of Drug Abuse in the United States: A Summary of Methods and Findings

NICHOLAS J. KOZEL~

444

Epidemiology has recently been used to effectively track and analyze drug abuse patterns. This article generally desm’bes methods used in the United States for estimating and monitoring drug abuse. It outlines the advantages and limitafions of suck sources as surveys, indicators, and etknograpky, and briefly explores the work and utility of local, national, and international drug surveillance net- works. In addition, it desrribes national and local patterns of heroin, cocaine, and marijuana abuse.

he recent use of epidemiology to METHODS FOR ESTIMATING AND T study drug abuse has been of great MONITORING DRUG ABUSE value. Although drug abuse, because of its illicit nature and because of the unique The fact that nor-medical use of licit behavior patterns of abusers, has proven drugs and the abuse of illicit drugs is pro- very difficult to measure, the epidemio- scribed in society poses major difficulties logic approach has provided tools to ac- and limitations for most methodologies curately quantify data and to calculate used to measure the nature and extent of with scientific rigor such things as inci- drug abuse. However, there exist several dence and rates. These rates, data sources, each with its own unique in turn, can provide insight into the con- perspective, from which drug abuse ditions which place people at risk for trends can be tracked. The main data sys- drug abuse and into the etiology and con- tems used in the United States are sur- sequences of abuse. Medical epidemiol- veys, indicators, and ethnography. ogy holds that once the causes and risk factors of a have been identified, Surveys a program of education, intervention, and prevention can be implemented. Surveys provide the most direct mea- Even though the study of drug abuse dif- surement of the scope of drug abuse, of- fers significantly from the study of infec- fering the most comprehensive technique tious disease-the phenomenon upon for estimating the prevalence and inci- which medical epidemiology origin- dence of drug abuse as well as patterns of ated-the still applies. use and opinions about drugs; in addi- tion, surveys allow for in-depth question- ing on a variety of behavioral and attitu- ‘Division of Epidemiology and Statistical Analysis, dinal issues. Futhermore, cross-sectional National Institute on Drug Abuse. Mailing ad- dress: 5600 Fishers Lane, 11-A-55, Rockville, Mary- surveys repeated over time can be used land 20857, U.S.A. to monitor changes in trends. Surveys

Bulletin ofPAH0 24(Z), 1990 53 can cover the general population or a sive and time-consuming, and collecting special population, and they can be con- data on a sensitive subject such as drug ducted through a variety of techniques, abuse poses reliability and validity prob- including face-to-face interviews, tele- lems. Also, surveys cannot reasonably be phone or mail , and inter- expected to provide information on rela- views administered privately or in group tively rare events such as heroin abuse. settings. In those cases, other methodologies are The National Institute on Drug Abuse needed to complement surveys in con- (NIDA) sponsors two major national ducting a descriptive drug abuse epide- surveys-the National Household Sur- miology program. vey on Drug Abuse and the High School Senior Survey. The former is a personal, Indicators face-to-face interview with household residents based on a multistage, strati- Drug abuse indicators reflect the health fied, random sample design; the latter is and social consequences of drug abuse, a self-administered con- and can be used to monitor changes in ducted in a group setting and based on a trends. Over the years, several indicators multistage random sample of high have emerged as the most reliable and schools in the contiguous United States. useful for monitoring trends. Primary Both surveys use probability samples, among these are treatment data. For ex- thus allowing for generalizations to be ample, treatment admission data can be made about the total population. analyzed to plot epidemic curves, and NIDA also includes drug-use questions demographic and geographic characteris- in ongoing surveys sponsored by other tics can help identify high risk popula- offices and agencies, such as the National tions and sites where drug abuse may be Health Interview Survey, the Hispanic prevalent. These analyses have implica- Health and Nutrition Evaluation Survey, tions for such policy decisions as where the Department of Labor National Longi- to direct intervention and outreach activi- tudinal Survey of Youth, the Maternal ties, where to locate treatment programs, and Infant Health Survey, the Family and in the identification of potential cli- Growth Survey, and the National Ado- ents for treatment. lescent Student Health Survey. Including Other significant indicators are drug- drug-related questions in comprehensive related emergencies and deaths. For health surveys, which often are con- more than 15 years, NIDA has sponsored ducted among populations that may be at the Drug Abuse Warning Network high risk for drug use, presents an op- (DAWN), a national morbidity and mor- portunity to analyze the association be- tality information system which collects tween drug use and a wide of data from more than 700 hospital health practices and social behaviors. emergency rooms and 85 medical exam- Population-based surveys have some iners in the United States. DAWN has es- limitations, however. For example, cer- tablished a consistent reporting of drug tain segments of the population-the abuse cases based on standardized homeless and street people in the house- guidelines, resulting in a system which hold survey and absentees and dropouts produces invaluable trend information in the high school survey-are excluded, on health consequences and which is a and often these groups represent particu- major data source for identifying new larly vulnerable populations for drug drug abuse substances. Data such as abuse. In addition, surveys can be expen- DAWN’s also can be collected and ana-

