29 results on '"Pedeli, X."'
Search Results
2. Detailed statistical assessment of the characteristics of the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS) threshold rules
- Author
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Dafni, U. Karlis, D. Pedeli, X. Bogaerts, J. Pentheroudakis, G. Tabernero, J. Zielinski, C.C. Piccart, M.J. De Vries, E.G.E. Latino, N.J. Douillard, J.-Y. Cherny, N.I.
- Abstract
Background The European Society for Medical Oncology (ESMO) has developed the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS), a tool to assess the magnitude of clinical benefit from new cancer therapies. Grading is guided by a dual rule comparing the relative benefit (RB) and the absolute benefit (AB) achieved by the therapy to prespecified threshold values. The ESMO-MCBS v1.0 dual rule evaluates the RB of an experimental treatment based on the lower limit of the 95%CI (LL95%CI) for the hazard ratio (HR) along with an AB threshold. This dual rule addresses two goals: inclusiveness: not unfairly penalising experimental treatments from trials designed with adequate power targeting clinically meaningful relative benefit; and discernment: penalising trials designed to detect a small inconsequential benefit. Methods Based on 50 000 simulations of plausible trial scenarios, the sensitivity and specificity of the LL95%CI rule and the ESMO-MCBS dual rule, the robustness of their characteristics for reasonable power and range of targeted and true HRs, are examined. The per cent acceptance of maximal preliminary grade is compared with other dual rules based on point estimate (PE) thresholds for RB. Results For particularly small or particularly large studies, the observed benefit needs to be relatively big for the ESMO-MCBS dual rule to be satisfied and the maximal grade awarded. Compared with approaches that evaluate RB using the PE thresholds, simulations demonstrate that the MCBS approach better exhibits the desired behaviour achieving the goals of both inclusiveness and discernment. Conclusions RB assessment using the LL95%CI for HR rather than a PE threshold has two advantages: it diminishes the probability of excluding big benefit positive studies from achieving due credit and, when combined with the AB assessment, it increases the probability of downgrading a trial with a statistically significant but clinically insignificant observed benefit. © 2017 European Society for Medical Oncology (unless otherwise stated in the text of the article) 2017. All rights reserved.
- Published
- 2017
3. Air pollution and nonmalignant respiratory mortality in 16 cohorts within the ESCAPE project
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Dimakopoulou, K. Samoli, E. Beelen, R. Stafoggia, M. Andersen, Z.J. Hoffmann, B. Fischer, P. Nieuwenhuijsen, M. Vineis, P. Xun, W. Hoek, G. Raaschou-Nielsen, O. Oudin, A. Forsberg, B. Modig, L. Jousilahti, P. Lanki, T. Turunen, A. Oftedal, B. Nafstad, P. Schwarze, P.E. Penell, J. Fratiglioni, L. Andersson, N. Pedersen, N. Korek, M. De Faire, U. Eriksen, K.T. Tjønneland, A. Becker, T. Wang, M. Bueno-De-Mesquita, B. Tsai, M.-Y. Eeftens, M. Peeters, P.H. Meliefste, K. Marcon, A. Krämer, U. Kuhlbusch, T.A.J. Vossoughi, M. Key, T. De Hoogh, K. Hampel, R. Peters, A. Heinrich, J. Weinmayr, G. Concin, H. Nagel, G. Ineichen, A. Jacquemin, B. Stempfelet, M. Vilier, A. Ricceri, F. Sacerdote, C. Pedeli, X. Katsoulis, M. Trichopoulou, A. Brunekreef, B. Katsouyanni, K.
- Abstract
Rationale: Prospective cohort studies have shown that chronic exposure to particulate matter and traffic-related air pollution is associated with reduced survival. However, the effects on nonmalignant respiratory mortality are less studied, and the data reported are less consistent. Objectives: We have investigated the relationship of long-term exposure to air pollution and nonmalignant respiratory mortality in 16 cohorts with individual level data within the multicenter European Study of Cohorts for Air Pollution Effects (ESCAPE). Methods: Data from 16 ongoing cohort studies from Europe were used. The total number of subjects was 307,553. There were 1,559 respiratory deaths during follow-up. Measurements and Main Results: Air pollution exposure was estimated by land use regression models at the baseline residential addresses of study participants and traffic-proximity variables were derived from geographical databases following a standardized procedure within the ESCAPE study. Cohort-specific hazard ratios obtained by Cox proportional hazard models from standardized individual cohort analyses were combined using metaanalyses. We found no significant associations between air pollution exposure and nonmalignant respiratory mortality. Most hazard ratios were slightly below unity, with the exception of the traffic-proximity indicators. Conclusions: In this study of 16 cohorts, there was no association between air pollution exposure and nonmalignant respiratorymortality.Copyright © 2014 by the American Thoracic Society.
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- 2014
4. Likelihood Estimation for the INAR(p) Model by Saddlepoint Approximation
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Pedeli, X., Davison, A.C., Fokianos, K., Pedeli, X., Davison, A.C., and Fokianos, K.
- Abstract
Saddlepoint techniques have been used successfully in many applications, owing to the high accuracy with which they can approximate intractable densities and tail probabilities. This article concerns their use for the estimation of high-order integer-valued autoregressive, INAR(p), processes. Conditional least squares estimation and maximum likelihood estimation have been proposed for INAR(p) models, but the first is inefficient for estimating parametric models, and the second becomes difficult to implement as the order p increases. We propose a simple saddlepoint approximation to the log-likelihood that performs well even in the tails of the distribution and with complicated INAR models. We consider Poisson and negative binomial innovations, and show empirically that the estimator that maximises the saddlepoint approximation behaves very similarly to the maximum likelihood estimator in realistic settings. The approach is applied to data on meningococcal disease counts. Supplementary materials for this article are available online.
- Published
- 2015
5. Development of NO2 and NOx land use regression models for estimating air pollution exposure in 36 study areas in Europe - The ESCAPE project
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Beelen, R. Hoek, G. Vienneau, D. Eeftens, M. Dimakopoulou, K. Pedeli, X. Tsai, M.-Y. Künzli, N. Schikowski, T. Marcon, A. Eriksen, K.T. Raaschou-Nielsen, O. Stephanou, E. Patelarou, E. Lanki, T. Yli-Tuomi, T. Declercq, C. Falq, G. Stempfelet, M. Birk, M. Cyrys, J. von Klot, S. Nádor, G. Varró, M.J. Dedele, A. Gražulevičiene, R. Mölter, A. Lindley, S. Madsen, C. Cesaroni, G. Ranzi, A. Badaloni, C. Hoffmann, B. Nonnemacher, M. Krämer, U. Kuhlbusch, T. Cirach, M. de Nazelle, A. Nieuwenhuijsen, M. Bellander, T. Korek, M. Olsson, D. Strömgren, M. Dons, E. Jerrett, M. Fischer, P. Wang, M. Brunekreef, B. de Hoogh, K.
