Racial/ethnic differences in patients with anemia and folate deficiency.

OBJECTIVE: To determine the presence of racial/ethnic differences in patients with anemia and serum folate deficiency. METHODS: We performed a retrospective analysis of data from patient samples collected from January 2010 to October 2018. Reference laboratory ranges were determined by Mayo Clinic Reference Laboratories. Race and ethnicity were classified according to National Institutes of Health categories. RESULTS: The analysis comprised 197 974 samples. Hemoglobin, hematocrit, and SF results were available for 173 337, 173 056, and 129 760 samples, respectively. Of the samples, 46 505 (26.8%) showed anemia, with a higher prevalence among American Indian/Alaskan Natives (AI/AN) 42.9% and African Americans (AA) 47.2% (P < .001). SF deficiency was present in 897 (0.7%), with a higher prevalence among AI/AN (9, [1.4%]) and AA (78, [1.2%]) and a lower prevalence in non-Hispanic whites (NHW) (758, [0.7%]), Hispanics (40, [0.6%]), and Asians (8, [0.3%]). In multivariable analysis, the prevalence of anemia was higher in all non-NHW racial/ethnic groups: AA (OR, 3.67, [95%CI: 3.47-3.88, P < .001]), AI/AN (OR, 3.25, [95%CI: 2.71-3.90, P < .001]), Asians (OR, 1.62, [95%CI: 1.47-1.77, P < .001]), and Hispanics (OR, 1.41, [95%CI: 1.32-1.50, P < .001]). SF deficiency was more common in AA (OR, 1.48, [95%CI: 1.17-1.88, P.001]) and less common in Asians (OR, 0.35, [95%CI: 0.17-0.70, P = .003]), compared with NHW. CONCLUSIONS: We showed significant racial/ethnic differences in anemia and SF deficiency. Differences were observed especially among NHW, AA, and Asians. We believe that these differences may be explained by social determinants of health. More research is needed regarding the causes of these differences and their clinical implications at a population level.