{"id":41237,"date":"2023-08-03T14:59:23","date_gmt":"2023-08-03T09:14:23","guid":{"rendered":"https:\/\/microbenotes.com\/sensitivity-and-specificity\/"},"modified":"2023-08-03T14:59:23","modified_gmt":"2023-08-03T09:14:23","slug":"sensitivity-and-specificity","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/sensitivity-and-specificity\/","title":{"rendered":"Sensitivity and Specificity- Definition, Formula, Calculation, Relationship"},"content":{"rendered":"\n<ul><li><span style=\"color: #000000;\">When developing diagnostic tests or evaluating results, it is important to understand how reliable those tests and therefore the results obtained are.<\/span><\/li><li><span style=\"color: #000000;\">By using samples of known disease status, values such as sensitivity and specificity can be calculated that allow its evaluation.<\/span><\/li><li><span style=\"color: #000000;\">Therefore, when evaluating diagnostic tests, it is important to calculate the sensitivity and specificity for that test to determine its effectiveness.<\/span><\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2021\/12\/Sensitivity-and-Specificity-Definition-Formula-Calculation-Relationship.jpg\" alt=\"Sensitivity and Specificity- Definition, Formula, Calculation, Relationship\" class=\"wp-image-29314\"\/><\/figure>\n\n\n\n<p>Image Source: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Sensitivity_and_specificity\" target=\"_blank\" rel=\"noopener noreferrer\">Wikipedia<\/a><\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/#sensitivity\" title=\"Sensitivity \">Sensitivity <\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/#calculating-sensitivity\" title=\"Calculating Sensitivity\">Calculating Sensitivity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/#specificity\" title=\"Specificity\">Specificity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/#calculating-specificity\" title=\"Calculating Specificity\">Calculating Specificity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/#relationship-between-sensitivity-and-specificity\" title=\"Relationship between Sensitivity and Specificity\">Relationship between Sensitivity and Specificity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/#references\" title=\"References\">References<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"sensitivity\"><\/span><span style=\"color: #000000;\"><strong>Sensitivity <\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li><span style=\"color: #000000;\">The term sensitivity was introduced by Yerushalmy in the 1940s as a statistical index of diagnostic accuracy.<\/span><\/li><li><span style=\"color: #000000;\">It is also called the&nbsp;true positive rate, the&nbsp;recall, or&nbsp;probability of detection.<\/span><\/li><li><span style=\"color: #000000;\">It has been defined as the ability of a test to identify correctly all those who have the disease, which is &#8220;true-positive&#8221;.<\/span><\/li><li><span style=\"color: #000000;\">A 90 percent sensitivity means that 90 percent of the diseased people screened by the test will give a &#8220;true-positive&#8221; result and the remaining 10 percent a &#8220;false-negative&#8221; result.<\/span><\/li><li><span style=\"color: #000000;\">Thus, a highly sensitive test rarely overlooks an actual positive (for example, showing &#8220;nothing bad&#8221; despite something bad existing).<\/span><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"calculating-sensitivity\"><\/span><span style=\"color: #000000;\"><strong>Calculating Sensitivity<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li><span style=\"color: #000000;\">The sensitivity of a diagnostic test is expressed as the probability (as a percentage) that a sample tests positive given that the patient has the disease.<\/span><\/li><li><span style=\"color: #000000;\">The following equation is used to calculate a test\u2019s sensitivity:<\/span><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"specificity\"><\/span><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-3040\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/10\/Sensitivity-Formula.jpg\" alt=\"Sensitivity Formula\" width=\"696\" height=\"163\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/10\/Sensitivity-Formula.jpg 696w, https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/10\/Sensitivity-Formula-300x70.jpg 300w\" sizes=\"(max-width: 696px) 100vw, 696px\" \/><strong>Specificity<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li><span style=\"color: #000000;\">It is defined as the ability of a test to identify correctly those who do not have the disease, that is, &#8220;true-negatives&#8221;.<\/span><\/li><li><span style=\"color: #000000;\">It is also called as the&nbsp;true negative rate.<\/span><\/li><li><span style=\"color: #000000;\">A 90 percent specificity means that 90 percent of the non-diseased persons will give a &#8220;true-negative&#8221; result, 10 percent of non-diseased people screened by the test will be wrongly classified as &#8220;diseased&#8221; when they are not.<\/span><\/li><li><span style=\"color: #000000;\">Thus, a highly specific test rarely registers a positive classification for anything that is not the target of testing.