CLINICAL RESEARCH STUDY
Routine human immunodeficiency virus testing:
An economic evaluation of current guidelines
Rochelle P. Walensky, MD, MPH,a,bMilton C. Weinstein, PhD,dApril D. Kimmel,a
George R. Seage III, ScD, MPH,cElena Losina, PhD,ePaul E. Sax, MD,b
Hong Zhang, SM,aHeather E. Smith,aKenneth A. Freedberg, MD, MSc,a
A. David Paltiel, PhDf
aFrom the Divisions of Infectious Disease and General Medicine, Department of Medicine, Massachusetts General
Hospital, and the Partners AIDS Research Center, Harvard Medical School, Boston, Massachusetts;
bDivision of Infectious Disease, Brigham and Women’s Hospital, Boston, Massachusetts;
cDepartment of Health Policy and Management, Center for Risk Analysis, and
dDepartment of Epidemiology, Harvard School of Public Health, Boston, Massachusetts;
eDepartment of Biostatistics, Boston University School of Public Health, Boston, Massachusetts; and
fYale School of Medicine, New Haven, Connecticut.
BACKGROUND: The Centers for Disease Control and Prevention guidelines recommend human
immunodeficiency virus (HIV) counseling, testing, and referral for all patients in hospitals with an HIV
prevalence of ?1%. The 1% screening threshold has not been critically examined since HIV became
effectively treatable in 1995. Our objective was to evaluate the clinical effect and cost-effectiveness of
current guidelines and of alternate HIV prevalence thresholds.
METHODS: We performed a cost-effectiveness analysis using a computer simulation model of HIV
screening and disease as applied to inpatients in U.S. hospitals.
RESULTS: At an undiagnosed inpatient HIV prevalence of 1% and an overall participation rate of
33%, HIV screening increased mean quality-adjusted life expectancy by 6.13 years per 1000 inpatients,
with a cost-effectiveness ratio of $35 400 per quality-adjusted life-year (QALY) gained. Expansion of
screening to settings with a prevalence as low as 0.1% increased the ratio to $64 500 per QALY gained.
Increasing counseling and testing costs from $53 to $103 per person still yielded a cost-effectiveness
ratio below $100 000 per QALY gained at a prevalence of undiagnosed infection of 0.1%.
CONCLUSION: Routine inpatient HIV screening programs are not only cost-effective but would
likely remain so at a prevalence of undiagnosed HIV infection 10 times lower than recommended
thresholds. The current HIV counseling, testing, and referral guidelines should now be implemented
nationwide as a way of linking infected patients to life-sustaining care.
© 2005 Elsevier Inc. All rights reserved.
This research was funded by the National Institute of Allergy and
R01AI42006, Center for AIDS Research P30AI42851), the National Insti-
tute of Mental Health (R01MH65869), the National Institute on Drug
Abuse (R01DA015612), and the Centers for Disease Control and Preven-
Requests for reprints should be addressed to Rochelle P. Walensky,
MD, MPH, Division of General Medicine, Massachusetts General Hospi-
tal, 50 Staniford Street, 9th Floor, Boston, Massachusetts 02114.
E-mail address: firstname.lastname@example.org.
0002-9343/$ -see front matter © 2005 Elsevier Inc. All rights reserved.
