Role of disease activity for decision making ability in early multiple sclerosis

Background and purpose: Decision making (DM) has been defined as the process through which a person forms preferences, selects and executes actions, and evaluates the outcome related to a selected choice. This ability represents an important factor for adequate behaviour in everyday life. DM impairment in multiple sclerosis (MS) has been previously reported. The purpose of the present study was to assess DM in patients with MS at the earliest clinically detectable time point of the disease. Methods: Patients with definite (n=109) or possible (clinically isolated syndrome, CIS; n=56) MS, a short disease duration (mean 2.3 years) and a minor neurological disability (mean EDSS 1.8) were compared to 50 healthy controls aged 18 to 60 years (mean age 32.2) using the Iowa Gambling Task (IGT). Subjects had to select a card from any of 4 decks (A/B [disadvantageous]; C/D [advantageous]). The game consisted of 100 trials then grouped in blocks of 20 cards for data analysis. Skill in DM was assessed by means of a learning index (LI) defined as the difference between the averaged last three block indexes and first two block indexes (LI=[(BI-3+BI-4+BI-5)/3-(BI-1+B2)/2]). Non parametric tests were used for statistical analysis. Results: LI was higher in the control group (0.24, SD 0.44) than in the MS group (0.21, SD 0.38), however without reaching statistical significance (p=0.7). Interesting differences were detected when MS patients were grouped according to phenotype. A trend to a difference between MS subgroups and controls was observed for LI (p=0.06), which became significant between MS subgroups (p=0.03). CIS patients who confirmed MS diagnosis by presenting a second relapse after study entry showed a dysfunction in the IGT in comparison to the other CIS (p=0.01) and definite MS (p=0.04) patients. In the opposite, CIS patients characterised by not entirely fulfilled McDonald criteria at inclusion and absence of relapse during the study showed an normal learning pattern on the IGT. Finally, comparing MS patients who developed relapses after study entry, those who remained clinically stable and controls, we observed impaired performances only in relapsing patients in comparison to stable patients (p=0.008) and controls (p=0.03). Discussion: These results raise the assumption of a sustained role for both MS relapsing activity and disease heterogeneity (i.e. infra-clinical severity or activity of MS) in the impaired process of decision making.

Multiple-scale hydrological and geophysical data integration through non-linear Bayesian sequential simulation

Significant progress has been made with regard to the quantitative integration of geophysical and hydrological data at the local scale. However, extending the corresponding approaches to the scale of a field site represents a major, and as-of-yet largely unresolved, challenge. To address this problem, we have developed downscaling procedure based on a non-linear Bayesian sequential simulation approach. The main objective of this algorithm is to estimate the value of the sparsely sampled hydraulic conductivity at non-sampled locations based on its relation to the electrical conductivity logged at collocated wells and surface resistivity measurements, which are available throughout the studied site. The in situ relationship between the hydraulic and electrical conductivities is described through a non-parametric multivariatekernel density function. Then a stochastic integration of low-resolution, large-scale electrical resistivity tomography (ERT) data in combination with high-resolution, local-scale downhole measurements of the hydraulic and electrical conductivities is applied. The overall viability of this downscaling approach is tested and validated by comparing flow and transport simulation through the original and the upscaled hydraulic conductivity fields. Our results indicate that the proposed procedure allows obtaining remarkably faithful estimates of the regional-scale hydraulic conductivity structure and correspondingly reliable predictions of the transport characteristics over relatively long distances.

