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OCR for page 1
Summary
More than 115,000 persons in the United States have been diagnosed with
acquired immune deficiency syndrome, or AIDS, since the illness was
first identified in this country almost 10 years~ago. As we enter the second
decade of the epidemic, residual problems from the first decade continue
to compel the nation's attention. Moreover, new issues are emerging
that call for immediate consideration and action. The dimensions of
the epidemic are sizable and will continue to grow, presenting enormous
challenges to the nation and to those individuals who must track its course,
design and implement intervention programs, and provide medical care
and other services. This report reviews the course of the epidemic and
its current status. It also discusses prevention activities designed to curb
the future spread of the human immunodeficiency virus (HIV) and offers
recommendations regarding potential avenues for achieving this goal.
This report was prepared by the Committee on AIDS Research and
the Behavioral, Social, and Statistical Sciences, which was established
in 1987. The formation of such a committee within the National Re-
search Council reflected a growing awareness that understanding HIV
transmission, facilitating behavioral change to prevent further spread of
infection, and coping with the social consequences of the epidemic raise
questions that properly lie within the domain of the social, behavioral,
and statistical sciences. At the request of the Public Health Service (PHS)
and with support from the Russell Sage and Rockefeller Foundations, the
committee reviewed estimates of the extent of HIV infection in the U.S.
~ This work builds on the past and ongoing work of the Institute of Medicine (IOM)/Naiional Academy
of Sciences (NAS). The IONVNAS has produced two major reports that focused on public health, bio-
logical research, and medical care issues: Confronting AIDS: Directions for Public Health, Health
Care, and Research (1986) and Confronting AIDS: Update 1988 (both published by the National
Academy Press, Washington, D.C.).
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2 ~ AIDS: THE SECOND DECADE
population and the patterns of sexual behavior and drug use that trans-
mit HIV. It also reviewed intervention strategies that showed promise of
producing behavioral change to slow the spread of HIV infection in the
general population. In 1989 the committee issued its first report, AIDS,
Sexual Behavior, and Intravenous Drug Use.2
The committee's studies dunng this most recent phase of its efforts
have considered the evolving shape of the epidemic, focusing attention
on populations and research topics that will be of increasing importance
in coming years. After discussions with liaison representatives of the
PHS, the committee accepted the following as its charge: to review
the changing nature of the epidemic in the United States and the needs
of the diverse populations being affected by it, such as adolescents and
women (including female prostitutes); to descnbe behavioral research and
intervention strategies that could assist in protecting the blood supply; and
to review a selected set of methodological issues that affect the quality of
data collected in surveys of drug use and sexual practices. This volume
is the committee's response to its charge. In preparing it, the committee
was assisted by a specially appointed Panel on AIDS Interventions and
Research.3
In continuing to monitor the progression of the epidemic and the
nation's response, the committee notes several important changes in this
evolving and enduring health problem. New populations that are at risk
are emerging from populations that heretofore have not been touched
directly by AIDS and from subgroups of populations that are already
known to bear infection. Moreover, shifts in patterns of risk-associated
behaviors are now becoming apparent. For example, although the threat
of disease transmission posed by intravenous (IV) Mug use has been
recognized since the early years of the epidemic, there is now a growing
appreciation of the indirect hazards (e.g., sexual risk taking in the context
of drug use) posed by drugs that are not injected, such as the form of
cocaine known as crack. There is also increasing awareness of the need
to maintain risk-reducing behaviors once they have been initiated. The
persistence of risk in the environment and the problem of relapse mandate
a long-term commitment to prevention.
2 turner' C. F., Miller, H. G. and Moses, L. E (1989) AIDS, Sexual Behavior, and Intravenous Drug
Use. Report of the National Research Council Committee on AIDS Research and the Behavioral,
Social, and Statistical Sciences. Washington, D.C.: National Academy Press.
3 The committee also benefited from the work of a second panel, which reviewed methodologies for
evaluating the effectiveness of AIDS prevention programs. The panel's report, Evaluating AIDS Pre-
vention Programs, Expanded Edition (S. L. Coyle, R. F. Boruch, and C. F. Turner), will be published
in mid-1990 by the National Academy Press.
OCR for page 3
SUMMARY ~ 3
In the second decade of the epidemic, new pockets of infection are
being identified in more diverse geographical locations in the United
States, and the changing distributions of AIDS cases and HIV infection
indicate that the disease is becoming more a generalized American phe-
nomenon and less a bicoastal, urban entity. Moreover, the pattern of
infection is also beginning to reveal some subtle shifts in the distribution
of AIDS cases across transmission categories; the proportion of cases
attributable to same-gender contact has decreased slightly as the propor-
tion ascribed to heterosexual contact has grown. Even the characteristics
of the disease itself are somewhat in flux. With the development of
drugs capable of decreasing morbidity associated with HIV infection and
prolonging the lives of those infected with the virus, the disease takes
on some of the characteristics of a long-tenn rather than an acute illness.
The changing locus of the epidemic, the new populations at risk, and
the emerging longer term nature of the disease point to the need for new
outreach and intervention strategies to prevent further spread of infection,
as well as services and treatment to assist those who are already infected.
The first two sections of this summary (and Chapters 1 and 2 of the
full report) describe the evolving nature of the epidemic and the range
of prevention activities that are being implemented to retard the spread
of HIV in the U.S. population. A particular focus of these sections
is the increasing burden of HIV infection and AIDS among women.
The next three sections (Chapters 3, 4, and 5, respectively, of the full
report) review three domains of particular interest: the ways in which
HIV infection is affecting adolescents and female prostitutes, and the
challenge of protecting the blood supply while simultaneously ensuring
the adequacy of that supply. The final section of the report (Chapter
6) reviews factors that affect the quality of data collected in surveys of
AIDS-related behaviors.
