lecture10 notes

N lt 0 exit fval n paint the blackboards decision

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: I COND E, F, 7, 1800, 0, C J COND E, G, 1, 900, 0, C … M PROB OF APPENDICITIS N UTIL M, I, J, K, L O IF N LT 0, EXIT FVAL N “Paint the Blackboards!” DECISION PATIENT STATE Disease (p) treat No treat UTILITY Treat disease No disease (1-p) Treat no disease Disease (p) No disease (1-p) No treat disease No treat no disease Threshold • Benefit B = U(treat dis) – U (no treat dis) • Cost C = U(no treat no dis) – U(treat no dis) • Threshold probability for treatment: Pauker, Kassirer, NEJM 1975 Test/Treat Threshold Figure removed due to copyright restrictions. See Kassirer, Jerome P., and Stephen G. Pauker. "Should Diagnostic Testing be Regulated?" New England Journal of Medicine (1978). Visualizing Thresholds Figure removed due to copyright restrictions. See Kassirer, Jerome P., and Stephen G. Pauker. "Should Diagnostic Testing be Regulated?" New England Journal of Medicine (1978). More Complex Decision Analysis Issues • • • • • • • Repeated decisions Accumulating disutilities Dependence on history Cohorts & state transition models Explicit models of time Uncertainty in the uncertainties Determining utilities – Lotteries, … • Qualitative models Example: Acute Renal Failure • Based on Gorry, et al., AJM 55, 473-484, 1973. • Choice of a handful (8) of therapies (antibiotics, steroids, surgery, etc.) • Choice of a handful (3) of invasive tests (biopsies, IVP, etc.) • Choice of 27 diagnostic “questions” (patient characteristics, history, lab values, etc.) • Underlying cause is one of 14 diseases – We assume one and only one disease Decision Tree for ARF • Choose: – Surgery for obstruction – Treat with antibiotics – Perform pyelogram – Perform arteriography – Measure patient’s temperature – Determine if there is proteinuria –… Decision Tree for ARF Surgery for obstruction Treat with antibiotics Perform pyelogram Perform arteriography Measure patient’s temperature Determine if there is proteinuria Value = ??? What happens when we act? • Treatment: leads to few possible outcomes – different outcomes have different probabilities • probabilities depend on distribution of disease probabilities – value of outcome can be directly determined • value may depend on how we got there (see below) • therefore, value of a treatment can be determined by expectation • Test: lead to few results, revise probabil...
View Full Document

This document was uploaded on 03/20/2014 for the course EECS 6.872 at MIT.

Ask a homework question - tutors are online