Drug Abuse: Studies Show Treatment Is Effective, but Benefits May Be
Overstated (Testimony, 07/22/98, GAO/T-HEHS-98-185).
Pursuant to a congressional request, GAO discussed its recent report on
drug abuse treatment research findings, focusing on: (1) the overall
effectiveness of drug abuse treatment; (2) the methodological issues
affecting drug abuse treatment evaluations; and (3) what is known about
the effectiveness of specific treatments for heroin, cocaine, and
adolescent drug addiction.
GAO noted that: (1) it found that large, multisite, longitudinal studies
have produced considerable evidence that drug abuse treatment is
beneficial to the individual undergoing treatment and to society; (2)
the studies have consistently found that a substantial proportion of
clients being studied report reductions in drug use and criminal
activity following treatment; (3) the studies also show that clients who
stay in treatment for longer periods report better outcomes; (4)
however, drug abuse treatment research is complicated by a number of
methodological challenges that make it difficult to accurately measure
the extent to which treatment reduces drug use; (5) in particular,
growing concerns about the validity of self-reported data, which are
used routinely in the major evaluations of drug abuse treatment, suggest
that the treatment benefit reported by these studies may be somewhat
overstated; (6) in addition, the research evidence to support the
relative effectiveness of specific treatment approaches or settings for
particular groups of drug abusers is limited; and (7) while one specific
treatment approach--methadone maintenance--has been shown to be the most
effective treatment for heroin addiction, research on the best treatment
approach or setting for cocaine addiction or adolescent drug users is
less definitive.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: T-HEHS-98-185
TITLE: Drug Abuse: Studies Show Treatment Is Effective, but
Benefits May Be Overstated
DATE: 07/22/98
SUBJECT: Drug abuse
Drug treatment
Evaluation methods
Statistical data
Alcohol or drug abuse problems
Public health research
Methadone maintenance
Rehabilitation programs
Narcotics
IDENTIFIER: NIDA Drug Abuse Treatment Outcome Study
SAMHSA National Treatment Improvement Evaluation Study
NIDA Treatment Outcome Prospective Study
NIDA Drug Abuse Reporting Program
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Cover
================================================================ COVER
Before the Subcommittee on National Security, International Affairs
and Criminal Justice, Committee on Government Reform and Oversight,
House of Representatives
For Release on Delivery
Expected at 10:00 a.m.
Wednesday, July 22, 1998
DRUG ABUSE - STUDIES SHOW
TREATMENT IS EFFECTIVE, BUT
BENEFITS MAY BE OVERSTATED
Statement of Marsha Lillie-Blanton, Associate Director,
Health Services Quality and Public Health Issues
Health, Education, and Human Services Division
GAO/T-HEHS-98-185
GAO/HEHS-98-185T
(108376)
Abbreviations
=============================================================== ABBREV
DARP - Drug Abuse Reporting Program
DATOS - Drug Abuse Treatment Outcome Study
HHS - Department of Health and Human Services
NIDA - National Institute on Drug Abuse
NTIES - National Treatment Improvement Evaluation Study
TOPS - Treatment Outcome Prospective Study
DRUG ABUSE: STUDIES SHOW
TREATMENT IS EFFECTIVE, BUT
BENEFITS MAY BE OVERSTATED
============================================================ Chapter 0
Mr. Chairman and Members of the Subcommittee:
We are pleased to be here today to discuss our recent report on drug
abuse treatment research findings.\1 As you know, illicit drug use in
the United States remains a serious and costly problem. In a 1996
survey, about 13 million Americans reported using illicit drugs in
the past month. Each year, as many as 11,000 deaths are linked to
illicit drug use. To combat the nation's drug abuse problem, the
federal government and states spend about $27 billion annually.
Further, the total annual cost of illicit drug use to society is
estimated at $67 billion for costs associated with health care and
drug addiction prevention and treatment programs, drug-related crime,
and lost resources resulting from reduced worker productivity or
death.
