Harry M. Rosenberg

Annual Report to the Nation on the status of cancer, 1973–1999, featuring implications of age and aging on U.S. cancer burden

The American Cancer Society, the National Cancer Institute, the North American Association of Central Cancer Registries (NAACCR), the National Institute on Aging (NIA), and the Centers for Disease Control and Prevention, including the National Center for Health Statistics (NCHS) and the National Center for Chronic Disease Prevention and Health Promotion, collaborated to provide an annual update on cancer occurrence and trends in the United States. This years report contained a special feature focusing on implications of age and aging on the U.S. cancer burden.

Estimating Deaths Attributable to Obesity in the United States

Estimates of deaths attributable to obesity in the United States rely on estimates from epidemiological cohorts of the relative risk of mortality associated with obesity. However, these relative risk estimates are not necessarily appropriate for the total US population, in part because of exclusions to control for baseline health status and exclusion or underrepresentation of older adults. Most deaths occur among older adults; estimates of deaths attributable to obesity can vary widely depending on the assumptions about the relative risks of mortality associated with obesity among the elderly. Thus, it may be difficult to estimate deaths attributable to obesity with adequate accuracy and precision. We urge efforts to improve the data and methods for estimating this statistic.

Increase in deaths caused by HIV infection due to changes in rules for selecting underlying cause of death.

With implementation of the International Classification of Diseases, 10th Revision (ICD-10), for U.S. vital statistics in 1999, the criteria for selecting HIV infection as the underlying cause of death were expanded. To estimate the effect of ICD-10 rules on the number of deaths attributed to HIV infection, we applied a simplified version of ICD-10 rules to data on causes of death from all U.S. death certificates for 1998 (previously classified by rules of the 9th revision of ICD [ICD-9]) and calculated the resulting increase in deaths for which HIV infection was selected as the underlying cause. Of the 17,186 deaths in 1998 with any mention of HIV infection on the death certificate, ICD-10 rules selected HIV infection as the underlying cause for 15,145, which was 1,719 (13%) more than the 13,426 for which it had been selected by ICD-9 rules. The proportional increase differed by demographic group, being less among non-Hispanic blacks (9%) and Hispanics (13%) than among non-Hispanic whites (18%). Thus, comparison of deaths attributed to HIV infection in 1999 or later with those in 1998 or earlier should take into account the changes in ICD rules for selecting the underlying cause of death.

MISCLASSIFICATION OF RACE IN CARDIOVASCULAR DISEASE MORTALITY DATA

Graber and colleagues found an ominous deterioration in the quality of race data for American Indian deaths in Maine.1 Specifically, errors because of coding and data entry increased from 0% during 1978–1982 to 33% in 1993–1997; errors in reporting increased from 3% to 22% during the same periods. Part of the problem of race misclassification is being resolved. Coding errors have been reduced as a result of new procedures introduced in April 2003 and have been used by a growing number of states, including Maine, in conjunction with the National Center for Health Statistics (NCHS). The new procedures, in which NCHS codes and edits race/ethnicity data and then quickly returns the data to the states for additional processing, are described on the NCHS Web site (http://www.cdc.gov/nchs/data/dvs/multiple_race_documentation_5-10-04.pdf). Graber et al. did not mention misclassification of race in the denominators of death rates. Errors in the denominators tend to offset, somewhat, errors in the numerators, as shown in an NCHS study of misclassification of race/ethnicity at the national level.2 The authors present 2 types of death rates, those based on “any mention” of cardiovascular disease and those based on “immediate” cause of death. Do the authors mean underlying cause rather than immediate cause? Underlying cause of death is the standard basis for tabulating cause-of-death data as recommended by the World Health Organization.3 While the new NCHS procedures reduce errors introduced during data processing, they do not resolve errors resulting from misreporting of race/ethnicity on death certificates, which Graber et al. show account for almost half the racial/ethnic misclassifications for American Indian deaths in Maine. Errors in reporting can be reduced only by training funeral directors, who obtain information on race/ethnicity from informants or by observation, to be more accurate. Until funeral directors are better trained, NCHS and the states will have solved only half the problem of misclassification of race/ethnicity in mortality data. Graber and colleagues make an important contribution by demonstrating a relationship between state budget resources and data quality. Maine’s race/ethnicity data deteriorated in part because of relaxed quality control standards owing to budget constraints. During the past decade, federal budgets for vital statistics, which support state operations, have failed to keep up with inflation, while—as the authors point out—state budgets, too, have been reduced, with consequences for data quality. The public health community needs to ensure that the state and federal governments provide adequate resources to maintain the data sets used to monitor the health of our citizens.