The Relationship Between Anaemia and Frailty: A Systematic Review and Meta-Analysis of Observational Studies

Background There is increasing evidence that frailty may play a role in chronic diseases, but the associations with specific chronic disorders are still unclear. Objectives To conduct a systematic review and meta-analysis assessing the association of anaemia and frailty in observational studies. Methods The review was performed according to PRISMA guidelines. We searched PubMed, Web of Science, and Embase from 01/01/2002-10/09/2017. Pooled estimates were obtained through random effect models and Mantel-Haenszel weighting. Homogeneity was assessed with the I2 statistic. Publication bias was assessed with Egger’s and Begg’s tests. Results Nineteen studies were included; two longitudinal, seventeen cross-sectional. All studies except three reported an association between anaemia and frailty. The pooled prevalence of prefrailty in individuals with anaemia was 49% (95% CI=38-59%; I2=89.96%) and 24% (95% CI=17-31%; I2= 94.78%) for frailty. Persons with anaemia had more than a twofold odds of frailty (pooled OR=2.24 95% CI=1.53-3.30; I2=91.8%). Only two studies longitudinally examined the association between anaemia and frailty, producing conflicting results. Conclusions Frailty and prefrailty are common in anaemic persons. Older persons with anaemia have more than a two-fold increased odds of frailty. These results may have clinical implications, as they identify the need to assess frailty in anaemic people and investigate any potential negative effects associated with the co-occurrence of both conditions. Longitudinal research that examines temporal changes in anaemia and effect of treatment are needed to further clarify the relationship between anaemia and frailty.