HSS 4303 Lecture Notes - Lecture 7: Randomized Controlled Trial, Survival Analysis, Empirical Probability
10 Oct 2018
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Measure of association above 1 means its increasing. Standardized incidence ratio same as direct standardization, above 1 means its decreasing. Kaplan meier curve: curve showing survival rates over time; used in experimental studies i. e myocardial infraction kaplan meier curve. Patients admitted to hospital for myocardial infarction, then separated into groups to receive different treatment. Y-axis = survival rate; x-axis = days since discharge, can be years, months etc: group with aspirin and ibuprofen had highest survival rates, outcome is mortality, therefore line goes down. Estimate time-to-event for a group of individuals, such as time until second heart-attack for a group of mi patients. To compare time-to-event between two or more groups, such as treated vs. placebo mi patients in a randomized controlled trial. Time-to-event: time from entry into study until a subject has a particular outcome i. e u(cid:374)til perso(cid:374) dies, lost to follo(cid:449) up, does(cid:374)"t ha(cid:448)e disease a(cid:374)y(cid:373)ore.
