Abstract:
:Various aspects of portfolio management and project prioritization within the pharmaceutical industry are examined. It is shown that the cost and probability architecture of a project is a crucial aspect of its value. An appropriate simple tool for ranking projects is the Pearson index. Various difficulties are considered.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Senn Sdoi
10.1002/(SICI)1097-0258(19961230)15:24<2689::AID-Ssubject
Has Abstractpub_date
1996-12-30 00:00:00pages
2689-702issue
24eissn
0277-6715issn
1097-0258pii
10.1002/(SICI)1097-0258(19961230)15:24<2689::AID-Sjournal_volume
15pub_type
杂志文章abstract::Proportional odds regression models for multinomial probabilities based on ordered categories have been generalized in two somewhat different directions. Models having scale as well as location parameters for adjustment of boundaries (on an unobservable, underlying continuum) between categories have been employed in t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780141105
更新日期:1995-06-15 00:00:00
abstract::Regression to the mean arises often in statistical applications where the units chosen for study relate to some observed characteristic in the extreme of its distribution. Gardner and Heady attribute the effect of regression to the mean to measurement errors. They assume the model Yi = U + ei, where U is a fixed withi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780100812
更新日期:1991-08-01 00:00:00
abstract::The mixed effect models for repeated measures (MMRM) analysis is sometimes used as a primary analysis in longitudinal randomized clinical trials. The SE for the treatment effect in the MMRM analysis is usually estimated by assuming the orthogonality of the fixed effect and variance-covariance parameters, which is the ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8474
更新日期:2020-04-30 00:00:00
abstract::We present methods for binomial regression when the outcome is determined using the results of a single diagnostic test with imperfect sensitivity and specificity. We present our model, illustrate it with the analysis of real data, and provide an example of WinBUGS program code for performing such an analysis. Conditi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1656
更新日期:2004-04-15 00:00:00
abstract::The correct identification of change-points during ongoing outbreak investigations of infectious diseases is a matter of paramount importance in epidemiology, with major implications for the management of health care resources, public health and, as the COVID-19 pandemic has shown, social live. Onsets, peaks, and infl...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8807
更新日期:2021-02-20 00:00:00
abstract::The problem of testing symmetry about zero has a long and rich history in the statistical literature. We introduce a new test that sequentially discards observations whose absolute value is below increasing thresholds defined by the data. McNemar's statistic is obtained at each threshold and the largest is used as the...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5384
更新日期:2012-11-20 00:00:00
abstract::Summarizing the information of many studies using a meta-analysis becomes more and more important, also in the field of diagnostic studies. The special challenge in meta-analysis of diagnostic accuracy studies is that in general sensitivity and specificity are co-primary endpoints. Across the studies both endpoints ar...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6583
更新日期:2015-12-20 00:00:00
abstract::One may encounter the application of the two independent samples t-test to ordinal scaled data (for example, data that assume only the values 0, 1, 2, 3) from small samples. This situation clearly violates the underlying normality assumption for the t-test and one cannot appeal to large sample theory for validity. In ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780060110
更新日期:1987-01-01 00:00:00
abstract::A survey is conducted at w of K selection units or lists, e.g. health care institutions or weeks in a year, to estimate N, the total number of individuals with particular characteristics. Our estimator utilizes two items determined for each survey participant: the number, u, among the w lists in S and the number, j, a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3614
更新日期:2009-07-30 00:00:00
abstract::The original article to which this Correction refers was published in Statistics in Medicine 2000 19(14): 1901-1914. ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20001115)19:21<3017::aid-sim785>
更新日期:2000-11-15 00:00:00
abstract::This paper considers the problem of selecting a set of regressors when the response variable is distributed according to a specified parametric model and observations are censored. Under a Bayesian perspective, the most widely used tools are Bayes factors (BFs), which are undefined when improper priors are used. In or...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6249
更新日期:2014-11-20 00:00:00
abstract::Both traditional phase I designs and the increasingly popular continual reassessment method (CRM) designs select an estimate of maximum tolerable dose (MTD) from among a set of prespecified dose levels. Although CRM designs use an implied dose-response model to select the next dose level, in general it is neither assu...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.903
更新日期:2001-08-30 00:00:00
abstract::Interpretation of the Mantoux test for tuberculous infection can be complicated by cross-reactions caused by infection with non-specific mycobacteria. Thus, the distribution of positive indurations is a mixture of two distributions. To estimate tuberculous infection prevalence, the marginal distribution of indurations...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.745
更新日期:2001-04-15 00:00:00
abstract::Competing compartment models of different complexities have been used for the quantitative analysis of dynamic contrast-enhanced magnetic resonance imaging data. We present a spatial elastic net approach that allows to estimate the number of compartments for each voxel such that the model complexity is not fixed a pri...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5997
更新日期:2014-03-15 00:00:00