Although many of the specific issues raised in this report are persist-
ing problems from the first decade of the epidemic, it is important to note
that some predicted problems have not emerged. For example, despite
considerable speculation regarding the role prostitution could play in a
self-sustaining heterosexual epidemic, the data presented in Chapter 4
do not support the notion that HIV infection is an occupational disease
of sex workers. Rather, the infection found among female prostitutes
appears to have been acquired through IV drug use or from sexual con-
tact with a husband or boyfriend, and, in several surveys, substantial
proportions of prostitutes reported condom use with paying customers.
Moreover, in a field where there have been few real successes, the story
of the blood supply stands out. The development of HIV antibody tests,
OCR for page 4
4 ~ AIDS: THE SECOND DECADE
which when coupled with behavioral interventions to enhance appropriate
blood donor deferral, has dramatically reduced the number of infections
associated with the blood supply. However, as donor deferral becomes
more effective, there will be fewer individuals to contribute to the blood
supply, thus raising additional problems concerning adequate supplies.
The committee cautions that encouraging results and promising situa-
tions should not lead to complacency. The lessons learned from the first
decade of the epidemic warn us of the need for vigilance as the patterns
of disease shift and new problems emerge.
THE CHANGING EPIDEMIOLOGY OF AIDS
IN THE UNITED STATES
Despite the greater diversity now recognized to exist among at-nsk and
infected populations, gay men still account for the majority of AIDS cases
in this country. Yet more and more cases are reportedly associated with
IV drug use and heterosexual transmission, and this shift has resulted in
a noticeable increase in the number of women who are affected by the
AIDS epidemic. Among adolescents in contact with the military (either
as applicants or on active duty), rates of HIV infection among females
are comparable with those for males. Gender panty in seroprevalence
(i.e., prevalence of HIV infection) for this population indicates that for
some groups women will be bearing a larger share of the AIDS burden
in the future.
Although the majority of female AIDS cases have been attributed to
IV drug use, substantial numbers of infected women report heterosexual
contact with an infected male IV drug user. Thus, injection of illicit sub-
stances poses direct and indirect threats to women in this country. The
stabilization of infection rates seen among drug users in some cities (e.g.,
New York, San Francisco, Amsterdam) affords some hope that inter-
ventions directed toward this population can be effective.4 Nevertheless,
stable rates of infection in selected cities do not signify the elimination
Of viral transmission. Other areas of the United States, as well as for-
eign countnes, are seeing rapid increases in the incidence of infection
among IV drug users. The mobility of this population coupled with the
4For some groups at highest risk for HIV infection, stable rates signify that all vulnerable individuals
are already infected, a phenomenon known as saturation. This phenomenon does not appear to explain
stable rates in New York City, however, where approximately 50 percent of IV drug users are esti-
mated to be infected. If saturation had occurred, one would expect to see higher seroprevalence rates.
For example, approximately 90 percent of IV drug users in New York City have been infected with
hepatitis, a virus that is transmitted in the same manner as HIV and appears to have reached saturation
in this population.
OCR for page 5
SUMMARY | 5
persistence of the behaviors that transmit HIV (namely, sharing injection
equipment) indicates that the potential for very rapid spread still exists.
Furthermore, growing awareness of the indirect threat posed by drugs
such as crack and alcohol supports the notion that HIV risk related to
drug use now goes beyond the use of contaminated injection equipment.
Although crack and alcohol do not directly transmit HIV, researchers
note that both Mugs are associated with high-nsk sexual practices and
thus confer an indirect risk for the acquisition and transmission of the
virus. The rapid emergence of new, drug-related threats highlights the
need for vigilance regarding changing patterns of transmission. Thus,
the committee recommends that the Public Health Service establish
mechanisms across its agencies for rapid identification and assess-
ment of the relationship of new drug use problems to the spread
of HIV. At present it is clear that crack use and its associated unsafe
sexual activity represent a potentially important new mode of HIV trans-
mission in the United States, but it is unclear how large an impact this
mode might have. The committee recommends that the Public Health
Service support additional research on crack use, including its epi-
demiology, its relationship to sexual behavior, strategies to reduce
its occurrence (both initiation of use and continuance among low-
and high-frequency users), and methods for facilitating change in
the sexual behavior of persons who continue to use crack.
Among the changing facets and aspects of the epidemic, one epidemi-
ological trend has remained disturbingly constant. Black and Hispanic
men and women continue to be overrepresented in every AIDS risk cate-
gory. The committee urges a renewed commitment to providing effective
AIDS prevention programs for at-nsk minority individuals. Therefore,
the committee recommends that the agencies of the Public Health
Service encourage and strengthen behavioral science research aimed
at understanding the transmission of HIV in various black and His-
panic subpopulations, including men who have sex with men, drug
users and their sexual partners, and youth. The committee further
recommends that the PHS ~levelop plans for appropriate interven-
tions targeted toward these groups and support the implementation
of intervention strategies (together with appropriate evaluation com-
portents) in both demonstration projects and larger scale efforts.
The evolutionary, dynamic nature of this epidemic imposes additional
demands on surveillance data collection. High-quality data on changing
rates of risk-associated behavior and HIV infection are needed to track the
course of the epidemic and to evaluate the effectiveness of intervention
efforts to stop its progression. To facilitate the Centers for Disease
OCR for page 6
6 ~ AIDS: THE SECOND DECADE
Control's (CDC) ongoing efforts to improve its AIDS-related data
collection systems, the committee recommends that the agency initiate
a systematic review of current programs. This effort should draw on
the expertise of both CDC staff and outside experts.
