Did the acute frailty network improve outcomes for older people living with frailty? A staggered difference-in-difference panel event study

Objectives: To evaluate whether the Acute Frailty Network (AFN) was more effective than usual practice in supporting older people living with frailty to return home from hospital sooner and healthier. Design: Staggered difference-in-difference panel event study allowing for differential effects across intervention cohorts. Setting: All English National Health Service (NHS) acute hospital sites. Participants: All 1 410 427 NHS patients aged 75+ with high frailty risk who had an emergency hospital admission to acute, general or geriatric medicine departments between 1 January 2012 and 31 March 2019. Intervention: Membership of the AFN, a quality improvement collaborative designed to support acute hospitals in England deliver evidence-based care for older people with frailty. 66 hospital sites joined the AFN in six sequential cohorts, the first starting in January 2015, the sixth in May 2018. Usual care was delivered in the remaining 248 control sites. Main outcome measures: Length of hospital stay, in-hospital mortality, institutionalisation, hospital readmission. Results: No significant effects of AFN membership were found for any of the four outcomes nor were there significant effects for any individual cohort. Conclusions: To realise its aims, the AFN might need to develop better resourced intervention and implementation strategies.