AJR Am J Roentgenol. 2020 Sep 9:1-7. doi: 10.2214/AJR.19.22414. Online ahead of print.
OBJECTIVE. This study evaluates the prevalence of an abnormal international normalized ratio (INR) and platelet count before image-guided percutaneous needle biopsies over a 10-year period, comparing data from patients with and those without known conditions predisposing to coagulopathy. MATERIALS AND METHODS. A review of electronic medical records identified patients who were scheduled for a biopsy in a single institution's radiology department for the period of 2007-2016. The following information was recorded: demographic data, patient history of conditions that predispose to bleeding (e.g., liver disease, anticoagulant therapy, history of coagulopathy), and INR and platelet values within 30 days before biopsy. Data were stratified by biopsies that were performed versus those that were cancelled. RESULTS. Over 10 years, 3864 percutaneous biopsies were performed, and 6371 were cancelled. Approximately half of the biopsies (48.2%) were performed in patients without a predisposing condition; of those patients, 0.8% and 0.1% had an INR greater than 1.5 and greater than 1.8, respectively, and 0.4% had a platelet count of 50,000/μL or less (≤ 50 × 109/L). In patients with no known predisposing condition, 0.6% and 0.0% of biopsies cancelled were in patients who had an INR greater than 1.5 and greater than 1.8, respectively, and 0.1% of biopsies cancelled were in patients who had a platelet count of 50,000/μL or less. Ordering prebiopsy testing of patients with no predisposing conditions for the 1864 percutaneous biopsies performed over the 10-year study period resulted in more than $850,000 in laboratory-related health care costs. Our results suggest that the cost of identifying one abnormal INR is nearly $700,000. CONCLUSION. For patients without any known bleeding risks who are scheduled to undergo image-guided percutaneous biopsies, identifying an abnormal INR or abnormal platelet count is rare. Eliminating this testing in patients without predisposing conditions has the potential to create savings in costs and time for both physicians and patients.