Evaluation of conjunctival pallor in the diagnosis of anaemia.

The diagnosis of anaemia using conjunctival pallor was evaluated using the concept of predictive values. The presence or absence of pallor in 951 individuals and their haemoglobin levels were matched, defining haemoglobin of 10 g dl-1 or less as representing anaemia. The sensitivity and specificity of the test of pallor were 18.6% and 95.8%, respectively. At 16.3% prevalence of anaemia the positive and negative predictive values were 46.3% and 85.8%, respectively. The findings suggest that conjunctival pallor as a screening test for anaemia may not be very reliable.