Evaluation of Capillary Hemoglobin Estimation in Blood Donors by Using Specific Gravity (CuSO4) and Portable Hemoglobin Photometer

Abstract

The  hemoglobin screening  test is the most important part prior  to blood donation to

guarantee donor safety and blood product quality. Even  though several hemoglobin measure-

ments are available, no single screening method is most suitable for mobile donation setting. The

purpose of the study was to evaluate the performance  and cost of three screening methods for

capillary hemoglobin estimation by using automated hematology analyzer as a reference method.

The prospective study was performed on 311 voluntary blood donors. Capillary  blood samples

were tested by CuSO4    method, HemoCue®   Hb 301 and Hemocroma PLUS   and venous blood samples were also tested by Sysmex  KX-21NTM.   The  result showed that the sensitivity and specificity of the test were 100.0%  and 38.9%  for CuSO4    method, 99.0%  and 11.1%  for HemoCue®  Hb 301 and 97.6% and 55.5% for Hemocroma PLUS. The positive predictive values (PPV)  were 96.4%,  94.7%  and 97.3%  and their negative predictive values (NPV)  were 100.0%,

40.0% and 58.8%, respectively. Hemoglobin level (mean ± SD) of capillary-HemoCue® Hb 301 was 14.99  ± 1.32  g/dL  which  was significantly  higher  than that of the venous-hematology analyzer whereas capillary-hemoglobin level of Hemocroma PLUS (14.63 ± 1.27 g/dL) was quite similar to that of the venous-hematology analyzer. Bland-Altman plot analysis demonstrated that the mean difference (95%  CI) between HemoCue®   Hb 301 and Sysmex KX-21NTM was 0.60  ±

0.50 g/dL and between Hemocroma PLUS   and Sysmex KX-21NTM was 0.58  ± 0.51 g/dL. Cost

analysis  showed that CuSO4    method was the most affordable method for using in screening procedure  with a cost of 2.2 baht per test, while the cost of HemoCue®   Hb 301 and Hemocroma PLUS were 50.0  and 40.0  baht per test, respectively.  Our  results  suggested that the hemoglobin level given by all three hemoglobin screening tests showed almost perfect agreement with venous

hematology  analyzer,  however,  the variation  of those values between tests was observed.  To protect donor safety, consideration  of implementation of the appropriate  screening  method and establishment of the best way to minimize this error should be done before the test is performed.