abstract::The FDA permits marketing of a generic formulation of a drug G for the same indications as a standard preparation S if one can show that G is bioequivalent to S. Present implementation requires convincing evidence that the population mean difference in bioavailability (drug exposure) between the two preparations lies ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780111311
更新日期:1992-09-30 00:00:00
abstract::Motivated by a previously published study of HIV treatment, we simulated data subject to time-varying confounding affected by prior treatment to examine some finite-sample properties of marginal structural Cox proportional hazards models. We compared (a) unadjusted, (b) regression-adjusted, (c) unstabilized, and (d) s...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5317
更新日期:2012-08-30 00:00:00
abstract::We propose to use a very simple model to test whether a cancer cluster is due to chance alone. We focus on the acute childhood leukaemia cluster in Columbus, Ohio. In 1975, 12 leukaemia cases were observed in Columbus while the expected number is 6 cases per year. According to our simple model, the probability of such...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000830)19:16<2195::aid-sim522>
更新日期:2000-08-30 00:00:00
abstract::Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the c...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.2151
更新日期:2005-09-30 00:00:00
abstract::Random forest is a supervised learning method that combines many classification or regression trees for prediction. Here we describe an extension of the random forest method for building event risk prediction models in survival analysis with competing risks. In case of right-censored data, the event status at the pred...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5775
更新日期:2013-08-15 00:00:00
abstract::In this paper, we consider a full likelihood method to analyze continuous longitudinal responses with non-ignorable non-monotone missing data. We consider a transition probability model for the missingness mechanism. A first-order Markov dependence structure is assumed for both the missingness mechanism and observed d...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5359
更新日期:2012-12-10 00:00:00
abstract::Most statistical methodology for phase III clinical trials focuses on the comparison of a single experimental treatment with a control. An increasing desire to reduce the time before regulatory approval of a new drug is sought has led to development of two-stage or sequential designs for trials that combine the defini...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1362
更新日期:2003-03-15 00:00:00
abstract::Population dynamic models, commonly used tools in the study of epidemics and other complex population processes, are implicit non-linear mathematical equations. Inference based on such models can be difficult due to the problems associated with high dimensional parameters that may be non-identified and complex likelih...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1258
更新日期:2002-12-15 00:00:00
abstract::Prognostic models are used in medicine for investigating patient outcome in relation to patient and disease characteristics. Such models do not always work well in practice, so it is widely recommended that they need to be validated. The idea of validating a prognostic model is generally taken to mean establishing tha...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(20000229)19:4<453::aid-sim
更新日期:2000-02-29 00:00:00
abstract::A personalized treatment strategy formalizes evidence-based treatment selection by mapping patient information to a recommended treatment. Personalized treatment strategies can produce better patient outcomes while reducing cost and treatment burden. Thus, among clinical and intervention scientists, there is a growing...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6783
更新日期:2016-04-15 00:00:00
abstract::Systematic reviews often provide recommendations for further research. When meta-analyses are inconclusive, such recommendations typically argue for further studies to be conducted. However, the nature and amount of future research should depend on the nature and amount of the existing research. We propose a method ba...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5524
更新日期:2013-01-15 00:00:00
abstract::Clinical trials often assess therapeutic benefit on the basis of an event such as death or the diagnosis of disease. Usually, there are several additional longitudinal measures of clinical status which are collected to be used in the treatment comparison. This paper proposes a simple non-parametric test which combines...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1002/(sici)1097-0258(19990615)18:11<1341::aid-s
更新日期:1999-06-15 00:00:00
abstract::This paper reviews Bayesian strategies for monitoring clinical trial data. It focuses on a Bayesian stochastic curtailment method based on the predictive probability of observing a clinically significant outcome at the scheduled end of the study given the observed data. The proposed method is applied to derive efficac...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2204
更新日期:2006-07-15 00:00:00
abstract::The risk that a drug newly introduced into medical use will occasionally cause adverse reactions is neither negligible nor totally avoidable. Only well organized systems of monitoring can bring early detection and appropriate action. These in turn require either detailed supervision or spontaneous reporting. The paper...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780010208
更新日期:1982-04-01 00:00:00
abstract::Reference ranges which take time (such as age) into account are often required in medicine, but simple, systematic and efficient statistical methods for constructing them are lacking. A method is described which is based on low order polynomial curves (linear, quadratic or occasionally cubic), together with guidelines...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1002/sim.4780100502
更新日期:1991-05-01 00:00:00
abstract::Case-control studies are usually defined to investigate risk factors for a single disease of interest. However, subsequent to data collection, investigators may wish to examine as an 'outcome' a variable that was an exposure in the original study. A naive analysis that disregards the sampling strategy that gave rise t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2398
更新日期:2005-12-30 00:00:00