PREVENTION: THE CONTINUING CHALLENGE
The first decade of the AIDS epidemic in this country brought consid-
erable progress in solving the biological and epidemiological puzzles
of AIDS and HIV infection. The causative agent was discovered, and
serologic tests to detect infection were devised, produced, and imple-
mented. In addition, drugs were developed to treat both the underlying
viral infection and the opportunistic infections that are the hallmarks of
the disease. Yet despite this progress, the epidemiological data reveal a
steady progression of HIV-related morbidity and mortality, in part be-
cause the development of HIV prevention strategies has not kept pace
with He growing dimensions of risk. Effective intervention strategies are
needed to sustain healthy behavioral patterns in individuals who are not
currently at risk and to facilitate change among individuals who are. The
committee finds that ongoing efforts fall far short of the magnitude of in-
tervention needed, given the current prevalence of infection and evidence
of continued nsk-associated behavior among many of the groups at risk
for AIDS.
AIDS Prevention Challenges in the Coming Decade
At the beginning of the epidemic, interventions to prevent the spread of
HIV infection focused pr~manly on adult gay men; subsequent prevention
efforts encompassed the population of IV Hug users. Today, that focus
requires redefinition and expansion once again as changing epidemio-
logical patterns reveal greater diversity among at-risk groups. A further
requirement is to consolidate study findings from cohorts of gay men
and to incorporate relevant findings into the design and development of
prevention activities for other groups. Unfortunately, an understanding
of such lessons has been hampered by a host of methodological com-
plications that preclude meaningful cross-study comparisons. Therefore,
the committee recommends that the Public Health Service assemble
and summarize data reported by gay men in PHS-funded studies re-
garding seroprevalence, seroconversion, and high-risk behavior and
determine what conclusions can be drawn from the research.
Of particular concern to the committee are the epidemiological data
indicating that HIV infection is spreading to disparate subpopulations
of women. The diversity of the at-nsk female population mandates the
OCR for page 7
SUMMARY ~ 7
development of multiple approaches to prevent both horizontal transmis-
sion from sexual and Hug use partners and vertical transmission from
a mother to her infant. In general, the best way to prevent vertical
transmission is to prevent infection in women of childbearing age.
Prevention efforts focused on women during the first decade of the
epidemic relied heavily on testing and counseling, but several studies
have shown that the information provided to women by such a strat-
egy did not necessarily prevent transmission. Therefore, the committee
recommends careful review of the goals of testing and counseling
programs for women of childbearing age and the implementation
of research efforts to ascertain the effect of such programs on fu-
ture risk-taking behavior. Additional, innovative strategies are clearly
needed to prevent vertical transmission; there may be important lessons
to be learned from existing programs that have sought to prevent other
vertically transmitted diseases, such as genetic disorders. The committee
recommends that the Public Health Service convene a symposium of
experts in genetic counseling to consider the potential contribution
of this field's expertise and experience to the design and implementa-
tion of counseling programs for HIV-infected women and to identify
research opportunities in this area.
In its first report, the committee recommended that knowledge con-
cerning the efficacy of intervention programs be built in a systematic
fashion through the use of planned variations of key program elements
accompanied by rigorous evaluation. This process is admittedly quite
time-consuming, but unfortunately there is no shortcut to the accumu-
lation of such cntical information. Behavioral interventions are still the
only available means of disease containment, and the committee an-
ticipates that the need for well-designed, carefully implemented, and
thoughtfully evaluated intervention efforts will not decrease over the
course of the next 10 years. Therefore, the committee reiterates its
earlier recommendations and in addition recommends the following:
· that the Public Health Service encourage and support
behavioral research programs that study the behaviors
that transmit HIV infection and that the PHS develop
and evaluate mechanisms for facilitating and sustaining
change in those behaviors;
· that intervention programs incorporate planned varia-
tions that can be carefully evaluated to determine their
relative effectiveness;
· that the PHS regularly summarize the data derived
from currently funded behavioral and epidemiological
OCR for page 8
8 ~ AIDS: THE SECOND DECADE
research on AIDS (in terms of incidence of infection arid
high-risk behaviors) to determine intervention priorities
for various subpopulations at risk; and
· that all agencies of the PHS that are currently funding
intervention programs and evaluation research regularly
summarize the data derived from these studies to deter-
mine which, if any, programs can be recommended for
wider dissemination.
There is some indication that AIDS prevention activities to date
have, at least In part, achieved their goal; significant risk reduction has
been reported among subsets of gay adult mates and IV drug users. Yet
segments of every at-r~sk group continue to practice unsafe behaviors.
Some have not yet initiated change; others have not been able to sustain
changes initiated earlier. The committee recommends that the Alcohol,
Drug Abuse, and Mental Health Administration focus research ef-
forts on AIDS-related relapse prevention, including the determinants
of such relapse and the role that alcohol and other drugs play in the
return to unsafe sexual and injection practices.
The inconsistent use of condoms is a common theme that cuts
across all populations associated with this epidemic. Gay men, IV drug
users, and female sexual partners of infected or at-risk individuals have
all reported problems in initiating or maintaining condom use, despite
clear evidence of perceived risk. In its first report the committee urged
widespread availability and promotion of the use of condoms (with sper-
micides) as a means for preventing sexually transmitted HIV infection.
The epidemiological data show, however, that sexual transmission of the
virus continues to be a major route of infection, and self-reported data
on risk taking indicate that more research is needed to understand how
to help people take preventive action against sexually transmitted HIV
infection. The committee recommends that the Public Health Service
fund research on condoms to achieve the following objectives:
· understand the determinants of condom use for the di-
verse populations at risk for sexually transmitted HIV
infection;
· improve condom design and materials to make them
more acceptable to users; and
· develop interventions to promote their consistent use.
