EPI 320 Lecture Notes - Lecture 12: Net Present Value, False Positive Rate
Document Summary
Stages of prevention: epidemiology is prevention focused, types, primary: prevent disease process from starting (ex: anti-drunk driving campaigns, secondary: detect the disease early (ex: annual dental checkups, tertiary: treat the disease effectively (ex: anti-hypertensive drugs) Reasons for screening: individual, early detection and treatment initiation = better prognosis, community, prevent infectious disease from spreading, reduce burden of symptomatic disease, cost of treatment, etc, research, helps understand natural history of disease. Qualities of good screening tests: safe, low invasiveness (biopsies are invasive, urine tests not), acceptable to patient = for healthy people, low cost: balance cost of test/costs prevented by test, accurate (valid) and reliable. Evaluating screening: efficacy: how well the test does in a controlled research enviro, effectiveness: how well test does in real world (uncontrolled) Calculate measures (using table above: sensitivity: tp / (tp+ fn, fnr: fn / (tp +fn) or 1-sensitivity, specificity: tn / (fp + tn, fpr: fp / (fp+tn) or 1-specificity.