- Abstract
Estimating within-city variability in air pollution concentrations is important. Land use regression (LUR) models are able to explain such small-scale within-city variations. Transparency in LUR model development methods is important to facilitate comparison of methods between different studies. We therefore developed LUR models in a standardized way in 36 study areas in Europe for the ESCAPE (European Study of Cohorts for Air Pollution Effects) project.Nitrogen dioxide (NO2) and nitrogen oxides (NOx) were measured with Ogawa passive samplers at 40 or 80 sites in each of the 36 study areas. The spatial variation in each area was explained by LUR modelling. Centrally and locally available Geographic Information System (GIS) variables were used as potential predictors. A leave-one out cross-validation procedure was used to evaluate the model performance.There was substantial contrast in annual average NO2 and NOx concentrations within the study areas. The model explained variances (R2) of the LUR models ranged from 55% to 92% (median 82%) for NO2 and from 49% to 91% (median 78%) for NOx. For most areas the cross-validation R2 was less than 10% lower than the model R2. Small-scale traffic and population/household density were the most common predictors. The magnitude of the explained variance depended on the contrast in measured concentrations as well as availability of GIS predictors, especially traffic intensity data were important. In an additional evaluation, models in which local traffic intensity was not offered had 10% lower R2 compared to models in the same areas in which these variables were offered.Within the ESCAPE project it was possible to develop LUR models that explained a large fraction of the spatial variance in measured annual average NO2 and NOx concentrations. These LUR models are being used to estimate outdoor concentrations at the home addresses of participants in over 30 cohort studies. © 2013 Elsevier Ltd.
- Published
- 2013
6. Evaluation of land use regression models for NO2 and particulate matter in 20 European study areas: The ESCAPE project
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Wang, M. Beelen, R. Basagana, X. Becker, T. Cesaroni, G. De Hoogh, K. Dedele, A. Declercq, C. Dimakopoulou, K. Eeftens, M. Forastiere, F. Galassi, C. Gražulevičiene, R. Hoffmann, B. Heinrich, J. Iakovides, M. Künzli, N. Korek, M. Lindley, S. Mölter, A. Mosler, G. Madsen, C. Nieuwenhuijsen, M. Phuleria, H. Pedeli, X. Raaschou-Nielsen, O. Ranzi, A. Stephanou, E. Sugiri, D. Stempfelet, M. Tsai, M.-Y. Lanki, T. Udvardy, O. Varró, M.J. Wolf, K. Weinmayr, G. Yli-Tuomi, T. Hoek, G. Brunekreef, B.
- Abstract
Land use regression models (LUR) frequently use leave-one-out-cross- validation (LOOCV) to assess model fit, but recent studies suggested that this may overestimate predictive ability in independent data sets. Our aim was to evaluate LUR models for nitrogen dioxide (NO2) and particulate matter (PM) components exploiting the high correlation between concentrations of PM metrics and NO2. LUR models have been developed for NO2, PM2.5 absorbance, and copper (Cu) in PM10 based on 20 sites in each of the 20 study areas of the ESCAPE project. Models were evaluated with LOOCV and "hold-out evaluation (HEV)" using the correlation of predicted NO2 or PM concentrations with measured NO2 concentrations at the 20 additional NO2 sites in each area. For NO2, PM2.5 absorbance and PM10 Cu, the median LOOCV R2s were 0.83, 0.81, and 0.76 whereas the median HEV R 2 were 0.52, 0.44, and 0.40. There was a positive association between the LOOCV R2 and HEV R2 for PM2.5 absorbance and PM10 Cu. Our results confirm that the predictive ability of LUR models based on relatively small training sets is overestimated by the LOOCV R2s. Nevertheless, in most areas LUR models still explained a substantial fraction of the variation of concentrations measured at independent sites. © 2013 American Chemical Society.
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- 2013
7. Development of land use regression models for PM2.5, PM 2.5 absorbance, PM10 and PMcoarse in 20 European study areas; Results of the ESCAPE project
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Eeftens, M. Beelen, R. De Hoogh, K. Bellander, T. Cesaroni, G. Cirach, M. Declercq, C. Dedele, A. Dons, E. De Nazelle, A. Dimakopoulou, K. Eriksen, K. Falq, G. Fischer, P. Galassi, C. Gražulevičiene, R. Heinrich, J. Hoffmann, B. Jerrett, M. Keidel, D. Korek, M. Lanki, T. Lindley, S. Madsen, C. Mölter, A. Nádor, G. Nieuwenhuijsen, M. Nonnemacher, M. Pedeli, X. Raaschou-Nielsen, O. Patelarou, E. Quass, U. Ranzi, A. Schindler, C. Stempfelet, M. Stephanou, E. Sugiri, D. Tsai, M.-Y. Yli-Tuomi, T. Varró, M.J. Vienneau, D. Klot, S.V. Wolf, K. Brunekreef, B. Hoek, G.
- Abstract
Land Use Regression (LUR) models have been used increasingly for modeling small-scale spatial variation in air pollution concentrations and estimating individual exposure for participants of cohort studies. Within the ESCAPE project, concentrations of PM2.5, PM2.5 absorbance, PM10, and PMcoarse were measured in 20 European study areas at 20 sites per area. GIS-derived predictor variables (e.g., traffic intensity, population, and land-use) were evaluated to model spatial variation of annual average concentrations for each study area. The median model explained variance (R2) was 71% for PM2.5 (range across study areas 35-94%). Model R2 was higher for PM2.5 absorbance (median 89%, range 56-97%) and lower for PMcoarse (median 68%, range 32- 81%). Models included between two and five predictor variables, with various traffic indicators as the most common predictors. Lower R2 was related to small concentration variability or limited availability of predictor variables, especially traffic intensity. Cross validation R2 results were on average 8-11% lower than model R2. Careful selection of monitoring sites, examination of influential observations and skewed variable distributions were essential for developing stable LUR models. The final LUR models are used to estimate air pollution concentrations at the home addresses of participants in the health studies involved in ESCAPE. © 2012 American Chemical Society.
- Published
- 2012
8. Interobserver variability, and visual and quantitative parameters of 123I-FP-CIT SPECT (DaTSCAN) studies
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Papathanasiou, N. Rondogianni, P. Chroni, P. Themistocleous, M. Boviatsis, E. Pedeli, X. Sakas, D. Datseris, I.
