Type | Journal Article |
---|---|
Author | Valerii Fedorov |
Author | Frank Mannino |
Author | Rongmei Zhang |
URL | http://dx.doi.org/10.1002/pst.331 |
Volume | 8 |
Pages | 50-61 |
Publication | Pharm Stat |
Date | 2009 |
Extra | Citation Key: fed09con tex.citeulike-article-id= 13265728 tex.citeulike-attachment-1= fed09con.pdf; /pdf/user/harrelfe/article/13265728/1027987/fed09con.pdf; 7e1edf1558bbca47ebed9e0ccb36ec439f5e402d tex.citeulike-linkout-0= http://dx.doi.org/10.1002/pst.331 tex.posted-at= 2014-07-14 14:10:03 tex.priority= 0 |
DOI | 10.1002/pst.331 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
optimal cutpoint depends on unknown parameters;should only entertain dichotomization when "estimating a value of the cumulative distribution and when the assumed model is very different from the true model";nice graphics
Type | Journal Article |
---|---|
Author | Heiko Belcher |
Volume | 11 |
Pages | 1747-1758 |
Publication | Stat Med |
Date | 1992 |
Extra | Citation Key: bec92con tex.citeulike-article-id= 13263733 tex.posted-at= 2014-07-14 14:09:22 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | Petra Buettner |
Author | Claus Garbe |
Author | Irene Guggenmoos-Holzmann |
Volume | 50 |
Pages | 1201-1210 |
Publication | J Clin Epi |
Date | 1997 |
Extra | Citation Key: bue97pro tex.citeulike-article-id= 13263825 tex.posted-at= 2014-07-14 14:09:23 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
choice of cut point depends on marginal distribution of predictor
Type | Journal Article |
---|---|
Author | D. R. Ragland |
URL | http://dx.doi.org/10.1097/00001648-199209000-00009 |
Volume | 3 |
Pages | 434-440 |
Publication | Epi |
Date | 1992 |
Extra | Citation Key: rag92dic tex.citeulike-article-id= 13264722 tex.citeulike-linkout-0= http://dx.doi.org/10.1097/00001648-199209000-00009 tex.posted-at= 2014-07-14 14:09:40 tex.priority= 0 See letters to editor May 1993 P. 274-, Vol 4 No. 3 |
DOI | 10.1097/00001648-199209000-00009 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | Gary S. Collins |
Author | Emmanuel O. Ogundimu |
Author | Jonathan A. Cook |
Author | Yannick L. Manach |
Author | Douglas G. Altman |
URL | http://dx.doi.org/10.1002/sim.6986 |
Volume | 35 |
Issue | 23 |
Pages | 4124-4135 |
Publication | Stat Med |
ISSN | 02776715 |
Date | 2016-10 |
Extra | Citation Key: col16qua tex.citeulike-article-id= 14257702 tex.citeulike-attachment-1= col16qua.pdf; /pdf/user/harrelfe/article/14257702/1098563/col16qua.pdf; 777d21c7dafcffd5012b9f8f9928c2aeac69dcbd tex.citeulike-linkout-0= http://dx.doi.org/10.1002/sim.6986 tex.day= 15 tex.posted-at= 2017-01-19 01:17:02 tex.priority= 4 |
DOI | 10.1002/sim.6986 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
used rms package hazard regression method (hare) for survival model calibration
Type | Journal Article |
---|---|
Author | Caroline Bennette |
Author | Andrew Vickers |
URL | http://dx.doi.org/10.1186/1471-2288-12-21 |
Volume | 12 |
Issue | 1 |
Pages | 21+ |
Publication | BMC Med Res Methodol |
ISSN | 1471-2288 |
Date | 2012-02 |
Extra | Citation Key: ben12aga tex.citeulike-article-id= 10398554 tex.citeulike-attachment-1= ben12aga.pdf; /pdf/user/harrelfe/article/10398554/1105032/ben12aga.pdf; 30d8b922169fca1fda79552f2539c4c5b4a6a32f tex.citeulike-linkout-0= http://dx.doi.org/10.1186/1471-2288-12-21 tex.citeulike-linkout-1= http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3353173/ tex.citeulike-linkout-2= http://view.ncbi.nlm.nih.gov/pubmed/22375553 tex.citeulike-linkout-3= http://www.hubmed.org/display.cgi?uids=22375553 tex.day= 29 tex.pmcid= PMC3353173 tex.pmid= 22375553 tex.posted-at= 2017-03-18 15:24:49 tex.priority= 0 |
DOI | 10.1186/1471-2288-12-21 |
