Background–The World Health Organisation(WHO) haemoglobin colour scale is an inexpensive,simplemethod for diagnosing anaemia.

Methods–The haemoglobin of 1400 patients attending a tertiary care hospitalwas estimated by WHO haemoglobin colour scale (HCS) which were later compared with measurements of haemoglobin by the standard laboratory methods to determine its reliability and to determine interobserver variation.

Results–In present study, comparison of  HCS with coulter counter ERBA HAEMOLAB–8 in 500 blood samples showed sensitivity of 90.48% ,specificity of 98.88%,false positive rate 1.12%,false negative rate 9.52% and reliability coefficient of 0.94%.  In comparison of  HCS with cyanmethaemoglobin method in 500 blood samples, results showed sensitivity of 69.84%, specificity of 77.15%, false positive rate 22.85%,false negative rate 30.16% and reliability coefficient of 0.76%.  In contrast, comparison of  HCS withSahlimethodin 200 blood samples of ANC patients showed sensitivity of 90.83%,specificity of 30.00%, false positive rate 70.00%, and false negative rate 9.10% and reliability coefficient of 0.72%. While doing comparison of HCSwith copper sulphate specific gravity methodin 200 blood samples, we noticed sensitivity of 90.48%,specificity of 98.88%, false positive rate 1.12%,and false negative rate 9.52% and reliability coefficient of 0.94%. Reliability of the HCS in detecting anaemia and assessing its severity was 55.67% in nonanaemic cases(more than 12gm% haemoglobin), 87.67% in mild anaemia (8–12gm% Hb),100% in cases of moderate anaemia(6–8gm%)andcritical anaemia (less than 4 gm %) and 91% in severe anaemia(4–6gm% Hb. 20% of samples showed interobserver variation within the range of 1gm/dl.

Conclusion:– The present study concluded that WHO scale is a useful, quick, easy and reliable method of detecting anaemia in areas where proper laboratory setup is not there.