Anemia in general medical inpatients prolongs length of stay and increases 30-day unplanned readmission rate

South Med J. 2013 May;106(5):316-20. doi: 10.1097/SMJ.0b013e318290f930.


Objectives: Anemia, either chronic or newly developed in the hospital as a result of underlying disease and/or phlebotomy, is seen commonly among general medical inpatients, and its impact on the quality and efficiency of care is unknown.

Methods: This study investigated the relation among hemoglobin level, length of stay, and 30-day unplanned readmission rates in a cohort of 314 general medical inpatients 18 years old and older admitted to a teaching hospital during a period of 4 months in a large urban academic medical center, using retrospective chart review of the electronic health record.

Results: Anemia was common among this cohort of general medical inpatients (44.6%), and there was a statistically significant decrease in hemoglobin levels during their hospitalization. Anemic patients, as compared with nonanemic patients, had significantly longer mean and median length of stay. More important, the admission hemoglobin level and its change during hospitalization were significant predictors of increased length of stay. For every 1-U increase in admission hemoglobin level, the median length of stay was reduced by 0.5 days. For every 1-U increase in the level of hemoglobin change, the median length of stay was extended by 1.5 days. Likewise, the discharge hemoglobin level predicted the rate of 30-day unplanned readmission. For every 1-U decrease in discharge hemoglobin level, the readmission rate increased by nearly 4%. These relations remained after adjusting for common demographic and clinical variables, including age, sex, nutritional status, and number of comorbidities.

Conclusions: Anemia is common among general medical inpatients and adversely affects their length of stay and 30-day unplanned readmission rate.

MeSH terms

  • Anemia / epidemiology*
  • Female
  • Hemoglobins / analysis
  • Humans
  • Inpatients / statistics & numerical data
  • Length of Stay / statistics & numerical data*
  • Male
  • Middle Aged
  • Patient Readmission / statistics & numerical data*
  • Quality of Health Care / statistics & numerical data
  • Retrospective Studies


  • Hemoglobins