Performance of the Haemoglobin Colour Scale in diagnosing severe and very severe anaemia

To assess the accuracy of Haemoglobin Colour Scale (HCS) in identifying severely anaemic [haemoglobin (Hb) <7 g/dl] and very severely anaemic (Hb <5 g/dl) individuals, and to compare the performances of a group of health workers using HCS after training with a standard method.

The study consisted of two parts. In part 1, the performance of HCS was compared with clinical examination in a hospital population of which more than 450 individuals were severely anaemic and more than 120 very severely anaemic. Part 2 of the study was conducted in eight dispensaries where the performances of 13 health workers using the colour scale were compared with the performances of eight other health workers using clinical signs to estimate Hb.

The colour scale was 92% sensitive for both severe anaemia and very severe anaemia and performed better than clinical examination. Health workers who used the colour scale did better in identifying anaemic and severely anaemic individuals, than those who used clinical examination.

The colour scale improves health workers' capacity to identify severely anaemic individuals and could be used as a basis for referral. Although the diagnostic accuracy of the workers using HCS varied widely, in most cases they did significantly better than those who used clinical investigation alone.