée au mode de vie et au comportement des individus par rapport à l'activité physique, expression des choix individuels et de l'interaction avec l'environnement. Les mesures du comportement au niveau de l'activité physique des individus face à leur environnement, la répartition des types d'activité physique, la durée, la fréquence, l'intensité, et la dépense énergétique sont d'une grande importance. Aujourd'hui, il y a un manque de méthodes permettant une évaluation précise et objective de l'activité physique et du comportement des individus. Afin de compléter les recherches relatives à l'activité physique, à l'obésité et à certaines maladies, le premier objectif du travail de thèse était de développer un modèle pour l'identification objective des types d'activité physique dans des conditions de vie réelles et l'estimation de la dépense énergétique basée sur une combinaison de 2 accéléromètres et 1 GPS. Le modèle prend en compte qu'une activité donnée peut être accomplie de différentes façons dans la vie réelle. Les activités quotidiennes ont pu être classées en 8 catégories, de sédentaires à actives, avec une précision de 1 min. La dépense énergétique a pu peut être prédite avec précision par le modèle. Après validation du modèle, le comportement des individus de l'activité physique a été évalué dans une seconde étude. Nous avons émis l'hypothèse que, dans un environnement caractérisé par les pentes, les personnes obèses sont tentées d'éviter les pentes raides et de diminuer la vitesse de marche au cours d'une activité physique spontanée, ainsi que pendant les exercices prescrits et structurés. Nous avons donc caractérisé, par moyen du modèle développé, le comportement des individus obèses dans un environnement vallonné urbain. La façon dont on aborde un environnement valloné dans les déplacements quotidiens devrait également être considérée lors de la prescription de marche supplémentaire afin d'augmenter l'activité physique.SummaryOrigin of obesity, that reached epidemic proportion, is complex and may be linked to different lifestyle and physical activity behaviour. Measurement of physical activity behaviour of individuals towards their environment, the distribution of physical activity in terms of physical activity type, volume, duration, frequency, intensity, and energy expenditure is of great importance. Nowadays, there is a lack of methods for accurate and objective assessment of physical activity and of individuals' physical activity behaviour. In order to complement the research relating physical activity to obesity and related diseases, the first aim of the thesis work was to develop a model for objective identification of physical activity types in real-life condition and energy expenditure based on a combination of 2 accelerometers and 1 GPS device. The model takes into account that a given activity can be achieved in many different ways in real life condition. Daily activities could be classified in 8 categories, as sedentary to active physical activity, within 1 min accuracy, and physical activity patterns determined. The energy expenditure could be predicted accurately with an accuracy below 10%. Furthermore, individuals' physical activity behaviour is expression of individual choices and their interaction with the neighbourhood environment. In a second study, we hypothesized that, in an environment characterized by inclines, obese individuals are tempted to avoid steep positive slopes and to decrease walking speed during spontaneous outdoor physical activity, as well as during prescribed structured bouts of exercise. Finally, we characterized, by mean of the developed model, the physical activity behaviour of obese individuals in a hilly urban environment. Quantifying how one tackles hilly environment or avoids slope in their everyday displacements should be also considered while prescribing extra walking in free-living conditions in order to increase physical activity.