54 Bulletin ofPAH0 24(l), 1990 lyzed from a few or even one hospital or searcher tallies the number of persons or medical examiner’s office in a city or activities occurring in a given area, such small region, if there is reason to believe as a street comer or a known drug mar- that drug-related cases would appear in ket; and (3) the participant observer ap- those facilities. proach in which the researcher plays an A third major indicator is law enforce- active role in a situation, such as asking ment records. Information on drug- conversational questions, while simulta- related arrests, numbers and amounts of neously observing activities and record- drug seizures, and drug price and purity ing responses unobtrusively. The choice gathered from local, regional, and na- of methodology has less to do with pref- tional police and from military, drug en- erence than with the options that circum- forcement, and customs officials and stances permit. The overall advantage of then analyzed by drug type, time, place, these approaches is that they involve and person can be extremely important real-life situations; their main limitation in documenting ongoing trends and in is the anecdotal nature of the data and identifying new patterns of abuse. It the lack of scientific control. should be kept in mind, however, that law enforcement are particularly EPIDEMIOLOGY WORK GROUP subject to fluctuations from policy changes based on manpower, funding, The Community Epidemiology Work and community pressure. Group (CEWG), established by NIDA in The overriding limitation inherent in all November 1976, is composed of research- of these indicators is the fact that rather ers, primarily state, city, and local offi- than measuring prevalence or the magni- cials, who periodically analyze drug tude of the drug problem, they measure abuse patterns and trends in selected trends associated with the consequences metropolitan communities throughout of abuse. Also, unlike surveys, they often the United States. CEWG meets twice involve secondary analysis of limited in- yearly to (1) provide timely assessment of formation. However, with careful inter- drug abuse patterns and trends, (2) iden- pretation, treatment, health, and law en- tify emerging drugs of abuse, (3) deter- forcement data can be analyzed together mine at-risk populations, and (4) develop to yield a dynamic picture of specific as- methodologies for assessing data. pects of drug abuse. The importance of tapping local exper- tise in assessing drug abuse trends and in Ethnography identifying potential outbreaks cannot be overemphasized. While national data Ethnography offers another valuable systems provide valuable epidemiologic tool for studying drug abuse. It provides information, they often are limited by the an informal description of a specific situa- delay between , process- tion, applying as much rigor to the study ing, analysis, and the dissemination of as circumstances will allow. Ethno- findings. In contrast, local-level data col- graphic studies usually involve one of lection and analysis, such as that pro- three general approaches: (1) the snow- vided by CEWG, have shorter lag time ball technique, in which a researcher will and, in some cases, increased accuracy. use a contact to provide someone to in- For example, local drug abuse experts’ terview, who, in turn, provides another unique knowledge regarding data pertur- person to interview, and so on; (2) a di- bations becomes critical during data in- rect count approach in which the re- terpretation. These researchers also have

