-
Understanding diagnostic tests 1: sensitivity, specificity and predictive values
by Alan Batt. Last modified: 11/12/14
Akobeng AK. Understanding diagnostic tests 1: sensitivity, specificity and predictive values. Acta Paediatr. 2007 Mar;96(3):338-41. PMID: 17407452.Free full text: http://onlinelibrary.wiley.com/doi/10.1111/j.1651-2227.2006.00180.x/pdf
Abstract
The usefulness of diagnostic tests, that is their ability to detect a person with disease or exclude a person without disease, is usually described by terms such as sensitivity, specificity, positive predictive value and negative predictive value. In this article, the first of the series, a simple, practical explanation of these concepts is provided and their use and misuse discussed. It is explained that while sensitivity and specificity are important measures of the diagnostic accuracy of a test, they are of no practical use when it comes to helping the clinician estimate the probability of disease in individual patients. Predictive values may be used to estimate probability of disease but both positive predictive value and negative predictive value vary according to disease prevalence. It would therefore be wrong for predictive values determined for one population to be applied to another population with a different prevalence of disease.
Sensitivity and specificity are important measures of the diagnostic accuracy of a test but cannot be used to estimate the probability of disease in an individual patient. Positive and negative predictive values provide estimates of probability of disease but both parameters vary according to disease prevalence.
The following two tabs change content below.Alan Batt
Paramedic, educator, researcherAlan is a critical care paramedic, paramedic educator and prehospital researcher, currently working around the world as an educator and researcher. He has previously worked and studied across Europe, North America and the Middle East. He holds a Graduate Certificate in Intensive Care Paramedic Studies, and an MSc in Critical Care. His main interests are in care of the elderly, end-of-life care, patient safety, professionalism (including role and identity), and paramedic education.Latest posts by Alan Batt (see all)
- Free access: Resuscitation Today Vol 3 Issue 2 - 27/06/16
- Free CPD at the Emergency Services Show - 23/05/16
- Care at the Scene – Research for Ambulance Services - 17/05/16
- Canadian Paramedicine Feb/Mar 2016 – Open Access Issue - 11/04/16
- Eat, sleep and be healthy – a paramedic’s guide to healthier shift work - 10/04/16
Understanding diagnostic tests 1: sensitivity, specificity and predictive values
Get weekly email updates!
Cast Your Vote

Categories
- Blogs (40)
- Case Studies (8)
- Featured Article (23)
- How-To (47)
- FOAM (8)
- News (117)
- Conference Tweets (31)
- Pharmacology (1)
- Adrenaline (1)
- Research (180)
- Advanced Practice (2)
- Airway Management (6)
- Anaphylaxis (2)
- Cardiac (15)
- Community Paramedic (2)
- Critical Care Paramedic (4)
- Diagnostics (3)
- Dispatch (1)
- ECG (4)
- Education (10)
- EMS Operations (2)
- End-of-Life Care (3)
- Geriatrics (9)
- Guidelines (22)
- HEMS (4)
- Mass Casualty (2)
- Medical Conditions (5)
- Mental Health (7)
- Military & Tactical (2)
- Neonatal (1)
- Neuro (11)
- Obstetrics (1)
- Paediatrics (4)
- Pain Management (4)
- Poster Presentations (5)
- Professionalism (5)
- Remote, Industrial & Austere (6)
- Respiratory (5)
- Resuscitation (27)
- Rural (3)
- Safety (3)
- Sepsis (7)
- Shock (2)
- Simulation (7)
- Sports Medicine (1)
- Trauma (20)
- Reviews (6)
- Conferences (5)
- Courses (1)
Upcoming Events
There are no upcoming events at this time.
News
- Free access: Resuscitation Today Vol 3 Issue 2 (27/06/16)
- Free CPD at the Emergency Services Show (23/05/16)
- Canadian Paramedicine Feb/Mar 2016 – Open Access Issue (11/04/16)
- Free access: Resuscitation Today Volume 3 Issue 1 (01/04/16)
- Introducing the Irish Journal of Paramedicine (22/11/15)
Latest How-To Articles
- Paramedic students…write something! (28/04/16)
- Understanding diagnostic tests 2: likelihood ratios, pre- and post-test probabilities and their use in clinical practice (30/01/15)
- Understanding diagnostic tests 1: sensitivity, specificity and predictive values (11/12/14)
- GRADE guidelines – best practices using the GRADE framework (22/11/14)
- How to get started with EMS research – JEMS (16/05/14)
Recent Comments
- Jin Sook Hyun on Case Study #2: Anaphylaxis
- Joe on Case Study #1: Heroin overdose
- Stef on C.R.A.S.H.E.D – A model for structured reflection in prehospital care.
- G. Yabut, RN on Rapid Reviews: Vital signs in CVAs – which arm?
ReSEARCH
Tags
academic ACS AED airway management ambulance AMI Australia Canada cardiac cardiac arrest case study CCP clinical management computer conference consensus CPG CPR CPR UL critical care CVA database ECG education elderly emergency EMS evidence based FOAM FPHC geriatric guide guideline guidelines haemorrhage HEMS immobilisation Ireland journal medication mental health neurology news OHCA online pain management paramedic prehospital PTSD reference research resuscitation review safety sepsis simulation social media software spinal STEMI stress stroke study TBI training Translational Health Sciences trauma Twitter UK USA
Archives