HIV laboratory monitoring reliably identifies persons engaged in care.
BACKGROUND
Attendance at biannual medical encounters has been proposed as a minimum national standard for adequate engagement in HIV care. Using data from the HIV Outpatient Study, we analyzed how well dates of HIV-related laboratory testing correlated with attendance at biannual medical encounters.


METHODS
HIV Outpatient Study is an open prospective cohort study of HIV-infected patients receiving outpatient care in the United States. The data set included dates for laboratory measurements and medical encounters. We included patients with at least 1 HIV laboratory test (CD4 cell count or plasma HIV RNA viral load) during 2010-2011. An HIV laboratory test was defined as associated with a medical encounter if it occurred within 3 weeks of the encounter. We assessed the predictive value of HIV laboratory tests as a proxy for adequate engagement in clinical care, defined as having had ≥2 HIV laboratory tests within 1 year and performed >90 days apart.


RESULTS
A total of 10,321 HIV laboratory tests were recorded from 2909 patients. Adequate engagement in clinical care based on medical encounters was 88.2% and 77.3% when based on laboratory tests. Using HIV laboratory tests to assess engagement had a sensitivity of 85.7%, specificity of 86.0%, and positive and negative predictive values of 97.9% and 44.5%, respectively. Of the 22.7% classified as not engaged in care by the proxy measure, over half (55.5%) were actually engaged.


CONCLUSIONS
Using laboratory monitoring reliably classified persons as engaged in care. Of the 22.7% of patients classified as not engaged in care, most were actually engaged.
*Cerner Corporation, Kansas City, MO; †Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA; and ‡Department of Medicine, Division of Infectious Diseases, University of California San Diego, La Jolla, CA.
Bonnie B
BB
Dean
Rachel L D
RL
Hart
Kate
K
Buchacz
Samuel A
SA
Bozzette
Kathy
K
Wood
John T
JT
Brooks
D000293:Adolescent; D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D019411:Clinical Laboratory Techniques / Q000379:methods*; D015331:Cohort Studies; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006678:HIV / Q000302:isolation & purification; D015658:HIV Infections / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D010349:Patient Compliance; D011446:Prospective Studies; D014481:United States; D019562:Viral Load; D055815:Young Adult