Lack of clinical utility of folate levels in the evaluation of macrocytosis or anemia

PURPOSE: Folate levels are routinely ordered in the evaluation of macrocyto sis with or without frank anemia, yet the value of these tests is questiona ble. We evaluated the clinical utility of folate testing in routine clinica l practice. SUBJECTS AND METHODS: We conducted a retrospective review of all serum and erythrocyte folate assays performed over a one-year period at three hospita ls. We determined the frequency of low values, then reviewed the medical re cords of all patients with low values to determine whether low folate level s changed clinician behavior. We also performed a cost analysis to determin e the cost of testing per case in which behavior changed. RESULTS: Only 2.3% of the 2,998 folate levels obtained during the study per iod were low. The low levels were noted in the record in 53% of cases, and folic acid was prescribed or continued at discharge in only 24%. The cost a nalysis showed that nearly $10,000 was spent in folate testing per patient in which behavior changed. CONCLUSIONS: Folate values were rarely low in the population tested, and lo w values infrequently led to a change in clinician behavior. Given the limi ted clinical value of folate tests, we propose that, in cases of macrocytos is with or without anemia, to minimize cost and prevent missed cases of tru e folate deficiency, empirical supplementation with folic acid should be us ed in place of testing for deficiency. (C) 2001 by Excerpta Medica, Inc.