Cost-effectiveness of adopting a postoperative delirium risk prediction tool with nonpharmacological delirium prevention interventions for surgical patients

Background Postoperative delirium (POD) arises among older surgical patients. Screening followed by prevention efforts are recommended. A risk prediction tool called PIPRA plus has been developed, yet its performance and whether adoption into health services is cost-effective are unknown. Objective To estimate the expected change to ‘total costs’ and ‘health benefits’ measured by quality adjusted life years (QALYs) from a decision to adopt PIPRA plus for screening purpose to find at-risk individuals who are then offered nonpharmacological interventions to reduce risks of POD. Design Cost-effectiveness modelling study that draws on a range of relevant data sources. Setting Swiss healthcare system. Subjects Surgical inpatients aged 60 or older, excluding cardiac and intracranial surgeries. Methods A decision tree model was used to capture the events likely to impact on cost and health outcomes. Information was harvested from a prospective before–after study done in Switzerland and augmented with other data. Probabilistic sensitivity analysis was undertaken to reveal the probability that adoption was cost-effective against a stated maximum willingness to pay threshold for decision-making in Switzerland. Results Patients in both phases of the study were similar. Costs were lower by 2898 CHF (SD 1050) per patient with the adoption of the risk screening tool and there was a modest gain to health benefits of 0.01 QALY (SD 0.026). There was a 99.7% probability that adoption would be cost-saving and 91% probability that adoption would be cost-effective. Conclusions We provide early-stage evidence that a decision to adopt the risk screening tool and offer risk-reducing interventions could be cost-effective.