Hierarchical Dirichlét Learning – Filling in the Thin Spots in a Database

  • Steen Andreassen
  • Brian Kristensen
  • Alina Zalounina
  • Leonard Leibovici
  • Uwe Frank
  • Henrik C. Schønheyder
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2780)


Estimation of probabilities by classical maximum likelihood estimators can give unreliable results when the number of cases is small. A Bayesian approach, where prior probabilities with Dirichlet distributions are used to temper the estimates, can reduce the variance enough to make the estimates useful. This is demonstrated by using this approach to estimate mortalities of severe infections from different sites, lungs, skin urinary tract, etc. The prior probabilities are provided in a hierarchical way, i.e. by deriving them from the same database, but without distinguishing between different sites of infection.


Antibiotic Therapy Classical Estimator Dirichlet Distribution Empirical Antibiotic Therapy Average Mortality 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • Steen Andreassen
    • 1
  • Brian Kristensen
    • 2
  • Alina Zalounina
    • 1
  • Leonard Leibovici
    • 3
  • Uwe Frank
    • 4
  • Henrik C. Schønheyder
    • 5
  1. 1.Center for Model-based Medical Decision SupportAalborg UniversityAalborg EastDenmark
  2. 2.Department of Clinical MicrobiologyAarhus University HospitalÅrhus CDenmark
  3. 3.Department of MedicinePetah-TiqvaIsrael
  4. 4.Institut für Umweltmedizin und KrankenhaushygieneFreiburg Universiy HospitalFreiburgGermany
  5. 5.Department of Clinical MicrobiologyAalborg HospitalAalborgDenmark

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