Objectives:
     
     This systematic review aimed to identify the nature and effects of implementation strategies used to improve the care of older people with frailty in hospital settings.
   

Methods:
     
     We included randomised controlled trials (RCTs), non-RCTs, before-after studies and interrupted time series describing clinical frailty-focussed interventions and implementation strategies aimed at improving outcomes for older people with frailty in hospital settings. We included peer-review articles and PhD theses published from the Year 2000 onwards. We excluded publications not in English and conference abstracts. Four electronic databases (Medline, PsycInfo, CINAHL and Scopus) were searched, alongside grey literature, in April 2024. Risk of bias was analysed using the NIH Quality Assessment Tool. A narrative synthesis approach was undertaken, with the RE-AIM framework used to present data for implementation outcomes and the Expert Recommendations for Implementing Change (ERIC) taxonomy used to categorise implementation strategies.
   

Results:
     
     Fifteen studies were included; all were pre-/postdesigns and published post-2014. Most studies involved implementing frailty assessments to trigger care planning and pathways for people with frailty. Twelve studies reported positive improvements in one or more primary outcomes. Common implementation strategies included developing quality monitoring tools, mandating change, promoting adaptability of the intervention and distributing educational materials.
   

Conclusions:
     
     Frailty interventions in hospital settings are usually multicomponent and highly influenced by context. This review confirms the feasibility of frailty screening and intervention in hospital settings, but implementation strategies are not well-reported. Future research should prioritise rigorous study designs and reporting to optimise the transferability of successful implementation strategies for frailty interventions to other health-care settings.