title: Time-to-readmission and Mortality After High-risk Surgery.
abstract: OBJECTIVE
  To determine if mortality varies by time-to-readmission (TTR).
  
  
  BACKGROUND
  Although readmissions reduction is a national health care priority, little progress has been made toward understanding why only some readmissions lead to adverse outcomes.
  
  
  METHODS
  In this retrospective cross-sectional cohort analysis, we used 2005-2009 Medicare data on beneficiaries undergoing colectomy, lung resection, or coronary artery bypass grafting (n = 1,033,255) to created 5 TTR groups: no 30-day readmission (n = 897,510), less than 6 days (n = 44,361), 6 to 10 days (n = 31,018), 11 to 15 days (n = 20,797), 16 to 20 days (n = 15,483), or more than 21 days (n = 24,086). Our analyses evaluated TTR groups for differences in risk-adjusted mortality (30, 60, and 90 days) and complications during the index admission.
  
  
  RESULTS
  Increasing TTR was associated with a stepwise decline in mortality. For example, 90-day mortality rates in patients readmitted between 1 and 5 days, 6 and 10 days, and 11 and 15 days were 12.6%, 11.4%, and 10.4%, respectively (P < 0.001). Compared to nonreadmitted patients, the adjusted odds ratios (and 95% confidence intervals) were 4.88 (4.72-5.05), 4.20 (4.03-4.37), and 3.81 (3.63-3.99), respectively. Similar patterns were observed for 30- and 60-day mortality. There were no sizable differences in complication rates for patients readmitted within 5 days versus after 21 days (24.8% vs 26.2%, P < 0.001).
  
  
  CONCLUSIONS
  Surgical readmissions within 10 days of discharge are disproportionately common and associated with increased mortality independent of index complications. These findings suggest 10-day readmissions should be specially targeted by quality improvement efforts.
authors.affiliation: *Center for Healthcare Outcomes and Policy (CHOP) and Department of Surgery, University of Michigan, Ann Arbor, MI †Department of Surgery, University of Illinois Hospital and Health Sciences System, Chicago, IL; and ‡University of Illinois at Urbana-Champaign, Urbana-Champaign, IL.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Gonzalez
authors.forename: Zaid M
authors.initials: ZM
authors.lastname: Abdelsattar
authors.forename: Justin B
authors.initials: JB
authors.lastname: Dimick
authors.forename: Shantanu
authors.initials: S
authors.lastname: Dev
authors.forename: John D
authors.initials: JD
authors.lastname: Birkmeyer
authors.forename: Amir A
authors.initials: AA
authors.lastname: Ghaferi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy / Q000009:adverse effects / Q000401:mortality* / Q000706:statistics & numerical data; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000401:mortality* / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D010359:Patient Readmission / Q000706:statistics & numerical data*; D011013:Pneumonectomy / Q000009:adverse effects / Q000401:mortality* / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000401:mortality; D012189:Retrospective Studies; D013997:Time Factors; D014481:United States / Q000453:epidemiology