Diagnostic Test Principles: Overview and Applications for Pain Medicine

Patients frequently present with undiagnosed medical complaints. Physician's assessments involve a history, physical examination and review of relevant investigations before arriving at a diagnosis. We present a clinical scenario of lower back pain and assist in the derivation of the diagnosis based upon information available in the literature. Common clinical issues are discussed from a statistical decision perspective with aids for the busy clinician. The need for diagnostic tests in decision making is discussed with an outline of key concepts such as measures of test efficacy, recognizing biases in diagnostic studies, critical appraisal tools. Common clinical situations such as ordering a test for patient reassurance, over-reliance on a diagnostic test are also discussed.