The Hidden Burden of Iron Deficiency Anemia Among Hispanic Adults: Evidence From Three National Data Sources

Background

Iron deficiency anemia is common, inexpensive to treat, and easy to miss. It is usually studied either through laboratory surveys, which show who has it, or through billing records, which show who carries the diagnosis. The two are rarely placed side by side, so the distance between how many Hispanic adults have iron deficiency anemia and how many are recognized as having it has not been measured directly.

Methods

We combined three national data sources covering adults aged 20 years and older. The National Health and Nutrition Examination Survey (2017 to 2020) provided measured burden from hemoglobin and ferritin in 8,457 non-pregnant adults, including 1,796 Hispanic adults, using World Health Organization anemia thresholds and a ferritin cutoff below 30 ng/mL. The Medical Expenditure Panel Survey (2017 to 2023) provided person-level coded prevalence in 136,172 adults, including 29,010 Hispanic adults. The National Ambulatory Medical Care Survey health center component (2022 to 2024) provided visit-level coding across 973,087 adult visits, including 283,743 by Hispanic patients. All estimates were survey-weighted. Logistic regression adjusted for age and sex.

Results

Among Hispanic adults, measured anemia prevalence was 7.03% (95% CI 5.64 to 8.73) and measured iron deficiency anemia was 4.08% (2.83 to 5.84), compared with 5.27% and 2.48% in non-Hispanic White adults (adjusted odds ratio 1.69, 1.00 to 2.85). This gap has narrowed over two decades: the same comparison in 1999 to 2002 gave an adjusted odds ratio of 2.38 (1.41 to 4.02), and the narrowing reflects a rising rate in White adults rather than any improvement among Hispanic adults. Coded prevalence told a different story. Any anemia was coded in 0.945% of Hispanic adults and 0.954% of non-Hispanic White adults. Iron deficiency anemia was coded in 0.398% and 0.399%, respectively. Documentation was therefore nearly identical between the two groups despite unequal measured burden, giving a measured-to-coded ratio of 10.3 in Hispanic adults versus 6.2 in non-Hispanic White adults. The pattern was widest in non-Hispanic Black adults, where measured iron deficiency anemia reached 8.63% against a coded prevalence of 0.575%, a ratio of 15.0. Visit-level data pointed the same way: iron deficiency anemia was coded at 0.93% of Hispanic adult health center visits versus 1.28% of non-Hispanic visits.

Conclusions

Hispanic adults are more likely than non-Hispanic White adults to have iron deficiency anemia, but they are no more likely to be diagnosed with it, and at health center visits they are coded for it less often. The disease is not being missed evenly. The groups carrying the most of it are the ones recognized the least. Two limits are worth stating. The three surveys sample different populations, so these numbers show a consistent direction rather than an exact difference, and a coded diagnosis only captures what a clinician wrote down. Even with those limits, all three sources point the same way. The fix is not a new test or a new drug. It is checking a ferritin instead of stopping at the hemoglobin in the patients already known to be at higher risk.