Regardless of belief in the efficacy of condoms to prevent HIV
transmission, not all subpopulations at risk will be able to implement
this means of protection. Women in particular often find condom use
OCR for page 9
SUMMARY ~ 9
problematic. Not only do condoms require the cooperation of the male
partner but they may also require substantial changes in the attitudes
and behaviors of some women. The gravity of the AIDS epidemic calls
for other methods of protection that are more "user friendly" (i.e., more
attractive, easier to purchase, and easier to use) and that can be uni-
laterally employed by women. The committee recommends that the
Public Health Service support research to develop protective mea-
sures other than condoms for preventing HIV transmission during
sexual contact~pecifically, methods that can be used unilaterally by
women and methods that will be acceptable to both men and women
who do not currently use condoms. The partnership between technol-
ogy and the behavioral sciences has succeeded in devising mechanisms
to protect the blood supply (see Chapter 5 of the report). Similar partner-
ships are needed to develop innovative means for protecting individuals
from sexual transmission of the disease.
Impediments to Improved Intervention
AIDS prevention programs must identify, contact, and help at-r~sk indi-
viduals to assess their level of risk and access appropriate services. Pro-
viding AIDS prevention also involves first facilitating and then sustaining
behavioral change. Delivering programs to at-nsk individuals becomes
extremely difficult if people believe that seeking help may threaten their
jobs, housing, and supportive relationships. During the first decade of
this epidemic, effective interventions and research were compromised by
difficulties in identifying and reaching those most in need. Now, it is
even more crucial to reach infected individuals because there are poten-
tially beneficial prophylactic treatments that may forestall the progression
of disease. Antidiscr~mination legislation has been proposed by several
organizations to provide the institutional underpinnings necessary to en-
able individuals to redress inequities and protect those who would seek
care and other AIDS-related services. The committee is gratified to see
that the federal antidiscnmination measures urged In its first report and
recommended by the President's Commission on the HIV Epidemic are
under active consideration. It would point out, however, that this legisla-
tion alone is unlikely to ameliorate all of the conditions associated with
discrimination in this country. For example, legislation may protect the
rights of HIV-infected children to education but cannot prevent hostile
encounters with the community. A separate pane] of the committee is
currently considering methods to monitor and measure the social impact
of the epidemic; the panel's report is expected to be released in 1991.
OCR for page 10
10
AIDS: THE SECOND DECADE
The progress made in instituting antidiscnmination provisions, how-
ever, cannot obscure the fact that other hurdles remain in the path of
improved intervention. The financial biers to health care that have im-
peded preventive care for other health conditions also affect individuals
seeking AIDS-related services. BaITiers to these services may be espe-
cially daunting for women, in particular women who need prenatal care
or treatment for Hug use. Moreover, even delivenng information to those
most in need is sometimes problematic, in part because societal attitudes
continue to hinder the implementation and evaluation of promising inter-
ventions. A significant controversy has surrounded the appropriate level
of sexual explicitness in AIDS prevention information and the degree to
which these interventions should emphasize the erotic. Political debate
abounds regarding the propriety of using public monies to support the
development of sexually explicit matenals, despite preliminary evidence
that, for some populations, they have a degree of effectiveness.
Programs to provide IV drug users with stenie needles have also
been stymied. Previous reports on AIDS from the National Academy
of Sciences and the Prostitute of Medicine recommended that the U.S.
government sponsor research on syringe exchange programs as a means
of reducing the spread of HIV infection in the drug-using population.
Evaluation of ongoing efforts abroad have found that participation in
syringe exchange programs is associated with the reduction but not the
elimination of behaviors that can transmit HIV and that syringe exchanges
do not lead to any detectable increase in illicit drug injection, either
among current users or by new injectors. The U.S. Department of Health
and Human Services has considered the types of research that would
be needed to evaluate the impact of syringe exchange programs on the
spread of HIV, but it has not officially determined whether it will support
such research now or in the future.
There is a general! fear expressed by many policy makers that explicit
messages concerning stenie injection equipment and condom use will
result in increased rates of {V drug use and sexual intercourse. Yet what
evidence there is from venous intervention programs suggests otherwise:
having the information and the means to protect oneself from a deadly
disease is likely to result in protective action against AIDS, as well as in
generalized increases in healthy behaviors (e.g., seeking drug treatment)
among people who are already engaging in risky activities. Furthermore,
inflation and services do not appear to entice the uninitiated into
risk-associated actions. The committee believes that the time has come
to commit sufficient resources to the task of collecting data that would
permit an assessment of whether current intervention strategies, including
OCR for page 11
SUMMARY ~ 1 1
needle exchange programs, effectively decrease risky behaviors and the
subsequent spread of HIV. To continue to rely on hunches and suspicions
rather than on data gives too much credence to guesswork and may
arbitrarily obstruct a promising course of action for preventing the spread
of the epidemic.
ADOLESCENTS
The committee finds no credible evidence that He AIDS epidemic will
cease in the foreseeable future in this country. As a result, prevention
efforts remain cntically important. In terms of the adolescent population,
the committee believes that intervention efforts will be most effective if
the programs reach teens before they begin practicing the behaviors that
put them at risk. Because patterns of both health behavior and risk taking
are often established during the teenage years, intervention efforts for
adolescents offer the hope of protecting our youth and preventing future
problems in the adult population.