- Abstract
Objective To evaluate the degree of interobserver agreement in the visual interpretation of 123I-FP-CIT studies and to investigate for potential associations between visual and semi-quantitative parameters. Methods Eighty-nine 123I-FP-CIT studies were blindly reviewed by 3 independent observers: a consultant, a resident doctor and a radiographer. They classified every study as either "normal" or "abnormal" and assigned visual 123I-FP-CIT uptake scores (2: normal, 1: reduced and 0: no uptake) in basal ganglia nuclei (right and left putamina and caudate nuclei) on every scan. Striatal 123I-FP-CIT binding ratios were calculated using crescent- ROI software. The interobserver agreement for the interpretation of studies and for visual score assignment was evaluated by means of κ statistics. We investigated for associations of binding ratios with visual scores and clinical parameters; patients' clinical diagnoses served as the reference standard. Results There was excellent interobserver agreement (j 0.89-0.93) in classifying studies as "normal" or "abnormal" and fine agreement in assignment of visual scores (j 0.71-0.80 for putamina and 0.50-0.79 for caudate nuclei). Nuclei with scores of 1 and 0 showed significantly reduced binding ratios (about 30 and 50%, respectively) compared with the nuclei scored as 2. ROC analysis indicated the optimal cutoff point of striatal binding ratio at 3.8 (sensitivity 98.5%, specificity 95%) for the detection of parkinsonian syndromes. Striatal binding ratios were negatively associated with age in normal subjects and disease duration in Parkinson's disease patients. Conclusion Visual interpretation of 123I-FP-CIT studies showed very good interobserver agreement. We found significant associations among visual, semi-quantitative and clinical parameters. © The Japanese Society of Nuclear Medicine 2012.
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- 2012
9. Risk assessment of diesel exhaust and lung cancer: Combining human and animal studies after adjustment for biases in epidemiological studies
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Pedeli, X. Hoek, G. Katsouyanni, K.
- Abstract
Background: Risk assessment requires dose-response data for the evaluation of the relationship between exposure to an environmental stressor and the probability of developing an adverse health effect. Information from human studies is usually limited and additional results from animal studies are often needed for the assessment of risks in humans. Combination of risk estimates requires an assessment and correction of the important biases in the two types of studies. In this paper we aim to illustrate a quantitative approach to combining data from human and animal studies after adjusting for bias in human studies. For our purpose we use the example of the association between exposure to diesel exhaust and occurrence of lung cancer. Methods. Firstly, we identify and adjust for the main sources of systematic error in selected human studies of the association between occupational exposure to diesel exhaust and occurrence of lung cancer. Evidence from selected animal studies is also accounted for by extrapolating to average ambient, occupational exposure concentrations of diesel exhaust. In a second stage, the bias adjusted effect estimates are combined in a common effect measure through meta-analysis. Results: The random-effects pooled estimate (RR) for exposure to diesel exhaust vs. non-exposure was found 1.37 (95% C.I.: 1.08-1.65) in animal studies and 1.59 (95% C.I.: 1.09-2.10) in human studies, whilst the overall was found equal to 1.49 (95% C.I.: 1.21-1.78) with a greater contribution from human studies. Without bias adjustment in human studies, the pooled effect estimate was 1.59 (95% C.I.: 1.28-1.89). Conclusions: Adjustment for the main sources of uncertainty produced lower risk estimates showing that ignoring bias leads to risk estimates potentially biased upwards. © 2011 Pedeli et al; licensee BioMed Central Ltd.
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- 2011
10. Medical students' perceptions on factors influencing a surgical career: The fate of general surgery in Greece
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Pikoulis, E. Avgerinos, E.D. Pedeli, X. Karavokyros, I. Bassios, N. Anagnostopoulou, S.
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education - Abstract
Background: A decline of medical students' interest in a general surgery career is occurring in the Western medical world. We sought data on the mentality of Greek students toward specialty selection, and we determined whether trends indicated a decline in interest for general surgery in Greece. Methods: A structured questionnaire was distributed to 3 groups of medical students: to pre-4th-year (group 1) surgical clerkship, post-4th-year (group 2) surgical clerkship, and post-6th-year internship students in surgery (group 3). The questions covered a wide spectrum of data including career choices, influential factors, and satisfaction rates on educational and training issues. Results: From a total of 500 distributed questionnaires 363 were returned. Most students (63.1%) indicated preference toward nonsurgical (medical) specialties. Surgical specialties within the 3 groups gathered 19.5% (group 1), 26.5% (group 2) and 31.2% (group 3) preference rates. Among surgical specialties, general surgery was chosen by 29.4% in group 1, 10.0% in group 2, and 17.9% in group 3. The most common criterion for specialty selection was "quality of life" (68.6%) among group 1 students and "patient contact" for group 2 and group 3 students (77.3% and 65.3%, respectively). Among the 96 students who chose surgical specialties, the most common criterion for specialty selection was "scientific challenge" (100%) in group 1 and "patient contact" in groups 2 and 3 (62.5% and 69.2%, respectively). The 3 more frequently chosen factors that influenced the "picture" of surgery positively were attending live surgery cases in the operating room (37.6%), clinical experience (29.6%), and patient care (14.4%), followed by assisting in the operating room (8.8%). Conclusion: Our survey suggests a limited interest of Greek medical students for surgical specialties and general surgery in particular. As the medical curriculum is restructured, our data underscore the need for actions by surgical educators and medical school authorities so as to enhance the interest of medical students in general surgery in Greece. © 2010 Mosby, Inc. All rights reserved.
- Published
- 2010
11. Seroepidemiology of hepatitis A among Greek children indicates that the virus is still prevalent: Implications for universal vaccination
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Kyrka, A. Tragiannidis, A. Cassimos, D. Pantelaki, K. Tzoufi, M. Mavrokosta, M. Pedeli, X. Athanassiadou, F. Hatzimichael, A. Konstantopoulos, A. Kafetzis, D. Papaevangelou, V.
- Abstract
A national cross-sectional seroprevalence survey was conducted in order to evaluate the current seroepidemiology of hepatitis A among 1,383 children, aged 0-14 years, residing in Greece. Stratification of the study population was conducted according to age and area of residence. Sera from study participants were tested for the presence of anti-HAV IgG antibodies. Immigrant children, as well as children residing in rural areas, had lower immunization rates. Among unvaccinated children, the seroprevalence rate of anti-HAV was 17.1%. Nationality was shown to have a marginally significant effect since non-immunized immigrant children had a higher seroprevalence rate (22.4% vs. 15.9%, OR = 1.52, P = 0.064). Significant differences between geographic areas for both vaccination coverage and natural immunity were observed. The study findings indicate that hepatitis A is prevalent in Greece and therefore universal infant hepatitis A immunization should be implemented. © 2009 Wiley-Liss, Inc.
