Clinical Pallor Is Useful to Detect Severe Anemia in Populations Where Anemia Is Prevalent and Severe

Abstract
Clinical pallor is recommended as a simple way to detect severe anemia, but more data are needed on its accuracy and usefulness when assessed by nonphysicians in diverse settings. We measured hemoglobin and trained non-physician health workers to assess clinical pallor of the conjunctiva, palm and nail beds in five population samples in Nepal and Zanzibar, where severe anemia is common. In total, 5,760 individuals were examined, 3,072 of whom were anemic and 192 of whom had severe anemia (hemoglobin 84% specificity. However, the sensitivity varied from 81% in Nepalese postpartum women to 29% in Zanzibari preschoolers in 1996. Overall estimates for sensitivity and specificity were 50 and 92%, respectively. Although imperfect, use of pallor to screen and treat severe anemia by primary care providers is feasible and worthwhile where severe anemia is common. Usually, the majority of persons with severe anemia will be detected at practically no cost. Many people who are not severely anemic will also receive treatment, but the costs of this error are low compared to the benefits.