Comparison of the measurements of the cerebral ventricles obtained by CT scanning and pneumoencephalography

Synek, V; Reuben, J. R.; Gawler, J; Boulay, G. H. du

doi:10.1007/bf00339871

Cited by 11 publications

(1 citation statement)

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“…There are various applications where proving the equivalence or showing non-inferiority is the goal [33,34]. Methods such as the power family of inner wedge tests for two-sided equivalence tests, as presented in Chapter 6 of reference [7], are applicable in these settings because of the general Brownian motion formulation demonstrated in this paper.…”

Section: Discussionmentioning

confidence: 99%

Group sequential design for comparative diagnostic accuracy studies

Mazumdar

Liu²

2003

Statistics in Medicine

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In the field of diagnostic medicine, comparative clinical trials are necessary for assessing the utility of one diagnostic test over another. The area under the receiver operating characteristic (ROC) curve, commonly referred to as AUC, is a general measure of a test's inherent ability to distinguish between patients with and without a condition. Standardized AUC difference is the most frequently used statistic for comparing two diagnostic tests. In therapeutic comparative clinical trials with sequential patient entry, fixed sample design (FSD) is unjustified on ethical and economical grounds and group sequential design (GSD) is frequently used. In this paper, we argue that the same reasoning exists for the comparative clinical trials in diagnostic medicine and hence GSD should be utilized in this field for designing trials. Since computation of the stopping boundaries of GSD and data analysis after a group sequential test rely heavily on Brownian motion approximation, we derive the asymptotic distribution of the standardized AUC difference statistic and point out its resemblance to the Brownian motion. Boundary determination and sample size calculation are then illustrated through an example from a cancer clinical trial.

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Section: Discussionmentioning

confidence: 99%

Group sequential design for comparative diagnostic accuracy studies

Mazumdar

Liu²

2003

Statistics in Medicine

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A computed tomographic prolective trohoc study of chronic schizophrenics

et al. 1980

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The maximal width of the third ventricle, the maximal distance between the outer tips of the anterior horns, and the number of enlarged cerebral sulci on the two highest CT slices were measured in 68 chronic schizophrenic patients on cranial computed tomograms in order to detect a possible enlargement of the cerebrospinal fluid (CSF) filled intracranial spaces. These results were compared with values obtained from a control group which was formed in accordance with definite exclusion criteria and matched-pair parameters (sex, age and maximal inner diameter of the skull). In a prolective trohoc study no difference was found in the size of the CSF spaces of schizophrenics and the controls. The psychopathological condition of the patients, which was classified in a semistandardized dialogue, also showed no correlation with the ventricular size or the number of enlarged cerebral sulci.

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