HIV behavioural surveillance in Switzerland: trends in drug consumption, injection and syringe distribution, 1993-2011

Background: As part of the second generation surveillance system for HIV/Aids in Switzerland, repeated cross-sectional surveys were conducted in 1993, 1994, 1996, 2000, 2006 and 2011 among attenders of all low threshold facilities (LTFs) with needle exchange programmes and/or supervised drug consumption rooms for injection or inhalation. The number of syringes distributed to the injectors has also been measured annually since 2000. Distribution in other settings, such as pharmacies, is also monitored nationally. Methods: Periodic surveys of LTFs have been conducted using an interviewer/self-administered questionnaire structured along four themes: socio-demographic characteristics, drug consumption, risk/preventive behaviour and health. Analysis is restricted to attenders who had injected drugs during their lifetime (IDU´s). Pearson's chi-square test and trend analysis were conducted on annual aggregated data. Trend significance was assessed using Stata's non parametric test nptrend. Results: Median age of IDU´s increased from 26 years in 1993 to 40 in 2011; most are men (78%). Total yearly number of syringes distributed by LTFs has decreased by 44% in 10 years. Use of cocaine has increased (Table 1). Injection, regular use of heroin and borrowing of syringes/needles have decreased, while sharing of other material remains stable. There are fewer new injectors; more IDU´s report substitution treatment. Most attenders had ever been tested for HIV (90% in 1993, 94% in 2011). Reported prevalence of HIV remained stable around 10%; that of HCV decreased from 62% in 2000 to 42% in 2011. Conclusions: Overall, findings indicate a decrease in injection as a means of drug consumption in that population. This interpretation is supported by data from other sources, such as a national decrease in distribution from other delivery points. Switzerland's behavioural surveillance system is sustainable and allows the HIV epidemic to be monitored among this hard-to-reach population, providing information for planning and evaluation.

Video-assisted right supradiaphragmatic thoracic duct ligation for non traumatic recurrent chylothorax

Introduction : Un chylothorax est une pathologie comprenant des manifestations respiratoires, nutritionnelles et immunologiques. La récidive du chylothorax ou l'échec du traitement conservateur imposent un traitement chirurgical. Ce travail rapporte notre expérience de ligature supra-diaphragmatique, vidéo-assistée du canal thoracique, pour chylothorax récurrent non traumatique. Patients et méthodes : Entre 1999 et 2004, nous avons recensé six observations (quatre du côté droit, un du côté gauche et un bilateral) Le chylothorax s'est développé chez trois patients traités par radio et chimiothérapie pour tumeur (deux lymphomes et une tumeur du sein) un dans le contexte d'une lymphangioléiomatose et un après greffe cardiaque. Résultats : Les patients ont bénéficié sous anesthésie générale, d'une ligature du canal thoracique supra-diaphragmatique, vidéo-assistée. Le temps opératoire moyen a été de 102 minutes. Le chylothorax a régressé chez cinq des six patients en sept jours. Un patient a été repris par thoracotomie droite au huitième jour pour chylothorax persistant. Dans la phase post-opératoire, un patient a développé une détresse respiratoire nécessitant une ventilation mécanique. Un autre patient a présenté un chylopéritoine important traité par un stent de Le Veen®. Le séjour moyen a été de quatorze jours sans mortalité péri-opératoire. Conclusion : Le traitement du chylothorax non traumatique récurrent est, en première intention, un traitement médical. En cas de récidive ou d'échec du traitement conservateur, le traitement chirurgical par ligature du canal thoracique supra- diaphragmatique, vidéo-assistée, permet de traiter avec succès le chylothorax récurrent non traumatique. -- Background: Chylothorax is an uncommon disorder with respiratory, nutritional and immunological manifestations. Surgical management is indicated in case of recurrence or failure after conservative treatment. We report our experience with video-assisted right-sided supradiaphrag¬matic thoracic duct ligation for non-traumatic, non-postoperative persistent or recurrent chylothorax. Patients and methods: The medical records of six patients operated at our institution between 1999 and 2004 were retrospectively reviewed. A right-sided chylothorax was found in four patients, a left-sided in one, and a bilateral in one. Three patients developed chylothorax after chemotherapy and chest irradiation for malignant diseases (lymphoma in two patients and breast cancer in one), one in the context of lymphangioleiomyomatosis, one due to a non-diagnosed lymphoma, and one after heart transplantation. Results: The mean operative time was 102 min, with an average length of hospital stay of 14 days. Persistent cessation of chylous effusion within 7 days after surgery was observed in 5/6 patients without recurrence during a mean follow-up time of 41 months. One patient with undiagnosed mediastinal lymphoma required re-operation and thoracic duct ligation on day 8 by right-sided thoracotomy due to persistent chylothorax. No 30-day mortality was recorded. Two patients presented postoperative complications including respiratory insufficiency requiring mechanical ventilation in one, and chylous ascites development requiring peritoneo-venous LeVeen shunting in one patient. Conclusions: Recurrent or persistent non-traumatic chylothorax may be successfully treated by video-assisted right supradiaphragmatic thoracic duct ligation.

