A proficiency testing program of hemoglobin analysis in prevention and control of severe hemoglobinopathies in...

No external quality assessment program for hemoglobin (Hb) analysis in the prevention and control of thalassemia has been established in Thailand. To improve the first line provisional diagnostics, the first proficiency testing (PT) program has been established.

External Hb controls prepared at our center were sent to Hb analysis laboratories all over the country. Three cycles per year were performed in 2010 and 2011. In each cycle, two control samples with corresponding hematological parameters, designated as husband and his pregnant wife were supplied for Hb analysis. Each member analyzed the control samples in their routine practices. The results of Hb analysis, laboratory interpretation and risk assessment of the expected fetus for severe thalassemia diseases targeted for prevention and control were entered into the report form and sent back to our center. Participants reports were analyzed and classified into four different quality groups; Excellent (when all the three parameters are correct), Good (correct Hb analysis and interpretation but incorrect risk assessment), Fair (correct Hb analysis but incorrect interpretation and risk assessment) and Needs improvement (incorrect Hb analysis).

It was found that most participants could report correct Hb types and quantifications but some misinterpretations and risk assessments were noted. These were clearly seen when control samples with more complexity were supplied.

These results indicate a further improvement is required in the laboratory interpretation and knowledge of the laboratory diagnosis of thalassemia. The established system should facilitate the prevention and control program of thalassemia in the region.