Longitudinal and cross-sectional changes in active commuting to school among Brazilian schoolchildren.

OBJECTIVE: The objective of the study is to evaluate cross-sectional and longitudinal changes in children's commuting to school in a representative sample of a Brazilian city. METHODS: Two school-based studies were carried out in 2002 (n=2936; 7-10years old) and 2007 (n=1232; 7-15years old) in Florianopolis, Brazil. Cross-sectional data were collected from children aged 7 to 10years in 2002 and 2007. Longitudinal analyses were performed with data from 733 children participating in both surveys. Children self-reported their mode of transportation to school using a validated illustrated questionnaire. Changes were tested with chi square statistics and McNemar's test. RESULTS: Cross-sectional data showed a 17% decline in active commuting; a decrease from 49% in 2002 to 41% in 2007. On the other hand, active commuting among the 733 children increased as they entered adolescence 5years later, rising from 40% to 49%. CONCLUSION: Active commuting to school decreased in Brazilian children aged 7-10years over a five year period; whereas, it increased among children entering adolescence. Policies should focus on safety and environmental determinants to increase active commuting.

Cumulative risk factors for adolescent alcohol misuse and its perceived consequences among 16 to 20 year old adolescents in Switzerland.

AIMS: To assess the cumulative impact of environmental and individual factors associated with adolescent alcohol misuse and their correlation with self-reported consequences of drinking. METHOD: Cross-sectional school-based survey of a nationally representative sample of 7548 post-mandatory school students and apprentices aged 16-20 years, Switzerland 2002. Alcohol misuse defined by frequency of alcohol use, episodes of drunkenness and driving while drunk. RESULTS: Fifteen significant risk factors were identified among both boys, and girls. An individual score of cumulated risk factors was created by adding the risk factors. The association between the score and the likelihood of being engaged in alcohol misuse was highly significant and dose-dependent (p<.001). A significant proportion of adolescents report perceived adverse consequences of their alcohol consumption. A linear trend (p<.001) was found between the score of risk factors and the proportion of respondents reporting problems related to drinking such as diminished school performance, physical hazard, relational problems and current risky sexual behavior. CONCLUSION: Risk factors for adolescent alcohol misuse are cumulative and can be synthesized into an individual score correlated with the likeliness of misuse. A further indication of the validity of this score is its linear relationship with self-reported problems related to drinking.

Chronic illness, life style and emotional health in adolescence: results of a cross-sectional survey on the health of 15-20-year-olds in Switzerland.

The objective was to evaluate the prevalence of chronic conditions (CC) in adolescents in Switzerland; to describe their behaviour (leisure, sexuality, risk taking behaviour) and to compare them to those in adolescents who do not have CC in order to evaluate the impact of those conditions on their well-being. The data were obtained from the Swiss Multicentre Adolescent Survey on Health, targeting a sample of 9268 in-school adolescents aged 15 to 20 years, who answered a self-administered questionnaire. Some 11.4% of girls and 9.6% of boys declared themselves carriers of a CC. Of girls suffering from a CC, 25% (versus 13% of non carriers; P=0.007) and 38% of boys (versus 25%; P=0.002) proclaimed not to wear a seatbelt whilst driving. Of CC girls, 6.3% (versus 2.7%; P=0.000) reported within the last 12 months to have driven whilst drunk. Of the girls, 43% (versus 36%; P=0.004) and 47% (versus 39%; P=0.001) were cigarette smokers. Over 32% of boys (versus 27%; P=0.02) reported having ever used cannabis and 17% of girls (versus 13%; P=0.013) and 43% of boys (versus 36%; P=0.002) admitted drinking alcohol. The burden of their illness had important psychological consequences: 7.7% of girls (versus 3.4%; P=0.000) and 4.9% of boys (versus 2.0%; P=0.000) had attempted suicide during the previous 12 months. CONCLUSION: experimental behaviours are not rarer in adolescents with a chronic condition and might be explained by a need to test their limits both in terms of consumption and behaviour. Prevention and specific attention from the health caring team is necessary.

Secular trends in legal and illegal substance use among 16 to 20 year old adolescents in Switzerland.