The American Journal of Medicine (2005) 118, 292–300
In 1993, the Centers for Disease Control and Prevention
(CDC) published guidelines for human immunodeficiency
virus (HIV) counseling, testing, and referral in an effort to
identify the estimated 300 000 patients in the United States
with undiagnosed HIV infection.1,2Because undiagnosed
HIV prevalence tends to mirror HIV diagnosis rates, these
guidelines, updated in 2001, recommend routine counsel-
ing, testing, and referral in hospitals with an HIV discharge
diagnosis rate of ?1%.3,4Although seroprevalence studies
reveal that many hospitals exceed the 1% prevalence thresh-
old, voluntary HIV counseling, testing, and referral services
historically have been offered only in prenatal settings or
when patients present with an HIV-associated illness or
request an HIV test, and not routinely in the inpatient
To date, only a very small number of inpatient facilities
provide HIV counseling, testing, and referral according to
guidelines.8Other infrequent interventions have explored
routine HIV testing in the outpatient, hospital-associated,
urgent care, and emergency department settings,6,9–12with
demonstrated success identifying cases of HIV infec-
tion.6–11Insufficient resources are commonly cited for fail-
ure to adhere to counseling, testing, and referral guide-
lines.13This paper sought to quantify the life expectancy
losses attributable to unidentified HIV infection and to as-
sess the cost-effectiveness of routine inpatient HIV coun-
seling, testing, and referral.
We constructed an inpatient screening model (hereafter
referred to as the “screening module”), building upon the
foundation of a previously designed and published model of
the natural history and treatment of HIV disease (hereafter
referred to as the “disease model”).14–16The purpose of the
screening module is to simulate the detection of HIV infec-
tion in a general inpatient target group, with a specified
prevalence of undetected HIV infection, whose members
are offered routine voluntary HIV counseling, testing, and
referral. Whether HIV is detected or not, all HIV-infected
patients in the defined target group enter the disease model,
which tracks disease progression based on natural history
data until death.17–19Only identified infected patients are
eligible for HIV-specific care in the model. Patients may be
detected as infected by one of three mechanisms: routine
HIV screening via the program under examination; devel-
opment of an opportunistic infection leading to the diagno-
sis of HIV; or later HIV testing outside the hospital, based
on current background HIV testing rates. Patients who are
detected after discharge through the latter two mechanisms
have the opportunity to receive HIV-related care at a later
time. This analysis evaluates the clinical outcomes and
cost-effectiveness of an inpatient screening program com-
pared with no screening program under alternative assump-
tions regarding undetected HIV prevalence, screening and
post-test counseling costs, and program participation. This
work has been approved by the Partners Human Research
Hypothetical inpatients enter the screening module one
at a time and are randomly assigned an HIV serostatus
based on a user-specified prevalence of undetected HIV.
Uninfected patients are offered an HIV test, which they may
accept or refuse. Patients who refuse testing accumulate no
HIV testing cost. Patients who accept the test accrue the cost
of both the test and pretest counseling time. Uninfected
patients who obtain a negative test result receive no health
benefit and accrue age-, race-, and sex-specific life expect-
ancy and quality-adjusted life expectancy.
The model uses input prevalence data to specify whether
an infected patient has acute (primary) or chronic HIV
infection. Patients with acute HIV infection who are tested
are not identified, receiving false-negative HIV enzyme
Infected patients presenting with an opportunistic infec-
tion are presumed to be HIV diagnosed via evaluation of
their presenting infection. Infected patients who do not have
an opportunistic infection enter the disease model with
untreated progression of their disease until they are detected
and become eligible for HIV-specific treatment. These pa-
tients, when screened, are offered an HIV test and may also
decline testing. Patients who are HIV infected, tested, and
test positive will receive care only if they return for their test
results and keep their HIV care appointment (linkage to
care). Patients identified as infected by a mechanism other
than the screening program are presumed to enter HIV care
at a later time.
To incorporate the various possible means by which
HIV-infected patients who are offered testing may ulti-
mately fail to receive care, we defined an “index of partic-
ipation” as the product of the following probabilities: being
offered and accepting the HIV test, and returning for test
results and being linked to HIV care.20
The disease model—the Cost-effectiveness of Preventing
AIDS Complications model—is a state-transition simulation
model of HIV-infected patients. Mutually exclusive health
states—acute HIV infection, chronic HIV infection, acute clin-
ical events, and death—incorporate the patients’ relevant clin-
ical details, including CD4 cell count, HIV RNA (viral load),
and cumulative history of opportunistic infections.14–16Each
infected patient enters the model one at a time and is tracked
individually until death to simulate the patient’s life course.