Frequency and chronology of extraintestinal manifestations in the Swiss Inflammatory Bowel Disease Cohort

Background: Data on the frequency of extraintestinal manifestations (EIM) in inflammatory bowel disease (IBD) is scarce, especially the one evaluating the time of occurrence of the EIM relative to IBD diagnosis. Aim: To assess the type and frequency of EIM in IBD patients and to evaluate when EIMs occur relative to IBD diagnosis. Methods: Analysis of data from the Swiss Inflammatory Bowel Disease Cohort (SIBDCS) which collects data on a large sample of IBD patients from hospitals and private practices across Switzerland starting in 2005. While parametric data are shown as mean ± SD, non-parametric data are presented as median and interquartile range (IQR). Results: A total of 1143 patients were analyzed (572 (50%) female, mean age 42.1 ± 14.4 years): 629 (55%) with Crohn's disease (CD), 501 (44%) with ulcerative colitis (UC), and 13 (1%) with indeterminate colitis (IC). Of 1143 patients, 374 (32.7%) presented with EIM (65% with CD, 33% with UC, 2% with IC). Of those patients suffering from EIMs, 37.4% presented with one, 41.7% with two, 12.4% with three, 5.3% with four, and 3.2% with five EIM during their lifetime. The IBD patients initially presented with the following EIMs: peripheral arthritis (PA) 63.4%, ankylosing spondylitis (AS) 8.1%, primary sclerosing cholangitis (PSC) 6.0%, uveitis 5.7%, oral aphthosis 5.7%, erythema nodosum (EN) 5.0%, pyoderma gangrenosum 1.8%, psoriasis 0.7%. While 92.9% of EIM occurred once IBD diagnosis was established (median 72 months, IQR 9-147 months, p < 0.001), 7.1% of EIMs preceded IBD diagnosis (median time 28 months before IBD diagnosis, IQR 7-60 months). Over a course of a lifetime, IBD patients presented with the following EIM (total exceeds 100 due to potential presence of multiple EIM): peripheral arthritis 69.3%, oral aphthosis 23%, ankylosing spondylitis 19.4%, uveitis 15.5%, erythema nodosum 14.5%, PSC 7.8%, pyoderma gangrenosum 6%, psoriasis 2.8%. Conclusion: EIMs frequently occur in a lifetime of IBD patients. The vast majority of patients present with EIMs once IBD diagnosis has been established. IBD patients most often present with peripheral arthritis, ankylosing spondylitis and PSC as their first EIM. However, peripheral arthritis, oral aphthosis, and ankylosing spondylitis are the most common EIMs in a lifetime of IBD patients.

