Proficiency testing program for hemoglobin E, A2 and F analysis in Thailand using lyophilized hemoglobin control materials.

BACKGROUND

There is no external quality assessment (EQA) program for hemoglobin analysis that uses lyophilized hemoglobin control materials with HbA2/E in levels as high as those found in people with the β-thalassemia trait, HbE trait, β-thalassemia/HbE disease or homozygous HbE; these are all found frequently in the southeast Asian population. The aim of this study was to evaluate the efficiency of the control materials used in the established proficiency testing (PT) program at the Associated Medical Sciences-Clinical Service Center (AMC-CSC), Chiang Mai University, Chiang Mai, Thailand.

METHODS

The PT program for Hb analysis and the thalassemia interpretation was established in compliance with ISO/IEC17043:2010. Three cycles per year were performed in 2015 and 2016. In each cycle, three different types of control material were provided to the participants. Each participant analyzed the control materials in the same manner as in their routine practices. Hb analysis results and their thalassemia interpretation codes were entered into the report form and sent back to AMC-CSC.

RESULTS

The number of participants increased from 63 in 2015 to 76 in 2016. In addition, the number of participants who took part in all three cycles increased from 95.2% (60/63) in 2015 to 100% (76/76) in 2016. All participants reported the correct Hb measurement and type; however, misinterpretations in thalassemia diagnosis were noted.

CONCLUSIONS

The lyophilized hemoglobin control materials prepared at AMC-CSC were used successfully in our PT program. However, the study results indicate the need for further improvement in thalassemia interpretation skills for laboratory staff.