6 results on '"Koëter, M"'
Search Results
2. The Influence of Treatment Decisions on the Outcome of Esophageal Cancer
- Author
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Koëter, M. (Marijn) and Koëter, M. (Marijn)
- Published
- 2018
3. Levels of red blood cell fatty acids in patients with psychosis, their unaffected siblings, and healthy controls
- Author
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Medema, S. (Suzanne), Mocking, L.P.C.M. (Remco), Koëter, M. (Maarten), Vaz, F.M. (Frédéric M.), Meijer, C. (Carin), Haan, L. (Lieuwe) de, De Van Beveren, N.J.M. (Nico J. M.), Kahn, R. (René), Van Os, J. (Jim), Wiersma, D. (Durk), Bruggeman, R. (Richard), Cahn, W. (Wiepke), Myin-Germeys, I. (Inez), Medema, S. (Suzanne), Mocking, L.P.C.M. (Remco), Koëter, M. (Maarten), Vaz, F.M. (Frédéric M.), Meijer, C. (Carin), Haan, L. (Lieuwe) de, De Van Beveren, N.J.M. (Nico J. M.), Kahn, R. (René), Van Os, J. (Jim), Wiersma, D. (Durk), Bruggeman, R. (Richard), Cahn, W. (Wiepke), and Myin-Germeys, I. (Inez)
- Abstract
Background: Two recent meta- Analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta- Analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder. Methods: For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups. Results: Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings. Conclusions: We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting
- Published
- 2016
- Full Text
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4. Economic Evaluation of Internet-Based Interventions for Harmful Alcohol Use Alongside a Pragmatic Randomized Controlled Trial
- Author
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Blankers, Matthijs, Nabitz, Udo, Smit, Filip, Koeter, Maarten WJ, and Schippers, Gerard M
- Subjects
Computer applications to medicine. Medical informatics ,R858-859.7 ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundInternet interventions with and without therapist support have been found to be effective treatment options for harmful alcohol users. Internet-based therapy (IT) leads to larger and longer-lasting positive effects than Internet-based self-help (IS), but it is also more costly to provide. ObjectiveTo evaluate the cost effectiveness and cost utility of Internet-based interventions for harmful use of alcohol through the assessment of the incremental cost effectiveness of IT compared with IS. MethodsThis study was performed in a substance abuse treatment center in Amsterdam, the Netherlands. We collected data over the years 2008–2009. A total of 136 participants were included, 70 (51%) were female, and mean age was 41.5 (SD 9.83) years. Reported alcohol consumption and Alcohol Use Disorders Identification Test (AUDIT) scores indicated harmful drinking behavior at baseline. We collected self-reported outcome data prospectively at baseline and 6 months after randomization. Cost data were extracted from the treatment center’s cost records, and sex- and age-specific mean productivity cost data for the Netherlands. ResultsThe median incremental cost-effectiveness ratio was estimated at €3683 per additional treatment responder and €14,710 per quality-adjusted life-year (QALY) gained. At a willingness to pay €20,000 for 1 additional QALY, IT had a 60% likelihood of being more cost effective than IS. Sensitivity analyses attested to the robustness of the findings. ConclusionsIT offers better value for money than IS and might therefore be considered as a treatment option, either as first-line treatment in a matched-care approach or as a second-line treatment in the context of a stepped-care approach. Trial RegistrationNetherlands Trial Register NTR-TC1155; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1155 (Archived by WebCite at http://www.webcitation.org/6AqnV4eTU)
- Published
- 2012
- Full Text
- View/download PDF
5. Missing Data Approaches in eHealth Research: Simulation Study and a Tutorial for Nonmathematically Inclined Researchers
- Author
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Blankers, Matthijs, Koeter, Maarten W J, and Schippers, Gerard M
- Subjects