Patient statistics are accrued and can be studied individually or
in aggregate, and are summarized as the frequency and type of
293Walensky et alRoutine HIV Testing
opportunistic infections, mean time on therapy, mean life ex-
pectancy, quality-adjusted life expectancy, and lifetime cost.
The disease model can distinguish between identified
and unidentified HIV-infected patients. While all patients
with HIV infection enter the disease model, they only be-
come eligible for antiretroviral therapy and opportunistic
infection care once infection is detected. All undiagnosed
patients follow natural history disease progression accord-
ing to their HIV RNA titer and are at risk of opportunistic
infections based on their CD4 cell count. Once infected
patients are identified, they enter into care, which includes
regular CD4 cell count and HIV RNA laboratory tests.
When patients reach a CD4 cell count of 200 cells/mm3,
antiretroviral therapy is administered.21Four unique se-
quential antiretroviral regimens, with a diminishing efficacy
of viral load suppression, are assumed to be available to
patients once they are identified as infected (Table 1).
HIV-infected patients are at risk of opportunistic infec-
tions based on their CD4 cell count.14,15,17If a previously
unidentified patient develops an opportunistic infection, the
model presumes that an HIV diagnosis is then made and that
the patient is immediately referred to care. In care, patients
receive guideline-recommended opportunistic infection pro-
phylaxis regimens at the appropriate CD4 cell count thresh-
HIV-infected patients may die from non–HIV-related
causes, opportunistic infections, or other chronic HIV-re-
lated causes, depending on CD4 cell counts and prior op-
portunistic infection history.17,18The non–HIV-related
probability of death is based on background age-, sex-, and
race-dependent death rates.45
To achieve stability in estimates, we simulated more than
100 million patients in the screening module. Both the
screening module and the disease model are programmed
using C and compiled in C?? 6.0 software (Microsoft,
Redmond, Washington). Further disease model specifica-
tions are described in detail elsewhere.14–16
A summary of model input data is found in Table 1.
Because we were examining a cohort of inpatients in the
United States, we used the 2000 Nationwide Inpatient Sam-
Base case input data
Variable Base CaseRange Explored Reference
CD4 count among those infected
Acute infection (1.7%)
Chronic infection (98.3%)
Index of participation
Test offer/acceptance rate
Rate of return/linkage to care
Antiretroviral starting criterion
Antiretroviral efficacy at viral suppression
Enzyme immunoassay test characteristics
Linkage to care
Antiretroviral therapy-associated costs (per month)
CD4 cell count (per test)*
HIV RNA (per test)*
Genotypic antiretroviral resistance testing (per test)
CD4 ? 200 cells/mm3
No therapy ? CD4 ? 350 cells/mm3
70% at 48 weeks
60% at 24 weeks
34% at 12 weeks
22% at 12 weeks
HIV ? human immunodeficiency virus.
*Performed every 3 months.
294 The American Journal of Medicine, Vol 118, No 3, March 2005
ple to estimate the mean (? SD) age (55.8 ? 11.9 years)
and sex distribution (39% male) of hospitalized patients
?18 years of age.46
We used published test characteristics of the HIV en-
zyme immunoassay with a sensitivity for chronic HIV in-
fection of 99.6% and a specificity of 97.5%, and a per test
cost of $3, which includes kit, laboratory, and confirmation
costs.38,39,41Although the literature suggests a pretest coun-
seling cost of $25,39–41HIV counseling may be performed
in many settings by higher-paid professionals (eg, registered
nurses, social workers, or physicians). Recognizing that it is
not always possible to provide counseling for $25, we
adopted a conservatively high value of $50 as our base case
assumption and explored values in the range of $25 to $100
in sensitivity analyses. We further assumed that acute cases
would not be identified by enzyme immunoassay.47,48Test
results that are positive by enzyme immunoassay are con-
firmed with Western blot (100% specific).40,41
Undetected HIV prevalence: CD4 cell count and
Blinded seroprevalence studies suggest that the preva-
lence of undetected HIV disease is approximately equal to
the prevalence of diagnosed HIV disease.4Using previously
reported data on patients presenting for initial HIV care, we
ascertained a mean CD4 cell count of 320 ? 260 cells/mm3
for patients with chronic undiagnosed HIV infection.20
Given the importance of this uncertain variable, we ex-
plored how variations in these CD4 estimates influenced our
results in sensitivity analyses.