Prevalence of cognitive disorders in HIV plus patients with long-term suppression of viremia

Background: HAART has contributed to decrease the HIV-related mortality and morbidity. However, the prevalence of HIV-associated neurocognitive disorders (HAND) seems to have increased. The aim of this study was to determine the prevalence of cognitive complaint and of HAND in a cohort of aviremic HIV_patients in the South-western part of Switzerland. Design/Methods: Two hundred HIV_ patients who had (1) undetectable HIV RNA concentrations in the plasma for_3 months, (2) no history of major opportunistic infection of the CNS in the past three years, (3) no current use of IV drugs and (4) no signs of major depression according to the DSM-IV criteria, answered a questionnaire designed to elicit cognitive complaints. Cognitive functions of a subset of HIV_ patients with or without cognitive complaints were assessed using the HIV Dementia scale (HDS) and a battery of neuropsychological tests evaluating the sub-cortical functions. Cognitive impairment was defined according to the revised diagnostic criteria for HAND. Non-parametric tests were used for statistics and a Bonferroni corrected standard p level of pB0.002 was applied for multiple comparisons. Results: The prevalence of cognitive complaints was 27% (54 patients) among the 200 questioned patients. At the time of writing this abstract, cognitive functions of 50 complaining and 28 noncomplaining aviremic patients had been assessed with the HDS and the full neuropsychological battery. The prevalence of HAND producing at least mild interference in daily functioning (mild neurocognitive disorders [MND] or HIV-associated dementia [HAD]) was 44% (34/78 patients) in the group who underwent neuropsychological testing. Objective evidences of HAND were more frequent in complaining than in non-complaining patients (pB0.001). Using a ROC curve, a cut-off of 13 on the HDS was found to have a sensitivity of 74% and a specificity of 71% (p_0.001) for the diagnosis of HAND. A trend for lower CNS Penetrating-Effectiveness scores for HAART in patients with MND or HAD as compared to the others was present (1.59 0.6 vs. 1.990.6; p_0.006 [Bonferroni correction]). Conclusions/Relevance: So far, our results suggest that (1) the prevalence of HAND is high in HIV_ patients with a long-term suppression of viremia, and (2) cognitive complaints expressed by aviremic HIV_ patients should be carefully investigated as they correlate with objective evidences of cognitive decline in a neuropsychological testing. HAART with a high CNS penetrating-effectiveness may contribute to prevent HAND. Funding: Swiss HIV Cohort Study.

Characterization of gait in female patients with moderate to severe hallux valgus deformity.

BACKGROUND: Hallux valgus is one of the most common forefoot problems in females. Studies have looked at gait alterations due to hallux valgus deformity, assessing temporal, kinematic or plantar pressure parameters individually. The present study, however, aims to assess all listed parameters at once and to isolate the most clinically relevant gait parameters for moderate to severe hallux valgus deformity with the intent of improving post-operative patient prognosis and rehabilitation. METHODS: The study included 26 feet with moderate to severe hallux valgus deformity and 30 feet with no sign of hallux valgus in female participants. Initially, weight bearing radiographs and foot and ankle clinical scores were assessed. Gait assessment was then performed utilizing pressure insoles (PEDAR®) and inertial sensors (Physilog®) and the two groups were compared using a non-parametric statistical hypothesis test (Wilcoxon rank sum, P<0.05). Furthermore, forward stepwise regression was used to reduce the number of gait parameters to the most clinically relevant and correlation of these parameters was assessed with the clinical score. FINDINGS: Overall, the results showed clear deterioration in several gait parameters in the hallux valgus group compared to controls and 9 gait parameters (effect size between 1.03 and 1.76) were successfully isolated to best describe the altered gait in hallux valgus deformity (r(2)=0.71) as well as showed good correlation with clinical scores. INTERPRETATION: Our results, and nine listed parameters, could serve as benchmark for characterization of hallux valgus and objective evaluation of treatment efficacy.

