       Document 0690
 DOCN  M9610690
 TI    Hazard function estimation using B-splines.
 DT    9601
 AU    Rosenberg PS; National Cancer Institute, Epidemiologic Methods Section,;
       Rockville, Maryland 20852, USA.
 SO    Biometrics. 1995 Sep;51(3):874-87. Unique Identifier : AIDSLINE
       MED/96054334
 AB    A flexible parametric procedure is given to model the hazard function as
       a linear combination of cubic B-splines and to obtain maximum likelihood
       estimates from censored survival data. The approach yields smooth
       estimates of the hazard and survivorship functions that are intermediate
       in structure between strongly parametric and non-parametric models. A
       simple method is described for selecting the number and location of
       knots. Simulation results show favorable root mean square error compared
       to non-parametric estimates for both the hazard and survivorship
       functions. Three methods are given to calculate confidence intervals
       based on the delta method, profile likelihood, and bootstrap,
       respectively. The procedure is applied to estimate hazard rates for
       acquired immunodeficiency syndrome (AIDS) following infection with human
       immunodeficiency virus (HIV). Spline methods can accommodate complex
       censoring mechanisms such as those that arise in the AIDS setting. To
       illustrate, HIV infection incidence is estimated for a cohort of
       hemophiliacs in which the dates of HIV infection are interval-censored
       and some subjects were born after the onset of the HIV epidemic.
 DE    Acquired Immunodeficiency Syndrome/*EPIDEMIOLOGY/MORTALITY  *Biometry
       Bisexuality  Comparative Study  Confidence Intervals  Homosexuality,
       Male  Human  HIV  HIV Infections/*EPIDEMIOLOGY/PHYSIOPATHOLOGY  Male
       Mathematics  *Models, Statistical  Survival Rate  Time Factors  JOURNAL
       ARTICLE

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