Index of participation
Rates of acceptance for voluntary HIV antibody testing
have been documented at 3% to 100%; in 1990, rates spe-
cific to hospitalized inpatients ranged from 11% to 91%,13
while prenatal testing acceptance rates ranged from 28% to
98%.28,30For the base case, we used an offer/acceptance
rate of 37%, regardless of serostatus, as reported by a
routine HIV counseling, testing, and referral demonstration
Rates of return for HIV test results for uninfected pa-
tients (67%) were obtained from the CDC.31An 88% rate of
return and linkage to care for infected patients came from
the demonstration program;29this figure is consistent with
published reports of nonreturn rates varying from 10% to
27%.32–34Therefore, our base case overall index of partic-
ipation was as follows: (offer/accept) ? (return/linkage to
care) ? (0.37) ? (0.88) ? 0.33. We considered alternative
values ranging from 0.01 to 1.00 in sensitivity analyses.
Costs for antiretroviral therapy and opportunistic infec-
tion treatment and prophylaxis were provided by the 2001
Red Book.42Laboratory test costs were taken from the
Medicare Fee Schedule.43The AIDS Costs and Services
Utilization Survey provided charges for treatment of oppor-
tunistic infections and routine HIV- and acquired immuno-
deficiency syndrome (AIDS)-related care that were con-
verted to economic costs using a national cost-to-charge
ratio for HIV/AIDS.49,50
The analysis was conducted from the societal perspective
in accordance with the recommendations of the Panel on
Cost-Effectiveness in Health and Medicine using a discount
rate of 3%.51All costs are presented in 2001 U.S. dollars.
The model yields results denominated in costs, life expect-
ancy, and quality-adjusted life expectancy; cost-effective-
ness ratios of the screening strategies are reported incre-
mentally to the no screening strategy in dollars per quality-
adjusted life-year (QALY) gained.
A routine inpatient HIV screening program increased
projected, discounted life expectancy from 5602.56 to
6215.15 QALYs per 1000 HIV-infected patients, or approx-
imately 7.35 quality-adjusted life-months per infected per-
son (Table 2). At a 37% test acceptance rate, screening of
1000 uninfected patients on average cost $19,800, or ap-
proximately $20 per uninfected person. By advancing the
time of identification with screening, the mean CD4 cell
count at detection was increased from 196 to 244 cells/mm3.
At an undetected HIV prevalence of 1% and a pretest
counseling and test cost of $53, quality-adjusted life expect-
ancy per 1000 inpatients increased by 6.13 QALYs and cost
an additional $216 600 per 1000 persons, yielding a cost-
effectiveness ratio of $35 400 per QALY gained (Table 3).
Cost-effectiveness ratios for the screening program re-
mained favorable: $64 500 per QALY gained, even at an
undetected HIV prevalence of 0.1%. At very high preva-
lences of HIV infection (10%), these ratios plateaued at
approximately $32 400 per QALY gained.
Mechanisms of detection
Without a screening program, 53% of patients were iden-
tified after presenting with an opportunistic infection, com-
pared with 35% with a screening program. The screening
program identified 32% of infected patients.
295Walensky et al Routine HIV Testing
When the cost of testing (counseling and test costs)
increased from $53 to $103 per patient, the cost-effective-
ness ratio for an inpatient screening program increased to
$38 400 per QALY gained at a 1% undiagnosed HIV prev-
alence and to $94 900 per QALY gained at a 0.1% undiag-
nosed HIV prevalence (Figure 1). At a lower testing cost of
$28 and an HIV prevalence of 0.1%, the cost-effectiveness
ratio for inpatient testing was $49 400 per QALY gained.