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- 2009
12. Adolescents' wellbeing and functioning: Relationships with parents' subjective general physical and mental health
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Giannakopoulos, G. Dimitrakaki, C. Pedeli, X. Kolaitis, G. Rotsika, V. Ravens-Sieberer, U. Tountas, Y.
- Abstract
Background: This study aimed at examining the relationship between parental subjective health status and adolescents' health-related quality of life (HRQoL) as well as the role of gender, socioeconomic status, presence of chronic health care needs and social support on the above interaction.Methods: Questionnaires were administered to a Greek nation-wide random sample of adolescents (N = 1 194) aged 11-18 years and their parents (N = 973) in 2003. Adolescents' and parents' status was assessed, together with reports of socio-economic status and level of social support. Various statistical tests were used to determine the extent to which these variables were related to each other.Results and Discussion: Parental subjective mental health status was significantly correlated with adolescents' better physical and psychological wellbeing, moods and emotions, parent-child relationships, school environment and financial resources. Parental subjective physical health status was strongly associated with more positive adolescents' self-perception. Adolescents' male gender, younger age, absence of chronic health care needs, high social support, and higher family income were positively associated with better HRQoL.Conclusions: This study reinforces the importance of parental subjective health status, along with other variables, as a significant factor for the adolescents' HRQoL. © 2009 Giannakopoulos et al; licensee BioMed Central Ltd.
- Published
- 2009
13. Development of Land Use Regression Models for PM(2.5), PM(2.5) Absorbance, PM(10) and PM(coarse) in 20 European Study Areas; Results of the ESCAPE Project.
- Author
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Risk Assessment of Toxic and Immunomodulatory Agents, Dep IRAS, Eeftens, M.R., Beelen, R.M.J., de Hoogh, K., Bellander, T., Cesaroni, G., Cirach, M., Declercq, C., Dedele, A., Dons, E., de Nazelle, A., Dimakopoulou, K., Eriksen, K., Falq, G., Fischer, P., Galassi, C., Grazuleviciene, R., Heinrich, J., Hoffmann, B., Jerrett, M., Keidel, D., Korek, M., Lanki, T., Lindley, S., Madsen, C., Molter, A., Nador, G., Nieuwenhuijsen, M., Nonnemacher, M., Pedeli, X., Raaschou-Nielsen, O., Patelarou, E., Quass, U., Ranzi, A., Schindler, C., Stempfelet, M., Stephanou, E., Sugiri, D., Tsai, M.Y., Yli-Tuomi, T., Varro, M.J., Vienneau, D., von Klot, S., van der Wolf, K., Brunekreef, B., Hoek, G., Risk Assessment of Toxic and Immunomodulatory Agents, Dep IRAS, Eeftens, M.R., Beelen, R.M.J., de Hoogh, K., Bellander, T., Cesaroni, G., Cirach, M., Declercq, C., Dedele, A., Dons, E., de Nazelle, A., Dimakopoulou, K., Eriksen, K., Falq, G., Fischer, P., Galassi, C., Grazuleviciene, R., Heinrich, J., Hoffmann, B., Jerrett, M., Keidel, D., Korek, M., Lanki, T., Lindley, S., Madsen, C., Molter, A., Nador, G., Nieuwenhuijsen, M., Nonnemacher, M., Pedeli, X., Raaschou-Nielsen, O., Patelarou, E., Quass, U., Ranzi, A., Schindler, C., Stempfelet, M., Stephanou, E., Sugiri, D., Tsai, M.Y., Yli-Tuomi, T., Varro, M.J., Vienneau, D., von Klot, S., van der Wolf, K., Brunekreef, B., and Hoek, G.
- Published
- 2012
14. Investigating the Independent and Synergistic Effects of Heat Waves and Air Pollution on Health: The EuroHEAT Project
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Analitis, A, primary, Katsouyanni, K, additional, Pedeli, X, additional, Kirchmayer, U, additional, Michelozzi, P, additional, and Menne, B, additional
- Published
- 2008
- Full Text
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15. Estimating the Independent Short-Term Effect of Temperature and Humidity on Mortality: Assessing Various Modelling Strategies
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Pedeli, X, primary, Katsouyanni, K, additional, Analitis, A, additional, Baccini, M, additional, Biggeri, A, additional, and Kirchmayer, U, additional
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- 2008
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16. Interobserver variability, and visual and quantitative parameters of (123)I-FP-CIT SPECT (DaTSCAN) studies.
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Papathanasiou N, Rondogianni P, Chroni P, Themistocleous M, Boviatsis E, Pedeli X, Sakas D, Datseris I, Papathanasiou, Nikolaos, Rondogianni, Phivi, Chroni, Panagiota, Themistocleous, Marios, Boviatsis, Efstathios, Pedeli, Xanthi, Sakas, Damianos, and Datseris, Ioannis
- Abstract
Objective: To evaluate the degree of interobserver agreement in the visual interpretation of (123)I-FP-CIT studies and to investigate for potential associations between visual and semi-quantitative parameters.Methods: Eighty-nine (123)I-FP-CIT studies were blindly reviewed by 3 independent observers: a consultant, a resident doctor and a radiographer. They classified every study as either "normal" or "abnormal" and assigned visual (123)I-FP-CIT uptake scores (2: normal, 1: reduced and 0: no uptake) in basal ganglia nuclei (right and left putamina and caudate nuclei) on every scan. Striatal (123)I-FP-CIT binding ratios were calculated using crescent-ROI software. The interobserver agreement for the interpretation of studies and for visual score assignment was evaluated by means of κ statistics. We investigated for associations of binding ratios with visual scores and clinical parameters; patients' clinical diagnoses served as the reference standard.Results: There was excellent interobserver agreement (κ 0.89-0.93) in classifying studies as "normal" or "abnormal" and fine agreement in assignment of visual scores (κ 0.71-0.80 for putamina and 0.50-0.79 for caudate nuclei). Nuclei with scores of 1 and 0 showed significantly reduced binding ratios (about 30 and 50%, respectively) compared with the nuclei scored as 2. ROC analysis indicated the optimal cutoff point of striatal binding ratio at 3.8 (sensitivity 98.5%, specificity 95%) for the detection of parkinsonian syndromes. Striatal binding ratios were negatively associated with age in normal subjects and disease duration in Parkinson's disease patients.Conclusion: Visual interpretation of (123)I-FP-CIT studies showed very good interobserver agreement. We found significant associations among visual, semi-quantitative and clinical parameters. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
