Cautiously Adjusting to the New Millennium: Changing to the 2000 Population Standard

Readers of the Journal are probably so accustomed to seeing age-adjusted rates and percentages in government reports on health that they scarcely give them a second thought. The value of recalibrating summary measures of health to eliminate confounding by differences in age distributions was recognized very early in the development of health statistics. The basic technique of age adjustment is generally attributed to the English actuary F. G .P. Neison, who advocated its use for comparing death rates of different geographic areas. Neison made this recommendation in a paper presented to the Statistical Society of London in 1844.1 His argument proved so convincing that the use of age-adjusted rates and ratios has been a standard feature of official publications of health data since the middle of the 19th century. It is one of the first techniques taught to students of epidemiology, biostatistics, and demography.2