Effects of multi-domain interventions in (pre)frail elderly on frailty, functional, and cognitive status: a systematic review

BACKGROUND: Frailty is an aging syndrome caused by exceeding a threshold of decline across multiple organ systems leading to a decreased resistance to stressors. Treatment for frailty focuses on multi-domain interventions to target multiple affected functions in order to decrease the adverse outcomes of frailty. No systematic reviews on the effectiveness of multi-domain interventions exist in a well-defined frail population. OBJECTIVES: This systematic review aimed to determine the effect of multi-domain compared to mono-domain interventions on frailty status and score, cognition, muscle mass, strength and power, functional and social outcomes in (pre)frail elderly (≥65 years). It included interventions targeting two or more domains (physical exercise, nutritional, pharmacological, psychological, or social interventions) in participants defined as (pre)frail by an operationalized frailty definition. METHODS: The databases PubMed, EMBASE, CINAHL, PEDro, CENTRAL, and the Cochrane Central register of Controlled Trials were searched from inception until September 14, 2016. Additional articles were searched by citation search, author search, and reference lists of relevant articles. The protocol for this review was registered on PROSPERO (CRD42016032905). RESULTS: Twelve studies were included, reporting a large diversity of interventions in terms of content, duration, and follow-up period. Overall, multi-domain interventions tended to be more effective than mono-domain interventions on frailty status or score, muscle mass and strength, and physical functioning. Results were inconclusive for cognitive, functional, and social outcomes. Physical exercise seems to play an essential role in the multi-domain intervention, whereby additional interventions can lead to further improvement (eg, nutritional intervention). CONCLUSION: Evidence of beneficial effects of multi-domain compared to mono-domain interventions is limited but increasing. Additional studies are needed, focusing on a well-defined frail population and with specific attention to the design and the individual contribution of mono-domain interventions. This will contribute to the development of more effective interventions for frail elderly.