Iron deficiency anemia did not worsen outcomes in patients hospitalized with bacterial pneumonia

NASHVILLE, Tenn. — Patients who were hospitalized with bacterial pneumonia with co-existing iron deficiency anemia did not have worse outcomes, including mortality, septic shock, acute respiratory failure and cardiac arrest.

Researchers conducted a study to evaluate the impact of iron deficiency anemia in an acute bacterial infection.

“On a day-to-day basis, my colleagues and I tend to manage patients who both have an acute bacterial infection and an underlying iron deficiency anemia, so we decided to conduct a retrospective cohort study using a large database to look at the possible outcomes,” Mubarak Yusuf, MD, third-year internal medicine resident at NYC Health + Hospitals/Lincoln Medical Center, Bronx, New York, told Healio.

Researchers extracted data from approximately 452,040 adult hospitalizations — primarily for bacterial pneumonia — from the Nationwide Inpatient Sample Database 2016-2019. Patients were then categorized based on presence or absence of iron deficiency anemia as a secondary diagnosis.

The primary outcome was inpatient mortality. Secondary outcomes included odds of septic shock, acute respiratory failure, cardiac arrest, mean length of hospital stay and mean total hospital charges.

According to results presented at the CHEST Annual Meeting, 5.5% of patients with a primary diagnosis of bacterial pneumonia also had iron deficiency anemia (mean age, 68.8 years; 58.5% women).

The rate of inpatient mortality was 2.89% among patients hospitalized for bacterial pneumonia.

Compared with patients without iron deficiency anemia, those with this diagnosis had decreased odds of mortality (OR = 0.74; 95% CI, 0.624-0.878) after adjusting for age, sex, disease severity and race. Patients with iron deficiency anemia also had decreased odds of septic shock (OR = 0.71; 95% CI, 0.53-0.96), acute respiratory failure (OR = 0.78; 95% CI, 0.73-0.83) and cardiac arrest (OR = 0.57; 95% CI, 0.38-0.85).

The researchers reported an increase in mean length of stay of 0.3 days (95% CI, 0.13-0.51) and a nonsignificant increase in mean total hospital charges of $402.50 among patients with iron deficiency anemia compared with patients without.

“In both primary and secondary outcomes measured, there was a protective/better prognostic impact of iron deficiency anemia in patients admitted for bacterial pneumonia,” Yusuf told Healio.

According to the researchers, more research is required to more clearly explain improved outcomes observed in this patient population.

“We have plans for further analysis, some of which can be easily done using the same database and some of which may be a new study whereby we can correlate patient laboratory values to the outcomes observed and also address some of the limitations in our initial study,” Yusuf said. “This is a retrospective cohort study, which does answer prognosis questions in this population, but recommendations cannot be derived from this study.”

Reference:

Yusuf M, et al. Chest. 2022;doi:10.1016/j.chest.2022.08.509.