17. Source, timing and dynamics of ionic species mobility in the Svalbard annual snowpack.
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Spolaor A, Varin C, Pedeli X, Christille JM, Kirchgeorg T, Giardi F, Cappelletti D, Turetta C, Cairns WRL, Gambaro A, Bernagozzi A, Gallet JC, Björkman MP, and Barbaro E
- Abstract
Nearly all ice core archives from the Arctic and middle latitudes (such as the Alps), apart from some very high elevation sites in Greenland and the North Pacific, are strongly influenced by melting processes. The increases in the average Arctic temperature has enhanced surface snow melting even of higher elevation ice caps, especially on the Svalbard Archipelago. The increase of the frequency and altitude of winter "rain on snow" events as well as the increase of the length of the melting season have had a direct impact on the chemical composition of the seasonal and permanent snow layers due to different migration processes of water-soluble species, such as inorganic ions. This re-allocation along the snowpack of ionic species could significantly modify the original chemical signal present in the annual snow. This paper aims to give a picture of the evolution of the seasonal snow strata with a daily time resolution to better understand: a) the processes that can influence deposition b) the distribution of ions in annual snow c) the impact of the presence of liquid water on chemical re-distribution within the annual snow pack. Specifically, the chemical composition of the first 100 cm of seasonal snow on the Austre Brøggerbreen Glacier (Spitsbergen, Svalbard Islands, Norway) was monitored daily from the 27th of March to the 31st of May 2015. The experimental period covered almost the entire Arctic spring until the melting season. This unique dataset gives us a daily picture of the snow pack composition, and helps us to understand the behaviour of cations (K
+ , Ca2+ , Na+ , Mg2+ ) and anions (Br- , I- , SO4 2- , NO3 - , Cl- , MSA) in the Svalbard snow pack. We demonstrate that biologically related depositions occur only at the end of the snow season and that rain and melting events have different impacts on the snowpack chemistry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2021
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18. Pairwise likelihood estimation of latent autoregressive count models.
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Pedeli X and Varin C
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- Computer Simulation, Italy, Likelihood Functions, Models, Statistical
- Abstract
Latent autoregressive models are useful time series models for the analysis of infectious disease data. Evaluation of the likelihood function of latent autoregressive models is intractable and its approximation through simulation-based methods appears as a standard practice. Although simulation methods may make the inferential problem feasible, they are often computationally intensive and the quality of the numerical approximation may be difficult to assess. We consider instead a weighted pairwise likelihood approach and explore several computational and methodological aspects including estimation of robust standard errors and the role of numerical integration. The suggested approach is illustrated using monthly data on invasive meningococcal disease infection in Greece and Italy.
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- 2020
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19. An integer-valued time series model for multivariate surveillance.
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Pedeli X and Karlis D
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- Disease Outbreaks, Humans, Population Surveillance, Public Health, Sentinel Surveillance, Communicable Diseases epidemiology, Epidemics
- Abstract
In recent days, different types of surveillance data are becoming available for public health purposes. In most cases, several variables are monitored and events of different types are reported. As the amount of surveillance data increases, statistical methods that can effectively address multivariate surveillance scenarios are demanded. Even though research activity in this field is increasing rapidly in recent years, only a few approaches have simultaneously addressed the integer-valued property of the data and its correlation (both time correlation and cross-correlation) structure. In this article, we suggest a multivariate integer-valued autoregressive model that allows for both serial and cross-correlations between the series and can easily accommodate overdispersion and covariate information. Moreover, its structure implies a natural decomposition into an endemic and an epidemic component, a common distinction in dynamic models for infectious disease counts. Detection of disease outbreaks is achieved through the comparison of surveillance data with one-step-ahead predictions obtained after fitting the suggested model to a set of clean historical data. The performance of the suggested model is illustrated on a trivariate series of syndromic surveillance data collected during Athens 2004 Olympic Games., (© 2019 John Wiley & Sons, Ltd.)
- Published
- 2020
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20. Feedback mechanisms between snow and atmospheric mercury: Results and observations from field campaigns on the Antarctic plateau.
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Spolaor A, Angot H, Roman M, Dommergue A, Scarchilli C, Vardè M, Del Guasta M, Pedeli X, Varin C, Sprovieri F, Magand O, Legrand M, Barbante C, and Cairns WRL
- Subjects
- Antarctic Regions, Environmental Monitoring, Saline Waters chemistry, Seasons, Air Pollutants analysis, Atmosphere chemistry, Mercury analysis, Snow chemistry
- Abstract
The Antarctic Plateau snowpack is an important environment for the mercury geochemical cycle. We have extensively characterized and compared the changes in surface snow and atmospheric mercury concentrations that occur at Dome C. Three summer sampling campaigns were conducted between 2013 and 2016. The three campaigns had different meteorological conditions that significantly affected mercury deposition processes and its abundance in surface snow. In the absence of snow deposition events, the surface mercury concentration remained stable with narrow oscillations, while an increase in precipitation results in a higher mercury variability. The Hg concentrations detected confirm that snowfall can act as a mercury atmospheric scavenger. A high temporal resolution sampling experiment showed that surface concentration changes are connected with the diurnal solar radiation cycle. Mercury in surface snow is highly dynamic and it could decrease by up to 90% within 4/6 h. A negative relationship between surface snow mercury and atmospheric concentrations has been detected suggesting a mutual dynamic exchange between these two environments. Mercury concentrations were also compared with the Br concentrations in surface and deeper snow, results suggest that Br could have an active role in Hg deposition, particularly when air masses are from coastal areas. This research presents new information on the presence of Hg in surface and deeper snow layers, improving our understanding of atmospheric Hg deposition to the snow surface and the possible role of re-emission on the atmospheric Hg concentration., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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21. Detailed statistical assessment of the characteristics of the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS) threshold rules.
