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An omnibus index offers a single summary expression for a fourfold table of binary concordance among two observers. Among the available other omnibus indexes, none offers a satisfactory solution for the paradoxes that occur with p0 and kappa. The problem can be avoided only by using ppos and pneg as two separate indexes of proportionate agreement in the(More)
We performed a Monte Carlo study to evaluate the effect of the number of events per variable (EPV) analyzed in logistic regression analysis. The simulations were based on data from a cardiac trial of 673 patients in which 252 deaths occurred and seven variables were cogent predictors of mortality; the number of events per predictive variable was (252/7 =)(More)
Boundaries for delta, representing a "quantitatively significant" or "substantively impressive" distinction, have not been established, analogous to the boundary of alpha, usually set at 0.05, for the stochastic or probabilistic component of "statistical significance". To determine what boundaries are being used for the "quantitative" decisions, we reviewed(More)
The opinions set forth in this report are those of the committee members and do not represent the Food and Drug Administration in any way. R osacea is well recognized as a chronic cuta-neous disorder primarily of the convexities of the central face (cheeks, chin, nose, and central forehead), often characterized by remissions and exacerbations. Based on(More)
Many epidemiologists argue that few cases of symptomless endometrial cancer can escape detection during life. This article provides empirical evidence which support a fundamental premise of the detection-bias hypothesis that many cases of endometrial cancer are unsuspected during life and first detected at autopsy. The authors reviewed all autopsies(More)
Many substances used in daily life, such as coffee, alcohol, and pharmaceutical treatment for hypertension, have been accused of "menace" in causing cancer or other major diseases. Although some of the accusations have subsequently been refuted or withdrawn, they have usually been based on statistical associations in epidemiologic studies that could not be(More)
BACKGROUND An interest in measuring subjective phenomena such as pain, nausea, anxiety, etc. has led clinicians to develop three types of ratings: the visual analog scale (VAS); the verbal rating scale (VRS), and the numeric rating score (NRS). These ratings are regarded as global scales because they lack criteria to demarcate diverse dimensions or(More)
To assess the efficacy of oestrogens in preventing the common major limb fractures of postmenopausal women, retrospective case-control research was used for a new purpose--to explore beneficial rather than adverse effect of treatment. Postmenopausal women admitted with fractures of the hip or distal radius and matched women admitted to the orthopaedic(More)
Despite extensive growth in recent years, the field of "quality-of-life" appraisal still evokes debate about basic perception of the concept and is accompanied by a plethora of indexes for measurement. One prime reason for the problems is that the measurements have been transferred from two separate sources - medical health status indexes and social-science(More)