Page 1 Prescription Drug Non-medical Use in Young Adults: National View of Prevalence and Patterns of Use Huiwen Keri Yang, MS Doctoral Student University of Maryland Baltimore School of Pharmacy Linda Simoni-Wastila, BSPharm, PhD Associate Professor University of Maryland Baltimore School of Pharmacy American Public Health Association 134th Annual Meeting and Exposition Boston, MA November 6, 2006 NIDA Grant R21 DA017730 This is the logo for the University of Maryland-Baltimore. Page 2 Outline Background Objectives Methods Results Conclusions Page 3 Definition Non-Medical Prescription Drug Use (NMPDU) = "Not prescribed for you" or "You took the drug only for the experience or feeling it caused" NMPDU not equal to Abuse/Dependency (Substance Abuse and Mental Health Services Administration, 2003) Page 4 What is the problem? Substance use in young adults Alcohol and illicit substances use "down arrow" while prescription drugs with addiction potential use "up arrow" (SAMHSA, 2003) Current knowledge gap in NMPDU - Prevalence? Patterns? Frequency? Correlates of use? Page 5 Objectives Aim 1: Provide national estimates of NMPDU among young adults Aim 2: Characterize patterns of NMPDU Aim 3: Examine correlates of NMPDU Page 6 Methods Data: 2003 National Survey on Drug Use and Health (NSDUH) The National Household Survey on Drug Abuse (NHSDA) Substance Abuse and Mental Health Services Administration (SAMHSA) U.S. civilian non-institutionalized population aged 12 and over Data collected on sociodemographics, self-reported lifetime, past-year and past-month tobacco, alcohol and drug use, general and mental health status, treatment, behavior, attitudes and problems related to substance use. Page 7 Methods Population of interest: 31.7 million non-institutionalized young adults aged 18 to 25 residing in the US in 2003 Page 8 Methods Drug Use Measures: Any past-year non-medical prescription drug use (NMPDU) NMPDU by therapeutic class: • Opioid analgesics (e.g. Oxycontin "registered trademark") • Minor tranquilizers (e.g. Valium "registered trademark") • Sedative-hypnotics (e.g. barbiturates) • CNS stimulants (e.g. Ritalin "registered trademark") Page 9 Methods (continued) Drug use measures: Predominant use: • Rx-Only: past-year use of prescription drugs only • Poly-Drug: past-year use of prescription drugs plus any illicit drugs (marijuana, cocaine and crack cocaine, heroin, hallucinogens, and inhalants) Poly-Rx drug use: # of prescription drug classes Frequency of NMPDU • "casual" use (0 to 2 times annually) • "moderate" use (3 to 26 times annually) • "heavy" use (27 or more times annually) Page 10 Methods Other substance use measures: Specific categories of illicit substances among Poly-Drug users Alcohol use: • no alcohol use (0 days drinking annually) • "casual" drinking (1 to 52 days drinking annually) • "moderate" drinking (53 to 178 days drinking annually) • "heavy" drinking (179 to 365 days drinking annually) Past-year cigarette use Correlates: gender, race, age groupings, population density, annual family income, health insurance, employment status, general health status, moved in the past year, current enrollment in college or other school. Page 11 Methods Analysis: Descriptive statistics Multivariate logistic regression analysis All analyses used SAS version 9.1 Used weights in NSDUH to provide national estimates Used Proc SURVEYestimators to control for the clustering complex sampling design in NSDUH and to provide properly adjusted standard errors Page 12 This is a table displaying characteristics of U.S. young adults aged 18 to 25 from 2003 NSDUH (N=31,728,286). The first column is a list of characteristics. The second column gives the N for the characteristic. The third column gives the percent of population for the characteristic. The table can be read as follows: "Female Gender": 15,808,360 N, 49.8 percent of population; "NH White": 19,641,923 N, 61.9 percent of population; "NH Black": 4,277,875 N, 13.5 percent of population; "Hispanic": 2,149,016 N, 17.8 percent of population; "Other": 5,659,472 N, 6.8 percent of population; "Age 18 to 19c: 8,433,699 N, 26.6 percent of population; "Age 20 to 21": 