The cost–effectiveness of point-of-care D-dimer tests compared with a laboratory test to rule out deep venous thrombosis in primary care

Abstract

Objective: Point-of-care (POC) D-dimer tests have been developed to exclude deep venous thrombosis quickly and on the spot, but are known to have lower sensitivity compared with laboratory-based tests. Their cost–effectiveness is still unknown. Methods: We updated and extended a previously published Markov model to assess the cost–effectiveness of POC D-dimer tests (‘Simplify’, ‘Cardiac’, ‘Triage’ and ‘Nycocard’) compared with a laboratory-based latex assay to diagnose deep venous thrombosis in primary care. Results: The ‘Laboratory’ strategy resulted in 6.986 quality-adjusted life years at the cost of €8354 per patient. All POC D-dimer tests resulted in health outcomes similar to the ‘Laboratory’ strategy. The ‘Simplify’ strategy maximized cost savings (–€155 [95% CI: –€246 to –€83]). Conclusions: POC D-dimer tests yield similar health outcomes as laboratory-based testing procedures but can be performed more easily and at lower costs. Therefore, these tests are an alternative to laboratory-based testing and might be considered for exclusion of deep venous thrombosis in primary care.

Keywords:

• cost–effectiveness
• D-dimer
• point-of-care test
• primary care
• venous thromboembolism

Financial & competing interests disclosure

H Koffijberg has received a personal grant from NWO, The Netherlands Organisation for Scientific Research (#916.11.126), for studying methods enhancing the economic evaluation of diagnostic tests. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Point-of-care (POC) D-dimer tests can be performed on the spot to exclude deep venous thrombosis, and are especially helpful in outpatient settings.

• However, the ease of POC testing comes at the price of a lower sensitivity compared with hospital-based laboratory testing (e.g., ELFA) and potentially leads to more missed cases.

• As part of the evaluation of a (new) diagnostic strategy, it is important to assess the full spectrum of health outcomes, which also includes costs involved and quality of life.

• The cost–effectiveness of a diagnostic strategy can be assessed by using a Markov model, a mathematical model that takes into account the probability of having an event like a deep venous thrombosis of pulmonary embolism, quality of life and the costs involved in the diagnosis and therapy of these diseases.

• Results of a cost–effectiveness analysis performed in one country cannot be translated into other settings indiscriminately, but results could be applicable to healthcare settings with a comparable primary care background to a great extent.

• If the main interest is reduction of costs, the use of a POC test in outpatients might be preferred over referral of patients to secondary care to undergo laboratory testing, yet at the expense of marginal health loss.

• Both quantitative and qualitative POC D-dimer tests do yield health outcomes comparable to laboratory-based D-dimer tests, but more rapidly and at lower costs.

Notes