661 research outputs found

    Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences

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    To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only 2D intermediate window and manual 3D) compared with measurements by linear probe. All CT colonography measurements judged polyps to be larger than optical colonoscopy, with differences ranging from 0.7 to 2.3 mm. A linear probe does not reduce the measurement variability of endoscopists compared with the forceps. Measurement differences between observers on CT colonography were usually smaller than at optical colonoscopy. Polyps appeared larger when using various CT colonography techniques than when measured during optical colonoscop

    The development of instruments to measure the work disability assessment behaviour of insurance physicians

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    <p>Abstract</p> <p>Background</p> <p>Variation in assessments is a universal given, and work disability assessments by insurance physicians are no exception. Little is known about the considerations and views of insurance physicians that may partly explain such variation. On the basis of the Attitude - Social norm - self Efficacy (ASE) model, we have developed measurement instruments for assessment behaviour and its determinants.</p> <p>Methods</p> <p>Based on theory and interviews with insurance physicians the questionnaire included blocks of items concerning background variables, intentions, attitudes, social norms, self-efficacy, knowledge, barriers and behaviour of the insurance physicians in relation to work disability assessment issues. The responses of 231 insurance physicians were suitable for further analysis. Factor analysis and reliability analysis were used to form scale variables and homogeneity analysis was used to form dimension variables. Thus, we included 169 of the 177 original items.</p> <p>Results</p> <p>Factor analysis and reliability analysis yielded 29 scales with sufficient reliability. Homogeneity analysis yielded 19 dimensions. Scales and dimensions fitted with the concepts of the ASE model. We slightly modified the ASE model by dividing behaviour into two blocks: behaviour that reflects the assessment process and behaviour that reflects assessment behaviour.</p> <p>The picture that emerged from the descriptive results was of a group of physicians who were motivated in their job and positive about the Dutch social security system in general. However, only half of them had a positive opinion about the Dutch Work and Income (Capacity for Work) Act (WIA). They also reported serious barriers, the most common of which was work pressure. Finally, 73% of the insurance physicians described the majority of their cases as 'difficult'.</p> <p>Conclusions</p> <p>The scales and dimensions developed appear to be valid and offer a promising basis for future research. The results suggest that the underlying ASE model, in modified form, is suitable for describing the assessment behaviour of insurance physicians and the determinants of this behaviour. The next step in this line of research should be to validate the model using structural equation modelling. Finally, the predictive value should be tested in relation to outcome measurements of work disability assessments.</p

    Efficacy of smoking prevention program 'Smoke-free Kids': study protocol of a randomized controlled trial

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    Contains fulltext : 77005.pdf (publisher's version ) (Open Access)Background - A strong increase in smoking is noted especially among adolescents. In the Netherlands, about 5% of all 10-year olds, 25% of all 13-year olds and 62% of all 17-year olds report ever smoking. In the U.S., an intervention program called 'Smoke-free Kids' was developed to prevent children from smoking. The present study aims to assess the effects of this home-based smoking prevention program in the Netherlands. Methods - A randomized controlled trial is conducted among 9 to 11-year old children of primary schools. Participants are randomly assigned to the intervention and control conditions. The intervention program consists of five printed activity modules designed to improve parenting skills specific to smoking prevention and parent-child communication regarding smoking. These modules will include additional sheets with communication tips. The modules for the control condition will include solely information on smoking and tobacco use. Initiation of cigarette smoking (first instance of puffing on a lighted cigarette), susceptibility to cigarette smoking, smoking-related cognitions, and anti-smoking socialization will be the outcome measures. To collect the data, telephone interviews with mothers as well as with their child will be conducted at baseline. Only the children will be examined at post-intervention follow-ups (6, 12, 24, and 36 months after the baseline). Discussion - This study protocol describes the design of a randomized controlled trial that will evaluate the effectiveness of a home-based smoking prevention program. We expect that a significantly lower number of children will start smoking in the intervention condition compared to control condition as a direct result of this intervention. If the program is effective, it is applicable in daily live, which will facilitate implementation of the prevention protocol. Trial registration: Netherlands Trial Register NTR146510 p

    Difference in balance measures between patients with chronic ankle instability and patients after an acute ankle inversion trauma

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    Neuromuscular control of the ankle is disturbed in patients with chronic ankle instability due to an initial ankle inversion trauma. Static balance is assumed to be a measure for this disturbance. Functional (ankle) scores are another way to evaluate ankle impairment. The hypothesis was that there is a difference in static balance measures between small groups of healthy subjects, patients after an acute ankle inversion trauma and patients with chronic ankle instability and that static balance measures correlate well with functional scores. Static balance in healthy subjects (N = 15), patients after a primary ankle inversion injury (N = 14) and patients with chronic ankle instability (N = 23) was tested with a single leg test on a force plate (Postural Sway test) and on a compliant floor (Simple Balance test). Functional impairment was evaluated with the Karlsson, AOFAS and SF-36 (ankle) scores. There was a statistically significant and clinically relevant difference in functional (ankle) scores, but not a statistically significant difference in balance measures between the groups. Balance measures did not correlate to the functional scores. It was concluded that, despite a clinically relevant difference in functional outcome measures between the groups, static balance measures do not appear to be useful for clinical application in the individual patient