Benchmarking therapeutic drug monitoring software: A review of available computer tools

Therapeutic drug monitoring (TDM) aims to optimize treatments by individualizing dosage regimens based on the measurement of blood concentrations. Dosage individualization to maintain concentrations within a target range requires pharmacokinetic and clinical capabilities. Bayesian calculations currently represent the gold standard TDM approach but require computation assistance. In recent decades computer programs have been developed to assist clinicians in this assignment. The aim of this survey was to assess and compare computer tools designed to support TDM clinical activities. The literature and the Internet were searched to identify software. All programs were tested on personal computers. Each program was scored against a standardized grid covering pharmacokinetic relevance, user friendliness, computing aspects, interfacing and storage. A weighting factor was applied to each criterion of the grid to account for its relative importance. To assess the robustness of the software, six representative clinical vignettes were processed through each of them. Altogether, 12 software tools were identified, tested and ranked, representing a comprehensive review of the available software. Numbers of drugs handled by the software vary widely (from two to 180), and eight programs offer users the possibility of adding new drug models based on population pharmacokinetic analyses. Bayesian computation to predict dosage adaptation from blood concentration (a posteriori adjustment) is performed by ten tools, while nine are also able to propose a priori dosage regimens, based only on individual patient covariates such as age, sex and bodyweight. Among those applying Bayesian calculation, MM-USC*PACK© uses the non-parametric approach. The top two programs emerging from this benchmark were MwPharm© and TCIWorks. Most other programs evaluated had good potential while being less sophisticated or less user friendly. Programs vary in complexity and might not fit all healthcare settings. Each software tool must therefore be regarded with respect to the individual needs of hospitals or clinicians. Programs should be easy and fast for routine activities, including for non-experienced users. Computer-assisted TDM is gaining growing interest and should further improve, especially in terms of information system interfacing, user friendliness, data storage capability and report generation.

Patterns of sex work contact among men in the general population of Switzerland, 1987-2000

OBJECTIVES: To analyse the prevalence of lifetime recourse to prostitution (LRP) among men in the general population of Switzerland from a trend and cohort perspective. METHODS: Using nine repeated representative cross-sectional surveys from 1987 to 2000, age-specific estimates of LRP were computed. Trends and period effect were analysed as the evolution of cross-sectional population estimates within age groups and overall. Cohort analysis relied on cohorts constructed from the 1989 survey and followed in subsequent waves. Age and cohort effects were modelled using logistic regression and non-parametric monotone regression. RESULTS: Whereas prevalence for the younger groups was found to be logically lower, there was no consistent increasing or decreasing trend over the years; there was no significant period effect. For the 17-30 year age group, the mean estimate over 1987-2000 was 11.5% (range 8.3 to 12.7%); for the 31-45 year group, the mean was 21.5% (range over 1989-2000 20.3 to 23.0%). Regarding cohort analysis, the prevalence of LRP was found to increase steeply in the youngest ages before reaching a plateau near the age of 40 years. At the age of 43 years, the prevalence was estimated to be 22.6% (95% CI 21.1% to 24.1%). CONCLUSIONS: The steep increase in the cohort-wise prevalence of LRP in younger ages calls for a concentration of prevention activities in young people. If the plateauing at approximately 40 years of age is not followed by a further increase later in life, which is not known, then consumers of paid sex would be repeat buyers only, a fact that should be taken into account by prevention.

Migraineurs without aura show microstructural abnormalities in the cerebellum and frontal lobe.

The involvement of the cerebellum in migraine pathophysiology is not well understood. We used a biparametric approach at high-field MRI (3 T) to assess the structural integrity of the cerebellum in 15 migraineurs with aura (MWA), 23 migraineurs without aura (MWoA), and 20 healthy controls (HC). High-resolution T1 relaxation maps were acquired together with magnetization transfer images in order to probe microstructural and myelin integrity. Clusterwise analysis was performed on T1 and magnetization transfer ratio (MTR) maps of the cerebellum of MWA, MWoA, and HC using an ANOVA and a non-parametric clusterwise permutation F test, with age and gender as covariates and correction for familywise error rate. In addition, mean MTR and T1 in frontal regions known to be highly connected to the cerebellum were computed. Clusterwise comparison among groups showed a cluster of lower MTR in the right Crus I of MWoA patients vs. HC and MWA subjects (p = 0.04). Univariate and bivariate analysis on T1 and MTR contrasts showed that MWoA patients had longer T1 and lower MTR in the right and left pars orbitalis compared to MWA (p < 0.01 and 0.05, respectively), but no differences were found with HC. Lower MTR and longer T1 point at a loss of macromolecules and/or micro-edema in Crus I and pars orbitalis in MWoA patients vs. HC and vs. MWA. The pathophysiological implications of these findings are discussed in light of recent literature.

