Relationship between depression and frailty in older adults: a systematic review and meta-analysis

AIM: Depression and frailty are prevalent and burdensome in older age. However, the relationships between these entities are unclear and no quantitative meta- analysis exists. We conducted a systematic review and meta-analysis to investigate the associations between depression and frailty. METHODS: Two authors searched major electronic databases from inception until November-2016 for cross-sectional/longitudinal studies investigating depression and frailty. The strength of the reciprocal associations between frailty and depression was assessed through odds ratios (ORs) adjusted for potential confounders. RESULTS: From 2306 non duplicated hits, 24 studies were included. The overall prevalence of depression in 8023 people with frailty was 38.60% (95% CI 30.07-47.10, I(2)=94%). Those with frailty were at increased odds of having depression (OR adjusted for publication bias 4.42, 95%CI 2.66-7.35, k=11), also after adjusting for potential confounders (OR=2.64; 95%CI: 1.59-4.37, I(2)=55%, k=4). The prevalence of frailty in 2167 people with depression was 40.40% (95%CI 27.00-55.30, I(2)=97%). People with depression were at increased odds of having frailty (OR=4.07, 95%CI 1.93-8.55, k=8). The pooled OR for incident frailty, adjusted for a median of 7 confounders, was 3.72 (95%CI 1.95-7.08, I(2)=98%, k=4), whilst in two studies frailty increased the risk of incident depression with an OR=1.90 (95%CI 1.55-2.32, I(2)=0%). CONCLUSION: This meta-analysis points to a reciprocal interaction between depression and frailty in older adults. Specifically, each condition is associated with an increased prevalence and incidence of the other, and may be a risk factor for the development of the other. However, further prospective investigations are warranted.