Because drug abuse treatment is a significant component of the
nation's drug control strategy, you asked us to examine the major
research findings on drug abuse treatment effectiveness. My remarks
today will focus on (1) the overall effectiveness of drug abuse
treatment; (2) the methodological issues affecting drug abuse
treatment evaluations; and (3) what is known about the effectiveness
of specific treatments for heroin, cocaine, and adolescent drug
addiction. My comments are based on our review and synthesis of
findings from major evaluations of drug abuse treatment
effectiveness.
In brief, we found that large, multisite, longitudinal studies have
produced considerable evidence that drug abuse treatment is
beneficial to the individual undergoing treatment and to society.
The studies have consistently found that a substantial proportion of
clients being studied report reductions in drug use and criminal
activity following treatment. The studies also show that clients who
stay in treatment for longer periods report better outcomes.
However, drug abuse treatment research is complicated by a number of
methodological challenges that make it difficult to accurately
measure the extent to which treatment reduces drug use. In
particular, growing concerns about the validity of self-reported
data, which are used routinely in the major evaluations of drug abuse
treatment, suggest that the treatment benefit reported by these
studies may be somewhat overstated. In addition, the research
evidence to support the relative effectiveness of specific treatment
approaches or settings for particular groups of drug abusers is
limited. While one specific treatment approach--methadone
maintenance--has been shown to be the most effective treatment for
heroin addiction, research on the best treatment approach or setting
for cocaine addiction or adolescent drug users is less definitive.
--------------------
\1 Drug Abuse: Research Shows Treatment Is Effective, but Benefits
May Be Overstated (GAO/HEHS-98-72, Mar. 27, 1998).
BACKGROUND
---------------------------------------------------------- Chapter 0:1
In general, drug abuse is defined by the level and pattern of drug
consumption and the severity of resulting functional problems.
People who are dependent on drugs often use multiple drugs and have
substantial health and social problems, including mental health
disorders. One of the many challenges to providing effective
treatment for addiction is the complicated nature of the disorder.
Unlike other chronic diseases, drug addiction extends beyond
physiological influence to include significant behavioral and
psychological aspects. For example, specific environmental cues that
a drug abuser associates with drug use can trigger craving and
precipitate relapse, even after long periods of abstinence.
Therefore, drug abusers may enter treatment a number of times, often
reducing drug use incrementally with each treatment episode.
Despite the potential for relapse to drug use, not all drug users
require treatment to discontinue use. For those who require
treatment, services are provided in either outpatient or inpatient
settings and via two major approaches--pharmacotherapy and behavioral
therapy--with many programs combining elements of both. Although
abstinence from illicit drug use is the central goal of all drug
abuse treatment, researchers and program staff commonly accept
reductions in drug use and criminal behavior as realistic, interim
goals.
Since the early 1990s, federal spending for drug abuse treatment has
grown steadily. Of the approximately $16 billion budgeted for drug
control activities in fiscal year 1998, drug abuse treatment
accounted for $3.2 billion, or 20 percent. Over half of federal drug
abuse treatment funds were allocated to the Department of Health and
Human Services (HHS) to support block grants to the states, drug
abuse treatment services, and related research. An additional third
of treatment dollars are spent by the Department of Veterans Affairs
to support drug abuse treatment services to veterans and their
inpatient and outpatient medical care. To meet the requirements of
the Government Performance and Results Act of 1993, agencies are
beginning to set goals and performance measures to monitor and assess
the effectiveness of federally funded drug abuse treatment efforts.
However, demonstrating the efficient and effective use of federal
drug abuse treatment funds is particularly challenging because most
of these funds support services provided by state and local grantees,
which are given broad discretion in how best to use them.
RESEARCH CONSISTENTLY
DEMONSTRATES BENEFITS OF DRUG
ABUSE TREATMENT
---------------------------------------------------------- Chapter 0:2
In numerous large-scale studies examining the outcomes of drug abuse
treatment provided in a variety of settings, researchers have
concluded that treatment is beneficial. Clients receiving treatment
report reductions in drug use and criminal activity as well as other
positive outcomes. The studies have also demonstrated that better
treatment outcomes are associated with longer treatment periods but
have found that retaining clients in treatment programs is
problematic.
