The Occupational Safety and Health Administration (OSHA) revised the Bloodb
orne Pathogen Standard and, on July 17, 2001, began enforcing the use of ap
propriate and effective sharps devices with engineered sharps-injury protec
tion. OSHA requires employers to maintain a sharps-injury log that records,
among other items, the type and brand of contaminated sharps device involv
ed in each injury. Federal OSHA does not require needlestick injury rates t
o be calculated by brand or type of device. A sufficient sample size to sho
w a valid comparison of safety devices, based on injury rates, is rarely fe
asible in a single facility outside of a formal research trial. Thus, calcu
lations of injury rates should not be used by employers for product evaluat
ions to compare the effectiveness of safety devices. This article provides
examples of sample-size requirements for statistically valid comparisons, r
anging from 100,000 to 4.5 million of each device, depending on study desig
n, and expected reductions in needlestick injury rates (Infect Control Hosp
Epidemiol 2001;22:456-458).