Document 0310
 DOCN  M9550310
 TI    Back-projection of German AIDS data using information on dates of tests.
 DT    9505
 AU    Dietz K; Seydel J; Schwartlander B; Department of Medical Biometry,
       Eberhard-Karls-University,; Tubingen, Germany.
 SO    Stat Med. 1994 Oct 15-30;13(19-20):1991-2008. Unique Identifier :
       AIDSLINE MED/95148997
 AB    The paper presents an application of back-projection methods to the
       reported AIDS data which are collected by the AIDS Center in the Federal
       Office of Health, Berlin. The analysis is based on all data reported up
       to 31 December 1992. The data are broken down by major risk groups.
       Correction for reporting delays takes into account temporal changes in
       their distribution. The paper applies the EMS algorithm for the
       estimation of HIV incidence. The incubation period is modelled according
       to a convolution of several exponential distributions which describe
       time dependent phenomena like change of case definition and therapy
       effects. For each case it is reported whether an antibody test has been
       performed before diagnosis, and if yes, at what time this test was
       performed. The modelling of the incubation distribution takes into
       account the transition from a state 'not yet tested' into a state
       'tested'. Only tested individuals in three pre-AIDS states are eligible
       for treatment. The model allows us to estimate not only the current
       total HIV prevalence but also a breakdown into those that are not yet
       tested, those that are tested but not yet treated and those that are
       under treatment. The results depend on the assumptions about the effect
       of treatment and on the degree of smoothing applied in the EMS
       algorithm.
 DE    Acquired Immunodeficiency Syndrome/*EPIDEMIOLOGY  Algorithms  Disease
       Notification/STATISTICS & NUMER DATA  Disease Progression
       Germany/EPIDEMIOLOGY  Human  HIV
       Infections/DIAGNOSIS/*EPIDEMIOLOGY/TRANSMISSION  Immunoassay/STATISTICS
       & NUMER DATA  Incidence  Likelihood Functions  *Models, Biological
       Prevalence  Risk Factors  Support, Non-U.S. Gov't  Support, U.S. Gov't,
       P.H.S.  Time Factors  JOURNAL ARTICLE

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