MAJOR STUDIES REPORT
REDUCTIONS IN DRUG USE AND
CRIME FOLLOWING TREATMENT
-------------------------------------------------------- Chapter 0:2.1
Comprehensive analyses of the effectiveness of drug abuse treatment
have been conducted by several major, federally funded studies over a
period of nearly 30 years: the Drug Abuse Treatment Outcome Study
(DATOS), the National Treatment Improvement Evaluation Study (NTIES),
the Treatment Outcome Prospective Study (TOPS), and the Drug Abuse
Reporting Program (DARP). These large, multisite studies--conducted
by research organizations independent of the groups operating the
treatment programs being assessed--were designed to measure people's
involvement in illicit drug and criminal activity before, during, and
after treatment. Although the studies report on reductions in drug
use from the year prior to treatment to the year after, most also
track a subset of treatment clients for followup interviews over
longer time periods. For example, DARP followed clients for as long
as 12 years, TOPS for 3 to 5 years following treatment, and DATOS
researchers are planning additional followup to determine long-term
outcomes. These studies are generally considered by the research
community to be the major evaluations of drug abuse treatment
effectiveness, and much of what is known about "typical" drug abuse
treatment outcomes comes from these studies.\2
All of these major studies, which have evaluated the progress of
thousands of people, concluded that drug abuse treatment was
effective when outcomes were assessed 1 year after treatment. They
found that reported drug use declined when clients received services
through any of three drug abuse treatment approaches--residential
long-term, outpatient drug-free, or outpatient methadone
maintenance--regardless of the drug and client type.\3 DATOS found
that, of the individuals in long-term residential treatment, 66
percent reported weekly or more frequent cocaine use in the year
prior to treatment, while 22 percent reported regular cocaine use in
the year following treatment. Also, 41 percent of this same group
reported engaging in predatory illegal activity in the year prior to
treatment, while 16 percent reported such activity in the year after
treatment.
Previous studies found similar reductions in drug use and criminal
activity. For example, researchers from the 1980s TOPS study found
that across all types of drug abuse treatment, 40 to 50 percent of
regular heroin and cocaine users who spent at least 3 months in
treatment reported near abstinence during the year after treatment,
and an additional 30 percent reported reducing their use. Only 17
percent of NTIES clients reported arrests in the year following
treatment--down from 48 percent during the year before treatment.
--------------------
\2 See Institute of Medicine, Treating Drug Problems (Washington,
D.C.: Institute of Medicine, 1990). See also "Drug Abuse Treatment
Outcome Study (DATOS)," Psychology of Addictive Behaviors, Vol. 11,
No. 4 (1997), pp. 211-323. For information on NTIES, see The
National Treatment Improvement Evaluation Study--Final Report (Mar.
1997), prepared by the National Opinion Research Center at the
University of Chicago in collaboration with the Research Triangle
Institute for the Center for Substance Abuse Treatment, Substance
Abuse and Mental Health Services Administration.
\3 In its 1990 report, Treating Drug Problems, the Institute of
Medicine concluded there was little evidence to suggest that
hospital-based chemical dependency programs, a type of inpatient
treatment, were either more or less effective for treating drug
problems than chemical dependency programs not located in hospitals.
DATOS found that clients receiving treatment in short-term inpatient
programs reported substantial reductions in drug use, but statistical
analysis did not show that the reductions were attributable to the
treatment.
LONGER TREATMENT EPISODES
HAVE BETTER OUTCOMES, BUT
TREATMENT DURATION IS
LIMITED BY CLIENT DROP-OUT
-------------------------------------------------------- Chapter 0:2.2
Another finding across these studies is that clients who stay in
treatment longer report better outcomes. For the DATOS clients that
reported drug use when entering treatment, fewer of those in
treatment for more than 3 months reported continuing drug use than
those in treatment for less than 3 months. DATOS researchers also
found that the most positive outcomes for clients in methadone
maintenance were for those who remained in treatment for at least 12
months. Earlier studies reported similar results. Both DARP and
TOPS found that reports of drug use were reduced most for clients who
stayed in treatment at least 3 months, regardless of the treatment
setting.