It is important to note that not all teens are equally at risk for HIV
infection. Some, by virtue of their low level of risky behavior or because
of the absence of the virus among their potential partners, will remain
uninfected. However, the available data on HIV seroprevalence indicate
Hat there are presently localized pockets of the teen population In which
the rates of infection are relatively high. Findings from CDC's neonatal
surveillance activity (i.e., anonymous antibody testing of newborn in-
fants)5 indicate, for example, that almost ~ percent of black teenagers
who delivered children in New York City during 1988 were infected with
HIV. The prevalence of HIV infection among Hispanic teenage mowers
is almost as high. Data from serosurveys of nonprobability samples of
hospital patients and data on infection rates among applicants for military
service confirm the fact that the REV virus is seeded In the adolescent
population, albeit at varying rates. Yet these sources of information are
limited; consequently, there is a paucity of appropriate data available
to scientists for monitoring He spread of HIV in He teen population.
To provide better information about HIV infection and AIDS among
adolescents, the committee recommends that the Centers for Disease
Control make available to the research community AIDS-related data
that permit separate consideration of teenagers and other age groups.
Specifically, the committee recommends that:
SThis testing provides unbiased estimates of the prevalence of HIV infection among childbearing
women because infants circulate maternal antibody during the first months of life whether or not they
are actually infected.
OCR for page 27
SUMMARY ~ 27
Audits of blood use and educational programs that go beyond dissemina-
tion of pamphlets and the traditional didactic method appear to hold the
most promise; however, more data are needed to specify the character-
istics of programs that are likely to be effective in modifying prescrib-
ing patterns of physicians. The committee recommends that agencies
of the Public Health Service sponsor the development, systematic
testing, and implementation of transfusion-related intervention and
education programs to facilitate change in physicians' attitudes and
behaviors with regard to:
· encouraging healthy patients to donate blood;
· encouraging autologous donation where medically ap-
propriate;
· eliminating the unnecessary use of blood and blood com-
ponents; and
· employing appropriate procedures (e.g., perioperative
blood salvage, use of erythropoietin) that reduce the
need for transfusion.
Standards or criteria regarding the appropriate use of blood and blood
components are currently lacking, making it difficult to determine with
certainty whether transfusions are being given appropriately. As a result,
the committee recommends that the Public Health Service sponsor
research to monitor trends in transfusion practices nationally to per-
mit evaluation of the appropriateness of blood and blood component
utilization and to identify targets for change. It further recommends
that the PHS develop and evaluate effective strategies for informing
patients about the risks and benefits of transfusion.
SURVEY METHODS IN AIDS RESEARCH
Surveys or, more generally, the method of asking questions and record-
ing answers from a sample of a population of interest continue to be
one of the most important techniques for obtaining essential information
about the epidemiology of AIDS and HIV, the behaviors that spread HIV,
and the effectiveness of AIDS prevention efforts. Given the important
role that this information plays in understanding the AIDS epidemic,
the committee has reviewed what is known about the quality of exist-
ing data on behaviors associated with HIV transmission and provides
recommendations on steps that can be taken to improve this information.
Sampling
Much of what is now known about the epidemiology of AIDS comes
OCR for page 28
28 ~ AIDS: THE SECOND DECADE
from small-scale, local studies targeted at subgroups thought to be at high
risk of infection. Participants in these studies are recruited from a variety
of sources from the clientele of local clinics or treatment facilities, from
the membership rosters of local organizations, from newspaper advertise-
ments and physician referrals, and occasionally from "street sampling."
The yield from this research has been remarkably rich. As valuable as
these studies are, however, the data they provide cannot address many
important public health questions that arise from the problem of AIDS,
such as how large is the epidemic and what is the potential for general
spread of HIV infection?
To answer questions such as these, lessons learned from local studies
of special subgroups must be applied in large-scale investigations of pop-
ulations that are chosen not because of convenience or ease of access but
because of their importance in understanding the course of the epidemic.
To review the adequacy of current survey work in the general population
and in local areas, the committee reviewed 15 selected surveys. Most
of these studies were initiated after the AIDS epidemic began and rep-
resent responses to the need for population-based estimates of behaviors
known to be associated with HIV transmission. The committee assessed
the execution of each survey's sampling plan and, in particular, the rat
of participation (i.e., the response rate). The committee also considered
the available evidence on nonresponse bias; that is, the disproportionate
underrepresentation of identifiable segments of the population, especially
those who differed on the characteristics being measured. Response rates
are used as a "yardstick" for assessing the accuracy of survey estimates
because high response rates reduce the influence of selective participation
in surveys and hence the potential for bias in the estimates.
There was substantial variation in the response rates achieved in
the surveys examined by the committee. No strong associations were
observed, however, between response rates and modes of data collec-
tion (i e., personal interviews, telephone interviews, or self-administered
questionnaires given in the context of a personal interview). There were
also no substantial associations between response rates and the scope of
the sampling (local versus national), the number of questions on sexual
behavior in the interview, or, surprisingly, whether sample persons were
asked to donate blood specimens for serologic testing.
From the review conducted by the committee, it appeared that "pig-
gybacking" a small number of questions about sexual behavior onto estab-
lished large-scale surveys is a particularly feasible strategy for obtaining
estimates of the prevalence of certain sk factors for sexual transmission
Of HIV in general populations. Relatively high rates of participation have
OCR for page 29
SUMMARY | 29
been achieved by several established surveys. The ingredients for such
success are well known to survey practitioners: prior experience with
similar surveys, continuity of interviewing staff, a high "target response
rate" combined with a field operation that promotes diligent follow-up
of nonrespondents, and adequate resources. Under these conditions, it is
possible to achieve response rates for small subsets of sex-related items
that are similar to the rates achieved by well-conducted surveys that do
not inquire about sensitive personal behaviors.