HIV-infected CD4 cell count
To understand the differences in CD4 cell count at de-
tection with and without a screening program, we examined
the mean CD4 cell count estimate of undetected chronically
HIV-infected inpatients (base case [? SD]: 320 ? 260
cells/mm3). The difference in mean CD4 cell count at the
time of detection increased as the mean count in the unde-
tected HIV-infected inpatients increased (Figure 2). Overall,
greater screening program benefits were realized (with
higher cost-effectiveness ratios) when the undetected HIV-
infected patients had higher CD4 cell counts.
Index of participation
We varied the probabilities of each component of the
index of participation (offer/accept and return/linkage to
care) from 0% to 100% in 10% increments at HIV preva-
lences of 0.1% and 1% (Table 4). Programs with increasing
participation rates and higher prevalences of undiagnosed
HIV infection were more attractive, with lower cost-effec-
tiveness ratios. Even in a program with poor rates of par-
ticipation, in which both test offer/acceptance and return/
linkage to care were 20% (index of participation ? 0.20 ?
0.20 ? 0.04), the program’s cost-effectiveness ratio re-
mained below $50 000 per QALY at an HIV prevalence of
Lead- and length-time bias
By model design, lead-time bias of the screening pro-
gram was not a factor. We confirmed this in a series of
analyses whereby neither the screened group nor the un-
screened group received any HIV care; the quality-adjusted
life expectancy for the two groups was identical. We also
examined length-time bias by examining the effect for each
HIV RNA set point. At an HIV prevalence of 1%, if all
infected patients had an HIV RNA set point of ?500 cop-
ies/mL (long length-time bias), then the life expectancy for
Costs and life expectancy per 1000 persons by infection and screening status
HIV-infected person, not screened
HIV-infected person, screened
HIV-uninfected person, not screened
HIV-uninfected person, screened
103 139 000
122 837 800
HIV ? human immunodeficiency virus.
Life expectancy, costs, and cost-effectiveness ratios for routine HIV screening at varying prevalences of undetected HIV
1% (base case)
17 118.91356 000
17 109.1064 500
1 031 400
1 248 000
17 010.9635 400
10 313 900
12 301 600
16 029.5232 400
HIV ? human immunodeficiency virus.
296The American Journal of Medicine, Vol 118, No 3, March 2005
1000 screened HIV-infected patients would be 6870.40
QALYs, compared with 6378.85 QALYs per 1000 un-
screened patients (cost-effectiveness ratio ? $39 500 per
QALY gained). At the opposite extreme, if all infected
patients had an HIV RNA set point of ?30 000 copies/mL
(short length-time bias), the life expectancy per 1000 HIV-
infected patients would be 5758.23 QALYs (screen) versus
5084.33 QALYs (no screen). In this more rapidly progress-
ing cohort, the screening program was more cost-effective,
yielding a cost-effectiveness ratio of $33 400 per QALY
Other sensitivity analyses
In other sensitivity analyses, we explored the efficacy
and the cost of antiretroviral therapy as well as alternative
CD4 cell counts for the initiation of antiretroviral therapy.
Prevalence thresholds for efficient HIV screening remained
stable. While cost-effectiveness ratios fluctuated with the
cost of antiretroviral therapy, overall policy conclusions did
not change. For example, at an HIV prevalence of 1%,
increasing antiretroviral costs by 50% increased the HIV
screening cost-effectiveness ratio from $35 400 to $45 800
per QALY; decreasing antiretroviral costs by 50% de-
creased the cost-effectiveness ratio to $24 900 per QALY.
