ABSTRACT
<p><b>AIM</b>To provide proof for Evidence-based Medicine as well quality control, our laboratory detected the thrombin activity on various body position.</p><p><b>METHODS</b>By autogenous contrast and cross matched survey, 105 volunteers divided into 3 season patches of winter, spring and summer, blood samples were drawn from the same part in both standing and lying position. Both samples and the quality control were detected to investigate the effect of the body position to thrombin activity's changing. The data were analyzed by SPSS 10.0.</p><p><b>RESULTS</b>Taking the lying's data as baseline, the average changing on all those the "5" index was 7.07% and the highest changing reached 9.33%. This kind changing had great significant differences (P < 0.01). According to the t value, sequences ranged: FIB > TT > PT > INR > APTT. FIB, TT and APTT's values slowly raised, adversely PT and INR slowly went down. While sitting for 15 min after lying, these indices returned to 95.2% of the original value in sitting position in addition. Season, age and device had no relationship with body position.</p><p><b>CONCLUSION</b>Changing body position can result in obvious physiological variation of thrombin activity.</p>