HbA1c measurements from dried blood spots: validation and patient satisfaction.
BACKGROUND
This study evaluates HbA1c measurements from dried blood spots collected on filter paper and compares HbA1c from filter paper (capillary blood) with HbA1c measured in venous blood.


METHODS
Patient satisfaction was evaluated using a questionnaire. The performance with the filter paper method was assessed by comparing HbA1c results from EDTA-blood samples obtained via dried blood spots with HbA1c results obtained with freshly hemolyzed blood (routine HbA1c). Adult patients visiting the outpatient clinic for HbA1c analyses were recruited for the evaluation of dried blood spot sampling at home. Laboratory personnel collected a capillary blood sample on filter paper as well as a venous EDTA-blood sample. The participants collected another capillary blood sample at home and sent the dried filter paper back to the laboratory. Samples were analyzed with an immunoturbidimetric assay.


RESULTS
Between-filter coefficient of variation was 1.8%. Filter paper HbA1c increased slightly during storage, particularly during the first 5 days. Filter paper HbA1c highly correlated with routine HbA1c (r=0.987). The evaluation of samples collected at home showed comparable HbA1c values by filter paper and routine sampling methods (n=93). Eighty-three percent of participants said they would like the filter method to be brought into practice.


CONCLUSIONS
Home HbA1c sampling on filter paper is an acceptable sampling alternative for analysis of HbA1c.
Fokkema
M Rebecca
MR
Stichting Klinisch Chemisch Laboratorium, Medical Center Leeuwarden, Leeuwarden, The Netherlands. m.r.heiner@lc.umcg.nl
Bakker
Andries J
AJ
de Boer
Fokje
F
Kooistra
Jeltsje
J
de Vries
Sifra
S
Wolthuis
Albert
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001774:Blood Chemical Analysis / Q000379:methods*; D002196:Capillaries / Q000737:chemistry; D005260:Female; D005374:Filtration; D006442:Glycated Hemoglobin / Q000032:analysis*; D006461:Hemolysis; D006801:Humans; D007753:Laboratories; D008297:Male; D008875:Middle Aged; D010209:Paper; D017060:Patient Satisfaction; D015203:Reproducibility of Results; D013048:Specimen Handling; D013997:Time Factors; D014680:Veins / Q000737:chemistry; D055815:Young Adult
D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human