An empirical hierarchical Bayesian unification of occupational exposure assessment methods.

In occupational exposure assessment of airborne contaminants, exposure levels can either be estimated through repeated measurements of the pollutant concentration in air, expert judgment or through exposure models that use information on the conditions of exposure as input. In this report, we propose an empirical hierarchical Bayesian model to unify these approaches. Prior to any measurement, the hygienist conducts an assessment to generate prior distributions of exposure determinants. Monte-Carlo samples from these distributions feed two level-2 models: a physical, two-compartment model, and a non-parametric, neural network model trained with existing exposure data. The outputs of these two models are weighted according to the expert's assessment of their relevance to yield predictive distributions of the long-term geometric mean and geometric standard deviation of the worker's exposure profile (level-1 model). Bayesian inferences are then drawn iteratively from subsequent measurements of worker exposure. Any traditional decision strategy based on a comparison with occupational exposure limits (e.g. mean exposure, exceedance strategies) can then be applied. Data on 82 workers exposed to 18 contaminants in 14 companies were used to validate the model with cross-validation techniques. A user-friendly program running the model is available upon request.

Early white matter alterations in men predisposed to FXTAS revealed by MT imaging.

Introduction: The Fragile X - associated Tremor Ataxia Syndrome (FXTAS) is a recently described, and under-diagnosed, late onset (≈ 60y) neurodegenerative disorder affecting male carriers of a premutation in the Fragile X Mental Retardation 1 (FMR1) gene. The premutation is an CGG (Cytosine-Guanine-Guanine) expansion (55 to 200 CGG repeats) in the proximal region of the FMR1 gene. Patients with FXTAS primarily present with cerebellar ataxia and intention tremor. Neuroradiological features of FXTAS include prominent white matter disease in the periventricular, subcortical, middle cerebellar peduncles and deep white matter of the cerebellum on T2-weighted or FLAIR MR imaging (Jacquemmont 2007, Loesch 2007, Brunberg 2002, Cohen 2006). We hypothesize that a significant white matter alteration is present in younger individuals many years prior to clinical symptoms and/or the presence of visible lesions on conventional MR sequences and might be detectable by magnetization transfer (MT) imaging. Methods: Eleven asymptomatic premutation carriers (mean age = 55 years) and seven intra-familial controls participated to the study. A standardized neurological examination was performed on all participants and a neuropsychological evaluation was carried out before MR scanning performed on a 3T Siemens Trio. The protocol included a sagittal T1-weighted 3D gradient-echo sequence (MPRAGE, 160 slices, 1 mm^3 isotropic voxels) and a gradient-echo MTI (FA 30, TE 15, matrix size 256*256, pixel size 1*1 mm, 36 slices (thickness 2mm), MT pulse duration 7.68 ms, FA 500, frequency offset 1.5 kHz). MTI was performed by acquiring consecutively two set of images; first with and then without the MT saturation pulse. MT images were coregistered to the T1 acquisition. The MTR for every intracranial voxel was calculated as follows: MTR = (M0 - MS)/M0*100%, creating a MTR map for each subject. As first analysis, the whole white matter (WM) was used to mask the MTR image in order to create an histogram of the MTR distribution in the whole tissue class over the two groups examined. Then, for each subject, we performed a segmentation and parcellation of the brain by means of Freesurfer software, starting from the high resolution T1-weighted anatomical acquisition. Cortical parcellations was used to assign a label to the underlying white matter by the construction of a Voronoi diagram in the WM voxels of the MR volume based on distance to the nearest cortical parcellation label. This procedure allowed us to subdivide the cerebral WM in 78 ROIs according to the cortical parcellation (see example in Fig 1). The cerebellum, by the same procedure, was subdivided in 5 ROIs (2 per each hemisphere and one corresponding to the brainstem). For each subject, we calculated the mean value of MTR within each ROI and averaged over controls and patients. Significant differences between the two groups were tested using a two sample T-test (p<0.01). Results: Neurological examination showed that no patient met the clinical criteria of Fragile X Tremor and Ataxia Syndrome yet. Nonetheless, premutation