Comparison of D-dimer point of care test (POCT) against current laboratory test in patients with suspected venous thromboembolism (VTE) presenting to the emergency department (ED).

Aims: To compare quantitative point of care (POC) with laboratory d-dimer testing in patients with suspected venous thromboembolism (VTE) presenting to the emergency department.
Methods: A prospective single centre diagnostic study in adults presenting with suspected VTE (pleuritic chest pain or leg swelling)
Results: Main outcome measures were the statistical correlation of the two methods. Secondary outcome measures were: test turnaround times, correlation between D-dimer levels, Wells score and final diagnosis. The results showed that there was strong evidence of POC D-dimer being sufficiently accurate to be used as a screening device. The correlation between the two logged assay scores was good. Both logged scores correlated similarly with the Wells score. Once an equivalent cut-off value for POC D-dimer (412 ng/mL) was established, there were only 4 of 100 cases all of which were extremely close to the cut-off. D-dimer turnaround time decreased by 83%. A further recent analysis of laboratory times done in 2013 demonstrates that POC D-dimer results remain 62% quicker. Based on the D-dimer results 27 patients were scanned. The median Wells score in this group was 3.0 (range 2-10) median POC D-dimer levels of 2590 (412-5000) and median lab D-dimer levels of 864 (230-13 000) showing good correlation between D-dimer positive patients and the Wells score. Seven patients had positive scans. There was a significant difference in both logged D-dimer scores between the negative and positive groups indicating that raised D-dimer levels correlate well with final diagnosis.
Conclusions: The POC device was comparable with the laboratory device and was sufficiently accurate to be used as a screening tool in the emergency department setting.