Aldridge C., Foster H.M.E., Albonico M., Ame S.M., Montresor A.
London School of Hygiene and Tropical Medicine, London, United Kingdom; Glasgow North-West GP Vocational Training Scheme, Glasgow, United Kingdom; Ivo de Carneri Foundation, Torino, Italy; Public Health Laboratory Ivo de Carneri, Pemba, Tanzania; Department of Control of Neglected Tropical Diseases, WHO, Geneva, Switzerland
Aldridge, C., London School of Hygiene and Tropical Medicine, London, United Kingdom; Foster, H.M.E., Glasgow North-West GP Vocational Training Scheme, Glasgow, United Kingdom; Albonico, M., Ivo de Carneri Foundation, Torino, Italy; Ame, S.M., Public Health Laboratory Ivo de Carneri, Pemba, Tanzania; Montresor, A., Department of Control of Neglected Tropical Diseases, WHO, Geneva, Switzerland
Objectives This study evaluates the diagnostic accuracy of Haemoglobin Colour Scale (HCS), compared with clinical diagnosis, to detect anaemia and severe anaemia in preschool-age children attending primary healthcare clinics in rural Zanzibar. Methods In all participants, haemoglobin (Hb) concentration was independently estimated by clinical examination for palmar pallor, HCS and HemoCue™. HemoCue was considered the reference method. Data collection was integrated into the usual health services and performed by local healthcare workers (HCWs). Sensitivity, specificity, positive and negative predictive values were calculated for HCS and clinical examination for palmar pallor. The limits of agreement between HCS and HemoCue, and inter-observer variability for HCS, were also defined. Results A total of 799 children age 2-59months were recruited to the study. The prevalence of anaemia (Hb<11g/dl) and severe anaemia (<5g/dl) were 71% and 0.8% respectively. The sensitivity of HCS to detect anaemia was 33% [95% confidence interval (CI) 29-36] and specificity was 87% (83-91). The sensitivity of HCS to detect severe anaemia was 14% (95% CI 0-58) and specificity was 100% (99-100). The sensitivity of palmar pallor to detect anaemia was low, but superior to HCS (58%vs. 33%, P<0.001); specificity was inferior to HCS (55%vs. 87%, P<0.001). There was no evidence of a difference in either sensitivity (P>0.1) or specificity (P>0.1) between HCS and palmar pallor to detect severe anaemia. Conclusions Haemoglobin Colour Scale does not improve the capacity of HCWs to diagnose anaemia in this population. Accuracy is limited by considerable variability in the performances of test operators. However, optimizing the training protocol for those using the test may improve performance. © 2012 Blackwell Publishing Ltd.
hemoglobin; accuracy assessment; anemia; child health; color; concentration (composition); disease prevalence; disease severity; health care; health services; population structure; sensitivity analysis; anemia; article; calculation; child; clinical assessment tool; clinical examination; diagnostic accuracy; disease severity; health care facility; health care personnel; health service; Hemoglobin Color Scale; human; infant; information processing; interrater reliability; major clinical study; pallor; predictive value; preschool child; primary health care; sensitivity and specificity; Tanzania; Anemia; Child Welfare; Child, Preschool; Diagnostic Tests, Routine; Female; Hemoglobinometry; Hemoglobins; Humans; Infant; Male; Mass Screening; Prevalence; Primary Health Care; Prospective Studies; Sensitivity and Specificity; Tanzania; Tanzania; Zanzibar Island