carriers showed some subtle neurological signs of the disorder. In fact, premutation carriers showed a significant increase of tremor (CRST, T-test p=0.007) and increase of ataxia (ICARS, p=0.004) when compared to controls. The neuropsychological evaluation was normal in both groups. To obtain general characterizations of myelination for each subject and premutation carriers, we first computed the distribution of MTR values across the total white matter volume and averaged for each group. We tested the equality of the two distributions with the non parametric Kolmogorov-Smirnov test and we rejected the null-hypothesis at a p=0.03 (fig. 2). As expected, when comparing the asymptomatic permutation carriers with control subjects, the peak value and peak position of the MTR values within the whole WM were decreased and the width of the distribution curve was increased (p<0.01). These three changes point to an alteration of the global myelin status of the premutation carriers. Subsequently, to analyze the regional myelination and white matter integrity of the same group, we performed a ROI analysis of MTR data. The ROI-based analysis showed a decrease of mean MTR value in premutation carriers compared to controls in bilateral orbito-frontal and inferior frontal WM, entorhinal and cingulum regions and cerebellum (Fig 3). The detection of these differences in these regions failed with other conventional MR techniques. Conclusions: These preliminary data confirm that in premutation carriers, there are indeed alterations in "normal appearing white matter" (NAWM) and these alterations are visible with the MT technique. These results indicate that MT imaging may be a relevant approach to detect both global and local alterations within NAWM in "asymptomatic" carriers of premutations in the Fragile X Mental Retardation 1 (FMR1) gene. The sensitivity of MT in the detection of these alterations might point towards a specific physiopathological mechanism linked to an underlying myelin disorder. ROI-based analyses show that the frontal, parahippocampal and cerebellar regions are already significantly affected before the onset of symptoms. A larger sample will allow us to determine the minimum CGG expansion and age associated with these subclinical white matter alterations.

Bodyweight and migration-related differences in motor abilities in preschool children "Ballabeina"

Introduction: Motor abilities in schoolchildren have been decreasing in the last two decades (Bös, 2003, Tomkinson et al., 2003). This may be related to the dramatic increase in overweight and adiposity during the same time period. Children of migrant background are especially affected (Lasserre et al., 2007). But little is known about the relationship between BMI and migration background and motor abilities in preschool children. Methods/Design We carried out a cross-sectional analysis with 665 children (age 5.1 ± 0.6 years; 49.8 % female) of 40 randomly selected kindergarten classes from German and French speaking regions in Switzerland with a high migrant background. We investigated BMI, cardiorespiratory fitness (20 m shuttle run), static (displacement of center of pressure (COP)) and dynamic (balancing forward on a beam) postural control and overall fitness (obstacle course). Results: Of the children, 9.6 % were overweight, 10.5 % were obese (Swiss national percentiles) and 72.8 % were of migrant background (at least one parent born outside of Switzerland). Mean BMI from children of non-migrant background was 15.5 ± 1.1 kg/m2, while migrant children had a mean BMI of 15.8 ± 1.7 kg/m2 (p=0.08). Normal-weight children performed better in cardiorespiratory fitness (3.1 ± 1.4 vs. 2.6 ± 1.1 stages, p<0.001), overall fitness (18.9 ± 4.4 vs. 20.8 ± 4.6 sec, p<0.001) and in dynamic balance (4.9 ± 3.5 vs. 3.8 ± 2.5 steps, p<0.001) compared to overweight and obese children, while the latter had less postural sway (COP: 956 ± 302 vs. 1021 ± 212 mm, p=0.008). There was a clear inverse dose-response relationship between weight status and dynamic motor abilities. There were no significant differences in most tested motor abilities between non-migrant and migrant. The latter performed less well in only one motor test (overall fitness: 20.2 ± 5.2 vs. 18.3 ± 3.5 sec, p<0.001). These findings persisted after adjustment for BMI. Conclusion In preschool children, differences in motor abilities are already present between normal weight and overweight/obese children. However, migrant children demonstrate similar motor abilities compared to non-migrant children for almost all tests, despite their slightly higher BMI.

