Factors influencing resilience to postoperative delirium in adults undergoing elective orthopaedic surgery

Delirium occurs after elective arthroplasty in 17 per cent of adults¹, and is associated with poor outcomes, including cognitive decline², dementia^3,4, and death⁵. Predisposing and precipitating risk factors accumulate and interact to precipitate delirium⁶. Much of the current literature analyses delirium as a dichotomous outcome, inevitably placing many people with symptoms of delirium, but falling short of a diagnosis, into the no-delirium group. Freedom from delirium symptoms should be investigated as an outcome. As evidence accumulates that delirium symptoms can also be associated with negative outcomes, it is important to identify the resilient groups in these studies and establish modifiable resilience predictors. Studies have explored risk factors for postoperative delirium; however, none to date has defined or considered delirium resilience as an outcome or phenotype. Resilience may be broadly defined as ‘the ability to withstand or recover quickly from difficult conditions’^7,8. The aim of this study was to identify predictors of delirium resilience in the perioperative setting.