Accuracy of anemia diagnosis by physical examination

Quantification of clinical signs such as the presence or absence of pallor at clinical examination is a key step for making diagnoses. The aim was, firstly, to evaluate two methods for anemia diagnosis by physical examination: four-level evaluation (crosses method: +/++/+++/++++) and estimated hemoglobin values, both performed by medical students and staff physicians; and secondly, to investigate whether there was any improvement in assessment accuracy according to the number of years in clinical practice.

Forty-four randomly selected physicians and medical students in a tertiary care teaching hospital completed a physical examination on five patients with mild to severe anemia.

The observers used four-level evaluation and also predicted the hemoglobin level. Both methods were compared with the real hemoglobin value as the gold standard.

The mean estimated hemoglobin value correlated better with the real hemoglobin values than did the four-level evaluation method, for attending physicians, residents and students (Spearman's correlation coefficients, respectively: 1.0, 1.0 and 0.9 for guessed hemoglobin and -0.8, -0.8 and -0.7 for the four-level evaluation method). There were no differences in the mean "guessed" hemoglobin values from attending physicians, residents and students. However, the correlation between guessed hemoglobin value and the four-level method was positive for attending physicians, thus suggesting some kind of improvement with time (p = 0.04).

This study showed that estimated hemoglobin was more accurate than evaluation by the four-level method. The number of years in clinical practice did not improve the accuracy of clinical examination for anemia.