D-dimers are proteins formed from the degradation of cross-linked fibrin through a normal body process called fibrinolysis, which breaks down naturally occurring blood clots to avoid their excessive accumulation in the blood.
D-dimers are present in only negligible amounts in the blood of healthy individuals. Resulting from an increased fibrinolytic activity, elevated concentration of D-dimer suggests the possibility of thrombotic diseases and intravascular coagulation. However, there are also many medical conditions unrelated to thrombosis which lead to high D-dimer concentrations in blood, making the predictive value of D-dimer tests rather poor in diagnosing a particular form of thrombotic disease. As a result, a D-dimer test cannot solely confirm the presence of a thrombotic disease – further imaging techniques are essential before important clinical decisions are made.
Despite these limitations, D-dimer is considered a highly valuable laboratory tool used to diagnose and manage a wide array of medical conditions related with thrombosis, including diagnosis of venous thromboembolism (VTE), identification of risks of recurrent VTE, identification of cases at an increased risk of first thrombotic stroke, and monitoring/diagnosis of disseminated intravascular coagulation (DIC).
Three types of D-dimer tests are currently on the market and are forming a part of routine check-ups in the first-line diagnosis of patients suspected of having a form of VTE – deep vein thrombosis (DVT) and pulmonary embolism (PE). These are the ELISA test (enzyme-linked immunosorbent assay), latex agglutination assay, and the whole-blood agglutination assay.
A recent report published by U.S.-based market intelligence company Transparency Market Research states that the global market for D-dimer tests is a billion-dollar industry in spite of the many limitations associated with D-dimer test results. The report states that the market had a net value of US$1.5 billion in 2013 and has prospects of growing at a 2.6% CAGR between 2014 and 2022, allowing the market to rise to a net value of US$1.9 billion by 2022.
In 2013, nearly 95 million D-dimer tests took place in North America. This volume is expected to rise to 126.4 million by 2022. The market also shows good growth prospects in Europe and the larger economies in Asia Pacific.
Though not entirely insignificant, the meager observable benefits of D-dimer tests raise several questions regarding their rising popularity. Here are the two main reasons responsible for the rise in demand for D-dimer tests market:
- High negative predictive value
When one considers the safe cutoff for the concentration of D-dimer in blood, studies have demonstrated that a higher value may not always indicate thrombosis (as explained earlier), but a lower than cut-off value can be reliably used for the exclusion of any such possibility. This high negative predictive value of these tests allows omission of thrombosis possibilities without the need for time-consuming and expensive imaging assays, making these tests worthy primary screening mechanisms.
- Cost and time saving
By helping avoid expensive imaging tests, D-dimer tests also lead to reduced hospitalization times, and thereby to reduced overall medical costs. D-dimer tests also help patients avoid invasive procedures, further reducing the chances of infection and resultant medical complexities and expenses for treating them.
In the past few years, there has been a constant rise in the number of patients undergoing coagulation tests. A general rise in health awareness amongst the masses, increased per capita incomes in developing countries, and technological breakthroughs , making test results accurately measurable, have all led to increased adoption of D-dimer tests.