Abstract | Quantiles are a staple of epidemiologic research: in contemporary epidemiologic practice, continuous variables are typically categorized into tertiles, quartiles and quintiles as a means to illustrate the relationship between a continuous exposure and a binary outcome. In this paper we argue that this approach is highly problematic and present several potential alternatives. We also discuss the perceived drawbacks of these newer statistical methods and the possible reasons for their slow adoption by epidemiologists. The use of quantiles is often inadequate for epidemiologic research with continuous variables. |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
terrific graphical examples; nice display of outcome heterogeneity within quantile groups of PSA
Type | Journal Article |
---|---|
Author | O. Naggara |
Author | J. Raymond |
Author | F. Guilbert |
Author | D. Roy |
Author | A. Weill |
Author | D. G. Altman |
URL | http://www.ajnr.org/content/32/3/437.abstract |
Volume | 32 |
Issue | 3 |
Pages | 437-440 |
Publication | Am J Neuroradiol |
Date | 2011 |
Extra | Citation Key: nag11ana tex.citeulike-article-id= 13265917 tex.citeulike-linkout-0= http://dx.doi.org/10.3174/ajnr.A2425 tex.citeulike-linkout-1= http://www.ajnr.org/content/32/3/437.abstract tex.posted-at= 2014-07-14 14:10:07 tex.priority= 0 |
DOI | 10.3174/ajnr.A2425 |
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. |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | Norbert Holländer |
Author | Willi Sauerbrei |
Author | Martin Schumacher |
URL | http://dx.doi.org/10.1002/sim.1611 |
Volume | 23 |
Pages | 1701-1713 |
Publication | Stat Med |
Date | 2004 |
Extra | Citation Key: hol04con tex.citeulike-article-id= 13265374 tex.citeulike-linkout-0= http://dx.doi.org/10.1002/sim.1611 tex.posted-at= 2014-07-14 14:09:55 tex.priority= 0 |
DOI | 10.1002/sim.1611 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
true type I error can be much greater than nominal level;one example where nominal is 0.05 and true is 0.5;minimum P-value method;CART;recursive partitioning;bootstrap method for correcting confidence interval;based on heuristic shrinkage coefficient;"It should be noted, however, that the optimal cutpoint approach has disadvantages. One of these is that in almost every study where this method is applied, another cutpoint will emerge. This makes comparisons across studies extremely difficult or even impossible. Altman et al. point out this problem for studies of the prognostic relevance of the S-phase fraction in breast cancer published in the literature. They identified 19 different cutpoints used in the literature; some of them were solely used because they emerged as the `optimal' cutpoint in a specific data set. In a meta-analysis on the relationship between cathepsin-D content and disease-free survival in node-negative breast cancer patients, 12 studies were in included with 12 different cutpoints ... Interestingly, neither cathepsin-D nor the S-phase fraction are recommended to be used as prognostic markers in breast cancer in the recent update of the American Society of Clinical Oncology."; dichotomization; categorizing continuous variables; refs alt94dan, sch94out, alt98sub
Type | Journal Article |
---|---|
Author | Barry K. Moser |
Author | Laura P. Coombs |
Volume | 23 |
Pages | 1843-1860 |
Publication | Stat Med |
Date | 2004 |
Extra | Citation Key: mos04odd tex.citeulike-article-id= 13265376 tex.posted-at= 2014-07-14 14:09:55 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
large loss of efficiency and power;embeds in a logistic distribution, similar to proportional odds model;categorization;dichotomization of a continuous response in order to obtain odds ratios often results in an inflation of the needed sample size by a factor greater than 1.5
Type | Journal Article |
---|---|
Author | Douglas G. Altman |
Volume | 78 |
Pages | 556-557 |
Publication | Brit J Cancer |
Date | 1998 |
Extra | Citation Key: alt98sub tex.citeulike-article-id= 13265377 tex.posted-at= 2014-07-14 14:09:55 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | Patrick Royston |
Author | Douglas G. Altman |
Author | Willi Sauerbrei |
URL | http://dx.doi.org/10.1002/sim.2331 |
Volume | 25 |
Pages | 127-141 |
Publication | Stat Med |
Date | 2006 |
