The effects of transport by car on coagulation tests

Background: This research investigated the effects of the transport of blood samples between centers/laboratories by car on coagulation tests. Methods: Five tubes of blood samples were taken from 20 healthy volunteers. The samples consisted of a baseline (control) group, centrifuged and noncentrifuged transported samples; centrifuged and noncentrifuged untransported samples. The groups of centrifuged and noncentrifuged samples were transported by car for 2 h. The centrifuged and noncentrifuged untransported samples were incubated in the laboratory until the transported samples arrived. Prothrombin time (PT) and activated partial thromboplastin time (APTT) tests were conducted for all samples. Results: Significant differences between the baseline group and the centrifuged and noncentrifuged transported samples and the noncentrifuged untransported samples were found for APTT levels (p < 0.05, for all). In addition, significant mean percentage differences in PT values were found between the baseline group and the noncentrifuged transported samples (p < 0.001) and the noncentrifuged untransported samples (p = 0.005). The mean level of PT in the noncentrifuged transported samples was outside the upper limit of the clinical decision level. Conclusions: Noncentrifuged transported samples showed clinically significant differences in PT test results that may have stemmed from mechanical agitation during transportation. Therefore, we recommend not transporting noncentrifuged specimens for PT testing by car.