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Dafni U, Karlis D, Pedeli X, Bogaerts J, Pentheroudakis G, Tabernero J, Zielinski CC, Piccart MJ, de Vries EGE, Latino NJ, Douillard JY, and Cherny NI
- Abstract
Background: The European Society for Medical Oncology (ESMO) has developed the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS), a tool to assess the magnitude of clinical benefit from new cancer therapies. Grading is guided by a dual rule comparing the relative benefit (RB) and the absolute benefit (AB) achieved by the therapy to prespecified threshold values. The ESMO-MCBS v1.0 dual rule evaluates the RB of an experimental treatment based on the lower limit of the 95%CI (LL95%CI) for the hazard ratio (HR) along with an AB threshold. This dual rule addresses two goals: inclusiveness: not unfairly penalising experimental treatments from trials designed with adequate power targeting clinically meaningful relative benefit; and discernment: penalising trials designed to detect a small inconsequential benefit., Methods: Based on 50 000 simulations of plausible trial scenarios, the sensitivity and specificity of the LL95%CI rule and the ESMO-MCBS dual rule, the robustness of their characteristics for reasonable power and range of targeted and true HRs, are examined. The per cent acceptance of maximal preliminary grade is compared with other dual rules based on point estimate (PE) thresholds for RB., Results: For particularly small or particularly large studies, the observed benefit needs to be relatively big for the ESMO-MCBS dual rule to be satisfied and the maximal grade awarded. Compared with approaches that evaluate RB using the PE thresholds, simulations demonstrate that the MCBS approach better exhibits the desired behaviour achieving the goals of both inclusiveness and discernment., Conclusions: RB assessment using the LL95%CI for HR rather than a PE threshold has two advantages: it diminishes the probability of excluding big benefit positive studies from achieving due credit and, when combined with the AB assessment, it increases the probability of downgrading a trial with a statistically significant but clinically insignificant observed benefit., Competing Interests: Competing interests: The authors have declared the following: JB: director of EORTC. EORTC conducts many studies sponsored by, or otherwise supported by, a large number of companies. EORTC is an independent research organisation. MJP: board member: Radius. Consultant (honoraria): AstraZeneca, Lilly, MSD, Novartis, Pfizer, Roche-Genentech, Crescendo Biologics, Periphagen, Huya, Debiopharm and PharmaMar. Research grants to institute: AstraZeneca, Lilly, MDS, Novartis, Pfizer, Roche-Genentech, Synthon, Radius and Servier. Speakers bureau/stock ownership: none. GP: consulting and advisory services, and research support: Amgen, Merck, AstraZeneca, Roche, BMS, MSD and Lilly. J-YD: compensated participation to advisory boards, lecture and symposia: Amgen, Merck Serono, Bayer, Roche/Genentech, Sanofi, AstraZeneca, Boehringer-Ingelheim and Sirtex until April 2016. No further compensated participation in industry events from May 2016 onwards. JT: advisory boards for Amgen, Bayer, Boehringer Ingelheim, Celgene, Chugai, Genentech, Lilly, MSD, Merck Serono, Novartis, Pfizer, Roche, Sanofi, Symphogen, Taiho and Takeda. CCZ: honoraria: AstraZeneca, Celgene, Roche, Novartis, Bristol Myers Squibb, MSD, Ariad and Newgen. EGEdV: currently conducting research sponsored by the following companies: Amgen, Roche/Genentech, Chugai Pharma, Synthon, AstraZeneca, Radius Health, CytomX Therapeutics and Nordic Nanovector (all payments to the institution). Consulting or advisory role for the following companies: Synthon, Medication and Merck (all payments to the institution). Not a member of any speakers' bureau.
- Published
- 2017
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22. Long-term exposure to traffic-related air pollution and cardiovascular health in a Greek cohort study.
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Katsoulis M, Dimakopoulou K, Pedeli X, Trichopoulos D, Gryparis A, Trichopoulou A, and Katsouyanni K
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- Adult, Cohort Studies, Female, Greece epidemiology, Humans, Male, Middle Aged, Air Pollutants analysis, Air Pollution statistics & numerical data, Cardiovascular Diseases epidemiology, Environmental Exposure statistics & numerical data
- Abstract
Our objective is to evaluate the association of exposure to traffic-related air pollution with the incidence of fatal and non-fatal ischemic heart disease (IHD), stroke and total cardiovascular disease (CVD) events in a Greek cohort. We used data from the European Prospective Investigation on Nutrition and Cancer (EPIC) for 2752 subjects followed from 1997 to 2011, whose residence was in 10 municipalities of the Greater Athens area. Air pollution exposure estimation was based on a spatio-temporal land use regression model linking geo-coded residential addresses to long-term average NO2 and PM10 concentrations. We conducted Cox proportional hazards regression analysis, adjusting for potential confounders. Hazard ratios (HR) above 1 (not all statistically significant) were associated with higher PM10 exposure for all outcomes. Weaker associations were found with NO2 exposure. Specifically, the estimated HR for a CVD event associated with 10 μg/m(3) increase in long-term exposure to PM10 was 1.50 (1.05-2.16, p-value: 0.027). The relationship was more evident for subjects ≤50 years old at recruitment. Associations of PM10 and NO2 exposure with IHD events were found only among women with HRs respectively of 2.24 (0.89-5.64, p-value: 0.086) and 1.54 (1.01-2.37, p-value: 0.046) associated with 10 μg/m(3) increase in the corresponding pollutant. In conclusion, the present study suggests that long-term exposure to traffic-related air pollution has an impact on CVD and IHD morbidity, particularly among women and younger subjects., (Copyright © 2014 Elsevier B.V. All rights reserved.)
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- 2014
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23. Spatio-temporal semiparametric models for NO₂ and PM₁₀ concentration levels in Athens, Greece.
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Gryparis A, Dimakopoulou K, Pedeli X, and Katsouyanni K
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- Greece, Models, Chemical, Models, Statistical, Seasons, Spatio-Temporal Analysis, Air Pollutants analysis, Air Pollution statistics & numerical data, Environmental Monitoring, Nitrogen Dioxide analysis, Particulate Matter analysis
- Abstract
Background and Aims: Studies of air pollution effects on health are often based on ecological measurements. Our aim was to develop spatio-temporal models that estimate daily levels of NO2 and PM10 at every point in space, within the greater Athens area., Methods: We applied a semiparametric approach using spatial and temporal covariates and a bivariate smooth thin plate function. We evaluated the predictions of our models against the exposure estimates that are typically used in health studies. For model validation we used a temporal and a spatial approach., Results: The adjusted-R(2) of the developed exposure models was 0.53 and 0.75 for PM10 and NO2 respectively; the spatial terms in our models explained 41.5% and 64.5% and the temporal explained 52.85% and 32.0% of the variability in PM10 and NO2, respectively. There was no temporal or spatial left over autocorrelation in the residuals. We performed a leave-one-out cross validation and the adjusted-R(2) were 0.41 for PM10 and 0.71 for NO2. The developed model showed good validity when comparing predicted and observed measures for the 2010 data. Our models performed better compared to the "ecological" estimates and estimates based on the "nearest monitoring site"., Conclusions: Our spatio-temporal model makes valid predictions, it introduces substantial geographical variability, it reduces the bias when compared with the "ecological" estimates and the estimates based on the "nearest monitoring site" and it can be used for a more personalized exposure assessment in health studies., (Copyright © 2014 Elsevier B.V. All rights reserved.)
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- 2014
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24. Air pollution and nonmalignant respiratory mortality in 16 cohorts within the ESCAPE project.