7,985,590 N, 25.2 percent of population; "Age 22 to 23": 7,949,471 N, 25.1 percent of population; "Age 24 to 25": 7,359,526 N, 23.2 percent of population; "Urban": 25,353,445 N, 79.9 percent of population; "Full-time": 14,580,304 N, 46.0 percent of population; "Part-time": 8,156,888 N, 25.7 percent of population; "Unemployed": 8,991,094 N, 28.3 percent of population Page 13 (Continued) Characteristics of U.S. young adults aged 18 to 25, 2003 NSDUH (N=31,728,286) This is a table displaying characteristics of U.S. young adults aged 18 to 25 from 2003 NSDUH (N=31,728,286). The first column is a list of characteristics. The second column gives the N for the characteristic. The third column gives the percent of population for the characteristic. The table can be read as follows: "Poor or Fair Health": 1,560,164 N, 4.9 percent of population; "Good Health": 7,517,309 N, 23.7 percent of population; "Very Good or Excellent Health": 22,650,813 N, 71.4 percent of population; "Health Insurance": 22,328,600 N, 70.4 percent of population; "Moved in Past Year": 15,503,211 N, 48.9 percent of population; "Enrolled in College or School": 14,144,484 N, 44.6 percent of population Page 14 This is a bar chart showing the percent of young adults aged 18 to 25 who have taken part in non-medical prescription drug use on the y-axis and listing the following drugs on the x-axis: Any Rx Drug, Opioids, Stimulants, Minor Tranquilizers, Sedative-Hypnotics. The following results are how the chart reads: Any Rx Drug: 14.7 percent, Opioids: 12.2 percent, Stimulants: 3.5 percent , Minor Tranquilizers: 5.2 percent, Sedative-Hypnotics: 0.5 percent Page 15 Predominant patterns of NMPDU among any past year NMPD users, 2003 NSDUH (N=4,655,564) This is a pie chart with two sections: "Used prescription drug plus one or more illicit substances (Poly-Drug)" equals 71 percent, "Prescription drug use only (Rx-Only)" equals 29 percent. Page 16 Poly-Drug use among any past year NMPD users, 2003 NSDUH (N=4,655,564) This is a vertical bar chart showing poly-drug use among any past-year non-medical prescription drug users based on the 2003 NSDUH. The y-axis shows the percentage of respondents, and the x-axis has five drugs listed: Marijuana, Cocaine/Crack, Heroin, Hallucinogens, Inhalants. The results of the chart read as follows: Marijuana: 66.3 percent, Cocaine/Crack: 27.6 percent, Heroin: 1.7 percent, Hallucinogens: 26.4 percent, Inhalants: 8.3 percent Page 17 Poly-Rx drug use among any past year NMPD users (N=4,655,564) This is a pie chart with three sections showing poly-Rx drug use among any past year non-medical prescription drug users; the chart reads as follows: "Only used one prescription drug class" represents 65 percent, "Used two prescription drug classes" represents 26 percent, and "Used three to four prescription drug classes" represents 9 percent. Page 18 Frequency of NMPDU among any past year NMPD users, 2003 NSDUH (N=4,655,564) This is a vertical bar chart representing the frequency of non-medical prescription drug use among any past year non-medical prescription drug users from the 2003 NSDUH. The y-axis represents the percentage of respondents. The x-axis has these three categories: Casual, Moderate, Heavy. The results of the chart are as follows:Casual: 19.5 percent, Moderate: 42.5 percent, Heavy: 38.0 percent Page 19 Correlates of any NMPDU among young adults aged 18 to 25, 2003 NSDUH This is a table displaying correlates of any NMPDU among young adults aged 18 to 25 from 2003 NSDUH. The first column is a list of characteristics. The second column gives the odds ratio (95 percent CI) for any NMPDU. The table can be read as follows: "Female Gender": 1.12 (0.99, 1.26) odds ratio (95 percent CI) for any NMPDU; "NH White": 1.58 (1.33, 1.87) odds ratio for any NMPDU; "NH Black": 0.65 (0.49, 0.86) odds ratio for any NMPDU; "Hispanic": 1.03 (0.76, 1.40) odds ratio for any NMPDU; "Age 20 to 21": 0.70 (0.60, 0.80) odds ratio for any NMPDU; "Age 22 to 23": 0.58 (0.50, 0.67) odds ratio for any NMPDU; "Age 24 to 25": 0.57 (0.48, 0.68) odds ratio for any NMPDU; "Health Insurance": 1.14 (1.00, 1.29) odds ratio for any NMPDU; "Poor or Fair Health": 