title: The impact of adverse events on health care costs for older adults undergoing nonelective abdominal surgery.
abstract: BACKGROUND
  Postoperative complications have been identified as an important and potentially preventable cause of increased hospital costs. While older adults are at increased risk of experiencing complications and other adverse events, very little research has specifically examined how these events impact inpatient costs. We sought to examine the association between postoperative complications, hospital mortality and loss of independence and direct inpatient health care costs in patients 70 years or older who underwent nonelective abdominal surgery.
  
  
  METHODS
  We prospectively enrolled consecutive patients 70 years or older who underwent nonelective abdominal surgery between July 1, 2011, and Sept. 30, 2012. Detailed patient-level data were collected regarding demographics, diagnosis, treatment and outcomes. Patient-level resource tracking was used to calculate direct hospital costs (2012 $CDN). We examined the association between complications, hospital mortality and loss of independence cost using multiple linear regression.
  
  
  RESULTS
  During the study period 212 patients underwent surgery. Overall, 51.9% of patients experienced a nonfatal complication (32.5% minor and 19.4% major), 6.6% died in hospital and 22.6% experienced a loss of independence. On multivariate analysis nonfatal complications (p < 0.001), hospital mortality (p = 0.021) and loss of independence at discharge (p < 0.001) were independently associated with health care costs. These adverse events respectively accounted for 30%, 4% and 10% of the total costs of hospital care.
  
  
  CONCLUSIONS
  Adverse events were common after abdominal surgery in older adults and accounted for 44% of overall costs. This represents a substantial opportunity for better patient outcomes and cost savings with quality improvement strategies tailored to the needs of this high-risk surgical population.
authors.affiliation: From the Division of General Surgery, Dalhousie University, Halifax, NS (Bailey, Davis, Molinari, Johnson); and the Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS (Levy, Molinari, Johnson).
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Bailey
authors.affiliation: From the Division of General Surgery, Dalhousie University, Halifax, NS (Bailey, Davis, Molinari, Johnson); and the Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS (Levy, Molinari, Johnson).
authors.forename: Philip J B
authors.initials: PJ
authors.lastname: Davis
authors.affiliation: From the Division of General Surgery, Dalhousie University, Halifax, NS (Bailey, Davis, Molinari, Johnson); and the Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS (Levy, Molinari, Johnson).
authors.forename: Adrian R
authors.initials: AR
authors.lastname: Levy
authors.affiliation: From the Division of General Surgery, Dalhousie University, Halifax, NS (Bailey, Davis, Molinari, Johnson); and the Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS (Levy, Molinari, Johnson).
authors.forename: Michele
authors.initials: M
authors.lastname: Molinari
authors.affiliation: From the Division of General Surgery, Dalhousie University, Halifax, NS (Bailey, Davis, Molinari, Johnson); and the Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS (Levy, Molinari, Johnson).
authors.forename: Paul M
authors.initials: PM
authors.lastname: Johnson
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data*; D008297:Male; D011183:Postoperative Complications / Q000191:economics* / Q000453:epidemiology / Q000401:mortality; D013514:Surgical Procedures, Operative / Q000009:adverse effects* / Q000191:economics* / Q000706:statistics & numerical data