HIV-related knowledge and adherence to
L. WEISS,1T. FRENCH,2R. FINKELSTEIN,1M. WATERS,2
R. MUKHERJEE1& B. AGINS2
1Office of Special Populations, New York Academy of Medicine &2New York State Department of
Health, AIDS Institute, New York, USA
medical recommendations is rarely so high. Supportive services and reminder tools may help
individuals to become adherent, yet it is difficult to determine who may need such interventions. In this
study, based on data from the NYSDOH/AIDS Institute Treatment Adherence Demonstration
Program, we look at the association between HIV-related knowledge and adherence, hypothesizing
that a better understanding of HIVand its treatment is associated with better adherence. In analyses
based on 997 participants, knowledge, as measured by five true/false questions, was significantly
associated with self-reported adherence. In multivariate analysis, compared to persons with four or five
items answered correctly, persons with fewer correct answers were more likely to report missed doses
(OR?/1.72 for 2?/3 correct, pB/0.01; OR?/2.92 for 0?/1 correct, pB/0.05). Our data suggest that
providers should include questions focused on knowledge of HIV in their assessments of medication
readiness and need for adherence support. Similarly, providers should be diligent with respect to patient
education, ensuring that each patient has the information needed to support reasoned decision making
and adequate adherence.
Near perfect adherence is considered essential for patients on HAART, yet adherence to
Highly active antiretroviral therapy (HAART) has significantly altered the implications of
HIV infection. In those places where HAART is available, HIV-infected populations have
significantly reduced morbidity and mortality (Lee et al., 2001; Mouton et al., 1997; Palella et
Yet HAART has many challenges: regimens involve several medications, some with
complicated schedules and dietary restrictions. Adverse drug reactions are common and
sometimes severe. And, because of the rapid replication and mutation of HIV (Havlir &
Richman 1996), near perfect adherence appears crucial (Maher et al., 1999; Paterson et al.,
2000). However, adherence to medical recommendations is rarely so high (Darnell et al.,
1986; Pablos-Mendez et al., 1997; Svensson et al., 2000), even among those with HIV
Address for correspondence: Linda Weiss, , PhD, Senior Research Associate, Office of Special Populations, New
York Academy of Medicine, Office of Special Populations, 1216 Fifth Avenue, Room 444, New York, NY 10029,
USA. Tel: ? /1 212 822 7298; Fax: ? /1 212 876 4220; E-mail: firstname.lastname@example.org
AIDS CARE (October 2003), VOL. 15, NO. 5, pp. 673?/679
ISSN 0954-0121 print/ISSN 1360-0451 online/03/050673-07 # Taylor & Francis Ltd
infection. In a study by Eldred et al. (1998), just 60% of patients reported 80% adherence to
HAART in the previous week. A study of insurance claims for HIV-infected pregnant women
found just 34% had sufficient supplies of antiretrovirals to maintain 80% adherence in their
final two trimesters (Laine et al., 2000).
The therapeutic value of HAART, in combination with its challenges, has made attention
to adherence essential within HIV care. Yet numerous studies have demonstrated how difficult
it is for providers to identify patients with adherence challenges (Haubrich et al., 1999;
Paterson et al., 2000). Commonly noted and easily ascertained characteristics, including
ethnicity and gender, are rarely associated with adherence. The more personal factors
including social support, level of stress and attitudes toward care are more likely to impact on
medication-taking behaviour (Chesney et al., 2000; Friedland & Williams, 1999; Gifford et
al., 2000; Holzemer et al., 1999).
Knowledge of HIV and its treatment is also likely to affect adherence. To date, however,
there has been little research examining this connection. Kalichman et al. (1999; Kalichman
& Rompa, 2000) have demonstrated associations between health literacy and adherence and
between health literacy and HIV knowledge, but have not explored the direct association
between HIV knowledge and adherence.
In this paper, based on data from 11 adherence support programmes developed through
the New York State Department of Health/AIDS Institute (NYSDOH/AI) Treatment
Adherence Demonstration Project, we look at the association between HIV-related knowledge
and adherence, hypothesizing that greater knowledge is associated with better adherence. We
intend to demonstrate that a limited number of assessment questions may assist providers in
identifying patients at risk for non-adherence. Identification of such individuals allows
providers to offer adherence support that may facilitate the achievement of treatment goals.
