Background: Troponin and D-dimer point of care tests (POCTs) can be used to aid the diagnosis of patients with symptoms suggestive of suspected acute coronary syndrome and venous thromboembolism respectively. Potential advantages of POCT include, for instance, a faster turnaround time, a reduced length of stay and reduced unnecessary hospitalisation/further testing.

This rapid assessment addresses the research question whether using the POCT for D-dimer and troponin (Tn) in symptomatic patients presenting at ambulatory (primary or community care) settings or emergency care settings is more effective and/or safer than current diagnostic practice.

Methods: The EUnetHTA Core Model® was used as a reporting standard. Assessment elements from the Rapid Relative Effectiveness Assessments Version 4.2 were utilised. Where applicable, further assessment elements from the HTA Core Model® Application for Diagnostic Technologies version 3.0. were used. This report comprises two guideline synopsises, two overviews of reviews (incl. update assessments) and expert consultations.

Results: For Tn-POCT, we identified 15 relevant point of care devices for this rapid evidence synthesis. Of these, 14 devices measure troponin quantitatively. For D-dimer POCT, eleven devices were identified, eight of which measure D-dimer quantitatively. POCT devices can be classified in different ways e.g., hand-held devices, fixed devices, etc., and manifest differences in measurement methods (e.g., quantitative vs. qualitative, the sample size and analytical range). The exact nature of POCT products in use in the Austrian and Romanian health care systems is unknown.

For the evaluation of the effectiveness of implementing Tn-POCT, two systematic reviews (42 primary studies) were included. The results for diagnostic test accuracy show that there are significant inconsistencies in estimates measured across settings as evident in the comparison of diagnostic test accuracy estimates of the 11 studies included in the one systematic review and significant limitations with the data (e.g., solely non-comparative studies) in the other review. The comparative evidence found by the one systematic review shows that, compared with Central Laboratory (CL) testing, Tn-POCT tended to have a lower sensitivity, lower negative predictive value, higher specificity and higher positive predictive value. Of the 32 studies in the included reviews that investigated the clinical utility of Tn-POCT, seven were randomised controlled trials. The evidence was insufficient to show non-inferiority in comparison to CL testing when implementing Tn-POCT if CL testing is onsite or readily available (e.g., in the emergency department). The evidence is also insufficient to clearly show superiority when compared to usual care in settings without or with delayed CL testing (e.g., certain ambulatory care settings, pre-hospital emergency medicine).

For D-dimer POCT, six systematic reviews, containing between four and nine studies relating to between 199 and 55,268 patients were included in this assessment. The quality of these reviews was moderate to high. A further two non randomised controlled trials with moderate to severe risk of bias were included to update one systematic review. One systematic review reported evidence regarding the effect of implementing D-dimer POCT in emergency care on patient management. Based on observational studies only, this review of moderate quality at most, found D-dimer POCT to be associated with a reduction of turnaround time, a reduction in number of hospital admissions and shorter length of stay. However, given the absence of RCT data, the evidence is insufficient to show a beneficial effect on patient management, and no evidence was found to evaluate the effect on mortality/morbidity and quality of life in the emergency department. Similarly, only a few prospective studies evaluating the effect of GP use of POCT on clinical diagnostic accuracy and clinical management in primary care patients with cardiopulmonary symptoms have been performed. As a consequence, there is a lack of reliable, good quality evidence to show non-inferiority compared to CL testing and superiority compared to the current situation (with no immediate CL testing) in emergency care or ambulatory care (primary and community care) settings. There is, however, some evidence suggesting that, in ambulatory care, the combination of D-dimer POCT (especially the quantitative type) with a sensitive clinical decision rule (e.g. when general practitioners use a D-dimer POCT in combination with the more sensitive Wells clinical decision rule) leads to a more accurate diagnosis of venous thromboembolism than without POCT. The negative predictive value of the combined D-dimer POCT and clinical decision rule can be quite high (>95%) which may indicate that some patients avoid referrals to imaging within a hospital setting. However, this assumes the correct use of D-Dimer POCT in combination with an established clinical prediction tool.

Conclusion: Before such tests are implemented or their use extended, further research on specific point of care tests (quantitative, with certain predefined analytical characteristics) in specific settings is needed. Here a health services research approach might be more appropriate than traditional evidence-based medicine, to assess potential benefits in different settings from a systems approach.