The Linkset Model for 2^n Contingency Tables

Abstract The linkset model is defined for parametrizing the general 2^n contingency table. The linkset parameters are designed to represent latent influences that promote the co-occurrences of binary events beyond that explained by chance. Linkages involving 2 through n binary variables are included in this parametrization. The intent of this process is to elucidate the patterns of linkage, no matter how complex they might be, rather than to fit simplifying models. The relationship between linkset parameters and the natural parameters for a 2n table are derived, and large sample inference methods are provided. Examples are given from medical diagnostics, survival from the Titanic sinking, and employment discrimination in Chicago

Recovery of the Baseline Incidence Density in Censored Time-to-Event Analysis

Abstract Time-to-event analyses are often concerned with the effects of explanatory factors on the underlying incidence density, but since there is no intrinsic interest in the form of the incidence density itself, a proportional hazards model is used. When part of the purpose of the analysis is to use actual cumulative incidence for simulation, or for providing informative visual displays of the results, an estimate of the baseline incidence density is required. The usual method for estimating the baseline hazards in Cox’s proportional hazards analysis yields values that are of little use, and furthermore no standard deviations of the estimates (SDEs) are available. In this article we present an alternative approach to recovering an estimate of the baseline incidence density that yields smooth estimates as well as smooth estimates of SDEs. We illustrate the method on a large dataset of inter-visit times for individuals in a diabetes registry, and indicate how it can be used to incorporate different baseline incidence densities in the analysis of different subgroups. Keywords: proportional hazards, exponential regression, survival analysis, diabete

Augmentation of Propensity Scores for Medical Records-based Research

Therapeutic research based on electronic medical records suffers from the possibility of various kinds of confounding. Over the past 30 years, propensity scores have increasingly been used to try to reduce this possibility. In this article a gap is identified in the propensity score methodology, and it is proposed to augment traditional treatment-propensity scores with outcome-propensity scores, thereby removing all other aspects of common causes from the analysis of treatment effects

Pseudomyxoma peritonei

The subject of Ovarian Tumours and their effects is an exceedingly interesting and important one, especially in view of the efforts that are now being spade to elucidate their origin and nature.I have abstracted and epitomised the whole of the literature on Pseudomyxoma Peritonea, and present it here in what I believe to be the only complete and up-to -date account of the subject, in the hope that it may throw some light on this obscure condition, and serve as a foundation for future study.I wish to draw attention to the Histological aspect of my subject, as it in of great importance, especially mentioning in this connection the works of WERTH, WESTPHALEN, STRASSMAIN, GREENFIELD, and others.For the more complete elucidation of the Histology of Pseudomyxoma Peritonea, I have endeavoured to give in full detail the separate accounts of these authorities, adding as opportunities presented themselves, deductions and abstracts of my own, together with a complete original Histological research, carried on by myself, and illustrated by a series of Microphotographs

Reduction of Murine Cutaneous UVB-Induced Tumor-Infiltrating T Lymphocytes by Dietary Canthaxanthin

The effect of dietary canthaxanthin, retinyl palmitate, or their combination on the tumor-infiltrating T-lymphocyte response (T-TIL) in de novo murine ultraviolet type B irradiation-induced tumors was investigated to elucidate potential mechanisms of action of these compounds. We found that dietary canthaxanthin greatly reduced the number of tumor-infiltrating helper/inducer, suppressor/cytotoxic, and interleukin-2 receptor-positive T lymphocytes and also observed a concomitant statistically significant increase in tumour incidence in canthaxanthin-fed animals. The addition of retinyl palmitate to the canthaxanthin diet ameliorated this negative effect on TIL and the development of skin tumors. We conclude that dietary retinyl palmitate and canthaxanthin can modulate the host T-cell immune response within a growing tumor and may affect tumorigenicity