The collection of survey data through telephone interviews has be-
come an increasingly popular alternative to face-to-face interviewing
(telephone interviews are less expensive and easier to conduct as a result
of developments in sampling and interviewing technology). Experience
with surveys of sexual behavior conducted by phone is too limited, how-
ever, to determine the levels of participation that can be achieved in
such surveys and whether the somewhat lower response rates in the few
available cases are a generic feature of telephone surveys or simply the
result of early and somewhat idiosyncratic first attempts. In view of
the substantially lower cost of telephone as compared with face-to-face
surveys, as well as the limited scope of current experience, carefully
designed experiments should be undertaken to test the feasibility of this
methodology for surveys of sexual behavior in general populations.
SeroprevaTence surveys involve the application of well-established
principles of probability sampling and survey methodology to the problem
of collecting sample blood specimens in such a way that population
prevalence can, in theory, be estimated with known margins of error.
However, the practical difficulties involved in mounting a seroprevaTence
survey on a local or national basis are formidable. Not the least of these
are the problems of potentially high levels of noncooperation among
sample persons and possible correlations between participation and HIV
serostatus.
A trade-off between streamlined designs that maximize response
rates and intensive epidemiological investigations with lower response
rates is apparent in the available examples of such surveys. Survey
designs that limit the demands on respondents by making participation
relatively easy, anonymous, and nonthreatening—may be a wise choice.
Further testing and refinement of this approach on a larger scale will
establish whether it constitutes a feasible design for a national survey.
Nonresponse Bias
Nonresponse bias occurs when participation in a survey is selective with
respect to a characteristic whose distribution is to be estimated from the
survey responses. A high response rate tends to minimize the effects of
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30 ~ AIDS: THE SECOND DECADE
such selectivity on survey estimates as Tong as the procedures used to
attain it do not in fact increase the correlation between the characteristic
of interest and the act of participation. Response rates in most surveys,
however, usually are not sufficiently high to justify ignoring problems of
. . . .
se ect~ve participation.
What is presently known about the structure of nonresponse bias in
sex and seroprevalence surveys comes from two kinds of compansons:
comparisons of survey estimates with census data and internal analyses
of the correlates of different levels of nonresponse. There is an appar-
ent positive correlation between years of schooling and participation in
several of the surveys, but the committee could detect few other regular-
ities in the available analyses of deviations between survey estimates and
census figures. In any case, a good match between census and sample
survey distributions, although encouraging in some respects, does not
imply unbiased estimates of prevalence rates for sexual behavior or HIV
infection.
In many surveys, it is possible to study nonresponse at a given stage
of the survey by looking at information collected at a previous stage- for
example, by comparing responses given by respondents and nonrespon-
dents in the preliminary interview or comparing the characteristics of
persons who agreed to give a blood specimen with those who refused.
In reviewing selected surveys, the committee found many opportunities
for such comparisons, few of which had been seized. The addition of a
careful study of nonresponse bias to the short sexual behavior component
of the 1988 National Opinion Research Center's General Social Survey
(GSS) is an important exception. In the GSS, nonresponse biases were
found to be quite small among those variables most closely associated
with differences in sexual behavior. Although these results are infor-
mative about the nature of nonresponse in this one survey, it would be
premature to generalize them to other surveys. Rather, careful studies are
required of the effects of nonresponse in a wider range of sexual behav-
ior and seroprevalence surveys. In this regard, the committee encourages
further exploitation of existing data from past sex and seroprevalence
surveys to learn more about the structure of nonresponse.
Validity and Reliability
Behind every e-way tabulation, logistic regression, or other analytical
model used in AIDS behavioral research lies a human encounter between
two individuals, an interviewer and a respondent. The situational, cogni-
tive, social, and psychological factors that arise within that interpersonal
exchange affect the answers that are given and the data that are thereby
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SUMMARY ~ 31
generated. To understand the sexual and drug-using behaviors that are at
issue in survey research on HIV transmission, one must ultimately con-
front the uncertainties introduced by this question-and-answer process.
Although there is a substantial literature on the effects of nonsam-
pling factors in survey measurements, the problems encountered in study-
ing sexual and drug use behavior are unique in some respects- most no-
tably, with respect to validation of responses. There is reason to believe
(and empirical evidence to support such a belief) that some respondents
conceal behaviors under even the most benign of survey circumstances.
This possibility must be given considerable weight in the face of statutes
in many states that classify some sexual behaviors (including male-female
and male-male oral and anal sex) as crimes. Finally, there is the possibil-
ity that behaviors engaged in while the respondent is under the influence
of drugs or alcohol may be poorly recalled, if at all. Given these con-
siderations, lingering concern about the trustworthiness of key survey
estimates is virtually inevitable. In light of such concern, the committee
reviewed the available evidence on the accuracy of self-reports of sexual
and drug use behaviors.
Sexual Behavior
There is only a very limited range of evidence that can be collected to
provide independent corroboration of the validity of self-reported sexual
behaviors. One type of evidence is the reports of sexual partners. Studies
by Kinsey and several later investigators find a rather high degree of
congruence between reports of sexual partners. Indeed, in some of the
instances, the levels of agreement are striking.
Although partners provide the most obvious source of independent
information on sexual behavior, they are not the only validation method
that has been used. One investigator, for example, went to unusual
lengths (including the use of a lie detector) to motivate respondents to
correct"misreports" they made in completing a survey questionnaire.
The "corrections" made to the original survey data provide an indication
of the types of reporting biases that afflict typical survey measures.
For every sexual behavior included in this study, a substantial fraction
of the respondents (college men) misreported their actual behaviors.