In 1998, the NYSDOH/AI developed the New York State Treatment Adherence Demonstra-
tion Project. Through this project, networks of providers were funded for the implementation
of programmes to support adherence to HAART. Each network targets populations at risk of
non-adherence, including individuals new to HAART, with a history of drug use, or with
previous non-adherence. Participating networks, whose members may include community-
based organizations, clinics and hospitals, provide differing configurations of adherence-
related services, such as regimen readiness, education and counselling. Eleven of the funded
projects are participating in a four-year evaluation being conducted by the New York
Academy of Medicine.
Participants in the programmes are expected to complete assessment interviews at
baseline and every three months thereafter. These assessments, developed in collaboration
with the funded programmes, include questions on demographics, health status, service
utilization, knowledge and adherence.
Our analysis is based on three-day self-report of adherence elicited during the baseline
assessment, according to a protocol adapted from the Adult AIDS Clinical Trials Group
Adherence Questionnaire (Chesney et al., 2000). For the analysis presented here, individuals
missing any HAART doses in the last three days are considered non-adherent.
Knowledge is measured by five true/false items:
It is OK to stop taking HIV medicines once you feel better.
You should take your medicines exactly as prescribed, or you may never be able to
use those medicines again.
L. WEISS ET AL.
Table 1. Sample characteristics at baseline (n?/997)
High school graduate
Less than high school
Used heroin or cocaine
Yes, in last 3 months
Ever, but not in the
last 3 months
Mental illness diagnosis, ever
First positive HIV test
Within 1 year
Previous adherence problems
Perfect adherence in the last 3 days
HIV-RELATED KNOWLEDGE AND ADHERENCE TO HAART 675
A CD4 or T-cell count is one measure of what HIV has done to the immune system.
HIV is cured when the viral load test comes back undetectable.
To fight HIV, it is better to take more than one medicine, rather than one medicine
For our analyses, client responses of ‘don’t know’ were considered incorrect. Non-responses
were considered missing and were excluded.
Data were analyzed using SPSS version 11.0. Characteristics associated with adherence
were identified using logistic regression; results are presented as odds ratios with 95%
Client enrolment began in January 1999. As of July 2001, baseline assessments were available
for 1,704 individuals. Of these, 647 were excluded from the analysis because they were not yet
on HAART. An additional 60 were excluded due to incomplete adherence or knowledge data,
leaving a sample of 997. Compared to those included in the analysis, those excluded were
likely to be younger, Latino, to have a first language other than English, to lack stable housing,
to be diagnosed with HIV within the last year, and to report a history of substance use. Those
included were more likely to have been diagnosed with mental illness and to have a high
school diploma or GED. Sociodemographic characteristics of the sample are presented in
Thirty-four per cent of the sample missed at least one dose of HAART in the prior three-
day period. Close to 20% of the sample missed at least two of the knowledge questions (see
Table 2). In multivariate analysis, compared to persons with four or five knowledge items
answered correctly, persons with fewer correct answers were significantly more likely to report
missed doses (OR?/1.72 for 2?/3 correct, p B/0.01; OR?/2.92 for 0?/1, p B/0.05).
Individuals with previous adherence problems, active drug users and those less recently
diagnosed with HIV were also likely to miss a dose (see Table 3). In separate multivariate
analyses, which considered each knowledge question separately, only one item was associated
with adherence: ‘You should take your medicines exactly as prescribed or you may never be
able to use those medicines again.’
Table 2. HIV knowledge at baseline (n?/997)
Knowledge questionsNumber with correct
It’s OK to stop taking HIV medicines once you feel better.
You should take your medicines exactly as prescribed, or you may never be
able to use those medicines again.
A CD4 or T-cell count is one measure of what HIV has done to the immune
HIV is cured when the viral load test comes back undetectable
To fight HIV, it is better to take more than one medicine, rather than one
medicine by itself.
