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Distribution atn farf obstr agn cn hs pye ae ri rvt

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Unformatted text preview: ity distribution of diseases, and impose disutility • Questions: lead to few results, revise probability distribution Full decision tree A1 A1 A1 A2 A2 P´ A2 A3 P A3 A4 A4 P´´ A3 A4 Initial probability distribution ATN FARF OBSTR AGN CN HS PYE AE RI RVT VASC SCL CGAE MH Acute tubular necrosis Functional acute renal failure Urinary tract obstruction Acute glomerulonephritis Renal cortical necrosis Hepatorenal syndrome Pyelonephritis Atheromatous Emboli Renal infarction (bilateral) Renal vein thrombosis Renal vasculitis Scleroderma Chronic glomerulonephritis, acute exacerbation Malignant hypertension & nephrosclerosis 0.250 0.400 0.100 0.100 0.020 0.005 0.010 0.003 0.002 0.002 0.050 0.002 0.030 0.030 ARF’s Database: P(obs|D) Conditional probabilities for Proteinuria Diseases Probabilities Trace 3+ to to 2+ 4+ 0 ATN FARF OBSTR AGN CN HS PYE AE RI RVT VASC SCL CGAE MH 0.1 0.8 0.7 0.01 0.01 0.8 0.4 0.1 0.1 0.001 0.01 0.1 0.001 0.001 0.8 0.2 0.3 0.2 0.8 0.2 0.6 0.8 0.7 0.1 0.2 0.4 0.2 0.4 0.1 0.001 0.001 0.8 0.2 0.001 0.001 0.1 0.2 0.9 0.8 0.5 0.8 0.6 Questions • Blood pressure at onset • proteinuria • casts in urine sediment • hematuria • history of prolonged hypotension • urine specific gravity • large fluid loss preceding onset • kidney size • urine sodium • strep infection within three weeks • urine volume • recent surgery or trauma • age • papilledema • flank pain • • • • • • • • • • • history of proteinuria symptoms of bladder obstruction exposure to nephrotoxic drugs disturbance in clotting mechanism pyuria bacteriuria sex transfusion within one day jaundice or ascites ischemia of extremities or aortic aneurism atrial fibrillation or recent MI Invasive tests and treatments • Tests – biopsy – retrograde pyelography – transfemoral arteriography • Treatments – – – – – – – – steroids conservative therapy iv-fluids surgery for urinary tract obstruction antibiotics surgery for clot in renal vessels antihypertensive drugs heparin Updating probability distribution Bayes’ rule Value of treatment • Three results: improved, unchanged, worsened – each has an innate value, modified by “tolls” paid on the way • Probabiliti...
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This document was uploaded on 03/20/2014 for the course EECS 6.872 at MIT.

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