RT Journal Article
SR Electronic
T1 Lack of Statistical Power
JF Pediatrics
JO Pediatrics
FD American Academy of Pediatrics
SP 313
OP 314
VO 79
IS 2
A1 PASCOE, JOHN M.
YR 1987
UL http://pediatrics.aappublications.org/content/79/2/313.4.abstract
AB To the Editor.— Dr Donowitz described an interesting research project in which the efficacy of overgown use in the prevention of pediatric intensive care unit nosocomial infection was examined.1 He concludes that "overgowns were an expensive and ineffective method of preventing or decreasing nosocomial infections."1 Although Dr Donowitz may be correct, his inattention to sample size and statistical power in this negative trial makes his argument less than compelling. Given the nosocomial "base rate" of about 10% without gowns, the detection of an infection rate difference of 50% between the nongown and gown subgroups (α = .05, β = .2) would require a sample size of about 500 in each subgroup.2