Kozel EpidemiologicStudies of Drug Abuse 55 access to local surveys and studies as well ditional research methods such as sur- as to other findings that provide an in- veys. Indicators such as treatment data, valuable complement to core drug abuse however, have been used effectively to indicator data such as morbidity, mortal- identify relative changes in by ity, and law enforcement information. calculating the year of first heroin use. Consequently, NIDA uses data from Because of the difficulty in identifying de- national-level systems in conjunction nominator data, raw counts rather than with local analysis as the foundation for rates often are used to analyze incidence its descriptive epidemiology program. trends. The utility of local networks of drug Figure 1 shows that epidemics of her- abuse researchers who attempt to collect oin abuse occurred in the United States and analyze data in a standardized way during the late 196Os, the mid-197Os, and has lead to the establishment of State Ep- the early 1980s. Unlike later epidemics, idemiology Work Groups. Modeled after the epidemic in the late 196Os, which con- CEWG, these groups comprise selected tinued until about 1972, was national in researchers and local authorities from scope and affected all regions of the throughout a state who periodically pre- United States. Some researchers believe pare drug abuse status reports for their that the widespread nature of this epi- area. This program aims at developing an demic came about as the baby boom pop- epidemiology network in each state ulation matured and the social conditions which would be capable of monitoring of the time sparked drug experimenta- patterns and trends at the local level. tion and subsequent addiction. As a way to implement a worldwide The heroin epidemic in the mid-1970s drug abuse surveillance capability, an in- was more prevalent in the West than in ternational network is being developed. the East. This may have been due to the The establishment of methods for the emergence at that time of heroin that rapid exchange of epidemiologic infor- originated in Mexico and was distributed mation through telecommunication link- primarily to the western United States. ages also is being pursued; these will be Some of this heroin made its way to the invaluable in the effort to track trends, New York City area, but it was relatively identify emerging problems, expedite in- scarce there. tervention, and share epidemiologic in- Heroin from Southeast Asia fueled the formation and findings. epidemic in the early 1980s. Between 1979 and 1985, heroin indicators in New PslXTERNS AND TRENDS OF York and other northeastern cities in- SELECTED DRUGS OF ABUSE creased sharply and then leveled off. However, indicators recently have begun This section briefly describes general to increase again in the northeastern sec- national trends regarding three major tion of the United States. Heroin indica- drug categories. tors in states bordering Mexico showed a severe problem with heroin abuse start- Heroin ing about 1981 and continuing through the mid-1980s. Current indicators in that Heroin abuse is a relatively rare event area of the country show a decline. involving a population that seeks to re- Along with these indicators of heroin main hidden. These factors make it diffi- availability and use, the western United cult to measure incidence, prevalence, States also experienced the appearance of and consequences of abuse through tra- “black tar” heroin, a gummy, dark

56 Bulletin ofPAH0 24(Z), 1990 20,000 1 15,000-

z 5E E 10,000- g% z

5,000-

0 ’ 1960 1965 1970 1975 1980 1985 Yearof first heroinabuse Figure 1. Incidence of heroin abuse, based on admissions to a panel of federally funded treatment programs. brown or black heroin that has a strong abusers were initiated into heroin abuse bitter odor. Law enforcement officials be- between the mid-1960s and the mid- lieve that this new form of the drug is the 1970s. product of poor or incomplete process- There also have been changes in the ing, which results in many impurities. patterns of heroin use, with trends to- Whether and to what extent these impu- ward combining heroin ingestion with al- rities contribute to the increase in adverse cohol consumption and mixing heroin health consequences and death is cur- with cocaine. The combination of heroin rently under epidemiologic investigation. with alcohol became a more prevalent Changes in the characteristics of abus- pattern of use around the middle to late ers also have occurred over time, most 1970s. An examination of heroin-related notably an aging of the heroin abusing mortality shows that when heroin is in- population. For example, according to re- gested shortly before or shortly after alco- ports to DAWN, the percentage of all hol consumption, it is particularly lethal. heroin-related nonfatal emergencies The heroin/cocaine combination takes which involved persons 30 years of age one of three forms: (1) cocaine is ingested or older increased from 36% in 1979 to at the same time as heroin in a combina- 68% in 1987, while a similar increase from tion called a “speedball”; (2) cocaine is 41% to 61% occurred during the period taken after the heroin in an attempt to from 1979 to 1985 among heroin treat- alleviate the adverse consequences of ment admissions. These age data make a heroin dependence, such as withdrawal; strong case that most current heroin or (3) the heroin is taken after prolonged

