U.S. decennial life tables for 1999-2001: methodology of the United States Life Tables.

OBJECTIVES This report describes the methodology used in the preparation of the 1999-2001 decennial life tables for the United States. METHODS Data used to prepare these life tables include population data by age on the census date April 1, 2000; deaths occurring in the 3-year period 1999-2001 classified by age at death; births for each of the years 1997-2001; and Medicare data for ages 66-100 years from the years 1999-2001. Methods that were kept the same as those of previous decennial tables include data sources used in constructing tables, the preliminary adjustment for misreported ages, the smoothing techniques for vital statistics and census data, and the calculations of death rates in different age groups. Two significant changes were made to the methodology used to estimate mortality for the populations aged 66 years and over. First, Medicare data were used to supplement vital statistics (number of deaths) and census data (population estimates) starting at age 66 years instead of age 85 years as was done in the estimation of previous U.S. decennial life tables. Second, smoothing and extrapolation of death rates for ages 66-109 was performed using a mathematical model given by Heligman and Pollard, instead of a Whittaker-Henderson Type B formula or modified Gompertz method.