Immunotherapy – 2069. Multi-center study on the performance characteristics of two skin test devices - Comforten® and Mult-Test II®

Results Overall, CF10 gave smaller wheals than MT, (combined sites and both histamines1.95 vs. 3.53, p<0.001). Wheals were also smaller at NJH than at AAC (combined devices and histamines 2.33 vs. 3.16, p<0.001). Comparing devicehistamine combinations as described by each company’s product insert, i.e. CF10 with 6mg/mL vs. MT with 1mg/mL, wheals were not significantly different (combined centers 4.00 vs. 4.07, p=0.62). The impact of wheal size on sensitivity and specificity to define a positive reaction was examined at 1, 3 and 5mm. Sensitivity increased as the cut-off decreased and trended higher for MT than CF10. Specificity was high (100%) for all cut-off levels at NJH but lower at AAC for MT (80%, 85% and 92%) and CF10 (98%, 98% and 99%). Optimal performance across sites showed that both devices required 6mg/mL histamine but with device specific cut-offs CF10-1mm (sensitivity=93%, specificity=99%), and MT3mm (sensitivity=94%, specificity=91%). Pain using the two devices appeared to be site-specific. At ACC, there was significantly lower pain using CF10 than there was using MT (0.77 vs. 1.68, p=0.001) while at NJH, there was no significant difference in pain scores. Overall, 57% of subjects showed preference to using CF10, while only 9% preferred MT. The remainder (34%) showed mixed preference.