1. TM Substance Use Transitions from Initial Use to Regular Use to Discontinuance Ralph S. Caraballo, Ph.D., MPH Office on Smoking and Health, CDC, Atlanta GA Gary A. Giovino, Ph.D Roswell Park Cancer Institute, Buffalo NY 2002 National Conference on Tobacco or Health: Trends in Tobacco Cessation: The Latest Evidence San Francisco, CA November 20, 2002

2. TM Introduction Transitional stages in the process of smoking uptake is a topic of considerable research interest Previous work assessing national transitional probabilities for selected substances (Giovino et al., Epidemiologic Reviews 1995) used data from 1993 National Household Survey on Drug Abuse (NHSDA) The 1993 NHSDA analyses are limited, because available items at the time only measured ever use and current use

3. TM Purposes of Today’s Talk Update analyses with more recent survey information (1996-1998 NHSDA) Expand upon previous analyses by using measures of ever use and early use that involve indicators of progression Compare current use among ever users and persons who have progressed to various stages across substances

4. TM Purposes of Today’s Talk (Cont.) Compare progression from ever use across substances Assess duration of cigarette smoking initiation from first trying to smoking daily among persons aged 30-39 years

5. TM Methods NHSDA 1996-1998 (combined data) Participants aged 12 years or older Persons who had ever used cigarettes, marijuana, cocaine, crack, heroin, hallucinogens, or inhalants Sample Population (n=68,274) Study Population (n=19,222)

6. TM Definitions Ever substance use was defined as reporting yes to question: “Did you ever use (substance)?” Current substance use was defined as reporting to have used 1 or more days during the past 30 days

7. Percent Distribution of the Unweighted Sample Population (n=68,274) by Age Group— NHSDA 1996-1998 Ages 18-25 17% Ages 26+ 57% Ages 12-17 26%

8. Percent Distribution of the Population (N = 216,232,778) by Age Group — NHSDA 1996-1998 Ages 18-25 12% 78% Ages 12-17 10% Ages 26+

9. TM Current* Use Prevalence in the U.S. Population Aged 12 Years or Older, by Substance—NHSDA 1996-1998 Percent *Used 1 or more days in the past 30 days Source: NHSDA 1996-1998 aggregated data

10. TM Percent that Still Use (Current) Among Ever Users, by Substance—NHSDA 1996-1998 *Used 1 or more days in the past 30 days Source: NHSDA 1996-1998 aggregated data Percent

11. TM Percent that Discontinued Using (Former) Among Ever Users, by Substance—NHSDA 1996-1998 Percent * Ever used, but not during past 30 days Source: NHSDA 1996-1998 aggregated data

12. TM Percent Current Users Among Ever* Users Aged 12-17 Years, by Number of Days They Ever Used— NHSDA, 1996-1998 *Ever is defined as any use (at least once) in lifetime Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

13. TM Percent Who Discontinued Using Among Ever* Users Aged 12-17 Years, by Number of Days They Ever Used— NHSDA, 1996-1998 *Ever is defined as any use (at least once) in lifetime Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

14. TM Percent Current Users Among Ever* Users Aged 18-25 Years, by Number of Days They Ever Used— NHSDA, 1996-1998 Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

15. TM Percent Who Discontinued Using Among Ever* Users Aged 18-25 Years, by Number of Days They Ever Used— NHSDA, 1996-1998 Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

16. TM Percent of Ever (at least once) Substance Users Aged 18-25 Years Who Were Current Regular* Users, by Number of Days They Ever Used—NHSDA, 1996-1998 * Regular user is defined as using it 6 or more days in past 30 days Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

17. TM Percent Current Users Among Ever* Users Aged 26 Years or Older, by Number of Days They Ever Used— NHSDA, 1996-1998 Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

18. TM Percent Who Discontinued Using Among Ever* Users Aged 26 Years or Older, by Number of Days They Ever Used—NHSDA, 1996-1998 Source: NHSDA 1996-1998 (aggregated data) Cigarettes Marijuana Inhalant Hallucinogen Crack Cocaine

19. Percent of Current Users Who Used  6 Days in Past 30 Days Among Current Users Who Used > 300 Days in Lifetime, by Age and Substance of Use

20. TM Percent of Ever Users (1+ days) Who Used the Substance at Least 3 Days, and Percent of Users of At Least 3 Days Who Used the Substance at Least 101 Days Ever Users Who Used At Least 3 Days Users for at Least 3 days that Used 101+ Days Substance No.%(95% CI)No.%(95% CI) Cigarettes 39,89683.3(±1.3)31,06177.0(±2.0) Marijuana 22,00576.3(±2.0)16,59740.1(±2.8) Cocaine 6,559 73.4(±3.6) 4,641 26.9(±4.2) Crack 1,74568.2(±7.9)1,16339.0(±9.1) Heroin 68066.6(±12.8)42343.4(±15.2) Hallucinogen 6,35565.8(±3.8)3,90620.2(±4.7) Inhalants 4,17858.4(±5.2)2,37012.5(±4.6)

21. TM Substance No.%(95% CI) Cigarettes 39,89664.1(±2.1) Marijuana 22,00530.6(±2.3) Cocaine 6,55919.8 (±3.3) Crack 1,74526.6(±6.8) Heroin 68028.9(±11.4) Hallucinogen 6,35513.3(±3.3) Inhalants 4,1787.3(±2.7) Percent of Ever Users (1+ days) Who Used the Substance at Least 101 Days

22. TM Cumulative Age of Initiation of Cigarette Smoking* Among Persons Aged 30-39 Years— United States, 1996-1998 * Among persons 30-39 years old who have ever smoked daily Source: National Household Survey on Drug Abuse, 1996-1998 public use data tapes Age First Tried a Cigarette Age Began Smoking Daily

23. TM Age Of First Tried a Cigarette and Duration to Become a Daily Smoker, by Age Cohort—NHSDA 1996-1998 Source: NHSDA 1996-1998 (aggregated data) Plot of the predicted values

24. TM Discussion Even when measures of progression beyond ever use are incorporated into the analyses, cigarette smokers are more likely to remain current users over time than are users of other substances Differences in the cost of, availability of, and social sanctions and controls applicable to each substance may account for some of the observed variability One interpretation: “Many people discontinue their use of illicit drugs as they assume adult roles.”

25. TM Discussion (Cont.) Even when not taking current use into account, EVER CIGARETTE SMOKERS are more likely to use cigarettes for a longer period of time (# days ever smoked) than are users of other substances There is definitely a decreasing trend in DURATION as the age of first trying a cigarette gets older. This is, as the age at which a person first tries a cigarette gets older, the time it takes them to start smoking daily gets shorter