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Dimakopoulou K, Samoli E, Beelen R, Stafoggia M, Andersen ZJ, Hoffmann B, Fischer P, Nieuwenhuijsen M, Vineis P, Xun W, Hoek G, Raaschou-Nielsen O, Oudin A, Forsberg B, Modig L, Jousilahti P, Lanki T, Turunen A, Oftedal B, Nafstad P, Schwarze PE, Penell J, Fratiglioni L, Andersson N, Pedersen N, Korek M, De Faire U, Eriksen KT, Tjønneland A, Becker T, Wang M, Bueno-de-Mesquita B, Tsai MY, Eeftens M, Peeters PH, Meliefste K, Marcon A, Krämer U, Kuhlbusch TA, Vossoughi M, Key T, de Hoogh K, Hampel R, Peters A, Heinrich J, Weinmayr G, Concin H, Nagel G, Ineichen A, Jacquemin B, Stempfelet M, Vilier A, Ricceri F, Sacerdote C, Pedeli X, Katsoulis M, Trichopoulou A, Brunekreef B, and Katsouyanni K
- Subjects
- Adult, Aged, Aged, 80 and over, Air Pollutants analysis, Air Pollution analysis, Cohort Studies, Environmental Exposure analysis, Europe epidemiology, Female, Follow-Up Studies, Humans, Male, Middle Aged, Particulate Matter analysis, Proportional Hazards Models, Regression Analysis, Respiratory Tract Diseases etiology, Air Pollutants adverse effects, Air Pollution adverse effects, Environmental Exposure adverse effects, Particulate Matter adverse effects, Respiratory Tract Diseases mortality
- Abstract
Rationale: Prospective cohort studies have shown that chronic exposure to particulate matter and traffic-related air pollution is associated with reduced survival. However, the effects on nonmalignant respiratory mortality are less studied, and the data reported are less consistent., Objectives: We have investigated the relationship of long-term exposure to air pollution and nonmalignant respiratory mortality in 16 cohorts with individual level data within the multicenter European Study of Cohorts for Air Pollution Effects (ESCAPE)., Methods: Data from 16 ongoing cohort studies from Europe were used. The total number of subjects was 307,553. There were 1,559 respiratory deaths during follow-up., Measurements and Main Results: Air pollution exposure was estimated by land use regression models at the baseline residential addresses of study participants and traffic-proximity variables were derived from geographical databases following a standardized procedure within the ESCAPE study. Cohort-specific hazard ratios obtained by Cox proportional hazard models from standardized individual cohort analyses were combined using metaanalyses. We found no significant associations between air pollution exposure and nonmalignant respiratory mortality. Most hazard ratios were slightly below unity, with the exception of the traffic-proximity indicators., Conclusions: In this study of 16 cohorts, there was no association between air pollution exposure and nonmalignant respiratory mortality.
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- 2014
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25. Evaluation of land use regression models for NO2 and particulate matter in 20 European study areas: the ESCAPE project.
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Wang M, Beelen R, Basagana X, Becker T, Cesaroni G, de Hoogh K, Dedele A, Declercq C, Dimakopoulou K, Eeftens M, Forastiere F, Galassi C, Gražulevičienė R, Hoffmann B, Heinrich J, Iakovides M, Künzli N, Korek M, Lindley S, Mölter A, Mosler G, Madsen C, Nieuwenhuijsen M, Phuleria H, Pedeli X, Raaschou-Nielsen O, Ranzi A, Stephanou E, Sugiri D, Stempfelet M, Tsai MY, Lanki T, Udvardy O, Varró MJ, Wolf K, Weinmayr G, Yli-Tuomi T, Hoek G, and Brunekreef B
- Subjects
- Air Pollution, Europe, Models, Theoretical, Nitric Oxide analysis, Particulate Matter analysis
- Abstract
Land use regression models (LUR) frequently use leave-one-out-cross-validation (LOOCV) to assess model fit, but recent studies suggested that this may overestimate predictive ability in independent data sets. Our aim was to evaluate LUR models for nitrogen dioxide (NO2) and particulate matter (PM) components exploiting the high correlation between concentrations of PM metrics and NO2. LUR models have been developed for NO2, PM2.5 absorbance, and copper (Cu) in PM10 based on 20 sites in each of the 20 study areas of the ESCAPE project. Models were evaluated with LOOCV and "hold-out evaluation (HEV)" using the correlation of predicted NO2 or PM concentrations with measured NO2 concentrations at the 20 additional NO2 sites in each area. For NO2, PM2.5 absorbance and PM10 Cu, the median LOOCV R(2)s were 0.83, 0.81, and 0.76 whereas the median HEV R(2) were 0.52, 0.44, and 0.40. There was a positive association between the LOOCV R(2) and HEV R(2) for PM2.5 absorbance and PM10 Cu. Our results confirm that the predictive ability of LUR models based on relatively small training sets is overestimated by the LOOCV R(2)s. Nevertheless, in most areas LUR models still explained a substantial fraction of the variation of concentrations measured at independent sites.
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- 2013
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26. Development of Land Use Regression models for PM(2.5), PM(2.5) absorbance, PM(10) and PM(coarse) in 20 European study areas; results of the ESCAPE project.
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Eeftens M, Beelen R, de Hoogh K, Bellander T, Cesaroni G, Cirach M, Declercq C, Dėdelė A, Dons E, de Nazelle A, Dimakopoulou K, Eriksen K, Falq G, Fischer P, Galassi C, Gražulevičienė R, Heinrich J, Hoffmann B, Jerrett M, Keidel D, Korek M, Lanki T, Lindley S, Madsen C, Mölter A, Nádor G, Nieuwenhuijsen M, Nonnemacher M, Pedeli X, Raaschou-Nielsen O, Patelarou E, Quass U, Ranzi A, Schindler C, Stempfelet M, Stephanou E, Sugiri D, Tsai MY, Yli-Tuomi T, Varró MJ, Vienneau D, Klot Sv, Wolf K, Brunekreef B, and Hoek G
- Subjects
- Absorbent Pads, Environmental Monitoring methods, Europe, Geographic Information Systems, Regression Analysis, Air Pollutants analysis, Air Pollution statistics & numerical data, Models, Chemical, Particulate Matter analysis
- Abstract
Land Use Regression (LUR) models have been used increasingly for modeling small-scale spatial variation in air pollution concentrations and estimating individual exposure for participants of cohort studies. Within the ESCAPE project, concentrations of PM(2.5), PM(2.5) absorbance, PM(10), and PM(coarse) were measured in 20 European study areas at 20 sites per area. GIS-derived predictor variables (e.g., traffic intensity, population, and land-use) were evaluated to model spatial variation of annual average concentrations for each study area. The median model explained variance (R(2)) was 71% for PM(2.5) (range across study areas 35-94%). Model R(2) was higher for PM(2.5) absorbance (median 89%, range 56-97%) and lower for PM(coarse) (median 68%, range 32- 81%). Models included between two and five predictor variables, with various traffic indicators as the most common predictors. Lower R(2) was related to small concentration variability or limited availability of predictor variables, especially traffic intensity. Cross validation R(2) results were on average 8-11% lower than model R(2). Careful selection of monitoring sites, examination of influential observations and skewed variable distributions were essential for developing stable LUR models. The final LUR models are used to estimate air pollution concentrations at the home addresses of participants in the health studies involved in ESCAPE.
