Predictive value of conjunctival pallor in the diagnosis of anaemia

Because of the need to develop a simple yet reliable method of diagnosing anaemia, a compelling health problem, several studies had examined the possibility of utilizing physical examination of mucous membranes as a test of anaemia, but have produced conflicting results. This study was undertaken to determine if physical examination of a patient's mucous membranes will give predictive values of his haemoglobin concentration. A representative sample was drawn from the population of the Local Government Area selected for the study. Data collected on each study subject included age, sex, body weight, diagnosis, if any and conjunctival tint. At the same time, a venous blood sample was also obtained and its haemoglobin concentration determined with the oxyhaemoglobin concentration method. This was matched with the survey data on each subject for analysis. Results showed that 2697 subjects were s surveyed and that the prevalence of anaemia in the study population, defined in this report as Hb < 100g/l, was 29.9%; 14.9% was found to have conjunctival pallor. Statistical analysis gave sensitivity and specificity scores of 25% and 89% respectively and positive and negative predictive values of 46.9% and 75.4% respectively. The study observed that these results indicate that while conjunctival pallor is not a reliable measure of the presence of anaemia, the probability that it correctly excludes those that are not anaemic is high. Conjunctival pallor is recommended as a screening rather than a diagnostic tool.