Effectiveness of interventions to prevent or reverse pre-frailty and frailty in middle-aged community dwelling adults: A systematic review

Introduction: Frailty, marked by diminished physiological capacity and higher health risks, is less understood in middle-aged individuals (40 -65 years) than older adults. This review synthesises intervention studies for prefrailty and frailty in this demographic, assessing effectiveness, feasibility, and implementation factors including participant experience and cost-effectiveness. Method: Registered on the Open Science Framework and adhering to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) and the template for intervention description and replication (TIDieR) guidelines, this review searched six databases for interventions targeting middle-aged adults. Dual screening, data extraction, risk assessment, and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) certainty evaluation were conducted. Findings were narratively synthesized due to heterogeneity. Results: Eight studies (2018 -2023) with 2838 participants were included. Resistance training and multicomponent exercise reduced frailty; though, not always significantly. Low-intensity exercises and education-based interventions yielded mixed results, suggesting a need for further research. Positive participant experiences and cost-effectiveness of interventions such as resistance training and educational interventions supports their feasibility. Varying quality, methodologies and levels of bias indicated a need for more rigorous future research. Discussion: This review reveals an evidence gap in middle-aged frailty interventions. Multicomponent interventions and resistance training showed promise, but their comparative effectiveness remains uncertain. Educational and low-intensity interventions need further research to establish their effectiveness. The findings diverge from those in older adults, emphasising the need for age-specific approaches. Future studies should employ higher-quality methods and explore emerging technologies to enhance intervention effectiveness for prefrailty and frailty in middle-aged adults.