0.79 (0.61, 1.01) odds ratio for any NMPDU; "Good Health": 0.92 (0.70, 1.20) odds ratio for any NMPDU; "Moved in Past Year": 1.12 (1.00, 1.26) odds ratio for any NMPDU; "Casual alcohol use": 1.97 (1.58, 2.46) odds ratio for any NMPDU; "Moderate alcohol use": 3.63 (2.90, 4.54) odds ratio for any NMPDU; "Heavy alcohol use": 6.01 (4.67, 7.72) odds ratio for any NMPDU; "Cigarette use": 2.56 (2.22, 2.95) odds ratio for any NMPDU Page 20 Correlates of NMPDU by predominant drug use pattern among any past year NMPD users, 2003 NSDUH This is a table displaying correlates of NMPDU by predominant drug use pattern among any past year NMPDU users from 2003 NSDUH. The first column is a list of characteristics. The second column gives the odds ratio (95 percent CI) for NMPDU Among Rx-Only Users. The third column gives the odds ratio (95 percent CI) for NMPDU Among Poly-Drug Users. The table can be read as follows: "Female Gender": 1.53 (1.26, 1.85) odds ratio (95 percentCI) for NMPDU among Rx-only users, 0.93 (0.81, 1.08) odds ratio (95 percent CI) for NMPDU among poly-drug users; "NH White": 1.11 (0.86, 1.44) odds ratio (95 percent CI) for NMPDU among Rx-only users, 1.84 (1.48, 2.30) odds ratio (95 percent CI) for NMPDU among poly-drug users; "NH Black": 0.78 (0.52, 1.16) odds ratio (95 percent CI) for NMPDU among Rx-only users, 0.55 (0.38, 0.80) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Hispanic": 0.76 (0.46, 1.24) odds ratio (95 percent CI) for NMPDU among Rx-only users, 1.23 (0.85, 1.77) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Age 20 to 21": 0.69 (0.54, 0.89) odds ratio (95 percent CI) for NMPDU among Rx-only users, 0.71 (0.60, 0.84) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Age 22 to 23": 0.83 (0.63, 1.10) odds ratio (95 percent CI) for NMPDU among Rx-only users, 0.51 (0.43, 0.61) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Age 24 to 25": 1.02 (0.77, 1.35) odds ratio (95 percent CI) for NMPDU among Rx-only users, 0.44 (0.35, 0.55) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Health Insurance": 1.28 (1.03, 1.58) odds ratio (95 percent CI) for NMPDU among Rx-only users, 1.06 (0.91, 1.23) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Poor or Fair Health": 0.62 (0.43, 0.90) odds ratio (95 percent CI) for NMPDU among Rx-only users, 0.92 (0.69, 1.22) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Good Health": 0.70 (0.47, 1.05) odds ratio (95 percent CI) for NMPDU among Rx-only users, 1.07 (0.79, 1.45) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Moved in Past Year": 1.00 (0.83, 1.22) odds ratio (95 percent CI) for NMPDU among Rx-only users, 1.17 (1.01, 1.34) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Casual alcohol use": 1.24 (0.93, 1.65) odds ratio (95 percent CI) for NMPDU among Rx-only users, 4.39 (2.91, 6.63) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Moderate alcohol use": 1.22 (0.90, 1.67) odds ratio (95 percent CI) for NMPDU among Rx-only users, 10.17 (6.77, 15.29) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Heavy alcohol use": 1.17 (0.78, 1.75) odds ratio (95 percent CI) for NMPDU among Rx-only users, 5.89 (4.47, 7.75) odds ratio (95 percent CI) for NMPDU among poly-drug users; "Cigarette use": 1.23 (0.98, 1.54) odds ratio (95 percent CI) for NMPDU among Rx-only users, 3.66 (3.07, 4.37) odds ratio (95 percent CI) for NMPDU among poly-drug users Page 21 Conclusions Over 4.6 million young adults reported NMPDU Although NMPDU were most common in opioid analgesics, other classes (notably the minor tranquilizers and stimulants) also were widely used NMPDU was not necessarily casual use Two distinct types of non-medical prescription drug users – Rx-Only and Poly-Drug Page 22 Limitations Self-reported Generalizability Cross-sectional study Page 23 Future Directions Better understand patterns of use – Frequency of NMPDU associated with use of other substances? – Certain patterns are more likely to result in development of prescription drug use disorders? Individual prescription drug classes among NMPDU Actual drug abuse and dependency (DSM-IV criteria) Tease out risk and protective factors Page 24 Thank you! hyang003@umaryland.edu