Reference limits for routine haematological measurements in 7-14-year-old children living at an intermediate altitude (1869 m, Erzurum, Turkey).

In order to obtain reference limits, complete blood counts were performed using an automated haematology analyser (Cell-Dyn 1500) on venous blood samples from 718 healthy children living at 1869 m altitude. At first, to obtain appropriate populations for obtaining reference values, the factors of per capita income, parental educational status and antecedent infection(s) were assessed with respect to their effects on each parameter. Of the subgroups classified according to these factors, those which were affected in terms of haematological values were excluded. The effects of age and sex on the parameters were evaluated, and reference values were arranged according to age groups to facilitate clinical use. Among the reference values which we suggest for children living at about 2000 m altitude, those of haemoglobin, haematocrit, red blood cell count and mean cell volume are significantly higher than sea-level values. In addition, our results indicate that intermediate altitude has no effect on other routine haematological values.