Model Diagnostics for Proportional and Partial Proportional Odds Models

The evaluation of Cox and Weibull proportional hazards models and their applications to identify factors influencing survival time in acute leukem

Introduction: The most important models used in analysis of survival data is proportional hazards models. Applying this model requires establishment of the relevance proportional hazards assumption, otherwise it world lead to incorrect inference. This study aims to evaluate Cox and Weibull models which are used in identification of effective factors on survival time in acute leukemia. Me...

Proportional Odds and Partial Proportional Odds Models for Ordinal Response Variables

Ordinal logistic regression models: application in quality of life studies.

Quality of life has been increasingly emphasized in public health research in recent years. Typically, the results of quality of life are measured by means of ordinal scales. In these situations, specific statistical methods are necessary because procedures such as either dichotomization or misinformation on the distribution of the outcome variable may complicate the inferential process. Ordina...

استفاده از مدل چندجمله‌ای کسری در تعیین عوامل مرتبط با بقای بیماران مبتلا به سرطان معده

Background & Objectives: Cox regression model is one of the statistical methods in survival analysis. The use of smoothing techniques in Cox model makes the more accurate estimates for the parameters. Fractional polynomial is one of these techniques in Cox model. The aim of this study was to assess the effects of prognostic factors on survival of patients with gastric cancer using the fractiona...

Examining Effective Factors on Duration Time of Recommitment Using Cox's Proportional Hazard Model

Abstract. Recently, in most of scientific studies, the use of survival analysis is performed for examining duration time models.  One of the important applications of survival analysis is the study of recommitment crime in criminology which has not yet been considered in Iran.  So, with attention to the necessity and importance of predicting recommitment time and the analysis of duration model...