{"id":365,"date":"2020-11-02T11:00:24","date_gmt":"2020-11-02T17:00:24","guid":{"rendered":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/?p=365"},"modified":"2021-03-19T16:05:22","modified_gmt":"2021-03-19T21:05:22","slug":"principles-of-diagnostic-testing-series-part-1","status":"publish","type":"post","link":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/principles-of-diagnostic-testing-series-part-1\/","title":{"rendered":"Principles of Diagnostic Testing Series | Part 1"},"content":{"rendered":"

Principles of Diagnostic Testing Series <\/strong><\/h1>\n

Part 1 – Test Characteristics: Sensitivity and Specificity<\/em><\/h2>\n
\n

The performance characteristics of a diagnostic test influence the circumstances that the test is most useful and how the results might be interpreted. Ideally, every diagnostic test would perfectly distinguish diseased from non-diseased individuals, however, this is rarely the case. All diagnostic tests make errors. It is useful to classify the possible results of a diagnostic test into four possible outcomes: test positive and diseased (true positive; TP), test positive and not diseased (false positive, FP), test negative and not diseased (true negative; TN), or test negative and diseased (false negative, FN). Commonly, a 2 x 2 table is created to visualize these outcomes.\"\"<\/a>Diagnostic tests are evaluated by conducting the test on a population with the disease and from a population without the disease.<\/p>\n

\n

\"\"<\/p>\n

Sensitivity<\/strong> is the proportion of individuals with a disease who test positive on a diagnostic test.<\/p>\n

 <\/p>\n

\n

 <\/p>\n

Spe\"\"<\/a>cificity<\/strong> is the proportion of individuals without a disease who test negative on a diagnostic test.<\/p>\n

 <\/p>\n

\n

Sensitivity and specificity are characteristics of a diagnostic test. Diagnostic tests with outcomes of continuous numbers have different sensitivity and specificity for each numerical value or cut-off point. The selection of a cut-point to increase test sensitivity reduces test specificity and vice versa. Therefore, a cut-off point is chosen to optimize either test sensitivity or test specificity depending on the relative cost of a false-positive or false-negative result.<\/p>\n","protected":false},"excerpt":{"rendered":"

Principles of Diagnostic Testing Series Part 1 – Test Characteristics: Sensitivity and Specificity The performance characteristics of a diagnostic test influence the circumstances that the test is most useful and how the results might be interpreted. Ideally, every diagnostic test … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":79,"featured_media":249,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[2,6],"tags":[],"coauthors":[31],"class_list":["post-365","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-animal-health","category-epi-methods"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/files\/2020\/06\/Cattle-85.jpg","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p7pWHv-5T","_links":{"self":[{"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/posts\/365","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/users\/79"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/comments?post=365"}],"version-history":[{"count":3,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/posts\/365\/revisions"}],"predecessor-version":[{"id":387,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/posts\/365\/revisions\/387"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/media\/249"}],"wp:attachment":[{"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/media?parent=365"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/categories?post=365"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/tags?post=365"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/blogs.extension.msstate.edu\/theriskproject\/wp-json\/wp\/v2\/coauthors?post=365"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}