Proficiency testing of hemoglobinopathy techniques in Ontario laboratories.

The Laboratory Proficiency Testing Program has been in effect for 20 years. During the past 6 years, samples were distributed for screening, investigation, and identification of hemoglobinopathies to test laboratory proficiency. Six samples for hemoglobin (Hb) S screening were distributed to from 37 to 163 laboratories that perform screening tests for sickle cell disease, and 10 samples were distributed to from 52 to 71 laboratories that perform Hb electrophoresis. Assessment of unacceptable results was based on clinical significance of the errors; educational follow-up was implemented to address these results. Most participants demonstrated acceptable performance. The error rates for sickle cell screening were 2.7% to 19.7%; the poorest performance was noted for Hb SC disease. The error rates for Hb electrophoresis were 1.4% to 36.8%; the poorest performance was noted in the investigation of Hb H disease and alpha-thalassemia trait. Improved survey performance was observed in the screening for Hb S trait and in the investigation of Hb H disease, which illustrates the benefits of proficiency testing and its positive effect on laboratory services.