<\/span><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"calculating-specificity\"><\/span><span style=\"color: #000000;\"><strong>Calculating Specificity<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><span style=\"color: #000000;\">The specificity of a test is expressed as the probability (as a percentage) that a test returns a negative result given that that patient does not have the disease.<\/span><\/p>\n\n\n\n<p><span style=\"color: #000000;\">The following equation is used to calculate a test\u2019s specificity:<\/span><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"relationship-between-sensitivity-and-specificity\"><\/span><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-3039\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/10\/Specificity-Formula.jpg\" alt=\"Specificity Formula\" width=\"703\" height=\"170\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/10\/Specificity-Formula.jpg 703w, https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/10\/Specificity-Formula-300x73.jpg 300w\" sizes=\"(max-width: 703px) 100vw, 703px\" \/><strong>Relationship between Sensitivity and Specificity<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li><span style=\"color: #000000;\">In&nbsp;medical tests, sensitivity is the extent to which actual positives are not overlooked (so false negatives are few), and specificity is the extent to which actual negatives are classified as such (so false positives are few).&nbsp;<\/span><\/li><li><span style=\"color: #000000;\">Although a screening test ideally is both highly sensitive and highly specific, we need to strike a balance between these characteristics, because most tests cannot do both.<\/span><\/li><li><span style=\"color: #000000;\">We determine this balance by an arbitrary cut-off point between normal and abnormal.<\/span><\/li><li><span style=\"color: #000000;\">If we want to increase sensitivity and to include all true positives, we are obliged to increase the number of false positives, which means decreasing specificity.<\/span><\/li><li><span style=\"color: #000000;\">Reducing the strictness of the criteria for a positive test can increase sensitivity, but by doing this the test\u2019s specificity is reduced.<\/span><\/li><li><span style=\"color: #000000;\">Likewise, increasing the strictness of the criteria increases specificity but decreases sensitivity.<\/span><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"references\"><\/span><span style=\"color: #000000;\"><strong>References<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol><li><span style=\"color: #000000;\">Park, K. (n.d.).&nbsp;Park&#8217;s textbook of preventive and social medicine.<\/span><\/li><li><span style=\"color: #000000;\">Beaglehole, Robert,&nbsp;Bonita, Ruth,&nbsp;Kjellstro\u0308m, Tord&nbsp;&amp;&nbsp;World Health Organization.&nbsp;(\u200e1993)\u200e.&nbsp;Basic epidemiology, Updated reprint.&nbsp;World Health Organization.&nbsp;<\/span><\/li><li><span style=\"color: #000000;\">Gordis, L. (2014).&nbsp;Epidemiology&nbsp;(Fifth edition.). Philadelphia, PA: Elsevier Saunders.<\/span><\/li><li><span style=\"color: #000000;\">Hennekens CH, Buring JE. Epidemiology in Medicine, Lippincott Williams &amp; Wilkins, 1987.<\/span><\/li><li><span style=\"color: #000000;\"><a style=\"color: #000000;\" href=\"https:\/\/www.technologynetworks.com\/analysis\/articles\/sensitivity-vs-specificity-318222\" target=\"_blank\" rel=\"noopener\">https:\/\/www.technologynetworks.com\/analysis\/articles\/sensitivity-vs-specificity-318222<\/a><\/span><\/li><li><span style=\"color: #000000;\"><a style=\"color: #000000;\" href=\"https:\/\/academic.oup.com\/bjaed\/article\/8\/6\/221\/406440\" target=\"_blank\" rel=\"noopener\">https:\/\/academic.oup.com\/bjaed\/article\/8\/6\/221\/406440<\/a><\/span><\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"<p>When developing diagnostic tests or evaluating results, it is important to understand how reliable those tests and therefore the results obtained are. By using samples of known disease status, values &#8230; <a title=\"Sensitivity and Specificity- Definition, Formula, Calculation, Relationship\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/sensitivity-and-specificity\/\" aria-label=\"Read more about Sensitivity and Specificity- Definition, Formula, Calculation, Relationship\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":41236,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6262],"tags":[4954,4956,4953,4957,4955],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2021\/12\/Sensitivity-and-Specificity-Definition-Formula-Calculation-Relationship.jpg","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":6262,"name":"Epidemiology","slug":"epidemiology","term_group":0,"term_taxonomy_id":6262,"taxonomy":"category","description":"<strong>Epidemiology is the discipline that deals with studies related to the determinants, occurrence, and distribution of health and disease in a defined population.<\/strong>\r\n<ul>\r\n \t<li>Epidemiology is a descriptive science and includes the determination of rates, that is, the quantification of disease occurrence within a specific population.<\/li>\r\n \t<li>Epidemiology can accurately describe a disease and many factors concerning its occurrence before its cause is identified.