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- 2012
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27. Risk assessment of diesel exhaust and lung cancer: combining human and animal studies after adjustment for biases in epidemiological studies.
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Pedeli X, Hoek G, and Katsouyanni K
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- Animals, Bias, Cricetinae, Disease Models, Animal, Epidemiologic Studies, Female, Humans, Male, Mice, Rats, Risk Assessment methods, Lung Neoplasms epidemiology, Occupational Diseases epidemiology, Occupational Exposure, Vehicle Emissions toxicity
- Abstract
Background: Risk assessment requires dose-response data for the evaluation of the relationship between exposure to an environmental stressor and the probability of developing an adverse health effect. Information from human studies is usually limited and additional results from animal studies are often needed for the assessment of risks in humans. Combination of risk estimates requires an assessment and correction of the important biases in the two types of studies. In this paper we aim to illustrate a quantitative approach to combining data from human and animal studies after adjusting for bias in human studies. For our purpose we use the example of the association between exposure to diesel exhaust and occurrence of lung cancer., Methods: Firstly, we identify and adjust for the main sources of systematic error in selected human studies of the association between occupational exposure to diesel exhaust and occurrence of lung cancer. Evidence from selected animal studies is also accounted for by extrapolating to average ambient, occupational exposure concentrations of diesel exhaust. In a second stage, the bias adjusted effect estimates are combined in a common effect measure through meta-analysis., Results: The random-effects pooled estimate (RR) for exposure to diesel exhaust vs. non-exposure was found 1.37 (95% C.I.: 1.08-1.65) in animal studies and 1.59 (95% C.I.: 1.09-2.10) in human studies, whilst the overall was found equal to 1.49 (95% C.I.: 1.21-1.78) with a greater contribution from human studies. Without bias adjustment in human studies, the pooled effect estimate was 1.59 (95% C.I.: 1.28-1.89)., Conclusions: Adjustment for the main sources of uncertainty produced lower risk estimates showing that ignoring bias leads to risk estimates potentially biased upwards.
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- 2011
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28. Medical students' perceptions on factors influencing a surgical career: the fate of general surgery in Greece.
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Pikoulis E, Avgerinos ED, Pedeli X, Karavokyros I, Bassios N, and Anagnostopoulou S
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- General Surgery, Greece, Humans, Job Satisfaction, Medicine, Physician-Patient Relations, Quality of Life, Surveys and Questionnaires, Waiting Lists, Career Choice, Choice Behavior, Perception, Specialties, Surgical, Students, Medical psychology
- Abstract
Background: A decline of medical students' interest in a general surgery career is occurring in the Western medical world. We sought data on the mentality of Greek students toward specialty selection, and we determined whether trends indicated a decline in interest for general surgery in Greece., Methods: A structured questionnaire was distributed to 3 groups of medical students: to pre-4th-year (group 1) surgical clerkship, post-4th-year (group 2) surgical clerkship, and post-6th-year internship students in surgery (group 3). The questions covered a wide spectrum of data including career choices, influential factors, and satisfaction rates on educational and training issues., Results: From a total of 500 distributed questionnaires 363 were returned. Most students (63.1%) indicated preference toward nonsurgical (medical) specialties. Surgical specialties within the 3 groups gathered 19.5% (group 1), 26.5% (group 2) and 31.2% (group 3) preference rates. Among surgical specialties, general surgery was chosen by 29.4% in group 1, 10.0% in group 2, and 17.9% in group 3. The most common criterion for specialty selection was "quality of life" (68.6%) among group 1 students and "patient contact" for group 2 and group 3 students (77.3% and 65.3%, respectively). Among the 96 students who chose surgical specialties, the most common criterion for specialty selection was "scientific challenge" (100%) in group 1 and "patient contact" in groups 2 and 3 (62.5% and 69.2%, respectively). The 3 more frequently chosen factors that influenced the "picture" of surgery positively were attending live surgery cases in the operating room (37.6%), clinical experience (29.6%), and patient care (14.4%), followed by assisting in the operating room (8.8%)., Conclusion: Our survey suggests a limited interest of Greek medical students for surgical specialties and general surgery in particular. As the medical curriculum is restructured, our data underscore the need for actions by surgical educators and medical school authorities so as to enhance the interest of medical students in general surgery in Greece., (Copyright 2010 Mosby, Inc. All rights reserved.)
- Published
- 2010
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29. Adolescents' wellbeing and functioning: relationships with parents' subjective general physical and mental health.
- Author
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Giannakopoulos G, Dimitrakaki C, Pedeli X, Kolaitis G, Rotsika V, Ravens-Sieberer U, and Tountas Y
- Subjects
- Adolescent, Child, Chronic Disease psychology, Female, Greece, Humans, Male, Multivariate Analysis, Qualitative Research, Social Class, Social Environment, Surveys and Questionnaires, Health Status, Mental Health, Parents psychology, Psychology, Adolescent, Quality of Life psychology, Social Support
- Abstract
Background: This study aimed at examining the relationship between parental subjective health status and adolescents' health-related quality of life (HRQoL) as well as the role of gender, socioeconomic status, presence of chronic health care needs and social support on the above interaction., Methods: Questionnaires were administered to a Greek nation-wide random sample of adolescents (N = 1,194) aged 11-18 years and their parents (N = 973) in 2003. Adolescents' and parents' status was assessed, together with reports of socio-economic status and level of social support. Various statistical tests were used to determine the extent to which these variables were related to each other., Results and Discussion: Parental subjective mental health status was significantly correlated with adolescents' better physical and psychological wellbeing, moods and emotions, parent-child relationships, school environment and financial resources. Parental subjective physical health status was strongly associated with more positive adolescents' self-perception. Adolescents' male gender, younger age, absence of chronic health care needs, high social support, and higher family income were positively associated with better HRQoL., Conclusions: This study reinforces the importance of parental subjective health status, along with other variables, as a significant factor for the adolescents' HRQoL.
- Published
- 2009
- Full Text
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