Question 2856
{"accessible":false,"alternatives":[{"id":13935,"text":"lead time"},{"id":13934,"text":"length time"},{"id":13933,"text":"overdiagnosis"},{"id":13936,"text":"stage migration"}],"archived":false,"correctAlternativeId":13935,"explanation":"\u003cp\u003eLead time bias occurs if screening results in the detection of cancer after it becomes incurable but before it would have been detected clinically (i.e., after the development of symptoms). Since we measure survival starting with the timepoint when a cancer is detected, there is a spurious increase in survival time in these aggressive screen-detected cancers compared to patients with similar cancers detected clinically because the diagnosis has been pushed back in time because of the screening.\u003c/p\u003e","id":2856,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2857","nextQuestionPath":"/articles/lung-cancer-screening/questions/2855","relatedArticles":[],"alsoUsedIn":[{"id":1823,"kind":"Course","title":"Papa \u0026 Papa Bear's Medical Statistics Short Course - page 1823","link":"https://radiopaedia.org/courses/medical-statistics-short-course/pages/1823"}],"stem":"\u003cp\u003eWhat type of cancer screening bias may result from a cancer that reaches the \"critical point\" (the point at which the cancer becomes difficult to cure) before it can be detected by screening?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/2856"}],"attemptsPercentages":[{"alternativeId":"13934","percentage":17},{"alternativeId":"13935","percentage":58},{"alternativeId":"13936","percentage":25},{"alternativeId":"13933","percentage":0}],"promptToLogin":false,"questionManager":false,"articleId":"lung-cancer-screening"}