A novel capillary collection method for obtaining current glycosylated haemoglobin levels in diabetic children.

A simple method for collecting capillary blood for measurement of glycosylated haemoglobin (HbA1c) was developed that allows samples to be obtained at home and then mailed to the laboratory 2 weeks before a hospital visit. A single drop of blood is collected into a 2 ml plastic tube and sent for HbA1c assay on the Diamat HPLC system which has inter- and intra-assay coefficients of variation < 2.6 and < 1.2%, respectively. Results of simultaneously obtained venous and capillary samples in 32 diabetic children agreed well with each other. A separate study of 25 patients was performed to determine whether transport conditions affected the samples. Posted samples were compared with venous samples; again the values were in good agreement. This method is now used routinely in the diabetic clinic. Its value was determined by questionnaire in 40 children with age range 4-17 years. No family experienced difficulty collecting samples and all samples received were suitable for analysis. Children preferred this method to blood collection in the clinic as they felt it was less traumatic and more convenient. Seventy-nine percent of them understood its value in the long-term control of diabetes. In 40.5% of visits changes to management were made at the clinic due to the availability of the results.