Calculating INR in Chronic Liver Disease

A nurse is reviewing the laboratory values of a 45-year-old patient who is being treated for chronic liver disease. The healthcare provider has ordered a series of tests to assess the patient's liver function. She notes that the patient's prothrombin time (PT) is extended, indicating a potential risk for bleeding. The normal range for PT is approximately 11-13.5 seconds. The nurse is concerned and needs to prepare for possible interventions related to the patient's coagulation profile.

Please fill in the blank regarding the calculated international normalized ratio (INR) based on the patient's PT, which is 18 seconds. The formula for calculating INR is: INR = (PT patient/PT control). For this question, consider the control PT value as 12 seconds. Fill in the blank: The patient's INR is __________.