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.