Activity 4B. Calculating APRI PDF Share Learning Objective Performance Indicators Discuss noninvasive indirect markers used for estimating liver fibrosis Describe noninvasive direct markers used for estimating liver fibrosis Summarize key radiologic methods that can estimate hepatic fibrosis List the transient elastography cutoff that is used to estimate cirrhosis in persons with chronic HCV Explain the indications, risks, and histologic assessment for liver biopsy in persons with chronic HCV A 61-year-old man with a recent diagnosis of hepatitis C infection is seen in the clinic for follow-up after an initial visit. His initial laboratory studies show the following: Total bilirubin = 1.6 mg/dL Aspartate aminotransferase (AST) level = 120 IU/L (upper limit of normal for men = 40 IU/L) Platelet count = 100 x 109/L Albumin = 3.4 g/dL Instructions Using the APRI Calculator tool, enter in the patient's laboratory data and calculate the patient's APRI score. Answer the Activity Question based on the patient's APRI score. AST to Platelet Ratio Index (APRI) Calculator ShareThis is an AST to Platelet Ratio Index (APRI) calculator tool. Enter the required values to calculate the APRI value. The APRI Score will appear in the oval on the far right (highlighted in yellow). Most experts recommend using 40 IU/L as the value for the AST upper limit of normal when calculating an APRI value. APRI = AST Level (IU/L) AST (Upper Limit of Normal) (IU/L) Platelet Count (109/L) x 100 = Interpretation: In a meta-analysis of 40 studies, investigators concluded that an APRI score greater than 1.0 had a sensitivity of 76% and specificity of 72% for predicting cirrhosis. In addition, they concluded that an APRI score greater than 0.7 had a sensitivity of 77% and specificity of 72% for predicting significant hepatic fibrosis.1 For detection of cirrhosis, using an APRI cutoff score of 2.0 was more specific (91%) but less sensitive (46%). The lower the APRI score (less than 0.5), the greater the negative predictive value (and ability to rule out cirrhosis) and the higher the value (greater than 1.5) the greater the positive predictive value (and ability to rule in cirrhosis); midrange values are less helpful. The APRI alone is likely not sufficiently sensitive to rule out significant disease. Some evidence suggests that the use of multiple indices in combination (such as APRI plus FibroTest) or an algorithmic approach may result in higher diagnostic accuracy than using APRI alone.2 Sources Lin ZH, Xin YN, Dong QJ, et al. Performance of the aspartate aminotransferase-to-platelet ratio index for the staging of hepatitis C-related fibrosis: an updated meta-analysis. Hepatology. 2011;53:726-36. Chou R, Wasson N. Blood tests to diagnose fibrosis or cirrhosis in patients with chronic hepatitis C virus infection: a systematic review. Ann Intern Med. 2013;158:807-20. Related ActivitiesYou may find more information and a scenario for which you can use this calculator in the following activities from our curriculum:Calculating APRICalculating APRICalculating APRI This calculator operates entirely from your device. No input variables or data is transmitted between your computer and our servers. Share by e-mail From:Enter your e-mail address To: Enter the e-mail address of the recipient Your Message: View all Clinical Calculators Activity QuestionYou should answer this question after completing the activity. You must answer all of the questions before checking your work. What is the APRI score for this 61-year-old man and what is the significance of this result in terms of predicting hepatic fibrosis? The APRI score is 0.1 and this patient is highly unlikely to have significant fibrosis The APRI score is 1.0 and this patient is highly unlikely to have significant fibrosis The APRI score is 3.0 and this patient is likely to have severe fibrosis or cirrhosis The APRI score is 30 and this patient has greater than 90% likelihood they have cirrhosis Share by e-mail From:Enter your e-mail address To: Enter the e-mail address of the recipient Your Message: Check-On-LearningQuestionsThe Check-on-Learning Questions are short and topic related. They are meant to help you stay on track throughout each lesson and check your understanding of key concepts.You must be signed in to customize your interaction with these questions.