BACKGROUND: Data targeting trends in legal and illegal substance use by adolescents are scarce. Using the data from two similar large national surveys run in 1993 and 2002, this paper assesses secular trends in rates of substance use among 16-20-year-old Swiss adolescents. METHODS: Self-reported regular use of tobacco, alcohol misuse, regular cannabis use (01 occasion over last 30 days) and lifetime use of psychoactive medication, LSD, ecstasy, cocaine and heroine were assessed through identical questions using an anonymous self-administered questionnaire. 9268 (1993) and 7428 (2002) high school students and apprentices were included in the analyses. RESULTS: There is a higher proportion of regular smokers among apprentices than among students (p <0.001). Between 1993 and 2002 the increase in regular tobacco consumption was significant among both female and male apprentices (p <0.001) but not among students. Between 1993 and 2002 alcohol misuse significantly increased in all four groups (p <0.001). It is more prevalent among males than among females (p <0.001) and higher among apprentices than among students (p <0.001). Regular use of cannabis has increased in the four groups (p <0.0001). It is higher among males than among females (p <0.001), while it is largely the same among students and apprentices. While the increase in ecstasy use is highly significant in all four groups (p <0.001), the increase in LSD and cocaine use is significant among apprentices only (p <0.001). Use of LSD, ecstasy and cocaine is more prevalent among males than among females (<0.001) and higher among apprentices than among students (p <0.001). CONCLUSION: The secular increase in psychoactive substance use among older Swiss adolescents calls for the implementation of effective strategies both from individual and public health viewpoints.

A quasi-randomized group trial of a brief alcohol intervention on risky single occasion drinking among secondary school students.

OBJECTIVES: To show the effectiveness of a brief group alcohol intervention. Aims of the intervention were to reduce the frequency of heavy drinking occasions, maximum number of drinks on an occasion and overall weekly consumption. METHODS: A cluster quasi-randomized control trial (intervention n = 338; control n = 330) among 16- to 18-year-old secondary school students in the Swiss Canton of Zürich. Groups homogeneous for heavy drinking occasions (5+/4+ drinks for men/women) consisted of those having medium risk (3-4) or high risk (5+) occasions in the past 30 days. Groups of 8-10 individuals received two 45-min sessions based on motivational interviewing techniques. RESULTS: Borderline significant beneficial effects (p < 0.10) on heavy drinking occasions and alcohol volume were found 6 months later for the medium-risk group only, but not for the high-risk group. None of the effects remained significant after Bonferroni corrections. CONCLUSIONS: Group intervention was ineffective for all at-risk users. The heaviest drinkers may need more intensive treatment. Alternative explanations were iatrogenic effects among the heaviest drinkers, assessment reactivity, or reduction of social desirability bias at follow-up through peer feedback.

Activation and inhibition of bimanual movements in school-aged children

The development of motor activation and inhibition was compared in 6-to-12 year-olds. Children had to initiate or stop the externally paced movements of one hand, while maintaining that of the other hand. The time needed to perform the switching task (RT) and the spatio-temporal variables show different agerelated evolutions depending on the coordination pattern (inor anti-phase) and the type of transition (activation, selective inhibition, non selective inhibition) required. In the anti-phase mode, activation perturbs the younger subjects' responses while temporal and spatial stabilities transiently decrease around 9 years when activating in the in-phase mode. Aged-related changes differed between inhibition and activation in the antiphase mode, suggesting either the involvement of distinct neural networks or the existence of a single network that is reorganized. In contrast, stopping or adding one hand in the in-phase mode shows similar aged-related improvement. We suggest that selectively stopping or activating one arm during symmetrical coordination rely on the two faces of a common processing in which activation could be the release of inhibition

Separating mismatch negativity (MMN) response from auditory obligatory brain responses in school-aged children.

Mismatch negativity (MMN) overlaps with other auditory event-related potential (ERP) components. We examined the ERPs of 50 9- to 11-year-old children for vowels /i/, /y/ and equivalent complex tones. The goal was to separate MMN from obligatory ERP components using principal component analysis and equal probability control condition. In addition to the contrast of the deviant minus standard response, we employed the contrast of the deviant minus control response, to see whether the obligatory processing contributes to MMN in children. When looking for differences in speech deviant minus standard contrast, MMN starts around 112 ms. However, when both contrasts are examined, MMN emerges for speech at 160 ms whereas for nonspeech MMN is observed at 112 ms regardless of contrast. We argue that this discriminative response to speech stimuli at 112 ms is obligatory in nature rather than reflecting change detection processing.

Effects of a school-based physical activity program on physical and psychosocial quality of life in elementary school children: a cluster-randomized trial.

The present study tested the effect of a school-based physical activity (PA) program on quality of life (QoL) in 540 elementary school children. First and fifth graders were randomly assigned to a PA program or a no-PA control condition during one academic year. QoL was assessed by the Child Health Questionnaire at baseline and postintervention. Based on mixed linear model analyses, physical QoL in first graders and physical and psychosocial QoL in fifth graders were not affected by the intervention. In first graders, the PA intervention had a positive impact on psychosocial QoL (effect size [d], 0.32; p < .05). Subpopulation analyses revealed that this effect was caused by an effect in urban (effect size [d], 0.38; p < .05) and overweight first graders (effect size [d], 0.45; p < .05). In conclusion, a school-based PA intervention had little effect on QoL in elementary school children.

