There is limited data on the performance of point of care HbA1c assays when fingerstick samples are tested by intended users in CLIA waived settings.
This study evaluated the precision of the Afinion HbA1c Dx (Afinion) when performed at CLIA waived sites (N=5) by operators with no laboratory training. The operators (N=12) self-trained using the materials provided with test purchase, had no prior Afinion system experience, and did not observe one another during testing. For each subject enrolled in the study (N=115) , 2 operators each obtained 2 fingerstick samples (4 total fingersticks per subject) and tested one sample on each of 2 Afinion instruments. The repeatability, between-operator, and between-instrument components of variance were calculated using the REML method for each of 4 HbA1c concentration intervals. The total imprecision was calculated as a composite of 6 relevant components of variance, including a) the components of variance estimated here (repeatability, between-operator, and between-instrument) , and b) components of variance estimated in prior studies (between-run, between-day, and between-lot) .
The repeatability was the dominant component, ranging from 0.83-1.14% CV across the HbA1c concentration intervals. The between-operator component was 0.00% CV for 3 out of the 4 HbA1c intervals, and was only 0.19% CV in the remaining interval, indicating the precision of the test is not operator dependent. The between-instrument component ranged from 0.22-0.39% CV. When combined with the other components of variance estimated in prior studies, the total imprecision does not exceed 1.80% CV, which is below the National Academy of Clinical Biochemistry’s (NACB) recommendation for a single method, interlaboratory CV of <3%. The results were similar to those obtained by trained operators testing fingerstick samples with the Afinion system.
These results indicate that the precision of the Afinion is comparable to many laboratory HbA1c assays, and suitable for use in CLIA waived settings.
M.Clendenin: Employee; Abbott. N.Ahmed: Employee; Abbott. K.Kupfer: Employee; Abbott. C.L.Green: Employee; Abbott Diagnostics, Siemens. K.S.Fortner: Employee; Abbott. T.S.Bailey: Advisory Panel; Abbott Diabetes, CeQur SA, MannKind Corporation, Medtronic, Novo Nordisk, Consultant; LifeScan, Sanofi, Research Support; Abbott Diabetes, Abbott Diagnostics, Biolinq, Capillary Biomedical, Inc., Dexcom, Inc., Eli Lilly and Company, Kowa Research Institute, Inc., Livongo, MannKind Corporation, Medtronic, Novo Nordisk, REMD Biotherapeutics, Sanofi, Sanvita Medical, Senseonics, ViaCyte, Inc., vTv Therapeutics, Zealand Pharma A/S, Speaker's Bureau; Becton, Dickinson and Company, Medtronic, Sanofi. S.Brick: None. S.I.Smiley: None. G.S.Strauss: None. A.A.Thorsell: None.