Teaching motivational interviewing to medical students : a pre-post test pilot study

Objective: To test the efficacy of teaching motivational interviewing (MI) to medical students. Methods: Thirteen 4th year medical students volunteered to participate. Seven days before and 7 days after an 8-hour interactive training MI workshop, each student performed a videorecorded interview with two standardized patients: a 60 year old alcohol dependent woman and a 50 year old cigarette smoking man. Students' counseling skills were coded by two blinded clinicians using the Motivational Interviewing Treatment Integrity 3.0 (MITI). Inter-rater reliability was calculated for all interviews and a test-retest was completed in a sub-sample of 10 consecutive interviews three days apart. Difference between MITI scores before and after training were calculated and tested using non-parametric tests. Effect size was approximated by calculating the probability that posttest scores are greater than pretest scores (P*=P(Pre<Post)+1/2P(Pre=Post)), P*>1/2 indicating greater scores in posttest, P*=1/2 no effect, and P*<1/2 smaller scores in posttest. Results: Median differences between MITI scores before and after MI training indicated a general progression in MI skills: MI spirit global score (median difference=1.5, Inter quartile range=1.5, p<0.001, P*=0.90); Empathy global score (med diff=1, IQR=0.5, p<0.001, P*=0.85); Percentage of MI adherent skills (med diff=36.6, IQR=50.5, p<0.001, P*=0.85); Percentage of open questions (med diff=18.6, IQR=21.6, p<0.001, P*=0.96); reflections/ questions ratio (med diff=0.2, IQR=0.4, p<0.001, P*=0.81). Only Direction global score and the percentage of complex reflections were not significantly improved (med diff=0, IQR=1, p=0.53, P*=0.44, and med diff=4.3, IQR=24.8, p=0.48, P*=0.62, respectively). Inter-rater reliability indicated weighted kappa ranged between 0.14 for Direction to 0.51 for Collaboration and ICC ranged between 0.28 for Simple reflection to 0.95 for Closed question. Test-retests indicated weighted kappa ranged between 0.27 for Direction to 0.80 for Empathy and ICC ranged between 0.87 for Complex reflection to 0.98 for Closed question. Conclusion: This pilot study indicated that an 8-hour training in MI for voluntary 4th year medical students resulted in significant improvement of MI skills. Larger sample of unselected medical students should be studied to generalize the benefit of MI training to medical students. Interrater reliability and test-retests suggested that coders' training should be intensified.

Detection of Optimal Models in Parameter Space with Support Vector Machines

The paper proposes an approach aimed at detecting optimal model parameter combinations to achieve the most representative description of uncertainty in the model performance. A classification problem is posed to find the regions of good fitting models according to the values of a cost function. Support Vector Machine (SVM) classification in the parameter space is applied to decide if a forward model simulation is to be computed for a particular generated model. SVM is particularly designed to tackle classification problems in high-dimensional space in a non-parametric and non-linear way. SVM decision boundaries determine the regions that are subject to the largest uncertainty in the cost function classification, and, therefore, provide guidelines for further iterative exploration of the model space. The proposed approach is illustrated by a synthetic example of fluid flow through porous media, which features highly variable response due to the parameter values' combination.