cox regression and power

  1. M

    Cox proportional hazard analysis with non-uniform samples; power analysis

    We have a study involving 10000 patients, 5000 of them treated with drug A and 5000 with drug B. We want to know if drug A is more effective than B. The median time to event (death) after treatment with drug A is 1000 days and for drug B it is 2000 days. There are two sampling scenario: In...
  2. M

    Power analysis for Cox regression...a twist?

    Hello, I am planning prospective trial using secondary data. My sample size is 480. I am using an artificial grouping based on an experimental variable where: Group 1 n= 72 Group 2 n = 408 I have not analyzed the data yet. I am seeking to determine if the experimental variable...