Application of trend analysis in evaluation of blood screening diagnostic kit for HIV

Objective To investigate the stability of trend analysis used for the evaluation of blood screening diagnostic kit for HIV. Methods The coincidence rates of negative results of reference S4 for cutoff value of sensitivity,HIV-1sample with moderate reactivity(P18),HIV-2 sample with low reactivity(P19)and negative reference were determined by consecutive batches of blood screening diagnostic kits from manufacturers A,B and C,based on which Levey-Jennings trend analysis curve was plotted,and the mean and standard deviation(SD)of each sample were calculated. The change trend of test indexes of diagnostic kits from various manufacturers were observed serving mean ± 2 SD as a warning limit and mean ± 3 SD as an action limit. Results The quality of kit A was stable,with any batch of which the determination results of samples S4,P18 and P19 were not beyond the action limit. The coincidence rates of negative results of negative reference with kits B and C were shown in the trend analysis. However,the determination results of sample P18 with kit B of two batches were beyond the action limits,while those of samples S4,P18 and P19 by kit C of eight consecutive batches were on the same sides of mean. In accelerated stability test at 37 ℃,the change trends of determination results of samples P18,P19 and S4 determined by 32 batches of kit C were in agreement. The results of accelerated stability test at 37 ℃ and stability test at 4 ℃ of sample S4 showed significant difference(P 0. 01). The results of accelerated stability tests of samples S4,P18 and P19 from various manufacturers showed significant difference with those from Na-tional Institutes for Food and Drug Control(NIFDC)(each P 0. 01). Conclusion The qualities of domestic blood screening diagnostic kits for HIV were stable,of which the change could by found by trend analysis. Trend analysis may be used for the evaluation on stability of in vitro diagnostic kits for HIV.