| — Not available. |
| a Beginning in 1982, the question about stimulant use (i.e., amphetamines) was revised to get respondents to exclude the inappropriate reporting of nonprescription stimulants. The prevalence rate dropped slightly as a result of this methodological change. |
| b To derive percentages for each racial subgroup, data for 2005 and 2006 have been combined to increase subgroup sample sizes and thus provide more stable estimates. In the original race/ethnicity question, respondents were asked to select the one race/ethnicity category that they thought best described them. In 2005, in half of the questionnaire forms respondents were instructed to mark all categories that applied. About 6% selected more than one racial/ethnic group. The following method was used to combine data from the original question and the revised question: For the original question, respondents were assigned to the racial/ethnic group specified in their response. For the revised question, those checking only White and no other racial/ethnic group were categorized as White; those checking Black and no other racial/ethnic group were categorized as Black; and those checking one or more of the four Hispanic categories but no other racial/ethnic group were categorized as Hispanic. In 2006, the race/ethnicity question was revised on the remaining forms. Note that, because some drug use questions occur in only a few forms, there is some variation in the version of the race/ethnicity question upon which the 2005 data are based. These permutations do not appear to make any appreciable difference in the results. For further details, see the race/ethnicity note at the end of Appendix D in the Monitoring the Future report referenced below. |
| c From 1977 to 2006, respondents who described themselves as White or Caucasian were reported as White. From 1977 to 1989, the Black subgroup included respondents who described themselves as Black or Afro-American; after 1990, the subgroup included those who described themselves as Black or African American. From 1977 to 1990, the Hispanic subgroup included those respondents who described themselves as Mexican American or Chicano, or Puerto Rican or other Latin American. After 1990, this group included those respondents who described themselves as Mexican American or Chicano, Cuban American, Puerto Rican American, or other Latin American. After 1994, the term Puerto Rican American was shortened to Puerto Rican. Racial and ethnic subgroup data from the Monitoring the Future Study are typically presented as 2-year averages in order to increase sample size and thus provide more stable estimates. The single-year estimates provided in the America's Children report are limited to the subgroups for which the sample size is adequate to provide stable estimates: White, Black, and Hispanic. |
| d Persons of Hispanic origin may be of any race. |
| NOTE: Use of “any illicit drug” includes any use of marijuana, LSD, other hallucinogens, crack, other cocaine, or heroin, or any use of other narcotics, amphetamines, barbiturates, or tranquilizers not under a doctor’s orders. For 8th and 10th graders, the use of other narcotics and barbiturates has been excluded because these younger respondents appear to overreport use (perhaps because they include the use of nonprescription drugs in their answers). |
| SOURCE: Johnston, L.D., O’Malley, P.M., and Bachman, J.G. (2006). Monitoring the Future national survey results on drug use, 1975-2005 Volume I: Secondary school students Table 2–3(NIH Publication No. 06-5883). Bethesda, MD: National Institute on Drug Abuse. Data for 2006 are from a press release of December 21, 2006, and demographic disaggregations are from unpublished tabulations from Monitoring the Future, University of Michigan. |