Km1 EpidemiologicStudies of Drug Abuse 57 cocaine use to diminish the depression those who used the drug during the that often ensues. month prior to the survey, increased The most dramatic issue of the day, from 4.2 million in 1982 to 5.8 million in though, is the association between intra- 1985, an increase of 38%. Based on the venous (IV) drug abuse and acquired im- 1988 survey, however, the number of cur- munodeficiency syndrome (AIDS). Not rent users showed a dramatic decline to only has the percentage of AIDS cases 2.9 million, a 50% decrease. The number associated with IV drug abuse been in- of people who reported using cocaine creasing, but in some areas of the United during the year prior to the survey re- States, such as the states of New York mained virtually level between 1982 and and New Jersey, IV drug abusers have 1985, 11.9 million and 12.2 million, re- become the main AIDS risk group, and spectively. However, this population also this group is viewed as the bridge to the showed a sharp decline in 1988, to 8.2 general population. million This strongly suggests that, as a result of education campaigns, the preva- Cocaine lence pool of cocaine users is beginning to recognize the dangers of cocaine use The Household Survey on Drug Abuse and to modify its behavior. Figure 2 shows that the number of current cocaine shows that current cocaine use has de- users in the United States, defined as creased in all age groups.

Figure 2. Trends in cocaine past-month use by age group, 1974-l 985.

10 -

8-

0 I , 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988

Note: In 1974, 1976, and 1977 the estimates were less than 0.5% for the 26+ years age group.

Source: National Institute on Drug Abuse, National Household Survey on Drug Abuse, 1988.

58 Bdletin ofPAl 24(l), 1990 Recent data also show an encouraging trend. Table 1 presents data from the 1988 High School Senior Survey. Similar to the Household Survey, it shows an in- creasing trend for cocaine use through 1985, with more than 17% of seniors re- porting ever having used cocaine and al- most 7% reporting having used it within the past month. Since 1985 there has been a significant decline in reported use of cocaine, with lifetime prevalence in 1988 down to 12.1%, annual prevalence at 7.9%, and current use at 3.4%. For the past few years, a form of free base known as “crack” has become quite visible in many areas of the United States. Rather than a new drug, crack is the product of a new marketing tech- nique. It is cocaine that has been con- verted to base form from hydrochloride using baking soda. The technique has been used for many years, but now the product is being sold on the street. Crack is sold in small amounts-about 65- 100 mg-at the relatively low cost of $lO- $20. This has made it affordable to a much larger population, including youth, who could not afford the average $100 per gram price of hydrochloride. The 1985 Household Survey data reflect the consequences-46% of the 12-17- year-olds who reported using cocaine at least once said they had smoked free base, compared to 21% of the 18-25-year- olds and 19% of the 26-34-year-olds. The greater and more dan- gerous use patterns are no doubt respon- sible for the more than fivefold increase in cocaine-related nonfatal emergencies and deaths reported to DAWN from the latter part of 1983 to the latter part of 1988, as shown in Figure 3.

Marijuana

The most widely abused illegal drug in the United States is marijuana. The 1988 National Household Survey on Drug

Kozel EpidemiologicStudies of Drug Abuse 59 Figure 3. Cocaine-related morbidity and mortality, 1983-l 988. Non-fatalemergencies No of deaths i50

ioo

150

100

8,000 350

300 6,000 259 5,ooc 200 4,ooc

150 3,oot

100 2,00(

1,OO( 50

1 l- 0

1983 1984 1985 1986 1987 1988 1983to 1988by quarter

Source: National Institute on Drug Abuse, Drug Abuse Warning Network Consistent Panel.

Abuse indicates that an estimated 66 mil- effect rather than a recent increase in inci- lion people in the United States had used dence.* marijuana at least once and an estimated Similar to those regarding cocaine, 12 million had consumed it during the these National Household Survey trends month prior to the survey. While these are reflected in data from high school se- estimates represent a substantial percent- nior classes, shown in Table 3, which also age of the national population, trends show a noteworthy decline in recent years, as shown in Table 2. Even the in- *Adams, E. H., J. C. Gfroerer, B. A. Rouse, and N. J. Kozel. Trends in prevalence and consequences of crease in lifetime prevalence among cocaine use. Adv Alcohol Subst Abuse 6(2):49-71, adults has been shown to be an aging 1986.

