OBJECTIVE: Iron-deficiency anemia is sometimes attributed to esophagitis and hiatal hernia; however, because these GI conditions are so common, such an association could be coincidental. We examined prospectively whether esophagitis and hiatal hernia increased the risk of iron-deficiency anemia in a national, population-based study. METHODS: The study population comprised 5069 adult participants in the first National Health and Nutrition Examination Survey, who were free of GI hemorrhage and anemia at baseline examination in 1971-1975 and who were hospitalized at some point during nearly 20 yr of follow-up. Rates of hospitalization with iron-deficiency or unspecified anemia were compared between patients with a hospital diagnosis of esophagitis or hiatal hernia and those who had not yet had a diagnosis of these disorders. Adjusted rate ratios were calculated using time-dependent, multivariable, proportional hazards analysis. RESULTS: During follow-up, 59 patients were hospitalized with esophagitis alone, 140 with hiatal hernia alone, and 70 with both diagnoses. A total of 102 participants were hospitalized with iron-deficiency anemia and 256 with unspecified anemia. Compared to those without a diagnosis of esophagitis or hiatal hernia, patients with a diagnosis of hiatal hernia had higher rates of subsequent hospitalization with iron-deficiency anemia. The hazard rate ratio (HRR) for hiatal hernia was 2.9 (95% confidence interval, 1.5-5.5). A trend was found for esophagitis with a HRR of 2.2 (95% confidence interval, 0.79-6.0). Results were similar with unspecified anemia as the outcome. CONCLUSIONS: Hiatal hernia should be considered as a possible cause of iron-deficiency anemia. The relationship of esophagitis with iron-deficiency anemia requires further study. (C) 2001 by Am. Coll. of Gastroenterology.