    A hinged external fixator for complex elbow dislocations: A multicenter prospective cohort study

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    Background: Elbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures of the radial head, olecranon, or coronoid process. The majority of patients with these complex dislocations are treated with open reduction and internal fixation (ORIF), or arthroplasty in case of a non-reconstructable radial head fracture. If the elbow joint remains unstable after fracture fixation, a hinged elbow fixator can be applied. The fixator provides stability to the elbow joint, and allows for early mobilization. The latter may be important for preventing stiffness of the joint. The aim of this study is to determine the effect of early mobilization with a hinged external elbow fixator on clinical outcome in patients with complex elbow dislocations with residual instability following fracture fixation. Methods/Design. The design of the study will be a multicenter prospective cohort study of 30 patients who have sustained a complex elbow dislocation and are treated with a hinged elbow fixator following fracture fixation because of residual instability. Early active motion exercises within the limits of pain will be started immediately after surgery under supervision of a physical therapist. Outcome will be evaluated at regular intervals over the subsequent 12 months. The primary outcome is the Quick Disabilities of the Arm, Shoulder, and Hand score. The secondary outcome measures are the Mayo Elbow Performance Index, Oxford Elbow Score, pain level at both sides, range of motion of the elbow joint at both sides, radiographic healing of the fractures and formation of periarticular ossifications, rate of secondary interventions and complications, and health-related quality of life (Short-Form 36). Discussion. The outcome of this study will yield quantitative data on the functional outcome in patients with a complex elbow dislocation and who are treated with ORIF and additional stabilization with a hinged elbow fixator. Trial Registration. The trial is registered at the Netherlands Trial Register (NTR1996)

    Estimating Dynamic Gait Stability Using Data from Non-aligned Inertial Sensors

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    Recently, two methods for quantifying the stability of a dynamical system have been applied to human locomotion: local stability (quantified by finite time maximum Lyapunov exponents, λs and λL) and orbital stability (quantified by maximum Floquet multipliers, MaxFm). In most studies published to date, data from optoelectronic measurement systems were used to calculate these measures. However, using wireless inertial sensors may be more practical as they are easier to use, also in ambulatory applications. While inertial sensors have been employed in some studies, it is unknown whether they lead to similar stability estimates as obtained with optoelectronic measurement systems. In the present study, we compared stability measures of human walking estimated from an optoelectronic measurement system with those calculated from an inertial sensor measurement system. Subjects walked on a treadmill at three different speeds while kinematics were recorded using both measurement systems. From the angular velocities and linear accelerations, λs, λL, and MaxFm were calculated. Both measurement systems showed the same effects of walking speed for all variables. Estimates from both measurement systems correlated high for λs and λL, (R > 0.85) but less strongly for MaxFm (R = 0.66). These results indicate that inertial sensors constitute a valid alternative for an optoelectronic measurement system when assessing dynamic stability in human locomotion, and may thus be used instead, which paves the way to studying gait stability during natural, everyday walking

    Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland

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    In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO(2) in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical variables. The analysis revealed a persistent and positive effect of elevated CO(2) on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO(2) mediated through increased litter C:N ratio. After eight years of treatment, however, the CO(2)-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term

    Primary uncleansed 2D versus primary electronically cleansed 3D in limited bowel preparation CT-colonography. Is there a difference for novices and experienced readers?

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    The purpose of this study was to compare a primary uncleansed 2D and a primary electronically cleansed 3D reading strategy in CTC in limited prepped patients. Seventy-two patients received a low-fibre diet with oral iodine before CT-colonography. Six novices and two experienced observers reviewed both cleansed and uncleansed examinations in randomized order. Mean per-polyp sensitivity was compared between the methods by using generalized estimating equations. Mean per-patient sensitivity, and specificity were compared using the McNemar test. Results were stratified for experience (experienced observers versus novice observers). Mean per-polyp sensitivity for polyps 6 mm or larger was significantly higher for novices using cleansed 3D (65%; 95%CI 57–73%) compared with uncleansed 2D (51%; 95%CI 44–59%). For experienced observers there was no significant difference. Mean per-patient sensitivity for polyps 6 mm or larger was significantly higher for novices as well: respectively 75% (95%CI 70–80%) versus 64% (95%CI 59–70%). For experienced observers there was no statistically significant difference. Specificity for both novices and experienced observers was not significantly different. For novices primary electronically cleansed 3D is better for polyp detection than primary uncleansed 2D
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