Computer applications to medicine. Medical informatics ,R858-859.7 ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundMissing data is a common nuisance in eHealth research: it is hard to prevent and may invalidate research findings. ObjectiveIn this paper several statistical approaches to data “missingness” are discussed and tested in a simulation study. Basic approaches (complete case analysis, mean imputation, and last observation carried forward) and advanced methods (expectation maximization, regression imputation, and multiple imputation) are included in this analysis, and strengths and weaknesses are discussed. MethodsThe dataset used for the simulation was obtained from a prospective cohort study following participants in an online self-help program for problem drinkers. It contained 124 nonnormally distributed endpoints, that is, daily alcohol consumption counts of the study respondents. Missingness at random (MAR) was induced in a selected variable for 50% of the cases. Validity, reliability, and coverage of the estimates obtained using the different imputation methods were calculated by performing a bootstrapping simulation study. ResultsIn the performed simulation study, the use of multiple imputation techniques led to accurate results. Differences were found between the 4 tested multiple imputation programs: NORM, MICE, Amelia II, and SPSS MI. Among the tested approaches, Amelia II outperformed the others, led to the smallest deviation from the reference value (Cohen’s d = 0.06), and had the largest coverage percentage of the reference confidence interval (96%). ConclusionsThe use of multiple imputation improves the validity of the results when analyzing datasets with missing observations. Some of the often-used approaches (LOCF, complete cases analysis) did not perform well, and, hence, we recommend not using these. Accumulating support for the analysis of multiple imputed datasets is seen in more recent versions of some of the widely used statistical software programs making the use of multiple imputation more readily available to less mathematically inclined researchers.
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- 2010
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6. Radiation dose does not influence anastomotic complications in patients with esophageal cancer treated with neoadjuvant chemoradiation and transhiatal esophagectomy.
- Author
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Koëter M, van der Sangen MJ, Hurkmans CW, Luyer MD, Rutten HJ, and Nieuwenhuijzen GA
- Subjects
- Adenocarcinoma mortality, Adenocarcinoma pathology, Adenocarcinoma therapy, Adult, Aged, Aged, 80 and over, Anastomosis, Surgical, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Carboplatin administration & dosage, Carcinoma, Squamous Cell mortality, Carcinoma, Squamous Cell pathology, Carcinoma, Squamous Cell therapy, Combined Modality Therapy, Esophageal Neoplasms mortality, Esophageal Neoplasms pathology, Esophagectomy, Female, Follow-Up Studies, Humans, Male, Middle Aged, Neoplasm Staging, Paclitaxel administration & dosage, Prognosis, Survival Rate, Anastomotic Leak, Chemoradiotherapy, Esophageal Neoplasms therapy, Neoadjuvant Therapy, Postoperative Complications, Radiotherapy Dosage standards
- Abstract
Background: Neoadjuvant chemoradiation might increase anastomotic leakage and stenosis in patients with esophageal cancer treated with neoadjuvant chemoradiation and esophagectomy. The aim of this study was to determine the influence of radiation dose on the incidence of leakage and stenosis., Methods: Fifty-three patients with esophageal cancer received neoadjuvant chemoradiation (23 × 1.8 Gy) (combined with Paclitaxel and Carboplatin) followed by a transhiatal esophagectomy between 2009 and 2011. On planning CT, the future anastomotic region was determined and the mean radiation dose, V20, V25, V30, V35 and V40 were calculated. Logistic regression analysis was conducted to examine determinants of anastomotic leakage and stenosis., Results: Anastomotic leaks occurred in 13 of 53 patients (25.5%) and anastomotic stenosis occurred in 24 of 53 patients (45.3%). Median follow-up was 20 months. Logistic regression analysis showed that mean dose, V20-V40, age, co-morbidity, method of anastomosis, operating time and interval between last radiotherapy treatment and surgery were not predictors of anastomotic leakage and stenosis., Conclusions: A radiation dose of 23 × 1.8 Gy on the future anastomotic region has no influence on the occurrence of anastomotic leakage and stenosis in patients with esophageal cancer treated with neoadjuvant chemoradiation followed by transhiatal esophagectomy.
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- 2015
- Full Text
- View/download PDF
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