Summary score, number correct
L. WEISS ET AL.
In our analysis, knowledge of HIV was associated with self-reported adherence over a three-
day period. These findings are consistent with research related to other medical conditions,
where knowledge is associated with adherence to a variety of medical recommendations
(Campbell et al., 1994; Fox et al., 2001; Powell et al., 2001). There are a number of reasons
why this relationship may exist. Knowledge of medication instructions is certainly a
precondition for adherence. Knowledge may also promote the development of adherence-
related skills (such as scheduling) and may increase motivation. Or, it may be that knowledge
Table 3. Adjusted odds ratios for missed doses in the last 3 days (with 95%
CharacteristicAdjusted OR (95% CI)
Not a high school graduate
High school grad/GED
Heroin or cocaine in last 3 days
Mental illness diagnoses
Tested positive for HIV
Within the last year
Previous adherence problems
4 or 5 correct
2 or 3 correct
0 or 1 correct
* p B/0.05 in mutivariate logistic regression.
HIV-RELATED KNOWLEDGE AND ADHERENCE TO HAART 677
is a proxy for motivation: a person who makes the effort to learn about an illness will also
make the effort to control it.
There are several limitations to our findings. Self-report is imprecise, overestimating
adherence by 20% or more (Wagner & Rabkin, 2000). A number of alternative adherence
measures exist, including pill counts and electronic devices. Like self-report, each has
disadvantages (Cinti, 2000; Hecht, 1998) and none are entirely reliable. Self-report was
selected for use in this study because it is easy and it is associated with more objective
measures of adherence and with clinical outcomes (Bangsberg et al., 2001; Chesney et al.,
2000; Haubrich et al., 1999).
Another limitation derives from the fact that we are reporting on data from multiple sites,
all with different staffing configurations and resources. Although each programme made
accommodations to promote consistency, and each was trained in the data collection
protocol, procedures could not be entirely uniform. Research design was affected by the
service delivery focus of the project. Items included in the assessments were limited to those
with greatest utility for providing care. In-depth explorations of any subject area were
Knowledge is a difficult attribute to measure. We are unaware of any widely used,
validated assessments of HIV knowledge that would have met our needs (brief and focused on
treatment, rather than prevention). Our set of questions, in retrospect, lacks sensitivity: 81%
of the sample answered at least four questions correctly. A set of questions that yields greater
variability would have been preferable.
Finally, there is likely to be bias in the sample. A number of individuals refused to
participate in the project; we lack even basic data on their characteristics and their adherence.
Despite these limitations, our data indicate that knowledge, as measured by a small
number of questions, is significantly associated with adherence. We would not claim that
knowledge is the only, or the main, factor affecting adherence. Furthermore, low levels of
knowledge should not be used to limit access to HAART. In our sample, 43% of those with 0
or 1 correct responses reported perfect adherence. However, clinicians should include
questions focused on knowledge of HIV and its treatment in their assessments of HAART
readiness and need for adherence support. Similarly, providers should be diligent with respect
to patient education, ensuring that each patient has the information needed to support
reasoned decision making and adequate adherence.
This publication was supported by grant number 2 H89 HA 00015-11 from the US Health
Resources and Services Administration (HRSA). This grant is funded through Title I of the
Ryan White Comprehensive AIDS Resources Emergency Act of 1990, as amended by the
Ryan White CARE Act Amendments of 2000, through the New York City Department of
Health to the Medical and Health Research Association of New York City, Inc. This
publication was also supported by grant number 5 H97 HA 00144-03 from HRSA. This
grant is funded through the Ryan White Comprehensive AIDS Resources Emergency Act of
1990, as amended by the Ryan White CARE Act Amendments of 2000. Its contents are solely
the responsibility of the New York Academy of Medicine and Health Research, Inc. and do
not necessarily represent the official views of the funders.
We would also like to gratefully acknowledge the assistance of the adherence support
demonstration programmes at: AIDS Community Resources, Albany Medical Center,
Bellevue Hospital Center, Brooklyn AIDS Task Force, Harlem Hospital Center, Montefiore
Medical Center, Mount Sinai Medical Center, New York Presbyterian Hospital, North Shore
L. WEISS ET AL.
Medical Center, Village Center for Care, and Westchester Medical Center, and at their
respective network sites.
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