Thus, although virtually every male ultimately indicated that he had
masturbated, approximately one out of every three In the initial survey
denied masturbating. Similarly, although 22 percent of these college
men ultimately reported some history of male-male sexual contact, the
majority of these men initially denied such contact.
In two instances, analyses have been reported of measurements of
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32 | AIDS: THE SECOND DECADE
sexual behavior derived from independent replications of surveys on sam-
ples of the same population. Although some deviations could be detected
statistically between the measurements made in different surveys, the dis-
crepancies found were actually quite small. Although only two behaviors
were compared (age at- first occurrence of heterosexual intercourse and
number of partners in past year), these examples demonstrate that sur-
veys can produce replicable measures of sexual behavior in well-defined
populations.
A parallel approach to the replication of entire surveys on new sam-
ples from a population is the repeated measurement of a stable character-
istic of the same respondent. Results of such studies indicate substantial
levels of consistency between answers to questions about sexual behav-
ior obtained at two different points in time. The observed consistency,
however, is not as high as the consistency obtained for some other topics,
such as smoking behaviors.
Drug-Using Behaviors
The methodological difficulties encountered in studying drug use be-
haviors are similar to those found in studying sexual behaviors. As
in measuring sexual behaviors, a major problem in measuring injection
behaviors arises from the fact that researchers usually cannot directly ob-
serve the behaviors of interest and thus must rely on self-reports. Several
studies have compared reports of drug use with the results of urinalysis.
Evidence from these studies suggests that there are moderate levels of
underreporting of drug use. Generalizations from such studies are con-
strained by the fact that past research has usually examined a relatively
restricted range of behaviors typically focusing on drug use per se in
populations that were already identified as ex-drug users. In AIDS re-
search, however, questions of particular interest include not just whether
drugs are used but how they are administered, how often needles are
shared or cleaned, and so forth. Little is known about the accuracy of
responses to more fine-grained questions such as these, although some
data suggest that respondents share needles at a rate higher than they
report to researchers.
Summary of Fintlings
Although there is ample evidence of error and bias in existing surveys of
sexual behavior and such evidence should be of concern to investigators,
some important and promising conclusions can nevertheless be drawn
from this body of work.
First, there appears to be little question that surveys of sexual and
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SUMMARY ~ 33
drug use behavior can enlist the cooperation of the vast majority of the
American public.
Second, the recent literature contains two instances in which inde-
pendently conducted surveys of aspects of sexual behavior (age of first
intercourse and number of sexual partners in past year) produced reas-
suringly similar results. This similarity was achieved despite variations
in survey methodology.
Third, in most sexual behavior and drug use surveys, it will be
difficult (if not impossible) to obtain convincing evidence of measurement
validity. The committee finds nonetheless that the research literature
contains several important demonstrations of the validity of behavioral
measures. These results are certainly encouraging, but there is also
a variety of other evidence that suggests that some behaviors may be
considerably underreported in surveys. For example, although the data
are limited, it appears that male-male sexual contacts may be significantly
underreported (at least by college student populations).
Finally, there is a fairly large body of research addressing the consis-
tency of responses over short periods of time in survey reports on various
aspects of sexual behaviors. These studies have generally demonstrated
moderate levels of response consistency over time. It must be noted,
however, that consistency in itself does not guarantee accuracy.
Improving Measurements
The above evidence leads naturally to questions regarding how to im-
prove the reliability and validity of self-reported data on these behaviors.
To begin answering those questions, the committee recommends that
the Public Health Service anti other organizations supporting AIDS
research provide increased support for methodological research on
the measurement of behaviors that transmit HIV. Such research
should consider inferential problems introduced by nonresponse and
by nonsampling factors, including (but not limited to) the effects of
question wording and question context, the time periods and events
that respondents are asked to recall, and the effects of anonymity
guarantees on survey responses. In addition to adopting procedures
that ensure that respondents can understand the questions they are being
asked, it is desirable to supplement self-reports with alternative mea-
sures whenever possible. Ethnographic observations, physical evidence,
skills demonstrations, and reports of "significant others" can provide
important data on the biases that may affect key measurements. The
committee recommends that, whenever feasible, researchers supple-
ment self-reports in behavioral surveys on HIV transmission with
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34 ~ AIDS: THE SECOND DECADE
other indicators of these behaviors that do not rely on respondent
reports. Furthermore, the committee recommends that, where ap-
propriate, researchers embed experimental studies within behavioral
surveys on HIV transmission to assess the effects of key aspects of
the survey measurement process.
Although it is impossible to provide firm guarantees as to the ben-
eficial effects of any particular tactic, the committee believes that there
is strong presumptive evidence to indicate that a considerably larger in-
vestment of resources needs to be made in exploratory work prior to the
fielding of major survey investigations. For surveys of behaviors that
risk HIV transmission, this lack of exploratory research is particularly
troubling, given the underdeveloped state of research in this field. In
this regard, the committee notes that some of the questionnaires it re-
viewed made impossible demands on the memory of respondents, an
unfortunate error that would have been detected if the questionnaires had
received more thorough pilot testing. The committee recommends that
researchers who conduct behavioral surveys on HIV transmission
make increased use of ethnographic studies, pretests, pilot studies,
cognitive laboratory investigations, and other similar developmental
strategies to aid in the design of large-scale surveys.
SYNOPSIS AND MAJOR RECOMMENDATIONS
Throughout the report the committee reviews a variety of issues and
presents a series of recommendations. Because the material is presented
in some detail, the committee wishes to highlight some of the major
points here.
