International survey on D-dimer test reporting: a call for standardization.

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Thrombosis Diagnostics

Background:

• D-dimer is a crucial biomarker for diagnosing thrombotic disorders.
• Current reporting of D-dimer results lacks standardization across clinical laboratories worldwide.
• This heterogeneity can impact diagnostic accuracy and patient management.

Purpose of the Study:

• To assess the current state of D-dimer test result reporting standardization globally.
• To identify variations in units of measurement and cutoff thresholds used in clinical practice.
• To highlight the need for international harmonization in D-dimer reporting.

Main Methods:

• A five-item online questionnaire was developed and disseminated globally.
• Data were collected from 409 respondents across various healthcare settings and countries.
• Responses were analyzed to identify trends in D-dimer reporting practices.

Main Results:

• Significant heterogeneity was observed in the units used for D-dimer results (e.g., ng/mL, mg/L, µg/L) and the application of fibrinogen equivalent units.
• At least 28 different combinations of measurement units are currently employed worldwide.
• Most laboratories (93%) use fixed cutoffs, with minimal variation across settings.

Conclusions:

• The current reporting of D-dimer results is highly variable globally.
• There is an urgent need for international collaborative efforts to standardize D-dimer reporting.
• Standardization will improve diagnostic consistency and clinical utility of D-dimer testing.