the National Center for Health Statistics (NCHS). The first survey (then called the Health Examination Survey), which took place between 1959 and 1962, included some measures of oral health status as did the second survey conducted from 1971 to 1974. Unfortunately, the measures, particularly the measure of periodontal disease, in the first survey are considered sufficiently imperfect that they are rarely cited in trend analyses (Spolsky et al., 1983), and debates about measurement continue. Recently, Caplan and Weintraub (1993, p. 856) stated that "until there is a reliable diagnostic tool for measuring active periodontal disease on a one-time basis, methods of evaluating periodontal health in cross-sectional studies will be inconsistent." The third NHANES (which took place from 1976 to 1980) did not include measures of oral health. The latest survey, which began in 1988 and does include oral health measures, is to be analyzed by the National Institute for Dental Research (NIDR) rather than NCHS, and results are yet to be published. No preliminary data from this survey were available to the committee.

The second source of data was the NIDR Examination Survey. The NIDR surveyed dental caries in children in 1979-1980 and in 1986-1987, and it surveyed employed adults and seniors attending senior centers in 1985-1986. Unfortunately, because the surveys differed in many of their measures or categories, the 1971-1974 NHANES and the three NIDR surveys permit only limited assessments of trends in health status for adults and children.

The third source of data was the National Health Interview Survey (NHIS), also conducted by the NCHS. The NHIS collected dental data in 1969, 1970, 1973, and 1975 through 1977, but it eliminated dental utilization data from the core survey in 1982 (NRC and IOM, 1992). It now collects such data irregularly for special supplements.

The committee also consulted various other sources. These included the RAND Health Insurance Experiment report on dental health status (Spolsky et al., 1983), some state surveys, a recent National Institute on Aging (NIA) study of elders in New England (Douglass et al., 1993), and selected historical sources (see Chapter 2). The background paper by White et al. provides a more extensive discussion of oral health status and trends.

As suggested in this review of sources, the collection of data on oral health status has been somewhat less regular and frequent than the collection of information about many other health problems. This oversight reflects the tendency noted elsewhere in this report for the health of the mouth to be considered an iso-