Hyle EP, Sax PE, Walensky RP. Potential Savings by Reduced CD4 Monitoring in Stable Patients With HIV Receiving Antiretroviral Therapy. JAMA Intern Med. 2013;173(18):1746-1748. doi:10.1001/jamainternmed.2013.9329
The appropriate monitoring of chronic disease conditions offers high-yield opportunities to improve the value of medical care by reducing excess testing. For people living with human immunodeficiency virus (HIV)/AIDS in the United States who are virologically suppressed while receiving antiretroviral treatment (ART), HIV has become a chronic condition. The 2013 Department of Health and Human Services Guidelines for Adult and Adolescent HIV Care recommend CD4 monitoring every 6 to 12 months “in clinically stable patients with suppressed viral load [no detectable HIV RNA in blood],” although some clinicians perform this test quarterly.1 Recently published data show that CD4 results in such patients rarely (if ever) influence management.2 We sought to estimate how reduced CD4 testing frequency in virologically suppressed patients could contribute to savings at the US population level.
The Centers for Disease Control and Prevention estimates that 28% (336 000) of the 1.2 million people living with HIV/AIDS in the United States are virologically suppressed while receiving ART.3 Of these, cohort data suggest that 80% (270 000) meet criteria for sustained suppression while receiving stable ART.4 Human immunodeficiency virus–associated life expectancies in the United States and Europe are estimated at 22 to 34 years after HIV diagnosis.5 The CD4 test costs range from $38 to $67 per test, depending on whether CD4% is included.6 Using these estimates, we examined national costs associated with strategies of CD4 monitoring in this selected population.
We project that the current strategy of biannual CD4 monitoring costs $20.5 million per year at the conservative cost of $38 per test; reducing CD4 monitoring to once per year could result in annual savings of $10.2 million (Table). Many clinicians routinely use the more expensive CD4% (frequently including quantitative CD8 count, at $67 per test), in which case annual savings could reach $18.1 million. Decreasing CD4 frequency could result in a population savings of $225.7 to $615.1 million over the lifetime of patients in care, depending on life expectancy and CD4 test cost. In clinical practices in which routine CD4 monitoring is obtained every 3 months, savings associated with annual CD4 monitoring would be 3-fold higher.
Reduced frequency of routine CD4 monitoring improves the value of care for all stable, virologically suppressed patients with HIV. Given the emphasis on “redirected” financing to improve health care spending, the potential $18 million savings annually might allow for more efficient use of these HIV care dollars. Even greater savings would occur if CD4 monitoring in stable patients were eliminated entirely, which warrants consideration.
The most important question regarding CD4 monitoring is whether reducing its frequency will adversely affect health outcomes by delaying clinical decisions, including initiation of opportunistic infection (OI) prophylaxis or ART modifications. Rarely do virologically suppressed patients with current CD4 counts of at least 300/μL experience acute OIs or CD4 decline to less than 200/μL, the threshold for Pneumocystis jirovecii pneumonia prophylaxis.2 Furthermore, clinicians use HIV RNA as the most sensitive method to monitor for treatment failure,1 typically owing to poor adherence or resistance. CD4 testing would still be indicated for patients who are no longer virologically suppressed.
Our results likely underestimate the potential savings from reduced frequency of routine CD4 monitoring. Variability in CD4 test results is common owing to diurnal variation, medications, infections, and laboratory variability. Unexpected decreases in CD4 counts are confirmed by repeated tests, the costs of which are not included in our estimates. Even a single low CD4 value requires extra reassurance to patients regarding its limited importance given ongoing viral suppression.
The number of virologically suppressed patients with HIV is growing; as the population eligible for a reduced frequency of CD4 monitoring is increasing, so are the opportunities for savings. Given the still unmet medical needs of people living with HIV/AIDS, a recommendation for at most annual CD4 monitoring in stable, virologically suppressed patients offers a high value opportunity for a wise reinvestment of care.
Corresponding Author: Emily P. Hyle, MD, Medical Practice Evaluation Center, Massachusetts General Hospital, 50 Staniford St, Ninth Floor, Boston, MA 02114-2696 (firstname.lastname@example.org).
Published Online: August 26, 2013. doi:10.1001/jamainternmed.2013.9329.
Author Contributions: Dr Hyle had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: All authors.
Acquisition of data: Hyle.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Hyle, Walensky.
Administrative, technical, or material support: Walensky.
Study supervision: Sax.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by the National Institutes of Allergy and Infectious Disease (grants R37 AI42006 and T32 A1007433).
Role of the Sponsor: The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: We thank the Cost Effectiveness of Preventing AIDS Complications (CEPAC) research group.