D-dimer testing as the initial test for suspected pulmonary embolism. Appropriateness of prescription and physician compliance to guidelines

Objectives: Recent studies have shown that strategies for pulmonary embolis m diagnosis which have included D-dimer testing have been most cost effecti ve. The objective of this study is to evaluate the impact of implementation of a new strategy for pulmonary embolism diagnosis based on D-dimer result s. Methods: A prospective survey was conducted in the emergency ward and th ree medical departments of a university teaching hospital. Guidelines for d iagnosis of PE were established and implemented through an educational inte rvention and a specific order form. D-dimer (ELISA) was required for all pa tients suspected of having PE. A result above 500 ng/ml was to be followed by a pulmonary imaging procedure. Appropriateness of prescription of D-dime r and non-compliance with guidelines (absence of diagnostic imaging procedu re following D-dimer results above 500 ng/ml) were evaluated. Results: One- hundred sixty patients were studied. D-dimer test was performed in 154 pati ents (96.3%) suspected of PE during a two-month period. Tests results were above 500 ng/ml in 111 cases. PE was confirmed in 20 cases. Twenty percent (31/154) of the D-dimer prescriptions were inappropriate. Among those with D-dimer results above 500 ng/ml, 45% (50/111) of the patients experienced n o imaging procedure. Conclusion: Despite implementation of clinical guideli nes for its use, D-dimer was excessively prescribed. A large proportion of results was not taken in consideration by prescribers. Often new technologi es have good experimental results, but behave differently when used routine ly in ordinary care settings. It is important that field studies be develop ed to evaluate the effectiveness of new technologies. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.