Is It Time to Begin Routine Screening for HIV Infection?

Current Centers for Disease Control and Prevention (CDC) estimates are that of the approximately 1 million persons in the United States infected with HIV, 250,000 to 300,000 are unaware of their serostatus. Therefore, they are not getting HIV-specific care or prevention counseling. It is this group, consequently, that significantly contributes to the progressing number (>40,000) of new infections seen annually in the United States.

Physicians Ignoring Plea for Aggressive Testing

Despite the call to clinicians for the past several years for more aggressive testing, this has not been taking place. And despite the CDC's recommendation since 2001 for routine testing of all persons living in areas with a seroprevalence of at least 1%, testing continues to be underutilized.¹ The CDC data show that 41% of HIV-infected patients develop AIDS within 1 year of diagnosis.² In addition, we continually see a substantial number of persons diagnosed late in the course of their disease, when they present with an AIDS-defining illness or with very low CD4⁺ cell count.

Early identification of HIV infection provides physicians the opportunity to reduce transmission by effecting changes in risk behavior. Treatment with highly active antiretroviral therapy (HAART) decreases morbidity, mortality, and?in some settings?infectivity. The public health reasons for aggressive testing and early identification of infected persons are quite compelling. But it is apparent that many physicians outside of the HIV treatment world, including my own colleagues in family medicine, seem to ignore or perhaps are unaware of these data. Commonly cited "barriers" to lack of testing include time, expense, or lack of perceived HIV risk on the part of the patients or their physicians.

New Evidence: Cost-Effectiveness

New England Journal of Medicine

The very recent publication of 2 studies in the February 10, 2005, issue of the expands the call for routine HIV screening in the United States. In the first study, Dr Sanders and colleagues used a Markov model to evaluate the cost-effectiveness of a voluntary HIV-screening program in relation to issues of quality of life, survival, and the likelihood of sexual transmission.³ The HIV transmission component of this study was based on viral load, knowledge of HIV status, and efficacy of counseling.

Given a 1% prevalence of unidentified HIV infection, the authors determined that regular screening increased life expectancy by 5.48 days at a one-time cost of $194 per screened patient. Identifying patients earlier in the course of their disease resulted in a survival advantage of 1.5 years for the average HIV-infected patient. A one-time screening program would reduce the annual transmission rate by more than 20% compared with the absence of screening.

The cost of one-time screening would be $41,736 per quality-adjusted life-year. If the community prevalence was more than 0.05%, the cost of screening would still be less than $50,000 per adjusted lifeyear, which is the commonly cited cost threshold for screening for other diseases, such as breast cancer, diabetes, or hypertension. The authors cite a variety of demographic, natural history, testing, and treatment variables that support their outcomes.

In the second study, Dr Paltiel and colleagues used a computer simulation model of HIV screening and treatment that compared routine voluntary counseling and testing with current testing practices in 3 target populations.⁴ These included "high-risk" (3% prevalence of undiagnosed infection)," CDC threshold" (1% prevalence, 0.12% incidence), and "US general" (0.1% prevalence, 0.01% incidence). Primary outcomes included quality-adjusted survival, costs, and cost-effectiveness.

Similar to the first study, the authors determined that one-time screening for HIV antibodies was associated with earlier diagnosis (mean CD4⁺ cell count of 210/?L vs 154/?L) and an improvement in average survival. Also in keeping with the findings of Dr Sanders and colleagues, the incremental cost-effectiveness was $36,000 per quality-adjusted life-year gained. Dr Paltiel and colleagues concluded that in all but the lowest risk population, routine, voluntary screening for HIV once every 3 to 5 years is justified on clinical and cost-effective grounds.

Screening in Primary Care

Of particular relevance to primary care physicians, Dr Paltiel and colleagues point out that HIV infection meets all the US Preventive Services Task Force criteria for targeted screening:

• It has a long preclinical, asymptomatic phase.
• It is a condition for which there is effective treatment.

So we now have strong evidence to support what many of us have been calling for during the past several years?markedly increased testing for HIV infection. I hope that the findings from these 2 studies will be accepted by policymakers and professional societies, such as the American College of Physicians or the American Academy of Family Physicians, to encourage and support clinicians in performing more widespread HIV screening as part of routine medical care. Of course, with screening must come a linkage to HIV treatment and prevention services.

As Dr Sam Bozzette notes in an accompanying editorial, screening programs ideally should be based in health care settings to minimize the stigma that has always surrounded HIV testing.⁵ Moreover, office-based testing can take advantage of the fact that about 80% of adults in the United States see a health care provider at least once annually. Amodel of sorts is already in place, showing that the majority of women receiving prenatal care (100% in our own program in Lancaster) undergo routine HIV testing as standard of care.

As with this population, my expectation is that the acceptance rate for routine testing would increase over time among patients visiting their physicians for an employment physical examination or a visit for hypertension, cholesterol, or diabetes management, or even for an acute problem.

Increased Treatment Costs?

A perceived downside to routine testing is that more patients will be identified who will need HIV therapy, thereby also increasing health care costs. This comes at a time when at least 10 states currently have waiting lists for their federal AIDS Drug Assistance Programs, and there has been little or no expansion of funding for these programs in the past few years under the Ryan White CARE Act.

However, as we expand the use of high-tech interventions at very low thresholds, such as implantable cardiac defibrillators, treating persons with HIV disease at a cost of roughly $10,000 a year has repeatedly been shown as a cost-effective intervention. And this pales in comparison with treating major opportunistic infections or AIDS-related malignancies, which result in lengthy hospitalizations and carry a much greater risk of death. Arather remarkable presentation at the recent 12th Conference on Retroviruses and Opportunistic Infections in Boston determined that HIV care has saved nearly 2 million lives in the United States since 1989.⁶

Talk to Your Patients

If we continue our failing to provide widespread HIV testing and subsequent identification of those infected, the numbers of newly infected patients in the United States will continue to expand, following the current patterns of the global AIDS epidemic. For a disease that has no cure and no effective vaccine in sight, this is a frightening prospect for our health care system to handle in the next decade and beyond.

My plea to physicians: Talk to and encourage your patients to be tested for HIV at least once, regardless of whether you work in New York City, Kansas City, or Sioux City. Do not completely depend on the perception that your patient is not from a high-risk group or has never engaged in high-risk behaviors. As Dr Bozzette aptly notes, failure to pursue a policy of more widespread HIV testing is a disservice to our patients who are infected but unaware, their prospective contacts, and the public health of ourcountry.⁵

MMWR

1. Revised guidelines for HIV testing, counseling, and referral. . 2001;9:1-58.

2. Neal JJ. Frequency and predictors of late HIV diagnosis in the United States 1994-1999. Presented at the 9th Conference on Retroviruses and Opportunistic Infections, February 2002; Seattle, Wash [Abstract].

N

Engl J Med

3. Sanders GD, Bayoumi AM, Sundaram V, et al. Cost-effectiveness of screening for HIV in the era of highly active antiretroviral therapy. . 2005;352:570-585.

N Engl

J Med

4. Paltiel AD, Weinstein MW, Kimmel AD, et al. Expanded screening for HIV in the United States?an analysis of cost-effectiveness. . 2005;352:586-595.

N Engl J Med

5. Bozzette SA. Routine screening for HIV infection?timely and cost-effective. . 2005;352:620-621.

6.Walensky RP, et al. Two million years of life saved. The survival benefit of AIDS therapy in the United States. Presented at the 12th Conference on Retroviruses and Opportunistic Infections, February 22-25, 2005; Boston, Mass [Abstract # 143LB].