Assessment of thalassemia screening program at peripheral health care facilities

Abstract

In Thailand, screening program for thalassemia has been implemented for more than a decade. In order to examine the operation and accuracy of thalassemia screening program at peripheral health care facilities, 1,200 left-over blood samples derived from subjects with both negative and positive screening results from 11 community hospitals in northeast Thailand were collected and sent to the Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, for further determinations of thalassaemia and hemoglobinopathies. Based on hemoglobin and DNA analyses, the overall prevalence of a⁰-thalassemia (a⁰-thal) was 5.6 %, of b-thalassemia (b-thal) 1.0 % and of hemoglobin E (Hb E) 41.4 %. While the proportion of b-thal and Hb E in each setting was similar, the rate of a⁰-thal varied from 1.9 % to 16.0 % between the locations. Of 1,200 samples, 574 (47.8 %) were positive for thalassemia screening. Assessing the operation and accuracy of thalassemia screening revealed unsatisfactory results in 3 laboratories with FN > 10 % and/or FP > 30 %. After conducting the training program, their performance was substantially improved with a FN rate of less than 10.0 %. The findings indicate that proficiency testing and regular training programs are needed to decrease false negative results and to monitor regularly the screening performance of the community hospitals.

Keywords:     Thalassemia screening,   OF-test,   DCIP-test