Association between anemia and mortality in patients with rheumatoid arthritis: A retrospective cohort study of the National Health and nutrition examination survey (NHANES) database

Abstract

Objectives

This study aimed to investigate the impact of anemia on all-cause and cardiovascular disease (CVD) mortality in patients with rheumatoid arthritis.

Methods

Data on patients with rheumatoid arthritis were extracted from the National Health and Nutrition Examination Survey (NHANES) dataset from 1999 to 2006 and 2017–2018. The associations of total anemia, ferritin, iron deficiency anemia, non‑iron deficiency anemia, and transferrin saturation with all-cause and CVD mortality were evaluated using a weighted multivariable Cox regression model, with hazard ratios (HRs) and 95 % confidence intervals (CIs) calculated.

Results

Among the 848 patients included, 495 (62.09 %) survived, 353 (37.91 %) died, and 135 (13.79 %) died from CVD. Total anemia (HR = 1.64, 95 %CI: 1.13–2.39) and iron deficiency anemia (HR = 2.02, 95 %CI: 1.37–2.96) were Aassociated with an increased risk of all-cause mortality, whereas total anemia (HR = 1.76, 95 %CI: 1.02–3.04) and non‑iron deficiency anemia (HR = 2.07, 95 %CI: 1.02–4.18) were associated with a higher risk of CVD mortality. No significant associations were found between ferritin and transferrin saturation and mortality in patients with rheumatoid arthritis (P > 0.05).

Conclusion

Iron deficiency anemia was associated with an increased risk of all-cause mortality in patients with rheumatoid arthritis, while non‑iron deficiency anemia was associated with CVD mortality.