title: Thirty-day rehospitalizations after acute myocardial infarction: a cohort study.
abstract: BACKGROUND
  Rehospitalization is a quality-of-care indicator, yet little is known about its occurrence and predictors after myocardial infarction (MI) in the community.
  
  
  OBJECTIVE
  To examine 30-day rehospitalizations after incident MI.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Population-based registry in Olmsted County, Minnesota.
  
  
  METHODS
  3010 patients who were hospitalized in Olmsted County with first-ever MI from 1987 to 2010 and survived to hospital discharge.
  
  
  METHODS
  Diagnoses, therapies, and complications during incident and subsequent hospitalizations were identified. Manual chart review was performed to determine the cause of all rehospitalizations. The hazard ratios and cumulative incidence of 30-day rehospitalizations were determined by using Cox proportional hazards regression models.
  
  
  RESULTS
  Among 3010 patients (mean age, 67 years; 40.5% female) with incident MI (31.2% ST-segment elevation), 643 rehospitalizations occurred within 30 days in 561 (18.6%) patients. Overall, 30.2% of rehospitalizations were unrelated to the incident MI and 42.6% were related; the relationship was unclear in 27.2% of rehospitalizations. Angiography was performed in 153 (23.8%) rehospitalizations. Revascularization was performed in 103 (16.0%) rehospitalizations, of which 46 (44.7%) had no revascularization during the index hospitalization. After adjustment for potential confounders, diabetes, chronic obstructive pulmonary disease, anemia, higher Killip class, longer length of stay during the index hospitalization, and a complication of angiography or reperfusion or revascularization were associated with increased rehospitalization risk. The 30-day incidence of rehospitalization was 35.3% in patients who experienced a complication of angiography during the index MI hospitalization and 31.6% in those who experienced a complication of reperfusion or revascularization during the index MI hospitalization, compared with 16.8% in patients who had reperfusion or revascularization without complications.
  
  
  CONCLUSIONS
  This study represents the experiences of a single community.
  
  
  CONCLUSIONS
  Comorbid conditions, longer length of stay, and complications of angiography and revascularization or reperfusion are associated with increased 30-day rehospitalization risk after MI. Many rehospitalizations seem to be unrelated to the incident MI.
  
  
  BACKGROUND
  National Institutes of Health.
authors: Mayo Clinic, Rochester, MN 55905, USA.
authors: Shannon M
authors: SM
authors: Dunlay
authors: Susan A
authors: SA
authors: Weston
authors: Jill M
authors: JM
authors: Killian
authors: Malcolm R
authors: MR
authors: Bell
authors: Allan S
authors: AS
authors: Jaffe
authors: Véronique L
authors: VL
authors: Roger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015986:Confounding Factors, Epidemiologic; D017023:Coronary Angiography / Q000009:adverse effects; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000628:therapy; D015425:Myocardial Reperfusion / Q000009:adverse effects; D009204:Myocardial Revascularization / Q000009:adverse effects; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012044:Regression Analysis; D012189:Retrospective Studies; D013997:Time Factors