title: Readmission and mortality one year after acute hospitalization in older patients with explained and unexplained anemia - a prospective observational cohort study.
abstract: BACKGROUND
  Few studies have examined whether specific subtypes of anemia in older persons are more related to adverse outcomes such as hospital readmissions and death after acute hospitalization and post-acute care.
  
  
  METHODS
  An observational prospective cohort study was conducted between 2011 and 2014. A total of 884 community-dwelling patients, ≥70 years of age were transferred from acute medical and orthopaedic hospital departments to a skilled nursing home where they were examined by comprehensive geriatric assessment and had laboratory tests taken for the investigation of anemia. They were divided into three major groups and compared; 1) no anemia (reference group), 2) explained anemia (renal insufficiency, iron deficiency, vitaminB12/folate deficiency or multifactorial anemia) and 3) unexplained anemia. The groups were compared, and association of anemia with hospital readmission and death was estimated by logistic regression analyses.
  
  
  RESULTS
  Compared to the patients with unexplained anemia (n=135), patients with explained anemia (n=275) had more often died (22 % vs. 14 %, p=0.05) and had more frequenlty been readmitted to hospital (39 % vs. 27 %, p=0.03). Compared to the patients without anemia (n=474), the patients with explained anemia had increased odds of hospital readmissions (OR = 1.54 (95 % CI: 1.05-2.25), p=0.03), while patients with unexplained anemia, (n=135), had neither increased odds of hospital readmissions, (OR=0.83, 95 % CI: 0.51-1.34, p=0.44) nor death (OR = 0.74, 95 % CI: 0.41-1.31, p=0.30), in adjusted regression analysis.
  
  
  CONCLUSIONS
  Since no increased risk of hospital readmissions or death was seen in older patients with unexplained anemia in the first year after acute hospitalization, no further invasive investigations might be necessary to investigate the cause of anemia in these patients. A close clinical follow up might be the best way to care for older patients with a mild and unexplained anemia.
authors.affiliation: Kavli Research Centre for Geriatrics and Dementia, Haraldsplass Deaconess Hospital, Ulriksdal 8, Bergen, 5009, Norway. jennyfossabrahamsen@gmail.com.|Department of Nursing Home Medicine, Municipality of Bergen, Norway. jennyfossabrahamsen@gmail.com.
authors.forename: Jenny Foss
authors.initials: JF
authors.lastname: Abrahamsen
authors.affiliation: Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway.
authors.forename: Anne-Lise Bjorke
authors.initials: AL
authors.lastname: Monsen
authors.affiliation: Facoltà di Medicina e chirurgia, Universita Cattoloca del Sacro Cuore, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Landi
authors.affiliation: Municipality of Bergen, Bergen, Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Haugland
authors.affiliation: Centre for Clinical Research, Haukeland -University Hospital, Bergen, Norway.
authors.forename: Roy Miodini
authors.initials: RM
authors.lastname: Nilsen
authors.affiliation: Departement of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Anette Hylen
authors.initials: AH
authors.lastname: Ranhoff
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000401:mortality*; D015577:Geriatric Assessment; D006760:Hospitalization; D006801:Humans; D010359:Patient Readmission; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000401:mortality*; D018570:Risk Assessment
keywords: Elderly; Hospitalization; Mortality; Readmission; Unexplained anemia