TY  - JOUR
T1  - THe ethics of underpowered clinical trials—reply
AU  - Halpern SD, Karlawish JT, Berlin JA
Y1  - 2002/11/06
N1  - 10.1001/jama.288.17.2118
JO  - JAMA
SP  - 2118
EP  - 2119
VL  - 288
IS  - 17
N2  - 
In Reply: Dr Janosky correctly points out that
statistical power is a continuous quantity. Accepting the value of .80 as
adequate power is as arbitrary as accepting .05 to denote statistical significance.
Greater power and stricter standards for significance will always be preferable,
but one is always obtained at the cost of the other. Our experience has been
that many peer reviewers still adhere to a dichotomy based on 80% or 90% power.
However, no numerical value for power will be adequate if it is generated
without carefully considering the size of the clinically important effect.
The 3-tiered model we propose may help investigators determine such effects
and calculate their power accordingly.

SN  - 0098-7484
M3  - doi: 10.1001/jama.288.17.2118
UR  - http://dx.doi.org/10.1001/jama.288.17.2118
ER  -