title: A comprehensive evaluation of the proficiency testing program for the HIV-1 BED incidence assay.
abstract: The HIV-1 BED incidence assay was developed at the Centers for Disease Control and Prevention and since 2005 has been available as a commercial kit for use in HIV-1 incidence surveillance. A BED-specific proficiency testing (PT) program was initiated in 2006 that included a panel of eight coded specimens (six unique and two duplicates) to participating laboratories. The number of participating laboratories increased from 12 to 38 from 2006 to 2009. Overall, 96.1% of the laboratories reported results, and 95.4% of those reporting achieved a 100% score. The observed mean normalized optical density (OD-n) values of all participants correlated well with the expected OD-n values for all specimens (R(2) = 0.98) used for seven PT rounds. BED testing demonstrated high reproducibility among all laboratories, with an agreement of 99.3% (574/578) between initial and confirmatory classification and regression statistics of R(2) = 0.96, slope = 1.022, and intercept = 0.0066. Reproducibility among duplicate specimens was very high during each PT round, with mean deviation of 1.8%. Analysis of controls and calibrator specimen for all 343 runs showed a coefficient of variation of ca. 20% for raw ODs in the dynamic range, which was reduced to <10% when the OD was normalized (OD-n). Most laboratories that failed the PT assessment had transcriptional errors, kit reagent problems, or specimen handling errors. Thus, the BED-specific PT program enabled us to track performance of different laboratories conducting the BED assay while identifying areas for improvements. This program will also serve as a template for future PT programs for new incidence assays as they become available.
authors.affiliation: International Laboratory Branch, Division of Global HIV/AIDS, Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30329, USA.
authors.forename: Trudy
authors.initials: T
authors.lastname: Dobbs
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Rebecca
authors.initials: R
authors.lastname: Anderson
authors.forename: John
authors.initials: J
authors.lastname: Nkengasong
authors.forename: Bharat S
authors.initials: BS
authors.lastname: Parekh
mesh_terms: D019411:Clinical Laboratory Techniques / Q000379:methods* / Q000592:standards*; D015483:HIV Antibodies / Q000097:blood; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards; D007074:Immunoglobulin G / Q000097:blood; D015994:Incidence; D015588:Observer Variation; D011786:Quality Control; D015203:Reproducibility of Results; D014773:Virology / Q000379:methods* / Q000592:standards*
chemical_list: D015483:HIV Antibodies; D007074:Immunoglobulin G