Although these studies show better results for longer treatment
episodes, they found that many clients dropped out of treatment long
before reaching the minimum length of treatment episode recommended
by those operating the treatment program. For example, a study of a
subset of DATOS clients found that all of the participating methadone
maintenance programs recommend 2 or more years of treatment, but the
median treatment episode by clients was about 1 year. Long-term
residential programs participating in DATOS generally recommended a
treatment duration of 9 months or longer, while outpatient drug-free
programs recommended at least 6 months in treatment; for both program
types, the median treatment episode was 3 months.
TREATMENT BENEFITS MAY BE
OVERSTATED BY MAJOR STUDIES
---------------------------------------------------------- Chapter 0:3
Because all of the effectiveness studies relied on information
reported by the clients, the level of treatment benefit reported may
be overstated. Typically, drug abusers were interviewed before they
entered treatment and again following treatment and asked about their
use of illicit drugs, their involvement in criminal activity, and
other drug-related behaviors.\4 Although this data collection method
is commonly used in national surveys and drug abuse treatment
evaluations, recent questions about the validity of self-reported
drug use raise concerns about this approach. In general,
self-reporting is least valid for (1) the more stigmatized drugs,
such as cocaine; (2) recent use; and (3) those involved with the
criminal justice system. A recent National Institute on Drug Abuse
(NIDA) review of current research on the validity of self-reported
drug use highlights the limitations of data collected in this
manner.\5 According to this review, recent studies conducted with
criminal justice clients (such as people on parole, on probation, or
awaiting trail) and former treatment clients suggest that 50 percent
or fewer current users accurately report their drug use in
confidential interviews.
As questions have developed about the accuracy of self-reported
data,\6 researchers have begun using more objective means, such as
urinalysis, to validate such data. For example, NTIES researchers
found that 20 percent of those in a validation group acknowledged
cocaine use within the past 30 days, but urinalysis revealed recent
cocaine use by 29 percent. TOPS researchers reported that only 40
percent of the individuals testing positive for cocaine 24 months
after treatment had reported using the drug in the previous 3 days.
Because results from the major studies of treatment effectiveness
were not adjusted for the likelihood of underreported drug use,
reductions in drug use found may be overstated. However, researchers
emphasize that client reporting on use of illicit drugs during the
previous year (the outcome measure used in most effectiveness
evaluations) has been shown to be more accurate than client reporting
on current drug use (the measure used to assess the validity of
self-reported data). Therefore, they believe that the overall
findings of treatment benefits are still valid.
Although supplementary data collection, such as hair analysis or
urinalysis, can help validate the accuracy of self-reported data,
these tools also have limitations. Urine tests can accurately detect
illicit drugs for about 48 hours following drug use but do not
provide any information about drug use during the previous year. In
addition, individual differences in metabolism rates can affect the
outcomes of urinalysis tests. Hair analysis has received attention
because it can detect drug use over a longer time--up to several
months. However, unresolved issues in hair testing include
variability across drugs in the accuracy of detection, the potential
for passive contamination, and the relative effect of different hair
color or type on cocaine accumulation in the hair. We have reported
on the limitations of using self-reported data in estimating the
prevalence of drug use and concluded that hair testing merited
further evaluation as a means of confirming self-reported drug use.\7
--------------------
\4 A large percentage of the clients participating in the studies we
reviewed were involved with the criminal justice system. For
example, 56 percent of DATOS clients reported being on probation or
parole or awaiting trial when they entered treatment; 31 percent of
DATOS clients were referred into treatment by the courts.
\5 National Institutes of Health, The Validity of Self-Reported Drug
Use: Improving the Accuracy of Survey Estimates, National Institute
on Drug Abuse Research Monograph Series 167 (Washington, D.C.: HHS,
1997).
\6 The research literature prior to the mid-1980s showed drug use
self-reporting to be generally valid, while studies conducted since
then have raised concerns about validity. The apparent change in
validity may be due in part to improved urinalysis testing that now
detects drug use more accurately. It is also possible that
individuals were more willing to admit to using illicit drugs when
societal reaction toward drug use was not as strong as it is today.