<\/li>\r\n \t<li>One goal of epidemiologic studies is to define the parameters of disease, including risk factors, in order to develop the most effective measures for control.<\/li>\r\n \t<li>Epidemiology is a data-driven discipline that relies on a systematic and unbiased approach to the collection, analysis, and interpretation of data.<\/li>\r\n \t<li>Epidemiology is considered the basic science of public health as\u00a0epidemiology acts as a quantitative science that relies on the knowledge of probability, statistics, and essential research methods.<\/li>\r\n \t<li>Besides, epidemiology also acts as a method of reasoning based on hypotheses in the scientific fields like biology, behavioral sciences, physics, and ergonomics to explain health-related behaviors, states, and events.<\/li>\r\n \t<li>Thus,\u00a0epidemiology is considered not just a research activity but an integral part of public health, providing the foundation for practical and appropriate public health actions based on data and causal reasoning.<\/li>\r\n \t<li>Epidemiology is similar to medicine in many aspects as it utilizes experience, epidemiologic judgment, and understanding of local conditions while diagnosing the health of a community.<\/li>\r\n \t<li>The discipline also helps in the proposition of appropriate, practical, and acceptable public health interventions to control and prevent disease in the community.<\/li>\r\n \t<li>Epidemiology has now become a standard practice during outbreaks, epidemics, and pandemics as it provides an example on how to deal with a new outbreak that might arise due to a different etiological agent.<\/li>\r\n \t<li>As infections are caused by infectious agents like bacteria, viruses, and fungi, epidemiological studies also support other disciplines like bacteriology and clinical medicine.<\/li>\r\n \t<li>Besides, the mode of transmission involves environmental factors like air, water, and soil, all of which are imperative in environmental microbiology.<\/li>\r\n<\/ul>","parent":0,"count":23,"filter":"raw","cat_ID":6262,"category_count":23,"category_description":"<strong>Epidemiology is the discipline that deals with studies related to the determinants, occurrence, and distribution of health and disease in a defined population.<\/strong>\r\n<ul>\r\n \t<li>Epidemiology is a descriptive science and includes the determination of rates, that is, the quantification of disease occurrence within a specific population.<\/li>\r\n \t<li>Epidemiology can accurately describe a disease and many factors concerning its occurrence before its cause is identified.<\/li>\r\n \t<li>One goal of epidemiologic studies is to define the parameters of disease, including risk factors, in order to develop the most effective measures for control.<\/li>\r\n \t<li>Epidemiology is a data-driven discipline that relies on a systematic and unbiased approach to the collection, analysis, and interpretation of data.<\/li>\r\n \t<li>Epidemiology is considered the basic science of public health as\u00a0epidemiology acts as a quantitative science that relies on the knowledge of probability, statistics, and essential research methods.<\/li>\r\n \t<li>Besides, epidemiology also acts as a method of reasoning based on hypotheses in the scientific fields like biology, behavioral sciences, physics, and ergonomics to explain health-related behaviors, states, and events.<\/li>\r\n \t<li>Thus,\u00a0epidemiology is considered not just a research activity but an integral part of public health, providing the foundation for practical and appropriate public health actions based on data and causal reasoning.<\/li>\r\n \t<li>Epidemiology is similar to medicine in many aspects as it utilizes experience, epidemiologic judgment, and understanding of local conditions while diagnosing the health of a community.<\/li>\r\n \t<li>The discipline also helps in the proposition of appropriate, practical, and acceptable public health interventions to control and prevent disease in the community.<\/li>\r\n \t<li>Epidemiology has now become a standard practice during outbreaks, epidemics, and pandemics as it provides an example on how to deal with a new outbreak that might arise due to a different etiological agent.<\/li>\r\n \t<li>As infections are caused by infectious agents like bacteria, viruses, and fungi, epidemiological studies also support other disciplines like bacteriology and clinical medicine.<\/li>\r\n \t<li>Besides, the mode of transmission involves environmental factors like air, water, and soil, all of which are imperative in environmental microbiology.<\/li>\r\n<\/ul>","cat_name":"Epidemiology","category_nicename":"epidemiology","category_parent":0}]},"_links":{"self":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/41237"}],"collection":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/comments?post=41237"}],"version-history":[{"count":0,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/41237\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media\/41236"}],"wp:attachment":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media?parent=41237"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/categories?post=41237"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/tags?post=41237"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}