%0 Journal Article %1 Naggara2011a %A Naggara, O %A Raymond, J %A Guilbert, F %A Roy, D %A Weill, A %A Altman, D G %D 2011 %J AJNR. American journal of neuroradiology %K Aneurysm Bias(Epidemiology) DataInterpretation Humans IntracranialAneurysm IntracranialAneurysm:diagnosis IntracranialAneurysm:epidemiology Prevalence ProportionalHazardsModels ReproducibilityofResults RiskAssessment RiskAssessment:methods RiskFactors Ruptured Ruptured:diagnosis Ruptured:epidemiology SensitivityandSpecificity Statistical %N 3 %P 437-40 %R 10.3174/ajnr.A2425 %T Analysis by categorizing or dichotomizing continuous variables is inadvisable: an example from the natural history of unruptured aneurysms. %U http://www.ncbi.nlm.nih.gov/pubmed/21330400 %V 32 %X In medical research analyses, continuous variables are often converted into categoric variables by grouping values into ≥2 categories. The simplicity achieved by creating ≥2 artificial groups has a cost: Grouping may create rather than avoid problems. In particular, dichotomization leads to a considerable loss of power and incomplete correction for confounding factors. The use of data-derived öptimal" cut-points can lead to serious bias and should at least be tested on independent observations to assess their validity. Both problems are illustrated by the way the results of a registry on unruptured intracranial aneurysms are commonly used. Extreme caution should restrict the application of such results to clinical decision-making. Categorization of continuous data, especially dichotomization, is unnecessary for statistical analysis. Continuous explanatory variables should be left alone in statistical models. %@ 1936-959X; 0195-6108

@article{Naggara2011a, abstract = {In medical research analyses, continuous variables are often converted into categoric variables by grouping values into ≥2 categories. The simplicity achieved by creating ≥2 artificial groups has a cost: Grouping may create rather than avoid problems. In particular, dichotomization leads to a considerable loss of power and incomplete correction for confounding factors. The use of data-derived "optimal" cut-points can lead to serious bias and should at least be tested on independent observations to assess their validity. Both problems are illustrated by the way the results of a registry on unruptured intracranial aneurysms are commonly used. Extreme caution should restrict the application of such results to clinical decision-making. Categorization of continuous data, especially dichotomization, is unnecessary for statistical analysis. Continuous explanatory variables should be left alone in statistical models.}, added-at = {2023-02-03T11:44:35.000+0100}, author = {Naggara, O and Raymond, J and Guilbert, F and Roy, D and Weill, A and Altman, D G}, biburl = {https://www.bibsonomy.org/bibtex/2f8a9205773126e974123dbfb56441089/jepcastel}, city = {Department of Radiology, Interventional Neuroradiology Research Unit, International Consortium of Neuroendovascular Centres, University of Montreal, CHUM Notre-Dame Hospital, Quebec, Canada.}, doi = {10.3174/ajnr.A2425}, interhash = {07e1ab2054692ee6da712aa67af28805}, intrahash = {f8a9205773126e974123dbfb56441089}, isbn = {1936-959X; 0195-6108}, issn = {1936-959X}, journal = {AJNR. American journal of neuroradiology}, keywords = {Aneurysm Bias(Epidemiology) DataInterpretation Humans IntracranialAneurysm IntracranialAneurysm:diagnosis IntracranialAneurysm:epidemiology Prevalence ProportionalHazardsModels ReproducibilityofResults RiskAssessment RiskAssessment:methods RiskFactors Ruptured Ruptured:diagnosis Ruptured:epidemiology SensitivityandSpecificity Statistical}, month = {3}, note = {6281<m:linebreak></m:linebreak>ClinicalTrials.gov/NCT00537134; GR: Canadian Institutes of Health Research/Canada; JID: 8003708; 2011/02/17 [aheadofprint]; ppublish;<m:linebreak></m:linebreak>Anàlisi de dades; Categorització}, number = 3, pages = {437-40}, pmid = {21330400}, timestamp = {2023-02-03T11:44:35.000+0100}, title = {Analysis by categorizing or dichotomizing continuous variables is inadvisable: an example from the natural history of unruptured aneurysms.}, url = {http://www.ncbi.nlm.nih.gov/pubmed/21330400}, volume = 32, year = 2011 }