The Successful Aging After Elective Surgery Study: Cohort Description and Data Quality Procedures

ObjectivesTo describe baseline characteristics and quality assurance procedures of the Successful Aging after Elective Surgery (SAGES) study, which was designed to examine novel risk factors and long-term outcomes associated with delirium. DesignLong-term prospective cohort study. SettingThree academic medical centers. ParticipantsIndividuals aged 70 and older (average age 77, 58% female) without recognized dementia scheduled for elective major surgery (N=566). MeasurementsParticipants were assessed preoperatively, daily during hospitalization, and at variable monthly intervals for up to 36months after discharge. Trained study staff assessed delirium in the hospital. Study outcomes included cognitive and physical function. Novel risk factors for delirium were assessed, including genetic and plasma biomarkers, neuroimaging markers, and cognitive reserve markers. Interrater reliability (kappa and weighted kappa) was assessed for critical variables in 119 of the participant interviews. ResultsEighty-one percent of participants were undergoing orthopedic surgery, and 24% developed delirium postoperatively. More than 95% of eligible participants were followed for 18months. There was greater than 99% capture of important study outcomes (cognitive and functional status) at every study interview, and interrater reliability was high (weighted kappa for delirium=0.92 and for overall cognitive and functional outcomes=0.94-1.0). Completion rates were 95% to 99% for plasma biomarkers (4 time points) and 86% for neuroimaging (1-year follow-up). ConclusionThe SAGES study will contribute to the understanding of novel risk factors, pathophysiology and long-term outcomes of delirium. This article describes the cohort and data quality procedures of the SAGES study and will serve as a reference source for future studies based on SAGES.