Document 0879
 DOCN  M9590879
 TI    Change points in the series of T4 counts prior to AIDS.
 DT    9509
 AU    Kiuchi AS; Hartigan JA; Holford TR; Rubinstein P; Stevens CE; Department
       of Statistics, Yale University, New Haven, Connecticut; 06511, USA.
 SO    Biometrics. 1995 Mar;51(1):236-48. Unique Identifier : AIDSLINE
       MED/95284239
 AB    The absolute number of T4 cells has been established as an important
       clinical marker of disease progression to acquired immunodeficiency
       syndrome (AIDS) in persons infected with human immunodeficiency virus
       (HIV). Series of T4 counts are analyzed from the 131 homosexual men who
       entered the New York Blood Center Study in 1984, mostly seropositive for
       HIV, and who developed AIDS as participants by 1990. These series
       exhibit a gradual decline of the log(T4) count followed by a more rapid
       decline close to the time of the development of AIDS. Empirical Bayes
       and hierarchical Bayes change point models are proposed to estimate the
       distribution of the time before AIDS when this rapid decline begins.
       Results using the EM Algorithm and Markov chain Monte Carlo indicate
       that the mean change point occurs approximately 1 year before diagnosis
       with a standard deviation of 9 months. Detection of a change point may
       indicate that an AIDS diagnosis is increasingly likely for an individual
       HIV-positive but AIDS-free.
 DE    Acquired Immunodeficiency Syndrome/COMPLICATIONS/*IMMUNOLOGY/
       PHYSIOPATHOLOGY  Algorithms  Bayes Theorem  Biometry/METHODS  *CD4
       Lymphocyte Count  Disease Progression  Homosexuality, Male  Human  HIV
       Seropositivity/*IMMUNOLOGY/PHYSIOPATHOLOGY  Longitudinal Studies  Male
       Markov Chains  Models, Statistical  Monte Carlo Method  Sarcoma,
       Kaposi's/EPIDEMIOLOGY/ETIOLOGY  Time Factors  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).