Basic life support teaching in the second year predraduate medical curriculum: quality of acquisition after 6 months

Purpose of the study: Basic life support (BLS) and automated externaldefibrillation (AED) represent important skills to be acquired duringpregraduate medical training. Since 3 years, our medical school hasintroduced a BLS-AED course (with certification) for all second yearmedical students. Few reports about quality and persistence over timeof BLS-AED learning are available to date in the medical literature.Comprehensive evaluation of students' acquired skills was performedat the end of the 2008 academic year, 6 month after certification.Materials and methods: The students (N = 142) were evaluated duringa 9 minutes «objective structured clinical examination» (OSCE) station.Out of a standardized scenario, they had to recognize a cardiac arrestsituation and start a resuscitation process. Their performance wererecorded on a PC using an Ambuman(TM) mannequin and the AmbuCPR software kit(TM) during a minimum of 8 cycles (30 compressions:2 ventilations each). BLS parameters were systematically checked. Nostudent-rater interactions were allowed during the whole evaluation.Results: Response of the victim was checked by 99% of the students(N = 140), 96% (N = 136) called for an ambulance and/or an AED. Openthe airway and check breathing were done by 96% (N = 137), 92% (N =132) gave 2 rescue breaths. Pulse was checked by 95% (N=135), 100%(N = 142) begun chest compression, 96% (N = 136) within 1 minute.Chest compression rate was 101 ± 18 per minute (mean ± SD), depthcompression 43 ± 8 mm, 97% (N = 138) respected a compressionventilationratio of 30:2.Conclusions: Quality of BLS skills acquisition is maintained during a6-month period after a BLS-AED certification. Main targets of 2005 AHAguidelines were well respected. This analysis represents one of thelargest evaluations of specific BLS teaching efficiency reported. Furtherfollow-up is needed to control the persistence of these skills during alonger time period and noteworthy at the end of the pregraduatemedical curriculum.

Birth weight, weight change, and blood pressure during childhood and adolescence: a school-based multiple cohort study.

OBJECTIVE: We assessed the association between birth weight, weight change, and current blood pressure (BP) across the entire age-span of childhood and adolescence in large school-based cohorts in the Seychelles, an island state in the African region. METHODS: Three cohorts were analyzed: 1004 children examined at age 5.5 and 9.1 years, 1886 children at 9.1 and 12.5, and 1575 children at 12.5 and 15.5, respectively. Birth and 1-year anthropometric data were gathered from medical files. The outcome was BP at age 5.5, 9.1, 12.5 or 15.5 years, respectively. Conditional linear regression analysis was used to estimate the relative contribution of changes in weight (expressed in z-score) during different age periods on BP. All analyses were adjusted for height. RESULTS: At all ages, current BP was strongly associated with current weight. Birth weight was not significantly associated with current BP. Upon adjustment for current weight, the association between birth weight and current BP tended to become negative. Conditional linear regression analyses indicated that changes in weight during successive age periods since birth contributed substantially to current BP at all ages. The strength of the association between weight change and current BP increased throughout successive age periods. CONCLUSION: Weight changes during any age period since birth have substantial impact on BP during childhood and adolescence, with BP being more responsive to recent than earlier weight changes.

Structural Brain Connectivity in School-Age Preterm Infants Provides Evidence for Impaired Networks Relevant for Higher Order Cognitive Skills and Social Cognition.

Extreme prematurity and pregnancy conditions leading to intrauterine growth restriction (IUGR) affect thousands of newborns every year and increase their risk for poor higher order cognitive and social skills at school age. However, little is known about the brain structural basis of these disabilities. To compare the structural integrity of neural circuits between prematurely born controls and children born extreme preterm (EP) or with IUGR at school age, long-ranging and short-ranging connections were noninvasively mapped across cortical hemispheres by connection matrices derived from diffusion tensor tractography. Brain connectivity was modeled along fiber bundles connecting 83 brain regions by a weighted characterization of structural connectivity (SC). EP and IUGR subjects, when compared with controls, had decreased fractional anisotropy-weighted SC (FAw-SC) of cortico-basal ganglia-thalamo-cortical loop connections while cortico-cortical association connections showed both decreased and increased FAw-SC. FAw-SC strength of these connections was associated with poorer socio-cognitive performance in both EP and IUGR children.