Fig. 3
From: Bacterial contamination upon the opening of injection needles
a Contamination of the lateral surface of the needle hub. b Contamination of the bottom surface of the needle hub. c Contamination of the inner lumen of the needle hub. Regarding (a) and (b), the Cochran-Mantel-Haenszel test considering the concentration of S. aureus as a stratum was used to compare between opening methods. The Jonckheere test was performed to evaluate the concentration of the S. aureus-contamination relationship for the push-off top method data and was not performed for the peel-apart method because only one needle hub was contaminated. Regarding (c), since fewer contaminated needle hubs were observed, the number of bacteria was classified into contaminated/uncontaminated, and Fisher’s exact test was used to compare opening methods