摘要：Objectives. This study determined the effects of changing from the 1940 to the 2000 standard million on monitoring socioeconomic and racial/ethnic inequalities in health. Methods. Using the 1940, 1970, and 2000 standard million, we calculated and compared age-adjusted rates for selected health outcomes stratified by socioeconomic level. Results. Changing from the 1940 to the 2000 standard million markedly reduced the age-adjusted relative risks for self-reported fair or poor health status of poor Americans compared with high-income Americans. Conclusions. Public health researchers and practitioners should give serious consideration to the implications of the change to the 2000 standard million for monitoring social inequalities in health. The year 2000 ushered in a major change in the standard million that the US National Center for Health Statistics (NCHS) employs for age-adjusting data. For more than 50 years, the official standard was the 1940 standard million, which was based on the age distribution of the US population in 1940. 1 During the past half century, however, life expectancy has increased considerably, leading the Secretary of Health and Human Services in 1998 to approve a change to the 2000 standard million, reflecting the older age distribution of the US population. 1 In discussing the impact of the new standard million, several reports have noted that the new standard may attenuate racial/ethnic disparities in health. 2 – 8 The age standard matters for comparing age-adjusted rates, because the age-adjusted rate is a weighted average of the age-specific rates, with the weights determined by the age structure of the age standard. If, say, the age-specific rates for 2 populations differ least among the elderly, then the magnitude of difference in their age-adjusted rates would appear to be smaller if the age standard includes a higher proportion of elderly than younger persons. For example, on the basis of mortality data age-adjusted to the 1940 standard, the relative risk of all-cause mortality in 1995 was 1.6 times higher among African Americans than among White Americans—as it also was in 1950, with the same 1940 age standard used. 6 , 9 If, however, the 2000 standard had been used, the excess risk in 1995 would have been reduced to 1.4, a 12.5% decline. 6 While this change may appear small, a true decline to 1.4 would actually have represented a welcome change. This raises the possibility of mistaking a reduction due to a technical change for a true decline representing progress in reducing racial/ethnic disparities in health. 2 To alert the public health community, the NCHS has prepared several reports. 1 , 8 , 10 Apart from these documents, however, there has been remarkably little discussion in public health literature about the impending changes. 7 Moreover, although the government documents and some research articles have briefly considered the implications of the new standard for Black–White comparisons, 2 – 8 there has been no discussion of the impact on comparisons involving other social inequalities in health, both with regard to other racial/ethnic groups and with regard to socioeconomic inequalities in health. This is a serious omission, given (a) the growing racial/ethnic diversity of the US population and (b) evidence indicating that socioeconomic inequalities in health often are larger than racial/ethnic inequalities in health. 9 , 11 , 12 Rendering this issue even more of concern is that the Healthy People 2010 objectives specifically state the goal of eliminating racial/ethnic disparities in health for 6 conditions. 13 Additionally, 30% of the 467 objectives include baseline socioeconomic data, allowing for possibilities of assessing changes in socioeconomic disparities in health over time. It therefore is useful to consider the possible impact of the new age standard on monitoring social inequalities in health.
