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- Botvinik-Nezer, Rotem, et al.
(author)
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Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
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Journal article (peer-reviewed)abstract
- Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed. The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.
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- Claassen, Yvette H. M., et al.
(author)
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Treatment and survival of rectal cancer patients over the age of 80 years : a EURECCA international comparison
- 2018
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In: British Journal of Cancer. - : Nature Publishing Group. - 0007-0920 .- 1532-1827. ; 119:4, s. 517-522
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Journal article (peer-reviewed)abstract
- BACKGROUND: The optimal treatment strategy for older rectal cancer patients remains unclear. The current study aimed to compare treatment and survival of rectal cancer patients aged 80+.METHODS: Patients of >= 80 years diagnosed with rectal cancer between 2001 and 2010 were included. Population-based cohorts from Belgium (BE), Denmark (DK), the Netherlands (NL), Norway (NO) and Sweden (SE) were compared side by side for neighbouring countries on treatment strategy and 5-year relative survival (RS), adjusted for sex and age. Analyses were performed separately for stage I-III patients and stage IV patients.RESULTS: Overall, 19 634 rectal cancer patients were included. For stage I-III patients, 5-year RS varied from 61.7% in BE to 72.3% in SE. Proportion of preoperative radiotherapy ranged between 7.9% in NO and 28.9% in SE. For stage IV patients, 5-year RS differed from 2.8% in NL to 5.6% in BE. Rate of patients undergoing surgery varied from 22.2% in DK to 40.8% in NO.CONCLUSIONS: Substantial variation was observed in the 5-year relative survival between European countries for rectal cancer patients aged 80+, next to a wide variation in treatment, especially in the use of preoperative radiotherapy in stage I-III patients and in the rate of patients undergoing surgery in stage IV patients.
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3. |
- Vermeer, Nina C. A., et al.
(author)
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Treatment and Survival of Patients with Colon Cancer Aged 80 Years and Older : A EURECCA International Comparison
- 2018
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In: The Oncologist. - : Wiley-Blackwell. - 1083-7159 .- 1549-490X. ; 23:8, s. 982-990
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Journal article (peer-reviewed)abstract
- Background. Colon cancer in older patients represents a major public health issue. As older patients are hardly included in clinical trials, the optimal treatment of these patients remains unclear. The present international EURECCA comparison explores possible associations between treatment and survival outcomes in elderly colon cancer patients.Subjects, Materials, and Methods. National data from Belgium, Denmark, The Netherlands, Norway, and Sweden were obtained, as well as a multicenter surgery cohort from Germany. Patients aged 80 years and older, diagnosed with colon cancer between 2001 and 2010, were included. The study interval was divided into two periods: 2001–2006 and 2007–2010. The proportion of surgical treatment and chemotherapy within a country and its relation to relative survival were calculated for each time frame.Results. Overall, 50,761 patients were included. At least 94% of patients with stage II and III colon cancer underwent surgical removal of the tumor. For stage II–IV, the proportion of chemotherapy after surgery was highest in Belgium and lowest in The Netherlands and Norway. For stage III, it varied from 24.8% in Belgium and 3.9% in Norway. For stage III, a better adjusted relative survival between 2007 and 2010 was observed in Sweden (adjusted relative excess risk [RER] 0.64, 95% confidence interval [CI]: 0.54–0.76) and Norway (adjusted RER 0.81, 95% CI: 0.69–0.96) compared with Belgium.Conclusion. There is substantial variation in the rate of treatment and survival between countries for patients with colon cancer aged 80 years or older. Despite higher prescription of adjuvant chemotherapy, poorer survival outcomes were observed in Belgium. No clear linear pattern between the proportion of chemotherapy and better adjusted relative survival was observed.
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