Even today, researchers are not in agreement on the limitations of
self-reported data. For example, the researchers for DATOS, the most
recently completed study of drug treatment, acknowledged limitations
to self-reported data but asserted that most of these data are
reasonably reliable and valid.
\7 See Drug Use Measurement: Strengths, Limitations, and
Recommendations for Improvement (GAO/PEMD-93-18, June 25, 1993).
EVIDENCE VARIES ON THE BEST
TREATMENT APPROACHES FOR
SPECIFIC GROUPS OF DRUG ABUSERS
---------------------------------------------------------- Chapter 0:4
Using federal treatment dollars most effectively requires an
understanding of which approaches work best for different groups of
drug abusers, but on this subject, research findings are less
definitive. Although strong evidence supports methadone maintenance
as the most effective treatment for heroin addiction, less is known
about the best ways to provide treatment services to cocaine users or
adolescents.
In addition, client and program-related factors can affect client
success. For example, outpatient drug abuse treatment programs
operate with different numbers and quality of staff and have varying
levels of coordination with local agencies that offer related
services generally needed to support recovering abusers. A treatment
program with close ties to local service providers, such as health
clinics and job training programs, is likely to have better treatment
outcomes than a program without such ties. Similarly, client
factors, such as motivation and readiness for treatment or
psychiatric status, can significantly affect the patient's
performance in treatment. Current research generally does not
account for these factors in evaluating the effectiveness of
alternative approaches for specific groups of drug abusers.
RESEARCH SUPPORTS METHADONE
MAINTENANCE AS THE MOST
EFFECTIVE TREATMENT FOR
HEROIN ADDICTION
-------------------------------------------------------- Chapter 0:4.1
Methadone maintenance is the most commonly used treatment for heroin
addiction, and numerous studies have shown that those receiving
methadone maintenance treatment have better outcomes than those who
go untreated or use other treatment approaches. Methadone
maintenance reduces heroin use and criminal activity and improves
social functioning. HIV risk is also minimized, since needle usage
is reduced.
As we have previously reported, outcomes among methadone programs
have varied greatly, in part because of the substantial differences
in treatment practices across the nation.\8 For example, in 1990, we
found that many methadone clinics routinely provided clients dosage
levels that were lower than optimum--or even subthreshold--and
discontinued treatment too soon. In late 1997, a National Institutes
of Health consensus panel concluded that people who are addicted to
heroin or other opiates should have broader access to methadone
maintenance treatment programs and recommended that federal
regulations allow additional physicians and pharmacies to prescribe
and dispense methadone.
Similarly, several studies conducted over the past decade show that
when counseling, psychotherapy, health care, and social services are
provided along with methadone maintenance, treatment outcomes improve
significantly. However, the recent findings from DATOS suggest that
the provision of these ancillary services--both the number and
variety--has eroded considerably during the past 2 decades across all
treatment settings. DATOS researchers also noted that the percentage
of clients reporting unmet needs was higher than the percentage in
previous studies.
--------------------
\8 See Methadone Maintenance: Some Treatment Programs Are Not
Effective; Greater Oversight Needed (GAO/HRD-90-104, Mar. 22, 1990).
COGNITIVE-BEHAVIORAL
TREATMENTS SHOW PROMISE FOR
COCAINE ADDICTION
-------------------------------------------------------- Chapter 0:4.2
Evidence of a best approach to treat cocaine addiction is not as
clear as it is for heroin addiction. Although a number of
pharmacotherapies have been studied and some have proven successful
in one or more clinical trials, no medication has demonstrated
substantial efficacy once subjected to several rigorously controlled
trials. Without a pharmacological agent, researchers have relied on
cognitive-behavioral therapies to treat cocaine addiction.
