Paul G. Barnett, Susan K. Schmitt, Wei Yu, Matthew Bidwell Goetz, Michael E. Ohl, Steven M. Asch

 Guidelines now recommend limited use of routine CD4 testing in HIV positive patients with successful viral control who are not immuno-compromised.  CD4 and viral load tests for patients receiving HIV care from the U.S. Department of Veterans Affairs (VA) during 2009-2013 were evaluated to determine trends in CD4 testing frequency and the number, cost, and results of CD4 tests considered optional under the guidelines.  There were 28,530 individuals with sufficient testing to be included. At the time of their last CD4 test, 19.8% of the cohort was eligible for optional monitoring and 15.6% was eligible for minimal monitoring. CD4 testing frequency declined by 10.8% over four years, reducing the direct cost of testing by $US 196 thousand per year. Full implementation of new treatment guidelines could reduce CD4 testing a further 28.9%, an additional annual saving of $US 600 thousand. CD4 tests conducted during periods of potentially reduced monitoring were rarely<200 cells/mm(3); 1.1% of the tests conducted when minimal monitoring was recommended were less than this value and just 0.3% of tests conducted when optional monitoring was recommended.  Reduced CD4 monitoring of HIV positive patients would result in modest cost savings and likely reduce patient anxiety, with little or no impact on the quality of care. VA has made substantial progress in reducing the frequency of optional CD4 testing, but further reductions may still be warranted.