Frailty as a predictor of disabilities among community-dwelling older people: a systematic review and meta-analysis

Background: Frailty has been shown to be associated with disability in the previous studies. However, it is not clear how consistently or to how much degree frailty is actually associated with the future disability risks. Methods: A systematic review of the literature was conducted using Embase, MEDLINE, CINAHL, PsycINFO, and the Cochrane Library for any prospective studies published from 2010 to September 2015 examining associations between baseline frailty status and subsequent risk of developing or worsening disabilities among community-dwelling older people. A meta-analysis was performed to synthesize pooled estimates. Results: Of 7012 studies identified through the systematic review, 20 studies were included in the meta-analysis. Twelve studies examined activities of daily living (ADL) disability risks, two studies examined instrumental activities of daily living (IADL) disability risks, and six studies examined both ADL and IADL disability risks. Overall, frail older people were more likely to develop or worsen disabilities in ADL (12 studies, pooled OR=2.76, 95% CI=2.23-3.44, p<0.00001; 5 studies, pooled HR=2.23, 95% CI=1.42-3.49, p<0.00001) and IADL (6 studies, pooled OR=3.62, 95% CI=2.32-5.64, p<0.00001; 2 studies, pooled HR=4.24, 95% CI=0.85-21.28, p=0.08). Prefrailty was also associated with incident or worsening disability risks to a lesser degree in most pooled analyses. High heterogeneity observed among 12 studies with OR of ADL disability risks for frailty was explored using subgroup analyses, which suggested methodological quality and mean age of the cohort were the possible causes. Conclusion: This systematic review meta-analysis quantitatively showed that frail older people are at higher risks of disabilities. These results are important for all related parties given population aging worldwide. Interventions for frailty are important to prevent disability and preserve physical functions, autonomy, and quality of life.