Studies have shown that clients receiving cognitive-behavioral
therapy have achieved long periods of abstinence and have been
successful at staying in treatment.\9
The cognitive-behavioral therapies are based largely on counseling
and education. One approach, relapse prevention, focuses on teaching
clients how to identify and manage high-risk, or "trigger,"
situations that contribute to drug relapse. A study of this approach
showed cocaine-dependent clients were able to remain abstinent at
least 70 percent of the time while in treatment. Another technique,
community reinforcement/contingency management, establishes a link
between behavior and consequence by rewarding abstinence and
reprimanding drug use. A program using this approach found that 42
percent of the participating cocaine-dependent clients were able to
achieve nearly 4 months of continuous abstinence. A third approach,
neurobehavioral therapy, addresses a client's behavioral, emotional,
cognitive, and relational problems at each stage of recovery. One
neurobehavioral program showed that 38 percent of the clients were
abstinent at the 6-month followup.
--------------------
\9 See Cocaine Treatment: Early Results From Various Approaches
(GAO-HEHS-96-80, June 7, 1996).
FAMILY THERAPY IS UNDER
STUDY FOR ADOLESCENT DRUG
ABUSERS
-------------------------------------------------------- Chapter 0:4.3
Drug use among teenagers is a growing concern. It is estimated that
9 percent of teenagers were current drug users in 1996--up from 5.3
percent in 1992. Unfortunately, no one method has been shown to be
consistently superior to others in achieving better treatment
outcomes for this group. Rather, studies show that success in
treatment for adolescents seems to be linked to the characteristics
of program staff, the availability of special services, and family
participation.
Many experts believe that family-based intervention shows promise as
an effective treatment for adolescent drug abusers. This approach,
based on the assumption that family behaviors contribute to the
adolescent's decision to use drugs, was identified by a 1997 study
and literature review as superior to other treatment approaches.\10
In fact, some researchers believe that family interventions are
critical to the success of any treatment approach for adolescent drug
abusers because family-related factors--such as parental substance
use, poor parent-child relations, and poor parent supervision--have
been identified as risk factors for the development of substance
abuse among adolescents. However, NIDA acknowledged in a recently
published article that further research is needed to identify the
best approach to treating adolescent drug abusers.\11 Similarly, the
American Academy of Child and Adolescent Psychiatry acknowledged in
its 1997 treatment practice parameters that research on drug abuse
treatment for adolescents has failed to demonstrate the superiority
of one treatment approach over another.\12
--------------------
\10 M. D. Stanton and W. R. Shadish, "Outcome, Attrition, and
Family/Couples Treatment for Drug Abuse: A Meta-Analysis and Review
of the Controlled, Comparative Studies," Psychology Bulletin, Vol.
122 (1997), pp. 170-91.
\11 Naimah Z. Weinberg, M.D., and others, "Adolescent Substance
Abuse: A Review of the Past 10 Years," Journal of the American
Academy of Child and Adolescent Psychiatry, Vol. 37, No. 3 (Mar.
1998), pp. 252-61.
\12 Oscar Bukstein, M.D. (principal author) and the Washington Group
on Quality Issues, "Practical Parameters for the Assessment and
Treatment of Children and Adolescents With Substance Use Disorders,"
Journal of the American Academy of Child and Adolescent Psychiatry,
Vol. 36, No. 10, Supp. (Oct. 1997), pp. 1405-1565.
CONCLUSIONS
---------------------------------------------------------- Chapter 0:5
With an annual expenditure of more than $3 billion--20 percent of the
federal drug control budget--the federal government provides
significant support for drug abuse treatment activities. Monitoring
the performance of treatment programs can help ensure that we are
making progress to achieve the nation's drug control goals. Research
on the effectiveness of drug abuse treatment, however, is problematic
given the methodological challenges and numerous factors that
influence the results of treatment. Although studies conducted over
nearly 3 decades consistently show that treatment reduces drug use
and crime, current data collection techniques do not allow accurate
measurement of the extent to which treatment reduces the use of
illicit drugs.
-------------------------------------------------------- Chapter 0:5.1
Mr. Chairman, this concludes my prepared statement. I will be happy
to answer any questions you and other members of the Subcommittee may
have.
*** End of document. ***