text: **Methods**
  
  **Data Collection**
  The study, with review and approval from the Weill Cornell institutional review board (IRB), was 
  
  conducted at an urban academic 840-bed quaternary-care hospital in New York City, with 
  
  approximately 71 000 adult ED visits and 21 000 admissions annually. EHR data from 1600 
  
  individual EM patient encounters leading to acute hospital admission were randomly selected from 
  
  visits occurring between April and September of 2023. We limited our analysis to EM patient 
  
  encounters occurring after April 2023, as the study site had updated the EM-handoff at that time. 
  
  Encounters before this date used an earlier version of the EM-handoff note that would have provided 
  
  suboptimal data for training labels. We used these data to fine-tune a pretrained LLM, which then 
  
  generated an abstractive EM-handoff note. For the 1600 patient encounters (the study participants), 
  
  Weill Cornell Medicine IRB approved a waiver of informed consent because the study used 
  
  retrospective data and posed minimal risk to patients. We used Strengthening the Reporting of 
  
  Observational Studies in Epidemiology (STROBE) reporting guidelines. 
  
  **EM-to-IP Handoff Note Template**
  The EM-to-IP handoff note template used in the study is a replication of the current manual handoff 
  
  note structure used at the study site. The generated EM handoff note consists of components 
  
  generated by a rule-based pattern-matching approach (laboratory tests, vitals, medications, consult 
  
  orders, and radiology impressions) and components generated by the trained abstractive 
  
  summarization model (history of present illness [HPI], differential diagnoses, immediate care plans, 
  
  in-ED events, and disposition). Each summary also included a header with the timestamp of ED triage 
  
  and discharge, patient’s birth date, patient’s unique identifier, patient’s encounter number, and the 
  
  total time of patient’s stay in the ED. 