Objective: To evaluate the active implementation of the Dutch Institute for Healthcare Improvement's guideline for the diagnostic work-up for pulmonary embolism in a general training hospital, and to analyse reasons for not following the guideline strategy.
Design: Partly retrospective and partly prospective.
Method: The diagnostic strategy was analysed for all consecutive patients with clinically suspected pulmonary embolism who underwent a perfusion lung scintigraphy. The extent to which the guideline was followed was investigated in the year before (July 1999-June 2000; n = 384) and the year after (July 2000-June 2001; n = 380) its active implementation. The possible reasons for not completing the strategy in the prospective cohort of the study were also analysed.
Results: Following a non-high-probability perfusion-ventilation scan, the guideline was completed in 23/117 (20%) patients prior to the implementation and in 50/109 (46%) patients after the implementation of the guideline. In 27% and 60%, respectively, an additional duplex ultrasound of the legs was made to check for deep vein thrombosis, and in 65% and 70% respectively, pulmonary angiography was performed after a normal ultrasound result. The main reasons for not following the diagnostic work-up included low clinical probability (41%, without a proper alternative diagnosis), an alternative diagnosis (36%; pneumonia, heart failure, malignancy) and a reluctance to perform angiography. The mean age of the patients for whom the guideline was completed was lower (51 years) compared to patients for whom the guideline was not followed (65 years; p < 0.001). The risk of not completing the diagnostic workup in accordance with the guideline was six-fold higher for patients > or = 80 years compared with patients < 40 years of age, whereas an alternative diagnosis was not more prevalent in patients > or = 65 years.
Conclusion: Although active implementation of the guideline-based diagnostic work-up for pulmonary embolism increased the number of adequate diagnoses, the diagnostic work-up was not completed in half of the patients with inconclusive lung scans. The main reasons for this were the advanced age of the patient, alternative diagnoses, and a reluctance to perform pulmonary angiography.