The committee finds that the broadening scope of the AIDS epidemic
calls for increased prevention efforts to reach a variety of subpopulations
at differential risk, such as adults and adolescents, men and women, ho-
mosexuals and heterosexuals. The committee is particularly concerned
about the epidemiological evidence that finds a disproportionate burden of
disease among minority subpopulations. Therefore, the committee rec-
ommencIs that the agencies of the Public Health Service encourage
and strengthen behavioral science research aimed at understanding
the transmission of HIV in various black and Hispanic subpopula-
tions, inclutiing men who have sex with men, drug users anti their
sexual partners, and youth. The committee further recommends
that the PHS develop plans for appropriate interventions targeted
toward these groups and support the implementation of intervention
strategies (together with appropriate evaluation components) in both
demonstration projects and larger scale efforts.
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SUMMARY | 35
Adolescents and women are other groups that present both impor-
tant opportunities to prevent future disease and challenges to providing
effective intervention programs. It is during the adolescent years (and
sometimes earlier) that many of the behaviors that risk transmission of
HIV are initiated. For programs to be most effective, however, teens must
be reached before they begin the behaviors that put them at risk. Thus,
the committee recommends that AIDS prevention programs make
special efforts to reach very young teens and, in some subpopula-
tions, to reach youth before they enter adolescence. Thus far over the
course of the epidemic, a considerable proportion of the resources allo-
cated to prevent horizontal and vertical transmission among women have
been devoted to counseling and testing programs. Yet important ques-
tions remain about how this service is delivered and what impact it has on
subsequent risk-associated behaviors. Therefore, the committee recom-
mends careful review of the goals of testing and counseling programs
for women of childbearing age and the implementation of research to
ascertain the effect of such programs on future risk-taking behavior.
Moreover, the committee recommends that the Public Health Service
support research to develop protective measures other than condoms
for preventing HIV transmission during sexual contact specifically,
methods that can be used unilaterally by women and methods that
will be acceptable to both men and women who do not currently use
condoms.
Designing and implementing relevant and effective programs re-
quires knowledge about the targeted population and the risk-associated
behaviors of concern. Thus, the committee recommends:
· that the Public Health Service encourage and support
behavioral research programs that study the behaviors
that transmit HIV infection and that the PHS develop
and evaluate mechanisms for facilitating and sustaining
change in those behaviors;
· that intervention programs incorporate planned varia-
tions that can be carefully evaluated to determine their
relative effectiveness;
· that the PHS regularly summarize the data derived
from currently funded behavioral and epidemiological
research on AIDS (in terms of incidence of infection and
high-risk behaviors) to determine intervention priorities
for various subpopulations at risk; and
· that all agencies of the PHS that are currently funding
intervention programs and evaluation research regularly
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36 ~ AIDS: THE SECOND DECADE
summarize the data derived from these studies to deter-
mine which, if any, programs can be recommended for
wider dissemination.
Understanding the behaviors that transmit the virus depends on the
availability of valid and reliable data regarding those behaviors, including
the distnbution and variation of the behaviors across venous subpopula-
tions. Unfortunately, the data on AIDS-related behaviors are extremely
limited, and most are out of date. Moreover, these data rely for the most
part on self-reported information of unknown quality. Consequently, the
committee recommends that the Public Health Service and other
organizations supporting AIDS research provide increased support
for methodological research on the measurement of behaviors that
transmit HIV. Such research should consider inferential problems
introduced by nonresponse and nonsampling factors, including (but
not limited to) the effects of question wording and question context,
the time periods and events that respondents are asked to recall, and
the effects of anonymity guarantees on survey responses.
In addition to the diversity of at-risk groups, the committee wishes
to note the dynamic nature of the patterns of behavior that contribute
to the spread of infection. The role played by IV drug use in HIV
transmission has been apparent since the early years of the epidemic,
but only recently has there beer a growing appreciation of the role of
over drugs, such as crack and cocaine, in sexual transmission of the
AIDS virus. Therefore, the committee recommends that the Public
Health Service establish mechanisms across its agencies for rapid
identification and assessment of the relationship of new drug use
problems to the spread of HIV. Given the continued threat of HIV
and AIDS and given the lack of biomedical solutions to this serious
health problem, the committee finds that sustaining behavioral change
and preventing relapse are issues that require immediate and sustained
attention. Thus, the committee recommends that the Alcohol, Drug
Abuse, and Mental Health Administration focus research efforts on
AIDS-related relapse prevention, including the determinants of such
relapse and the role that alcohol and other drugs play in the return
to unsafe sexual and injection practices.
There has been substantial progress in reducing the risks of HIV
transmission associated with the blood supply, progress achieved through
technological solutions, augmented by behavioral interventions. Yet, as
the risk of exposure to contaminated blood and blood products diminishes,
the issue of maintaining an adequate supply of blood arises. Efforts
to exclude at-nsk donors must take into account the need to maintain
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SUMMARY | 37
sufficient quantities of blood donated by individuals who pose no risk to
the blood supply. The committee recommends that:
· blood collection agencies strive for clearer communi-
cation of the exclusion criteria to potential and actual
donors;
· blood collection agencies work to increase donation by
those who can safely give and abstention by those who
are at even minimal risk through recruitment approaches
that stress altruistic appeals rather than the use of com-
petitions, incentives, and social pressure;
· the National Heart, Lung, and Blood Institute con-
tinue its support for research to investigate why some
donors with identifiable risk factors continue to donate
while others without risk factors inappropriately exclude
themselves; and
physicians and blood banks encourage autologous dona-
tion in cases in which surgery is anticipated.
Reducing the exposure of potential transfusion recipients to homol-
ogous blood can be accomplished in several ways, depending on the
circumstances that prompt transfusion. Educating physicians and their
patients, establishing guidelines for blood use, and modifying prescribing
behavior are necessary to achieve this goal.
.
Representative terms from entire chapter:
aids prevention
