Power Loss of Stratified Log-Rank Test in Homogeneous Samples

LIFETEST+ODS+IML=Stratified Log Rank Tests

When analyzing right-censored survival data, equality of survival curves across treatment groups is often tested using log rank tests (Peto and Peto 1972), aka Mantel-Haenszel tests. For instance, in a cancer trial, the primary response variable might be time to disease progression and the treatment groups might be chemotherapy regimens. To increase power and protect against baseline imbalances...

Log-rank Test for Two Groups

analysis of power in the network society

اندیشمندان و صاحب نظران علوم اجتماعی بر این باورند که مرحله تازه ای در تاریخ جوامع بشری اغاز شده است. ویژگیهای این جامعه نو را می توان پدیده هایی از جمله اقتصاد اطلاعاتی جهانی ، هندسه متغیر شبکه ای، فرهنگ مجاز واقعی ، توسعه حیرت انگیز فناوری های دیجیتال، خدمات پیوسته و نیز فشردگی زمان و مکان برشمرد. از سوی دیگر قدرت به عنوان موضوع اصلی علم سیاست جایگاه مهمی در روابط انسانی دارد، قدرت و بازتولید...

Crossing survival curves: alternatives to the log-rank test

Background It is not uncommon for clinical trials to present results on survival time as Kaplan-Meier survival curves that cross, indicating non-proportional hazards. A recent example was given in a pivotal trial in advanced nonsmall cell lung cancer (The ‘IPASS study’ [1]). Trials such as these present a hazard ratio and log-rank test for treatment comparison as this is their planned primary a...

A log-rank-type test to compare net survival distributions.

In population-based cancer studies, it is often interesting to compare cancer survival between different populations. However, in such studies, the exact causes of death are often unavailable or unreliable. Net survival methods were developed to overcome this difficulty. Net survival is the survival that would be observed if the disease under study was the only possible cause of death. The Poha...