Extra | Citation Key: roy06dic tex.citeulike-article-id= 13265458 tex.citeulike-linkout-0= http://dx.doi.org/10.1002/sim.2331 tex.posted-at= 2014-07-14 14:09:57 tex.priority= 0 |
DOI | 10.1002/sim.2331 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
destruction of statistical inference when cutpoints are chosen using the response variable; varying effect estimates when change cutpoints;difficult to interpret effects when dichotomize;nice plot showing effect of categorization; PBC data
Type | Journal Article |
---|---|
Author | Howard Wainer |
Volume | 19 |
Issue | 1 |
Pages | 49-56 |
Publication | Chance |
Date | 2006 |
Extra | Citation Key: wai06fin tex.citeulike-article-id= 13265473 tex.posted-at= 2014-07-14 14:09:57 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
can find bins that yield either positive or negative association;especially pertinent when effects are small;"With four parameters, I can fit an elephant; with five, I can make it wiggle its trunk." - John von Neumann
Type | Journal Article |
---|---|
Author | S. E. Maxwell |
Author | H. D. Delaney |
URL | http://dx.doi.org/10.1037//0033-2909.113.1.181 |
Volume | 113 |
Pages | 181-190 |
Publication | Psych Bull |
Date | 1993 |
Extra | Citation Key: max93biv tex.citeulike-article-id= 13265286 tex.citeulike-linkout-0= http://dx.doi.org/10.1037//0033-2909.113.1.181 tex.posted-at= 2014-07-14 14:09:53 tex.priority= 0 |
DOI | 10.1037//0033-2909.113.1.181 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | G. Schulgen |
Author | B. Lausen |
Author | J. Olsen |
Author | M. Schumacher |
Volume | 120 |
Pages | 172-184 |
Publication | Am J Epi |
Date | 1994 |
Extra | Citation Key: sch94out tex.citeulike-article-id= 13265375 tex.posted-at= 2014-07-14 14:09:55 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | Samy Suissa |
Author | Lucie Blais |
URL | http://dx.doi.org/10.1002/sim.4780140303 |
Volume | 14 |
Pages | 247-255 |
Publication | Stat Med |
Date | 1995 |
Extra | Citation Key: sui94bin tex.citeulike-article-id= 13264922 tex.citeulike-linkout-0= http://dx.doi.org/10.1002/sim.4780140303 tex.posted-at= 2014-07-14 14:09:45 tex.priority= 0 |
DOI | 10.1002/sim.4780140303 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | S. G. Hilsenbeck |
Author | G. M. Clark |
Volume | 15 |
Pages | 103-112 |
Publication | Stat Med |
Date | 1996 |
Extra | Citation Key: hil96pra tex.citeulike-article-id= 13264296 tex.posted-at= 2014-07-14 14:09:32 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | B. Lausen |
Author | M. Schumacher |
URL | http://dx.doi.org/10.1016/0167-9473(95)00016-X |
Volume | 21 |
Issue | 3 |
Pages | 307-326 |
Publication | Comp Stat Data Analysis |
Date | 1996 |
Extra | Citation Key: lau96eva tex.citeulike-article-id= 13264466 tex.citeulike-linkout-0= http://dx.doi.org/10.1016/0167-9473(95)00016-X tex.posted-at= 2014-07-14 14:09:36 tex.priority= 0 |
DOI | 10.1016/0167-9473(95)00016-X |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | D. G. Altman |
Volume | 64 |
Pages | 975 |
Publication | Brit J Cancer |
Date | 1991 |
Extra | Citation Key: alt91cat tex.citeulike-article-id= 13263691 tex.posted-at= 2014-07-14 14:09:21 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | D. G. Altman |
Author | B. Lausen |
Author | W. Sauerbrei |
Author | M. Schumacher |
Volume | 86 |
Pages | 829-835 |
Publication | J Nat Cancer Inst |
Date | 1994 |
Extra | Citation Key: alt94dan tex.citeulike-article-id= 13263692 tex.posted-at= 2014-07-14 14:09:21 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
Type | Journal Article |
---|---|
Author | David Faraggi |
Author | Richard Simon |
Volume | 15 |
Pages | 2203-2213 |
Publication | Stat Med |
Date | 1996 |
Extra | Citation Key: far96sim tex.citeulike-article-id= 13264063 tex.posted-at= 2014-07-14 14:09:28 tex.priority= 0 |
Date Added | 7/7/2018, 1:38:33 PM |
Modified | 11/8/2019, 8:01:59 AM |
bias in point estimate of effect from selecting cutpoints based on P-value; loss of information from dichotomizing continuous predictors