A multicentre, pragmatic, cluster randomised, controlled feasibility trial of the POD system of care.

Objective: to provide a preliminary estimate of the effectiveness of the prevention of delirium (POD) system of care in reducing incident delirium in acute hospital wards and gather data for a future definitive randomised controlled trial.

Design: cluster randomised and controlled feasibility trial.

Setting: sixteen acute care of older people and orthopaedic trauma wards in eight hospitals in England and Wales.

Participants: patients 65 years and over admitted to participating wards during the trial period.

Interventions: participating wards were randomly assigned to either the POD programme or usual care, determined by existing local policies and practices. The POD programme is a manualised multicomponent delirium prevention intervention that targets 10 risk factors for delirium. The intervention wards underwent a 6-month implementation period before trial recruitment commenced. Main outcome measure incidence of new-onset delirium measured using the Confusion Assessment Method (CAM) measured daily for up to 10 days post consent.

Results: out of 4449, 3274 patients admitted to the wards were eligible. In total, 714 patients consented (713 registered) to the trial, thirty-three participants (4.6%) withdrew. Adherence to the intervention was classified as at least medium for seven wards. Rates of new-onset delirium were lower than expected and did not differ between groups (24 (7.0%) of participants in the intervention group versus 33 (8.9%) in the control group; odds ratio (95% confidence interval) 0.68 (0.37-1.26); P = 0.2225).

Conclusions: based on these findings, a definitive trial is achievable and would need to recruit 5220 patients in 26 two-ward hospital clusters. Trial registration: ISRCTN01187372. Registered 13 March 2014.