Are the latest point-of-care D-dimer devices ready for use in general practice? A prospective clinical evaluation of five test systems with a capillary blood feature for suspected venous thromboembolism

INTRODUCTIONWe evaluated clinical performance of five novel point-of-care (POC) D-dimer devices with a capillary finger stick feature for predicting venous thromboembolism (VTE) in general practice: Exdia TRF Plus (E), AFIAS-1® (A), Standard F200® (S), LumiraDx™ (L) and Hipro AFS/1® (H).MATERIALS AND METHODSPrimary care patients with a low suspicion of a VTE were asked to consent to (i) draw additional venous blood samples, (ii) perform a capillary POC D-dimer test, (iii) approach their general practitioner afterwards for clinical outcomes. Venous plasma samples were processed on all POC devices and a laboratory-based assay (STA-Liatest®D-Di PLUS assay). Results were compared with clinical outcomes to generate performance characteristics. Capillary and venous blood results were used for a matrix comparison.RESULTSVenous plasma samples from 511 participants, of whom 57 had VTE, were used for clinical performance analyses. Areas under Receiving Operating Characteristic Curves ranged from 0.90 (95 % CI: 0.86-0.94) (H) to 0.93 (0.90-0.96) (E). All false-negative rates were below 1.4 % (95 % CI: 0.5 %-3.4 %). Matrix comparison demonstrated correlation coefficients ranging from r = 0.11 (95 % CI: -0.15-0.36) (H) to r = 0.94 (0.90-0.97) (A) with concordance percentages ranging from 71.4 % (applying a D-dimer cutoff of 500 ng/mL) (H) to 100 % (applying an age-dependent D-dimer cutoff) (A).CONCLUSIONSClinical performance of the POC D-dimer devices for predicting a VTE in low-risk patients was comparable to that of a laboratory-based assay. However, our results indicate that the finger stick feature of certain devices should be further improved. (NL71809.028.19.).