Original study
Anemia Status, Hemoglobin Concentration, and Mortality in Nursing Home Older Residents

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Background

Anemia status is a typical feature of the “frailty syndrome” of elderly subjects. Increasing evidences suggest that low hemoglobin concentration is common in elderly subjects and adversely affects morbidity and mortality.

Objective

In the present study, we evaluate the impact of hemoglobin concentration on the risk of all-cause mortality in a large population of frail and old subjects living in a nursing home.

Methods

There were 372 residents admitted to the teaching nursing home of Catholic University of Rome aged 65 years and older from January 2002 to November 2004 who were enrolled. For the present study we selected all the subjects with a full MDS-NH assessment within 14 days after admission. The main outcome measure was the relative hazard ratio of death after 2 years of follow-up for different levels of hemoglobin concentration.

Results

Based on the WHO criteria for anemia, 235 participants were anemic at enrollment (63.1% of the cohort). A total of 130 deaths (44 men and 86 women) occurred during 2-years of follow-up. Death rates for those with and without anemia based on the WHO criteria were 38% and 28%, respectively (P = .03). The age- and sex-adjusted hazard ratio for mortality was 1.56 (95% CI, 1.07–2.28) for persons with anemia. Compared with the lower tertile, the age- and sex-adjusted hazard ratios of mortality for hemoglobin in the second and third tertiles were 0.40 (95% CI, 0.26–0.61), and 0.39 (95% CI, 0.24–0.58), respectively. Adjusting for potential confounders, including markers of frailty, cognitive impairment, creatinine levels, cancer, stroke, body mass index, and pressure ulcer, somewhat reduced the strength of the association between hemoglobin level and mortality, but it remained statistically significant.

Conclusion

Our results obtained from a representative sample of very old and frail elderly subjects living in a nursing home expand the knowledge that high levels of hemoglobin are associated with better survival. Anemia should be actively sought, appropriate diagnostic strategies should be implemented to search for potentially correctable causes, and aggressive interventions may be warranted to reduce mortality and improve functional status.

Section snippets

Methods

This study was designed as a retrospective cohort study with development and validation cohorts, using available data from the Minimum Data Set assessment form for Nursing Home (MDS-NH). Informed consent was established using methods approved by the Catholic University of Sacred Heart of Rome. The Opera Santa Maria della Pace ethical committee ratified the entire study protocol.

Prevalence of Anemia

Of 425 participants, 372 (87.5%) had baseline hemoglobin concentration determined. The mean (SD) hemoglobin concentration was 11.6 (1.9) g/dL. Men had a slightly higher mean hemoglobin concentration than women (11.7 [2.2] versus 11.5 [1.7] g/dL; P = .4). Based on the WHO criteria for anemia, 235 participants were anemic at enrollment (63.1% of the cohort). The prevalence of anemia was significantly higher in men than women (71% versus 59%, respectively, P = .01) (Table 2).

Correlates of Hemoglobin Concentration

Compared with

Discussion

In this elderly cohort the prevalence of anemia was 63%. After 2 years of follow-up, lower hemoglobin concentrations were associated with increased mortality risk, independent of many potentially confounding factors. The magnitude of this association was similar whether the lowest tertile of hemoglobin or the WHO criteria for anemia were used.

Our findings agree with other studies relating anemia to mortality.21 A review of the recent literature shows a well-established association between low

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    Copyright © 2007 American Medical Directors Association. Published by Elsevier Inc. All rights reserved.