Background: Frailty is a state of increased vulnerability to poor resolution of homeostasis
as a consequence of age-related decreased physiological reserves. Although physical frailty and cognitive
impairment have been shown to be associated, evidence on the prevalence of frailty in Alzheimer's
disease is scarce.
Objective: To conduct a systematic review on the prevalence of frailty and to combine the data to
synthesize the pooled prevalence of physical frailty among patients with Alzheimer's disease.
Method: Five electronic databases (Embase, MEDLINE, CINAHL Plus, PsycINFO, and the Cochrane
Library) were searched for studies providing cross-sectional data on physical frailty among patients
with Alzheimer's disease published from 2000 to January 2016.
Results: Of 2,564 studies identified through the systematic review, five studies incorporating 534 patients
with Alzheimer's disease were included for the meta-analysis. The prevalence of frailty varied
with a wide range from 11.1% to 50.0% and the pooled prevalence was 31.9% (five studies, 95%
confidence interval (CI)=15.7%-48.5%). The high degree of heterogeneity was observed in all analyses.
A borderline publication bias was detected.
Conclusion: The current study showed that frailty is highly prevalent in older patients with Alzheimer's
disease in the community with the pooled prevalence of 31.9%. The true prevalence may be
much higher given that end-stage patients may not be included. This information is important for clinicians