Intravenous iron showed no mortality benefit

Intravenous iron during acute infection did not reduce 90-day mortality in most hospitalized patients.
*Retrospective propensity-matched cohort study; Level 2 (OCEBM).

Citation

Wu R, Park YR, James LP, El-Fadel O, Bosch NA. Revisiting the impact on mortality of intravenous iron administration during acute inpatient infections. J Hosp Med. 2026;1-5. doi:10.1002/jhm.70457

Background

Iron deficiency anemia is common in hospitalized patients, but clinicians often avoid intravenous iron during infections because of concern it may worsen bacterial growth. A prior database study suggested a large survival benefit; this reanalysis tested whether that finding persisted after stronger bias adjustment.

Patients

Adults hospitalized from 2000 to 2025 with acute infection, iron deficiency anemia within 2 days, and antibiotic treatment. Exclusions included death within 7 days and intravenous iron in the prior 30 days.

Intervention

Intravenous iron within 7 days of infection-related hospitalization.

Control

No intravenous iron within the same 7-day window.

Outcome

All-cause mortality.

Follow-up Period

90 days after the hospital infection date.

Results

After matching, 27,796 patients were analyzed. Intravenous iron was not associated with lower mortality for bacteremia, pneumonia, colitis, or cellulitis.

Infection group 90-day mortality finding
Bacteremia NS
Pneumonia NS
Colitis NS
Cellulitis NS
Urinary tract infection, broad definition 7.0% vs 8.4%; HR 0.82 (95% CI 0.71 to 0.95); NNT 72

HR = hazard ratio; NNT = number needed to treat; NS = not statistically significant.

The urinary tract infection benefit disappeared when less specific diagnoses were removed: HR 0.84 (95% CI 0.65 to 1.09). The analysis used a landmark approach similar to intention-to-treat.

Limitations

Observational design prevents causal conclusions. Coding errors, unmeasured illness severity, clinician selection of healthier patients for iron, and treatment crossover may bias results. Findings apply only to patients surviving at least 7 hospital days.

Funding

No funding; no reported conflicts.

Clinical Application

Do not change practice based on survival benefit claims; consider intravenous iron case-by-case during infection until prospective trials clarify safety.