Trained PCPs diagnosed DVT as accurately as experts

Primary care physicians trained in compression ultrasound can diagnose deep vein thrombosis (DVT) with excellent accuracy and in close agreement with vascular experts, Italian researchers reported in a recent study in Annals of Family Medicine.

Patients with clinical signs and symptoms of DVT pose a diagnostic dilemma for general practitioners in primary care practices, the researchers noted. Time is of the essence: Should a provider make a preliminary diagnosis in the office and begin therapy promptly, or take a chance on sending a patient to a hospital for testing?

“Reliance on clinical findings alone can lead to misdiagnosis, unnecessary exposure to anticoagulant therapy, and high associated costs,” wrote researchers led by Nicola Mumoli, MD, Department of Internal Medicine, Ospedale Civile di Livorno, Livorno, Italy. “A more rapid diagnosis, directly obtained by general practitioners in primary care, could likely improve appropriate management of DVT, avoiding in-hospital evaluations and any pretest scores or laboratory evaluations.”

This study involved 18 general practitioners in primary care ambulatory clinics as well as 8 senior physicians skilled in vascular ultrasound. Before the study, the general practitioners received 2 months of formal training in compression ultrasound, which they used for prospectively examining a total of 1,107 outpatients who visited their primary care offices with clinically suspected DVT of the lower limbs.

The 8 vascular ultrasound experts also examined all 1,107 patients, and definitively diagnosed 200 of them with DVT.

The investigators used the experts’ diagnoses as a reference point for comparison, and found excellent agreement between general practitioners and experts. Compression ultrasound performed by general practitioners had diagnostic accuracy of 95.8% (95% confidence interval [CI]: 94.7%-97.0%), sensitivity of 90.0% (95% CI: 88.2%-91.8%), specificity of 97.1% (95% CI: 96.2%-98.1%), positive predictive value of 87.4% (95% CI: 85.4%-89.3%), and negative predictive value of 97.8% (95% CI: 96.9%-98.6%).

“Our findings suggest that in the diagnosis of DVT, general practitioners might be a potential alternative to vascular experts because they achieve an excellent agreement and an overall high accuracy of 95.8%,” wrote Dr. Mumoli and colleagues. “Although this approach may help reduce the time to diagnosis and then optimize proper management, future studies should include more rigorous assessment to maximize its accuracy.”

If further research confirms these preliminary results, general practitioners should be offered a training program in compression ultrasound, which could promote faster and better management of patients with suspected DVT, the authors noted.

As point-of-care instruments become more common, a greater number of general practitioners will have the technology available to perform ultrasound, they added.