Making a surgical diagnosis is an important first step in clinical management. Using the example of diagnostic testsDiagnostic tests on a thyroid noduleThyroid nodules, a literature searchLiterature search identified an article in which the TIRADS (Thyroid Imaging Reporting and Data System)Thyroid Imaging Reporting and Data System (TIRADS) for Ultrasound (US) features of thyroid nodule was followed by US-guided fine-needle aspiration cytology (FNAB) reported by the Bethesda System for reporting thyroid cytopathologyBethesda system for reporting thyroid cytopathology. From these two tests, the Likelihood Ratio (LR), its interpretation and its usefulness in sequenced tests to refine the diagnosis are emphasized. In this case, the pre-test probabilityPre-test probability (prevalence) of cancer of 3% was increased to 22% using Tl RADS (LR = 5.31) and further increased to 33% using the Bethesda System (LR = 1.7). A strategy to determine whether the test results in an article are valid, what the LRs are and whether the results will help in caring for your patient is presented.