Analyses examining access to antiretroviral therapy demon-
strated that at an HIV prevalence of 1%, the cost-effective-
ness of HIV screening programs exceeded $50 000 per
QALY only if fewer than 45% of patients had access to
antiretroviral therapy. Even at a prevalence of 0.1%, access
to antiretroviral therapy needed to be less than 54% for the
cost-effectiveness ratio of HIV screening to exceed
$100 000 per QALY. Alternative linkage to care costs had
a smaller overall effect on cost-effectiveness ratios than did
The 2001 CDC guidelines for HIV counseling, testing, and
referral recommend routine screening of all inpatients in
hospitals with an HIV prevalence of ?1%.3This threshold
is largely based on a single-blinded HIV seroprevalence
study of 20 acute care U.S. hospitals conducted by Janssen
et al. in 1992.4In that study, hospitals with AIDS diagnosis
rates of ?1/1000 discharges correlated to HIV seropreva-
lence rates of ?1%. The authors estimated that a routine
inpatient HIV screening program in similar hospitals would
detect nearly a quarter of a million HIV-infected, asymp-
Since that landmark study, several important events have
reshaped the HIV epidemic: effective antiretroviral thera-
py,21,52a revised of definition of AIDS,53and mandates for
HIV (rather than only AIDS) reporting in many states.54
Neither the Janssen study nor the current guidelines incor-
porate the cost of a testing program in the recommendations
for routine testing.3,4It is these costs, however, that are
generally cited as barriers to HIV counseling and testing
services.13Although cost-effectiveness assessments have
considered HIV testing in other venues (eg, prenatal and
premarital settings), these analyses have not addressed
screening as understood in the current guidelines.3,55,56Pre-
vious cost-effectiveness analyses in the inpatient setting
were conducted prior to the advent of highly active antiret-
Intentionally mirroring the CDC’s recommendations, we
evaluated the clinical benefits, costs, and cost-effectiveness
of a routine HIV screening program under alternative as-
sumptions about HIV prevalence, testing costs, CD4 cell
count of the undiagnosed patients, and program participa-
tion. We found that at an undiagnosed HIV prevalence of
1%, routine inpatient HIV screening programs would not
only increase mean HIV quality-adjusted life expectancy by
6.13 years per 1000 persons, but would also offer good
value for money, with a cost-effectiveness ratio of $35 400
per QALY gained.51This program compares favorably with
cost-effectiveness estimates for routine, standard screening
programs in other chronic diseases,59–61including type 2
50 100 150200
250300350 400 450500
Mean CD4 among Unscreened, Undiagnosed HIV-Infected Inpatients (cells/mm3)
aMean CD4 at Detection (cells/mm3)aa
No Routine Screening
tine screening at various potential values for the mean CD4 cell
count in a group of hospitalized patients. This mean CD4 value
will likely vary based on the severity and duration of undiagnosed
human immunodeficiency virus (HIV) infection in such patients.
The vertical distance between the screening program (triangles)
and no screening program (squares) represents the opportunity for
earlier intervention, referral to HIV care, and antiretroviral ther-
Sensitivity analysis demonstrating the effects of rou-
HIV Prevalence (%)
$53 (base case)
Cost of counseling and testing
munodeficiency virus (HIV) counseling and testing. At HIV preva-
lences of ?1%, the lines reflecting cost-effectiveness ratios con-
verge. Only at prevalences of ?0.1% do the costs of counseling
and testing drive the cost-effectiveness ratio.
Sensitivity analysis examining the cost of human im-
297Walensky et alRoutine HIV Testing
($80 400 per QALY gained), and colon cancer ($57 700 per
QALY gained). Even at an HIV prevalence as low as 0.1%,
routine HIV screening programs would likely remain cost-
effective ($64 500 per QALY).
