Document 0313
 DOCN  M9550313
 TI    Dependent HIV incidences in back-projection of AIDS incidence data.
 DT    9505
 AU    Becker NG; Chao X; Department of Statistics, La Trobe University,
       Bundoora VIC,; Australia.
 SO    Stat Med. 1994 Oct 15-30;13(19-20):1945-58. Unique Identifier : AIDSLINE
       MED/95148994
 AB    Techniques for reconstructing plausible HIV incidence curves from AIDS
       incidence data are called methods of back-projection, or
       back-calculation. Approaches to back-projection tend to make the
       simplifying assumption that the quarterly HIV incidences are
       independent, which is not even approximately true. Here we investigate
       whether smoothed non-parametric back-projection based on this
       simplifying assumption gives sensible back-projections and appropriate
       measures of precision for these reconstructed HIV incidence curves.
       Simple models for HIV transmission are shown to have much greater
       variation than the corresponding non-homogeneous Poisson process arising
       from the independence assumption. Nevertheless, bearing in mind that the
       objective is to reconstruct the HIV epidemic curve for the current
       epidemic, it is argued that such back-projection does give sensible HIV
       curves. This conclusion is supported by a simulation study, which also
       finds that confidence intervals for the HIV incidences are wider for
       transmission data than those determined from independent Poisson data.
 DE    Acquired Immunodeficiency Syndrome/*EPIDEMIOLOGY  Human  HIV
       Infections/*EPIDEMIOLOGY/*TRANSMISSION  Incidence  Likelihood Functions
       *Models, Biological  Poisson Distribution  Statistics, Nonparametric
       Time Factors  JOURNAL ARTICLE

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