       Document 0192
 DOCN  M9620192
 TI    A back-calculation method to estimate the age and period HIV infection
       intensity, considering the susceptible population.
 DT    9602
 AU    Verdecchia A; Mariotto AB; Istituto Superiore di Sanita, Roma, Italy.
 SO    Stat Med. 1995 Jul 30;14(14):1513-30. Unique Identifier : AIDSLINE
       MED/96000842
 AB    An extension of the back-calculation method to reconstruct the past
       history of HIV infections is presented. In this method the HIV infection
       intensity, as a function of age and calendar time, is assumed to belong
       to a family of parametric functions and is back-calculated from the
       observed AIDS incidence cases, knowledge of the incubation period and of
       the susceptible population, the final model being chosen as the one that
       gives the best fit. The model allows for the interaction between age and
       calendar time. The application to the main risk groups in Italy, male
       IVDUs and homosexuals, showed that age and the susceptible population
       were important in estimating the epidemic among IVDUs; interaction
       between age and calendar time was found to be significant, showing that
       among young IVDUs the risk of infection decreased faster than among
       older IVDUs. Sensitivity of the estimates to the assumption of
       population and choice of the infection function is investigated.
 DE    Acquired Immunodeficiency Syndrome/*EPIDEMIOLOGY/TRANSMISSION  Adult
       Cohort Studies  Disease Outbreaks/*STATISTICS & NUMER DATA  Female
       Homosexuality, Male/STATISTICS & NUMER DATA  Human  HIV
       Infections/*EPIDEMIOLOGY/TRANSMISSION  HIV Seroprevalence/*TRENDS
       Italy/EPIDEMIOLOGY  Male  Models, Statistical  Risk Factors  Substance
       Abuse, Intravenous/EPIDEMIOLOGY  Support, Non-U.S. Gov't  JOURNAL
       ARTICLE

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