Central to the HIV screening issue is who will pay for the
added expenditure. Thus far, testing recommendations and
initiatives remain unfunded mandates. If studies continue to
demonstrate the prevalence of undiagnosed HIV infection29
and the cost-effectiveness of HIV screening from the soci-
etal perspective, payers might be encouraged to cover this
practice, either separately or as part of the basis for payment
to hospitals. Those who currently fund guideline-concor-
dant care, such as private insurers, Medicare, and Medicaid,
could include routine, inpatient HIV testing as a reimburs-
able point of care.62Barring coverage changes, hospitals
may elect to either absorb the cost or cut back on other less
cost-effective programs. Such a commitment would also
have to recognize the personnel required to offer HIV coun-
seling and testing to all inpatients. Regardless of who is
most appropriate to pay for screening, this analysis quanti-
fies the costs of routine HIV testing and of achieving its
associated life expectancy benefits and demonstrates that
the cost-effectiveness of HIV screening falls below that of
other funded chronic disease screening programs.59–61
Because data on test acceptance and linkage are limited,
we conducted extensive sensitivity analysis with regard to
participation behavior. Our results demonstrate that moving
even a small number of HIV-infected patients into care,
with the associated increases in survival and costs, has the
single largest effect on the cost-effectiveness ratio of a
screening program. Only at very low HIV prevalences
(?0.1%) do high program costs and low participation rates
begin to alter this HIV-care driven cost-effectiveness ratio
Why is screening for HIV so cost-effective? HIV testing
is inexpensive, accurate, and identifies a disease for which
highly effective (although expensive) treatment is available.
($70 000per QALYgained),hypertension Infected patients have years of life to gain from viral load
suppression and the prevention of opportunistic infec-
tions.52Therefore, even in low-prevalence settings, the
overall cost of screening is effectively spread over years of
extended life for those who are infected.
There are important limitations to this study. First, the
analysis did not account for HIV screening benefits in terms
of secondary infections averted. If later infections may be
prevented by HIV counseling and case identification, this
analysis would underestimate the full benefit of a screening
program.63–65The additional benefit of simplified occupa-
tional health protocols related to needle stick injuries was
also not considered. Second, although the model included
quality-of-life estimates for health states, the short-term
anxiety and fear over the several days that the patient awaits
test results is difficult to capture adequately when looking at
total life years as the clinical endpoint. From a program-
matic standpoint, the CDC guidelines do not discuss prac-
tical issues of implementation, such as hospital readmission
rates, HIV incidence among patients who are readmitted,
and the optimal frequency of repeat testing.3Intentionally
modeling our analysis after these guidelines, we also did not
address these issues. However, in other settings, universal
screening programs have resulted in short-term decreases in
Given that reported efforts of routine HIV screening
among inpatients and outpatients have all documented suc-
cess at HIV case identification, this analysis suggests that
resources may be well utilized by initiating HIV screening
programs in hospitals with a diagnosed seroprevalence of as
low as 0.1%.6,8–11These programs should be established
with frequent assessments of their yield in terms of new
diagnoses of HIV infection, cost, and cost-effectiveness to
confirm their continued value.
Although HIV counseling, testing, and referral guide-
lines have been published in the United States since 1993,
they are seldom implemented; a resulting 300 000 patients
nationwide remain HIV infected and undiagnosed.1–3Be-
Cost-effectiveness of routine inpatient HIV screening program at alternative levels of program participation
Probability of Test Offer and
Probability of Return
for Results and
Linkage to Care
HIV Prevalence ? 0.1% HIV Prevalence ? 1%
Index of participation ? 0.04
Index of participation ? 0.40
Index of participation ? 0.90
HIV ? human immunodeficiency virus; QALY ? quality-adjusted life-year.
298The American Journal of Medicine, Vol 118, No 3, March 2005
fore dismissing expanded HIV counseling, testing, and re-
ferral programs as unaffordable, we should consider the
value of such efforts. We have demonstrated that an inpa-
tient routine HIV screening program is not only cost-effec-
tive, but would likely remain so at an undiagnosed HIV
prevalence 10 times lower than the currently recommended
threshold. With a renewed CDC emphasis on HIV testing,
nationwide action should focus on appropriate implementa-
tion of these guidelines in an effort to offer effective, life-
sustaining care to those who are infected.68
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