Question

Define how one goes about selecting a sample for a clinical trial.

Answer 1

Ans) Basic rules for estimate sample size in clinical trials:

1. The sample size increase as level of significance decrease. Usally it is taken as 5%

2. sample size increase with increasing of power

3. clinical meaningful differences

4. sample size requires equivalence is highest

calculating sample size:

1. comparing two porportions

2. comparing two means

Note: estimate sample size by typeI error and type II error

type I error is called level of significance and is denoted as

typeII error is denoted by

.