Project Details

Bedside Expedited Testing for Anemia (BETA)

Luke Smart, MD

Summary

BACKGROUND: Anemia is a common cause of global morbidity and mortality, disproportionately affecting women and children living in low-resource settings such as sub-Saharan Africa. Severe anemia is rapidly fatal in hospitalized children in Africa, often occurring within hours of admission, and must be quickly and accurately diagnosed so that a life-saving blood transfusion can be administered. GAP: Diagnosing anemia by physical examination is unreliable and inaccurate, and high quality laboratory equipment with adequate reagents is unavailable in many low-resource settings. A recently optimized version of a color-based point-of-care test for anemia has demonstrated excellent accuracy in a USA laboratory, but field-testing in a low-resource setting has not been performed. HYPOTHESIS: The new point-of-care assay will correlate well with HemoCue measurement of hemoglobin with r > 0.85. The new point-of-care assay will have >85% sensitivity and specificity for diagnosing severe anemia (hemoglobin <7.0 g/dL) and very severe anemia (hemoglobin <5.0 g/dL). METHODS: The Bedside Expedited Testing for Anemia (BETA) study is a prospective study of designed to determine the accuracy, sensitivity, and specificity of a novel point-of-care assay for anemia. Children receiving medical care at Bugando Medical Centre in Mwanza, Tanzania with a clinical concern for anemia will be enrolled. Bedside results from the new POC assay will be compared to HemoCue measurement of hemoglobin. RESULTS: BETA recruited 233 participants (mean age 5.8±4.3 years, range 0-20 years). The majority were recruited from the inpatient ward (87%) or the sickle cell clinic (9%). Three expert readers each interpreted a mean of 77.7 tests. Novice readers interpreted a mean of 1.4 tests each and included 164 intern doctors (31%), nurses (26%), family members (16%), medical students (12%), medical officers (7%), and others (7%). Interobserver agreement was excellent (r = 0.91, p < 0.001). The absolute difference (mean ± SD) between the AnemoCheck-LRS and the HemoCue 201+ was 0.7±0.6 g/dL for experts and 0.8±0.6 g/dL for novices. There was a strong correlation between AnemoCheck-LRS and the HemoCue 201+ hemoglobin concentration (r=0.78 and 0.72 respectively). AnemoCheck-LRS had 96% sensitivity and 51% specificity for detection of Hb ≤6 g/dL, and 70% sensitivity and 91% specificity for detection of Hb ≤ 5 g/dL. IMPACT: BETA provides essential data regarding the use of the AnemoCheck-LRS to diagnose anemia in a real-world setting within sub-Saharan Africa. The optimized, second-generation AnemoCheck-LRS demonstrated good correlation with the gold standard results and excellent interobserver agreement. The AnemoCheck-LRS could be used as a screening tool to quickly identify children who may benefit from blood transfusion or may have undiagnosed SCD.