1 Patients age≥65 account for nearly 40% of annual surgeries, and this proportion will increase as 2 the population ages. These older patients have more perioperative complications - e.g. acute 3 kidney injury (AKI) and myocardial infarction (MI) - and the complication rate increases by 2-4 4 fold after age 80. Anesthesia induction requirements are known to decrease significantly with 5 age. We believe perioperative complications in older surgical patients result in part from 6 a failure among anesthesiologists to follow FDA guidance to reduce induction anesthetic 7 doses for these patients – a population with polypharmacy, frailty, decreased functional 8 reserve, and multiple interacting comorbidities. Severe hypotension (mean arterial 9 pressure<55mmHg) during surgery - even for a few brief minutes - increases risk of AKI by 10 18%, and MI by 30%, highlighting the importance of preventive measures to reduce hypotensive 11 episodes. Our multi-center pilot data indicates that anesthetic induction dose substantially 12 exceeds FDA guidance for many patients age ≥65 and that high induction doses often provoke 13 hypotension among these elderly patients. Hypotension during surgery can have multiple 14 causes, but when provoked by induction anesthetic overdose, it is modifiable. We propose to 15 combine data from the Multicenter Perioperative Outcomes Group (MPOG) database – 16 containing over 9.3 million anesthetic records from 44 centers - with Medicare data to, 1) identify 17 the prevalence of deviation from FDA induction dosing guidance nationwide; 2) test the 18 contribution of anesthetic induction overdose to perioperative complications; and 3) feasibility 19 test a pilot, quality improvement (QI) tool concerning deviation from FDA guidance on induction 20 dosing for the elderly. Among patients age≥65, and separately among those age≥80, our aims 21 are: Aim 1: To measure provider variability and identify outliers in FDA-adherent anesthetic 22 induction practice; Aim 2: Measure the association of anesthetic induction overdose to, a) 23 clinically meaningful hypotension, and b) subsequent postoperative morbidity and mortality; and 24 Aim 3: Develop and feasibility test a QI feedback tool – leveraging an established MPOG 25 platform - focused on deviation from FDA guidance for induction dosing of the elderly. 26 Public Health Significance: Demonstrating patterns of anesthetic overdose in excess of FDA 27 guidance and the consequences of this care failure among vulnerable subsets of patients, we 28 will highlight a clear target – FDA-adherent age-adjustment of anesthesia induction dose - to 29 make healthcare safer for older patients. The proposed analyses will support the testing of an 30 intervention to increase FDA-adherent anesthesia induction dosing for older Americans.