title: Roles of disease severity and post-discharge outpatient visits as predictors of hospital readmissions.
abstract: Risks prediction models of 30-day all-cause hospital readmissions are multi-factorial. Severity of illness (SOI) and risk of mortality (ROM) categorized by All Patient Refined Diagnosis Related Groups (APR-DRG) seem to predict hospital readmission but lack large sample validation. Effects of risk reduction interventions including providing post-discharge outpatient visits remain uncertain. We aim to determine the accuracy of using SOI and ROM to predict readmission and further investigate the role of outpatient visits in association with hospital readmission.
  
  
  
  Hospital readmission data were reviewed retrospectively from September 2012 through June 2015. Patient demographics and clinical variables including insurance type, homeless status, substance abuse, psychiatric problems, length of stay, SOI, ROM, ICD-10 diagnoses and medications prescribed at discharge, and prescription ratio at discharge (number of medications prescribed divided by number of ICD-10 diagnoses) were analyzed using logistic regression. Relationships among SOI, type of hospital visits, time between hospital visits, and readmissions were also investigated.
  
  
  
  A total of 6011 readmissions occurred from 55,532 index admissions. The adjusted odds ratios of SOI and ROM predicting readmissions were 1.31 (SOI: 95 % CI 1.25-1.38) and 1.09 (ROM: 95 % CI 1.05-1.14) separately. Ninety percent (5381/6011) of patients were readmitted from the Emergency Department (ED) or Urgent Care Center (UCC). Average time interval from index discharge date to ED/UCC visit was 9 days in both the no readmission and readmission groups (p > 0.05). Similar hospital readmission rates were noted during the first 10 days from index discharge regardless of whether post-index discharge patient clinic visits occurred when time-to-event analysis was performed.
  
  
  
  SOI and ROM significantly predict hospital readmission risk in general. Most readmissions occurred among patients presenting for ED/UCC visits after index discharge. Simply providing early post-discharge follow-up clinic visits does not seem to prevent hospital readmissions.
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA. hwang01@jpshealth.org.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Johnson
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Robinson
authors.affiliation: Institute for Health Aging, Center for Alzheimer's and Neurodegenerative Disease Research, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA.
authors.forename: Vicki A
authors.initials: VA
authors.lastname: Nejtek
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Chet D
authors.initials: CD
authors.lastname: Schrader
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: JoAnna
authors.initials: J
authors.lastname: Leuck
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Johnbosco
authors.initials: J
authors.lastname: Umejiego
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Trop
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Delaney
authors.affiliation: Department of Emergency Medicine, Integrative Emergency Services, John Peter Smith Health Network, 1500 S. Main St., Fort Worth, TX, 76104, USA.
authors.forename: Nestor R
authors.initials: NR
authors.lastname: Zenarosa
mesh_terms: D000328:Adult; D000359:Aftercare; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D003953:Diagnosis-Related Groups; D005260:Female; D006703:Ill-Housed Persons; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016019:Survival Analysis
keywords: APR-DRG; Hospital readmission; Post-discharge visit; Prediction