Study methods affect findings of safety trial of blunt suture needles.
Jagger J; Berguer R; Gomaa AE
Am J Obstet Gynecol 2009 Oct; 201(4):E11-E12
TO THE EDITORS: Wilson et. al. assert that blunt suture needles are as likely to cause glove punctures as sharp suture needles during obstetric laceration repair. We believe that their conclusion, which is at odds with previous studies, is not supported by their evidence for the following reasons: First, the investigators greatly overestimated the expected puncture rate (20%), which led them to underestimate proportionately the required sample size. They selected a short procedure in which only 1 or 2 sutures were placed, which minimizes the potential for needlestick occurrence during the study period. Because the actual puncture rate (2%) fell far short of the expected rate and the sample size was insufficient, the conclusion that there was no difference in puncture rates between the 2 groups was a statistical certainty that was based on a flawed study design-not an experimental finding. Second, the investigators neglected to inspect a control sample of unused gloves for preexisting defects. The perforation rates they reported should have been corrected for the rate of defects that were found in unused gloves. When this study was conducted, the Food and Drug Administration allowed a 2.5% rate of "preexisting defects" in surgical gloves, which exceeds the perforation rates reported by Wilson et al (1.8% and 2.3%). It is possible that most or even all "perforations" that they found were preexisting defects. Third, the investigators do not state how many of the surgeons in each group wore single or double pairs of gloves or, more importantly, if perforations were to exterior or interior gloves. They do not state whether a perforation to both the exterior and interior gloves of 1 surgeon was counted as 1 perforation or 2. If glove perforation is a proxy for needlesticks, then there can be only 1 needlestick when a needle pierces a double layer of gloves. Similarly, perforation to an interior glove only should not be counted because this could not have been the result of a needle puncture. A further oversight of this study was that the gloves of other members of the surgical team were not checked for perforations. A multihospital study of injuries in the operating room showed that 25% of sharps injuries were to attending surgeons and that the rest were to other operating room personnel. Suture needles can cause injuries during passing, during disposal, and after disposal. Protective surgical devices have the potential to benefit all operating room personnel, not just surgeons.
Exposure-assessment; Exposure-levels; Exposure-methods; Gloves; Health-care-personnel; Medical-personnel; Needlestick-injuries; Occupational-accidents; Occupational-exposure; Occupational-hazards; Personal-protection; Protective-equipment; Protective-measures; Statistical-analysis; Work-environment; Work-practices; Surveillance-programs
Janine Jagger MPH, PhD, University of Virginia Health System, PO Box 800764, Charlottesville, VA 22908-0764
Healthcare and Social Assistance
American Journal of Obstetrics and Gynecology