60 Bulletin of PAHO 24(l), 1990 Table 2. Estimated prevalence of marijuana use among three age groups, 1971-1988. Population using marijuana (%) in: Prevalence 1971 1972 1974 1976 1977 1979 1982 1985 1988 12-l 7-year-olds N= (781) c3801 (952) (986) (1,272) CL165) (1,581) (2,287) (3,095) Ever used 14.0 14.0 23.0 22.4 28.0 30.9 26.7 23.6 17.4 Used in past year ...... 18.5 18.4 22.3 24.1 20.6 19.7 12.6 Used in past month 6.0 7.0 12.0 12.3 16.6 16.7 11.5 12.0 6.4 18-25-vear-olds N= (741) (772) (849) (882) U,500) CW44) (1,283) (1,804) (1,505) Ever used 39.3 47.9 52.7 52.9 59.9 68.2 64.1 60.3 56.4 Used in past year ...... 34.2 35.0 38.7 46.9 40.4 36.9 27.9 Used in past month 17.3 27.8 25.2 25.0 27.4 35.4 27.4 21.8 15.5

26 years and older N= (1,664) (1,613) (2,221) (1,708) (1,822) (3,015) W60) (3,947) (4,214) Ever used 9.2 7.4 9.9 12.9 15.3 19.6 23.0 27.2 30.7 Used in past year ...... 3.8 5.4 6.4 9.0 10.6 9.5 6.9 E Used in past month 1.3 2.5 2.0 3.5 3.3 6.0 6.6 6.1 3.9 Source: National Institute on Drug Abuse. National Household Survey on DrugAbuse: Main Findings. Rockville, MD, 1989.

3. 3 Table 3. Estimated prevalence of marijuana use among high school senior classes, 1975-l 988. 8 Percentage of high school seniors using marijuana q9 Prevalence 197547.3 197652.8 197756.4 197859.2 197960.4 198060.3 198159.5 1982 1983 1984 1985 1986 1987 1988 w Lifetime 58.7 57.0 54.9 54.2 50.9 50.2 47.2

i AnnualPast month 40.027.1 44.532.2 47.635.4 50.237.1 50.836.5 48.833.7 46.131.6 44.328.5 42.327.0 40.025.2 40.625.7 23.438.8 21.036.3 33.118.0 Daily (past month) 6.0 a.2 9.1 10.7 10.3 9.1 7.0 6.3 5.5 5.0 4.9 4.0 3.3 2.7 Source: L. D. Johnston, t? M. O’Malley, and J. G. Bachman.Monitoring the Future: A Continuing Studyof the Lifestylesand Valuesof Youth.University of Michigan, Institute for Social s Research,1989. demonstrate a declining trend through CONCLUSION 1988 after reaching a peak in 1978-1979. This decline is thought to be associated The dynamic nature of drug abuse, its with a current increase in the perceived multifaceted etiology, and the complex harmfulness of marijuana. For instance, set of behavioral, physical, and social cir- in 1978, monthly prevalence among high cumstances that place some people at school seniors was 37%, and almost 11% risk for drug abuse and its consequences used marijuana daily. At the same time, make it extremely difficult, if not impos- only 12% of seniors nationwide believed sible, to predict trends. However, an ef- that there was great risk associated with fective epidemiology surveillance and an- occasional use of marijuana and 35% per- alytical program can provide the basis for ceived great risk with regular use. By rapid identification of outbreaks of drug 1988, monthly prevalence declined to abuse and the risk factors involved, po- 18% and daily use to 2.7%, while per- tentially limiting adverse effects and im- ceived risk for regular use rose to 77%. proving the public health.

Workshops O@ed in Addiction Studies

The Institute for Addiction Studies of the Merritt Peralta Institute in Oak- land, California, U.S.A., offers a workshop series for persons working in the field of chemical dependency. Some of the upcoming one-day work- shops deal with the following topics: “Treatment Strategies for ‘Impos- sible’ Cases,” to be offered 27 April 1990, which will include descriptions of detox regimens and case studies; “Issues in Spirituality-God without Hysteria,” on 22 June 1990, which will address the role of spirituality in recovery from chemical dependency; and “Kid’s Power: Healing for Young Children of Alcoholics,” on 13 July 1990, which will focus on tech- niques to help young children who have lived in alcoholic and substance- abuse environments. All these workshops will be held at the Institute for Addiction Studies, Health Education Center, Oakland, California, and the cost for each is US$60. For further information, contact Margaret Saget, MI’1 CDRH, 435 Hawthorne Avenue, Oakland, CA 94609, telephone (415) 428-4104.

62 Buktin ofPM0 24(l), 2990